Modular seven-degree-of-freedom rope-driven humanoid robot arm

Abstract

The application discloses a modular seven-degree-of-freedom rope-driven humanoid robot arm, which comprises a three-degree-of-freedom parallel posture-adjusting rope-driven humanoid shoulder joint, a large arm connected to the output end of the three-degree-of-freedom parallel posture-adjusting rope-driven humanoid shoulder joint, a tension amplification constant torque constant stiffness rope-driven humanoid elbow joint installed at the other end of the large arm, a small arm installed at the output end of the tension amplification constant torque constant stiffness rope-driven humanoid elbow joint, a self-rotation decoupling differential rope-driven humanoid wrist joint installed at the other end of the small arm, and a simplified humanoid palm installed at the output end of the self-rotation decoupling differential rope-driven humanoid wrist joint. Compared with a motor direct driving mode, the application can absorb part of energy through elastic deformation of a rope when the robot is accidentally collided or overloaded, reduces damage risk to a joint body and an external environment, and thus significantly improves safety of the humanoid robot in a human-machine interaction process.

Description

Technical Field

[0001] This invention belongs to the field of robotic arm technology, specifically relating to a modular seven-degree-of-freedom rope-driven humanoid robotic arm. Background Technology

[0002] In the field of robot joint drive technology, the main methods can be summarized as direct motor drive and rope drive. While achieving high dynamic response, both methods face different levels of technical limitations.

[0003] On the one hand, while direct-drive joints are compact and offer direct control, they lack a buffering mechanism. In the event of a rigid collision or sudden external impact, the impact force is directly transmitted to the joint structure and drive unit, potentially causing damage or compromising safety. Attempts to achieve compliant control through a current loop are limited by system friction dead zones and response lag, resulting in limited dynamic buffering. Furthermore, direct-drive motors are typically installed near or even integrated within the joint, concentrating the drive unit's mass at the end of the motion. This not only increases the joint's rotational inertia but also affects the overall dynamic performance and energy efficiency of the arm.

[0004] On the other hand, traditional rope-pulley drive systems often employ a simple "single rope, single pulley" winding method. The tension in these systems fluctuates with changes in joint angle, making it difficult to maintain constant tension output under varying loads. Consequently, they lack stability in scenarios requiring constant force output. Furthermore, if multiple ropes are responsible for the joint's rotation and deflection, coupling interference can easily occur between them, severely impacting motion accuracy and independent controllability. Moreover, rope drive systems themselves are open-chain or low-rigidity structures, lacking closed-loop stiffness support, which contradicts the original design intent of robotic arms.

[0005] Currently, humanoid shoulder joints generally adopt a three-axis converging series rotation structure, achieving spherical rotational freedom through the progressive stacking of three sets of concurrent revolute pairs. This series configuration places the drive motor directly at each joint axis, resulting in a simple structural layout and strong motion decoupling, but it has inherent and unavoidable drawbacks. As the drive components such as motors and reducers are progressively stacked with each joint level, the overall kinematic mass and end-effector inertia increase significantly, resulting in extremely low structural lightweighting. At the same time, the series open-chain structure lacks closed-loop constraints, leading to weak overall structural rigidity and poor disturbance resistance. Under dynamic load impacts and high-speed motion conditions, it is prone to elastic deformation and joint misalignment, causing the virtual rotation center to drift. This severely weakens the motion alignment accuracy and dynamic stability of the shoulder joint, making it difficult to meet the requirements of high-precision, high-dynamic bionic interactive operations.

[0006] Compared to serial configurations, parallel mechanisms, with their multi-branch closed-loop constraints, offer advantages in high stiffness and load-bearing capacity. This effectively compensates for the insufficient stiffness and poor dynamic stability of serial shoulder joints, making them more suitable for high-load biomimetic shoulder joint designs. However, traditional non-coaxial spherical parallel mechanisms employ an inclined, staggered branch layout, with each branch's motion domain coupled to the others. This can easily lead to interference between links and dead points during large-angle rotations, severely limiting the effective rotation space. This presents an inherent contradiction between structural stiffness and the need for large-range biomimetic motion, failing to meet the demands of large-angle, high-precision biomimetic operations in humanoid shoulder joints. Summary of the Invention

[0007] This invention is proposed to solve the problems existing in the prior art, and its purpose is to provide a modular seven-degree-of-freedom rope-driven humanoid robotic arm.

[0008] The technical solution of the present invention is: a modular seven-degree-of-freedom rope-driven humanoid robotic arm, including a three-degree-of-freedom parallel attitude-adjusting rope-driven humanoid shoulder joint, with the upper arm connected to the output end of the three-degree-of-freedom parallel attitude-adjusting rope-driven humanoid shoulder joint. The three-degree-of-freedom parallel attitude-adjusting rope-driven anthropomorphic shoulder joint includes a shoulder joint module, a shoulder joint base, output shafts of a first wound motor, a second wound motor, and a third wound motor, a first wound disc, a second wound disc, a third wound disc, a first revolute joint, a second revolute joint, a third revolute joint, a revolute joint connecting rod, a moving platform, a shoulder joint steering connector, and a wire rope. The first wound disc is fixedly connected to the shoulder joint base via bearings and shaft retainers. The first, second, and third wound discs are nested sequentially with bearings via their respective shaft shoulders. Each of the first, second, and third revolute joints has a D-shaped hole in the center of its disc. D-shaped shafts and shaft shoulders are respectively provided on the upper sides of the first, second, and third wound discs, and are fixedly connected to the first, second, and third revolute joints via shaft retainers. L-shaped brackets are provided on the upper sides of the first, second, and third revolute joints, and bearing positioning shafts are mounted on the L-shaped brackets. The intersection of the three bearing positioning shaft axes is the rotation center of the humanoid shoulder joint; three lugs extend from the upper and lower sides of the moving platform, the upper lug being T-shaped and used to be fixed to one side of the shoulder joint steering connector by bolts, and the lower lug having bearing positioning holes; the L-shaped brackets on the upper sides of the first, second, and third rotating joints are connected to the three lugs on the lower side of the moving platform by three rotating joint connecting rods, forming three branches of the parallel 3-RRR mechanism; the other side of the shoulder joint steering connector is fixed to the upper arm by bolts; three positioning holes for the shoulder joint modules are evenly opened on the upper side of the shoulder joint base, used to position the central axis of the shoulder joint modules; the three shoulder joint modules are fixed to the shoulder joint base by bolts, and the output shafts of the first, second, and third wound motors are sequentially fixed to the three shoulder joint modules by bolts, with their heights being the same as the heights of the first, second, and third wound reels, respectively.

[0009] Furthermore, a tension-amplified constant torque constant stiffness rope-driven humanoid elbow joint is installed at the output end of the upper arm; a forearm is installed at the output end of the tension-amplified constant torque constant stiffness rope-driven humanoid elbow joint; a rotation-decoupling differential rope-driven humanoid wrist joint is installed at the output end of the forearm; and a simplified humanoid hand is installed at the output end of the rotation-decoupling differential rope-driven humanoid wrist joint.

[0010] Furthermore, the tension amplification constant torque constant stiffness rope-driven humanoid elbow joint and the rotation decoupling differential rope-driven humanoid wrist joint are flexibly driven by steel wire ropes guided by the main Bowden tube. The main Bowden conduit includes the first Bowden conduit and the second Bowden conduit; The tension amplification constant torque constant stiffness rope-driven anthropomorphic elbow joint includes a first set of steel wire ropes, a first Bowden conduit, a fixed end of the elbow joint, double-end connectors, a stepped double-layer pulley at the moving end, a moving end of the elbow joint, a pulley seat at the moving end, a guide wheel at the fixed end, a small pulley at the fixed end, a second set of steel wire ropes, a large pulley at the fixed end, a tension plate, a central shaft at the moving end, a rotating side of an absolute encoder, a magnetic base for the absolute encoder, a central shaft at the fixed end, a coupling rope, and a joint module. The four-sided planar side of the elbow joint fixed end is fixedly connected to one side of the upper arm. Two first Bowden tube wire-passing ends and two rope knot fixing ends are set on its upper side. Two protruding pentagonal bearing support platforms are set on its lower side. Each support platform is equipped with a four-step shaft. The shoulders of the above eight-step shafts and the open retaining rings are respectively fixed with eight small fixed end pulleys of the same diameter for guiding the rope winding. One end with a quarter-circle arc plane perpendicular to the four-sided plane of the elbow joint fixation end extends out of the four-sided plane and, through the joint action of the shoulders of the two stepped shafts and the open retaining ring, fixes two large fixed-end pulleys of different diameters used for rope winding guidance. The other end with the quarter-circle arc plane has a circular groove at the center of the arc and is evenly provided with eight threaded holes. The two fixed-end central shafts are fixed to the left and right end faces of the other end with the quarter-circle arc plane of the elbow joint fixation end by bolts. The fixed-end central shaft is connected to the shaft retaining spring through the shoulder of the stepped shaft and axially fixes the inner sides of two deep groove ball bearings of the same diameter and a third deep groove ball bearing of a different diameter. The outer sides of the two deep groove ball bearings of the same diameter are axially fixed to the fixed-end guide wheel through the hole retaining spring.

[0011] Furthermore, the four-sided planar side of the elbow joint moving end is fixedly connected to one side of the forearm. One end of the planar side with a quarter-circle arc, perpendicular to the four-sided planar side of the elbow joint moving end, extends out of the four-sided planar side. The other end of the planar side with a quarter-circle arc has a circular groove at the center of the arc and is evenly provided with eight threaded holes. The two moving end central shafts are fixedly connected to the left and right end faces of the other end of the elbow joint moving end with a quarter-circle arc by bolts. The moving end central shaft is connected to the shaft with a retaining circumferential through the shoulder of the stepped shaft and is axially fixed to the inner side of the deep groove ball bearing. The outer side of the deep groove ball bearing is fixed to the moving end pulley seat through the hole with a retaining circumferential. Two stepped shafts are arranged on the moving end pulley seat and are connected to the bolts through the shoulder of the stepped shaft. The stepped double-layer pulley of the moving end is axially fixed and used as a secondary rope winding guide. Four threaded holes are evenly arranged on the movable end pulley seat, and are fixed to one side of the double-end connector by bolts; the other side of the double-end connector has a bearing hole, and is axially fixed to the outer side of the third deep groove ball bearing on the outer side of the fixed end central shaft by a snap ring through the hole, thus connecting the fixed end of the elbow joint to the movable end of the elbow joint.

[0012] Furthermore, the rotating side of the absolute encoder is fixedly connected to the top of the central shaft of the moving end by a set screw, and the magnetic base of the absolute encoder is embedded in the circular groove on one side of the double-ended connector and fixed by bolts; there is a certain gap between the rotating side of the absolute encoder and the magnetic base of the absolute encoder. Two wire grooves and two knot holes are opened on the vertical surface of the other end of the elbow joint fixed end with a quarter-circle plane. Two wire grooves and two knot holes of the same size and position are opened on the vertical surface of the other end of the elbow joint movable end with a quarter-circle plane. One end of the two coupling ropes is fixed along the wire groove to the knot hole of the elbow joint fixed end and the tension plate on the elbow joint movable end side, respectively. The other end of the two coupling ropes is fixed along the wire groove to the knot hole of the elbow joint movable end and the tension plate on the elbow joint fixed end side, respectively. The tension plate has three holes, and the coupling rope knot is fixed to one of the holes on both sides of the tension plate. A long bolt is set on the bolt hole on the vertical surface of the four sides of the elbow joint fixed end. The middle threaded hole of the tension plate is connected to the long bolt by thread, and the axial displacement of the tension plate is achieved by tightening the bolt, thereby achieving the tension of the coupling rope. Two sets of steel wire ropes are fixed to the release end and the take-up end of the joint module, respectively. They are transmitted through the first Bowden conduit to the Bowden conduit threading end on the elbow joint fixing end and then wrapped around the elbow joint.

[0013] Furthermore, the three-degree-of-freedom parallel attitude-adjusting rope-driven anthropomorphic shoulder joint can mimic the three-directional posture movement of the ball-and-socket joint in the physiological structure of the human shoulder joint. The three-degree-of-freedom parallel attitude-adjusting rope-driven anthropomorphic shoulder joint includes three RRR (R-Rotate) branches, each driven independently by its own steel wire rope. The upper arm is a spatial transition between the three-degree-of-freedom parallel attitude-adjusting rope-driven humanoid shoulder joint and the tension-amplified constant torque constant stiffness rope-driven humanoid elbow joint, with the upper arm forming a mating assembly position at both ends. The tension amplification constant torque constant stiffness rope drive mimics the human elbow joint with a rigid structure and a rolling joint configuration. Its transmission adopts Bowden conduit-steel wire rope form to achieve tension amplification and constant torque constant stiffness of the elbow joint.

[0014] Furthermore, the forearm serves as a spatial transition between the tension-amplified constant torque constant stiffness rope-driven humanoid elbow joint and the rotation-decoupling differential rope-driven humanoid wrist joint, with the forearm forming a mating assembly position at both ends. The self-rotating decoupled differential rope-driven human wrist joint is a three-degree-of-freedom rope-driven hybrid joint.

[0015] Furthermore, the self-rotation decoupling differential rope-driven humanoid wrist joint includes a self-rotation decoupling mechanism and a differential mechanism, and is driven by a differential rope driven by a steel wire rope within the joint for self-rotation decoupling. The self-rotation decoupling mechanism and differential mechanism achieve flexible drive and transmission between the first joint module, the second joint module and the corresponding degree of freedom through the combination of the second Bowden tube, steel wire rope and guide wheel; The self-rotation decoupling mechanism includes a fixed wheel, a first left guide wheel of the fixed wheel, a first right guide wheel of the fixed wheel, a second left guide wheel of the fixed wheel, a second right guide wheel of the fixed wheel, a fixed rope end of the fixed wheel, a follower wheel, a first guide wheel of the follower wheel, a second guide wheel of the follower wheel, a third guide wheel of the follower wheel, a driving wheel, a first left guide wheel of the driving wheel, a first right guide wheel of the driving wheel, a second left guide wheel of the driving wheel, a second right guide wheel of the driving wheel, a fixed rope end of the driving wheel, a first self-rotating guide wheel, a first absolute encoder mounting base, a first absolute encoder rotating side, a first absolute encoder magnetic base, a first steel wire rope, and a fourth steel wire rope; The fixed wheel serves as the base. The annular boss end of the fixed wheel is fixedly connected to the forearm by bolts. The first left guide wheel and the first right guide wheel of the fixed wheel are symmetrically installed on one side of the annular boss end of the fixed wheel, and the second left guide wheel and the second right guide wheel of the fixed wheel are symmetrically installed on the other side. The fixing rope ends of the two fixed wheels are installed in the middle of the first left guide wheel and the first right guide wheel of the fixed wheel. L-shaped brackets extend symmetrically from both sides of the circular vertical surface of the fixed wheel, and the first self-rotating guide wheel is fixed by the axle shoulder and the open retaining ring. The first stepped shoulder of the fixed wheel's multi-step shaft end is fixed to the axial movement of the inner ring of the first bearing with a snap ring. The outer ring of the bearing is fixed to the follower wheel through a hole with a snap ring. The outer ring of the follower wheel has two stepped surfaces symmetrically designed, with cylindrical grooves on the stepped surfaces. The outer ring of the follower wheel has a fan-shaped groove, with two stepped shafts extending from the bottom plane of the groove, which respectively fix the first guide wheel and the second guide wheel of the follower wheel with different diameters. The inner ring of the follower wheel has a cylindrical groove; the inner ring of the follower wheel has a fan-shaped groove, and a stepped shaft extends from the bottom plane of the fan-shaped groove to fix the third guide wheel of the follower wheel; in terms of position, the semi-circular guide grooves of the first left guide wheel and the first right guide wheel of the fixed wheel are tangent to the semi-cylindrical guide groove of the inner ring of the follower wheel.

[0016] Furthermore, the semi-circular guide grooves of the second left guide wheel and the second right guide wheel of the fixed wheel are tangent to the semi-cylindrical guide groove of the inner ring of the follower wheel; The second stepped shaft shoulder of the fixed wheel multi-step shaft end is fixed to the shaft with a snap ring to fix the axial movement of the inner ring of the second bearing. The outer ring of the bearing is fixed to the driving wheel through the hole with a snap ring. The first left guide wheel and the first right guide wheel of the driving wheel are symmetrically installed on one side of the annular groove of the driving wheel, and the second left guide wheel and the second right guide wheel of the driving wheel are symmetrically installed on the other side. The semi-circular guide grooves of the first left guide wheel and the first right guide wheel of the driving wheel are tangent to the semi-circular guide groove of the inner ring of the follower wheel; The semi-circular guide grooves of the second left guide wheel and the second right guide wheel of the driving wheel are tangent to the semi-cylindrical guide groove of the inner ring of the follower wheel; the fixed rope ends of the two driving wheels are installed in the middle of the first left guide wheel and the first right guide wheel of the driving wheel; four cylindrical platforms extend from the annular groove of the driving wheel, and threaded holes are opened at their upper ends for fixing with the differential mechanism.

[0017] Furthermore, the differential mechanism includes a differential rotation shaft, a differential rotation shaft sleeve, a differential rotation shaft outer fixing seat, a first differential deflection base, a second differential deflection base, a differential rotating wheel, a second rotation guide wheel, a bearing end cover, a second absolute encoder mounting base, a second absolute encoder magnetic base, a second absolute encoder rotating side, and a third absolute encoder. One side of the differential rotation shaft is fixedly connected to a simplified humanoid hand by bolts, and the other side is sequentially installed with a first deep groove ball bearing, a differential rotation shaft sleeve, and a second deep groove ball bearing. The outer fixing seat of the differential rotation shaft has a groove, and the outer side of the bearing is fitted into the groove by the two outer fixing seats of the differential rotation shafts covering each other. After the two outer fixing seats of the differential rotation shafts are covered, a multi-step shaft is formed on the left and right sides. The axial movement of the inner side of the third deep groove ball bearing is fixed on the stepped shafts on both sides by the first step shaft shoulder and the shaft retainer. The outer side of the third deep groove ball bearing is fixed to the differential rotating wheel by the hole retainer. The second absolute encoder mounting base extends four legs and is fixedly connected to the outer fixed base of the differential rotation shaft. The rotating side of the second absolute encoder is interference-fitted with the top of the differential rotation shaft. The magnetic base of the second absolute encoder is fitted into the second absolute encoder mounting base and fixedly connected by bolts. There is a certain gap between the rotating side of the second absolute encoder and the magnetic base of the second absolute encoder. The third absolute encoder is fixed to the inside of the multi-step shaft formed on the left and right sides by its own shoulder after the outer fixed seats of the two differential rotating shafts are closed together. The groove on its rotating side fits into the corresponding boss on the bearing end cover.

[0018] The modular seven-degree-of-freedom rope-driven humanoid robotic arm of the present invention has the following beneficial effects: First, the shoulder, elbow, wrist, upper arm, and forearm can all be disassembled and assembled in a modular, decoupled manner via a rope-driven / transmission system, and each joint can be maintained or replaced independently.

[0019] Secondly, the elbow joint adopts an innovative structural design. The elbow joint achieves reduction ratio amplification and tension amplification through the rolling joint's moving pulley mechanism, reducing the demand on motor output torque. This allows for the selection of a drive unit with smaller overall mass and size. At the same time, the elbow joint has constant torque and constant stiffness, enabling the robot to maintain constant joint stiffness and output constant torque even in a large workspace.

[0020] Third, the wrist joint adopts an innovative structural design, effectively decoupling the motion of the two sets of steel cables as they pass through the self-rotating joint by using a set of movable pulley mechanisms. This design allows the drive unit to be centrally located on the robot base or proximal structure, optimizing the system layout.

[0021] Fourth, the structure of rope drive combined with rope transmission reduces the overall weight and inertia of the arm, enhances the flexibility of the joints, and effectively isolates the impact and vibration at the motor output end.

[0022] Fifth, compared with the direct drive method of motor, the present invention can absorb part of the energy through the elastic deformation of the rope when the robot is involved in an accidental collision or overload, thereby reducing the risk of damage to the joint body and the external environment, and thus significantly improving the safety of humanoid robots in the process of human-computer interaction. Attached Figure Description

[0023] Figure 1 This is an overall structural diagram of a modular seven-degree-of-freedom rope-driven humanoid robotic arm provided in an embodiment of the present invention; Figure 2 This is a side view of a modular seven-degree-of-freedom rope-driven humanoid robotic arm provided in an embodiment of the present invention; Figure 3This is a structural diagram of a three-degree-of-freedom parallel attitude-adjusting rope-driven humanoid shoulder joint provided in an embodiment of the present invention; Figure 4 This is a top view of the three-degree-of-freedom parallel attitude-adjusting rope-driven humanoid shoulder joint provided in the embodiments of the present invention; Figure 5 This is a bottom schematic diagram of the three-degree-of-freedom parallel attitude-adjusting rope-driven humanoid shoulder joint provided in the embodiments of the present invention; Figure 6 This is a front view of the three-degree-of-freedom parallel attitude-adjusting rope-driven humanoid shoulder joint provided in the embodiments of the present invention; Figure 7 yes Figure 6 A cross-sectional view along the AA direction; Figure 8 This is a structural diagram of a tension amplification constant torque constant stiffness rope-driven human elbow joint provided in an embodiment of the present invention; Figure 9 This is a side view of the tension-amplified constant torque constant stiffness rope-driven human elbow joint provided in the embodiments of the present invention; Figure 10 This is an internal sectional view of the tension-amplified constant torque constant stiffness rope-driven human elbow joint provided in the embodiments of the present invention; Figure 11 This is a structural diagram of a self-rotating decoupled differential rope-driven human wrist joint provided in an embodiment of the present invention; Figure 12 This is a schematic diagram showing the connection between the rotation decoupling differential rope-driven human wrist joint rotation decoupling mechanism and the differential mechanism provided in the embodiments of the present invention; Figure 13 This is an internal cross-sectional view of the connection between the rotation decoupling mechanism and the differential mechanism of the self-rotation decoupling differential rope-driven human wrist joint provided in the embodiments of the present invention; Figure 14 This is an exploded view of the connection between the rotation decoupling mechanism and the differential mechanism of the self-rotation decoupling differential rope-driven human wrist joint provided in the embodiments of the present invention; Figure 15 This is a side view of the connection between the fixed wheel, the follower wheel, and the driving wheel provided in an embodiment of the present invention; Figure 16 This is a schematic diagram of another side view of the connection between the fixed wheel, the follower wheel, and the driving wheel provided in the embodiment of the present invention; Figure 17 This is a partial exploded view of the connection between the rotation decoupling mechanism and the differential mechanism of the self-rotation decoupling differential rope-driven human wrist joint provided in the embodiments of the present invention.

[0024] The components include: 1. A three-degree-of-freedom parallel attitude-adjusting rope-driven humanoid shoulder joint; 10. Shoulder joint module; 11. Shoulder joint base; 12. First winding motor output shaft; 13. Second winding motor output shaft; 14. Third winding motor output shaft; 15. First winding disc; 16. Second winding disc; 17. Third winding disc; 110. First revolute joint; 19. Second revolute joint; 18. Third revolute joint; 111. Revolute joint connecting rod; 112. Moving platform; 113. Shoulder joint steering connector; 114. Steel wire rope; 2. Upper arm; 3. Tension amplification constant torque constant stiffness rope-driven humanoid elbow joint; 31. First set of steel wire rope; 3 2. First Bowden conduit; 33. Fixed end of elbow joint; 34. Double-end connector; 35. Stepped double-layer pulley of moving end; 36. Moving end of elbow joint; 37. Pulley seat of moving end; 38. Guide wheel of fixed end; 39. Small pulley of fixed end; 310. Second set of wire rope; 311. Large pulley of fixed end; 312. Tensioning plate; 313. Central shaft of moving end; 314. Rotating side of absolute encoder; 315. Magnet seat of absolute encoder; 316. Central shaft of fixed end; 317. Coupling rope; 318. Joint module; 4. Forearm; 5. Rotation decoupling differential rope driven humanoid wrist joint; 51. Rotation decoupling mechanism; 52. Differential mechanism; 54. First joint module; 55. Second joint module; 511. Second left guide wheel of fixed wheel; 512. First guide wheel of follower wheel; 513. Second right guide wheel of fixed wheel; 514. Second guide wheel of follower wheel; 515. Fixed wheel; 516. Follower wheel; 517. Driving wheel; 518. First left guide wheel of driving wheel; 519. First right guide wheel of driving wheel; 5110. First rotation guide wheel; 5111. Third guide wheel of follower wheel; 5112. Fixed rope end of fixed wheel; 5113. First left guide wheel of fixed wheel; 5114. First right guide wheel of fixed wheel; 5115. Second left guide wheel of driving wheel; 5116. Second right guide wheel of driving wheel; 5117. First absolute encoder mounting base; 5118. Rotating side of first absolute encoder; 5119. Magnet base of first absolute encoder 5120. Drive wheel fixed rope end; 5121. First wire rope left; 5122. First wire rope right; 521. First differential deflection base; 522. Bearing end cover; 523. Differential rotation shaft; 524. Differential rotation shaft outer fixed seat; 525. Differential rotation shaft bushing; 526. Second differential deflection base; 527. Differential rotating wheel; 528. Second rotation guide wheel; 529. Third absolute encoder; 210. Second absolute encoder mounting base; 5211. Second absolute encoder magnetic base; 5212. Rotating side of the second absolute encoder; 5213. Fifth wire rope; 540. Second Bowden conduit; 541. Third wire rope (left); 542. Third wire rope (right); 543. Second wire rope (left); 544. Second wire rope (right); 551. Fourth wire rope (left); 552. Fourth wire rope (right); 6. Humanoid simplified hand;7. Main Bowden conduit. Detailed Implementation

[0025] The present invention will now be described in detail with reference to the accompanying drawings and embodiments: like Figures 1 to 17 As shown, a modular seven-DOF rope-driven humanoid robotic arm includes a three-DOF parallel attitude-adjusting rope-driven humanoid shoulder joint 1, an upper arm 2 connected to the output end of the three-DOF parallel attitude-adjusting rope-driven humanoid shoulder joint 1, a tension-amplified constant torque constant stiffness rope-driven humanoid elbow joint 3 installed at the other end of the upper arm 2, a forearm 4 installed at the output end of the tension-amplified constant torque constant stiffness rope-driven humanoid elbow joint 3, a rotation-decoupling differential rope-driven humanoid wrist joint 5 installed at the other end of the forearm 4, and a simplified humanoid hand 6 installed at the output end of the rotation-decoupling differential rope-driven humanoid wrist joint 5.

[0026] Specifically, the three-degree-of-freedom parallel attitude-adjusting rope-driven humanoid shoulder joint 1 includes a shoulder joint module 10, a shoulder joint base 11, a first winding motor output shaft 12, a second winding motor output shaft 13, a third winding motor output shaft 14, a first winding disc 15, a second winding disc 16, a third winding disc 17, a first revolute joint 110, a second revolute joint 19, a third revolute joint 18, a revolute joint connecting rod 111, a moving platform 112, a shoulder joint steering connector 113, a steel wire rope 114, and other parts.

[0027] During installation, the first winding disc 15 is first fixedly connected to the shoulder joint base 11 via bearings and shaft retaining rings. The first winding disc 15, the second winding disc 16, and the third winding disc 17 are then nested sequentially with bearings via their respective shaft shoulders, achieving coaxial rotation without interference. The first rotary joint 110, the second rotary joint 19, and the third rotary joint 18 have D-shaped holes in their center. D-shaped shafts and shaft shoulders are respectively provided on the upper sides of the first winding disc 15, the second winding disc 16, and the third winding disc 17, which are fixedly connected to the first rotary joint 110, the second rotary joint 19, and the third rotary joint 18 via shaft retaining rings. Therefore, the first rotary joint 110, the second rotary joint 19, and the third rotary joint 18 can also achieve coaxial rotation without interference. Then, L-shaped brackets extend from the upper sides of the first rotary joint 110, the second rotary joint 19, and the third rotary joint 18. Further, a bracket extending at a 140° angle to the L-shaped bracket extends from this bracket. Bearing positioning shafts are mounted on these brackets, and the intersection of the three bearing positioning shaft axes is the rotation center of the human-like shoulder joint. Three lugs extend from the upper and lower sides of the moving platform 112. The upper lug is T-shaped and bolted to one side of the shoulder joint steering connector 113. The lower lug has bearing positioning holes. The brackets on the upper sides of the first rotary joint 110, the second rotary joint 19, and the third rotary joint 18 are interconnected with the three lower lugs of the moving platform 112 via three rotary joint connecting rods 111, thus forming three branches of a parallel 3-RRR mechanism. The other side of the shoulder joint steering connector 113 is bolted to the upper arm.

[0028] Three positioning holes for shoulder joint modules are evenly opened on the upper side of the shoulder joint base 11 to position the central axis of the shoulder joint module 10. The three shoulder joint modules 10 are fixed to the shoulder joint base 11 by bolts. The first winding motor output shaft 12, the second winding motor output shaft 13, and the third winding motor output shaft 14 are sequentially fixed to the three shoulder joint modules 10 by bolts, and their heights are the same as the heights of the first winding disc 15, the second winding disc 16, and the third winding disc 17, respectively.

[0029] Specifically, taking the output shaft 12 of the first winding motor as an example, the winding method of the rope drive has a winding groove and a knot hole on the upper side. One end of the two steel wire ropes 114 is tied and tensioned at the knot hole, and the other end passes through the knot hole and is wound around the winding groove on the output shaft 12 of the first winding motor in a clockwise / counterclockwise direction, and then cross-wound to the first winding disc 15. The first winding disc 15 has knot holes on both sides of its vertical surface for fixing the two steel wire ropes 114. The shoulder joint module 10 rotates, driving the output shaft 12 of the first winding motor to rotate, which in turn drives the two steel wire ropes 114 to further wind into / out of the winding groove. The two steel wire ropes 114 on the first winding reel 15 further wind away from / into the first winding reel 15, thereby driving the first winding reel 15 to rotate. At this time, the driving force is transmitted from the shoulder joint module 10 to the first rotating joint in the branch of the parallel 3-RRR mechanism. The diameter ratio between the output shaft 12 of the first winding motor and the first winding reel 15 is 5, thus achieving deceleration and torque increase. The winding method on the output shaft 13 of the second winding motor and the output shaft 14 of the third winding motor is similar, and they are respectively connected to the second winding reel 16 and the third winding reel 17 for driving force transmission.

[0030] With the combination of the rotation angles of the first rotating joint of the three branches of the parallel 3-RRR mechanism, the lateral swing range of the moving platform 112 can be greater than 45°, and the rotation range can be greater than 180°.

[0031] Specifically, the three-degree-of-freedom parallel attitude-adjusting tethered humanoid shoulder joint 1 can mimic the three-directional posture movements of the ball-and-socket joint in the physiological structure of the human shoulder joint, namely rotation, pitch, and yaw. The three-degree-of-freedom parallel attitude-adjusting tethered humanoid shoulder joint 1 includes three RRR branches, each driven independently by its own steel wire rope, and uses a parallel 3-RRR mechanism to achieve the three-directional fixed-center rotation of the humanoid shoulder joint.

[0032] The upper arm 2 is a spatial transition between the three-degree-of-freedom parallel attitude-adjusting rope-driven humanoid shoulder joint 1 and the tension-amplified constant torque and constant stiffness rope-driven humanoid elbow joint 3. The upper arm 2 forms a mating assembly position at both ends.

[0033] The tension amplification constant torque constant stiffness rope-driven humanoid elbow joint 3 is a rigid structure with a rolling joint configuration. Its transmission adopts Bowden conduit-steel wire rope form to achieve tension amplification and constant torque constant stiffness of the elbow joint.

[0034] Forearm 4 is a spatial transition between tension amplification constant torque constant stiffness rope-driven humanoid elbow joint 3 and rotation decoupling differential rope-driven humanoid wrist joint 5, with the forearm 4 forming a mating assembly position at both ends.

[0035] The self-rotation decoupled differential rope-driven human wrist joint 5 is a three-degree-of-freedom rope-driven hybrid joint.

[0036] Specifically, the tension amplification constant torque constant stiffness rope-driven humanoid elbow joint 3 and the self-rotation decoupling differential rope-driven humanoid wrist joint 5 are flexibly driven by steel wire ropes guided by the main Bowden tube 7.

[0037] The main Bowden conduit 7 includes the first Bowden conduit 32 and the second Bowden conduit 540.

[0038] The tension amplification constant torque constant stiffness rope-driven anthropomorphic elbow joint 3 includes the following parts: a first set of steel wire rope 31, a first Bowden conduit 32, a fixed end of the elbow joint 33, a double-end connector 34, a stepped double-layer pulley at the moving end 35, a moving end of the elbow joint 36, a pulley seat at the moving end 37, a guide wheel at the fixed end 38, a small pulley at the fixed end 39, a second set of steel wire rope 310, a large pulley at the fixed end 311, a tension plate 312, a central shaft at the moving end 313, a rotating side of the absolute encoder 314, a magnetic base of the absolute encoder 315, a central shaft at the fixed end 316, a coupling rope 317, and a joint module 318.

[0039] The four sides of the elbow joint fixing end 33 are fixedly connected to one side of the upper arm 2. Two first Bowden tubes 32 are provided on its upper side for threading and two knot fixing ends. Two protruding pentagonal bearing support platforms are provided on its lower side. Each support platform is provided with four stepped shafts. The shoulders of the eight stepped shafts and the open retaining ring work together to fix eight small fixed end pulleys 39 of the same diameter for guiding the rope winding.

[0040] One end of the elbow joint fixing end 33, perpendicular to the four-sided planar side, extends out of the four-sided planar side and, through the combined action of the shoulders of the two stepped shafts and the open retaining ring, fixes two large fixed-end pulleys 311 of different diameters used for rope winding guidance. The other end of the fixed-end with the quarter-circle planar side has a circular groove at the center of the arc and eight threaded holes evenly arranged. The two fixed-end central shafts 316 are fixedly connected to the left and right end faces of the other end of the elbow joint fixing end 33 with the quarter-circle planar side by bolts. The fixed-end central shaft 316, through the combined action of the shoulders of the stepped shafts and the shaft retaining springs, axially fixes the inner sides of two deep groove ball bearings of the same diameter and a third deep groove ball bearing of a different diameter. The outer sides of the two deep groove ball bearings of the same diameter are axially fixed to the fixed-end guide wheel 38 through the hole retaining springs.

[0041] The four-sided planar side of the elbow joint moving end 36 is fixedly connected to one side of the forearm 4. One end of the planar side with a quarter-circle arc, perpendicular to the four-sided planar side of the elbow joint moving end 36, extends out of the four-sided planar side. The other end of the planar side with a quarter-circle arc has a circular groove at the center of the arc and is evenly provided with eight threaded holes. The two moving end central shafts 313 are fixedly connected to the left and right end faces of the other end of the elbow joint moving end 36 with a quarter-circle arc plane by bolts. The moving end central shaft 313 is axially fixed to the inner side of the deep groove ball bearing by the joint action of the shoulder of the stepped shaft and the shaft retaining spring. The outer side of the deep groove ball bearing is fixed to the moving end pulley seat 37 by the hole retaining spring. Two stepped shafts are arranged on the moving end pulley seat 37. The stepped shafts are axially fixed to the moving end stepped double-layer pulley 35, which is used as a secondary rope winding guide, by the joint action of the shoulder of the stepped shaft and the bolts.

[0042] Four threaded holes are evenly arranged on the movable end pulley seat 37, which are fixed to one side of the double-end connector 34 by bolts. The other side of the double-end connector 34 has a bearing hole, which is axially fixed to the outermost third deep groove ball bearing on the fixed end central shaft 316 by a snap ring through the hole, thereby connecting the fixed end 33 of the elbow joint to the movable end 36 of the elbow joint.

[0043] Specifically, the absolute encoder rotating side 314 is fixedly connected to the top of the moving end central shaft 313 via a set screw, and the absolute encoder magnetic base 315 is embedded in a circular groove on one side of the double-ended connector and fixedly connected by bolts. There is a certain gap between the absolute encoder rotating side 314 and the absolute encoder magnetic base 315, which is not limited to 0.8mm. This electrical component is used to measure the rotation angle of the elbow joint in real time.

[0044] Two wire grooves and two knot holes are formed on the vertical surface of the other end of the elbow joint fixed end 33, which has a quarter-circle plane side. Correspondingly, two wire grooves and two knot holes of the same size and position are also formed on the vertical surface of the other end of the elbow joint movable end 36, which has a quarter-circle plane side. One end of each of the two coupling ropes 317 is fixed along the wire groove to the knot hole of the elbow joint fixed end 33 and the tension plate 312 on the elbow joint movable end 36 side, respectively. The other ends of each of the two coupling ropes 317 are fixed along the wire groove to the knot hole of the elbow joint movable end 36 and the tension plate 312 on the elbow joint fixed end 33 side, respectively. The tension plate 312 has three holes, and the knot of each coupling rope 317 is fixed to one of the holes on both sides of the tension plate 312. A long bolt is installed on the bolt hole on the four sides of the elbow joint fixing end 33. The middle threaded hole of the tensioning plate 312 is connected to the long bolt by thread. The axial displacement of the tensioning plate 312 can be achieved by turning the bolt, thereby achieving the tensioning of the coupling rope 317.

[0045] Since the radii of the two quarter-circle arcs are the same, and the length of the connecting line between the two circular grooves of the double-ended connector 34 is the same as the diameter of the quarter-circle arc, under the fixed length of the two coupling ropes 317, the elbow joint fixed end 33 and the elbow joint moving end 36 always maintain a tangential gear-like meshing motion state.

[0046] Two sets of steel wire ropes are respectively fixed to the release end and the take-up end of the joint module 318, and then transmitted through the first Bowden tube 32 to the Bowden tube threading end on the elbow joint fixing end 33, and further wound around to the elbow joint.

[0047] Specifically, the first set of wire rope 31, after being guided by the fixed end guide wheel 38, winds around to the small groove of the stepped double-layer pulley 35 on the opposite moving end. After being guided by the pulley, it is again guided by the fixed end guide wheel 38 on the opposite side and winds around to the two fixed end small pulleys 39. It then winds further through the fixed end guide wheel 38 to the large groove of the stepped double-layer pulley 35 on the opposite moving end. After being guided by the stepped double-layer pulley 35 on the moving end, it is again guided by the fixed end guide wheel 38 on the opposite side and winds around to the fixed end large pulley 311. Here, after being guided by the fixed end large pulley 311, it winds around to the other side of the elbow joint fixed end 33 with the quarter-circle upper meshing plate 319. The winding method here is exactly the same as that described above. That is, after the first set of steel wire rope 31 is guided by the fixed end guide wheel 38, it winds into the large groove of the stepped double-layer pulley 35 on the opposite side of the moving end. After being guided by the pulley, it is guided again by the fixed end guide wheel 38 on the opposite side and winds into the two fixed end small pulleys 39. Then, it winds further through the fixed end guide wheel 38 into the small groove of the stepped double-layer pulley 35 on the opposite side of the moving end. After being guided by the stepped double-layer pulley 35 on the moving end, it is guided again by the fixed end guide wheel 38 on the opposite side and then the knot is fixed to the knot fixing end of the elbow joint fixing end 33, or fixed to the rope end tensioning point of the elbow joint fixing end 33.

[0048] The complete path of the first set of steel wire rope 31 after passing through the Bowden conduit end on the elbow joint fixed end 33 is: fixed end guide wheel 38 Mobile terminal stepped double-layer pulley 35 Fixed end guide wheel 38 Fixed end small pulley 39 Fixed end guide wheel 38 Mobile terminal stepped double-layer pulley 35 Fixed end guide wheel 38 Fixed end large pulley 311 Fixed end guide wheel 38 Mobile terminal stepped double-layer pulley 35 Fixed end guide wheel 38 Fixed end small pulley 39 Fixed end guide wheel 38 Mobile terminal stepped double-layer pulley 35 Fixed end guide wheel 38 The knotted end of the elbow joint fixing end 33.

[0049] The winding method of the second set of steel wire ropes 310 is exactly the same as that of the first set of steel wire ropes 31. Since the second set of steel wire ropes 310 and the first set of steel wire ropes 31 are arranged in mirror image of each other, when the joint module 318 rotates clockwise or counterclockwise, the first set of steel wire ropes 31 and the second set of steel wire ropes 310 shorten / extend by the same length at the same time, causing the elbow joint moving end 36 to rotate relative to the center of a quarter circle arc of the elbow joint fixed end 33. Its intuitive movement is a tangential pure circular rolling relative to the outer contour of the elbow joint fixed end 33. The range of elbow joint yaw motion is >90°, and the change in rope length has a linear relationship with the change in the pure circular rolling angle.

[0050] Let the changes in rope length of the first set of wire rope 31 and the second set of wire rope 310 be respectively and The change in the rolling angle of a pure circle is The diameter of the fixed end guide wheel 38 is d The number of wire ropes that pass around the movable pulley block is n The change in rope length has a linear relationship with the change in the rolling angle of the pure circle, which can be expressed as formula (1): (1).

[0051] The tension amplification principle is achieved using the designed movable pulley system: Let the change in the tensile length of the wire rope be... The change in length of the movable pulley is The number of wire ropes that pass around the movable pulley block is n The tension at the tension end of the wire rope is The output tension at the end of the movable pulley is The stiffness coefficient of the wire rope body is The combined stiffness coefficient of the movable pulley end is Formulas (2)-(5) can be derived as follows. It can be seen that the mechanism achieves deceleration and force amplification through the constructed movable pulley system, and achieves an exponential increase in the stiffness coefficient. Since the number of steel wire ropes passing through the movable pulley system in this mechanism is 8, it can achieve an 8-fold increase in tension and a 64-fold increase in stiffness coefficient: .

[0052] The principle by which the elbow joint can achieve constant stiffness and constant torque is as follows: Let... This represents a small change in the output torque of the elbow joint. For joint angle The minute changes These represent the tension at the taut end and the slack end of the rope, respectively. This is the preload length of the rope. For a small change in the amount of change in the rope, The stiffness coefficient of the wire rope body. d The diameter of the fixed-end guide wheel. n The number of wire ropes that need to be bypassed by the movable pulley block, k This refers to the stiffness of the elbow joint.

[0053] Differentiating formula (1) yields: (6).

[0054] Based on the principle of virtual work, assuming the elbow joint rotates by a certain angle, Δ T Defined as the tension end of a rope and relaxation end From the tension difference, we can obtain: (7); Substituting equation (6) into equation (7) yields (8); Expand and achievable (9); (10); Then Δ T It can also be expressed as (11); Substituting equations (6) and (11) into equation (8) yields... (12); Therefore, the elbow joint stiffness can be obtained as follows: (13); As can be seen from equations (12) and (13), the torque and stiffness of the elbow joint do not change with the angle, and it has the characteristics of constant stiffness and constant torque.

[0055] Specifically, the self-rotation decoupling differential rope-driven humanoid wrist joint 5 includes a self-rotation decoupling mechanism 51 and a differential mechanism 52, and is driven by a differential rope through a steel wire rope inside the joint for self-rotation decoupling.

[0056] The self-rotation decoupling mechanism 51 and the differential mechanism 52 achieve flexible drive and transmission between the first joint module 54, the second joint module 55 and the corresponding degrees of freedom through the combination of the second Bowden conduit 540, the wire rope and the guide wheel.

[0057] The self-rotation decoupling mechanism 51 comprises a fixed wheel 515, a first left guide wheel 5113, a first right guide wheel 5114, a second left guide wheel 511, a second right guide wheel 513, a fixed rope end 5112, a follower wheel 516, a first guide wheel 512, a second guide wheel 514, a third guide wheel 5111, a driving wheel 517, a first left guide wheel 518, a first right guide wheel 519, a second left guide wheel 5115, a second right guide wheel 5116, a fixed rope end 5120, a first self-rotating guide wheel 5110, a first absolute encoder mounting base 5117, a first absolute encoder rotating side 5118, a first absolute encoder magnetic base 5119, a first wire rope, and a fourth wire rope.

[0058] The fixed wheel 515 serves as the base. The annular boss end of the fixed wheel 515 is bolted to the forearm 4. Symmetrically mounted on one side of the annular boss end of the fixed wheel 515 are the first left guide wheel 5113 and the first right guide wheel 5114, and symmetrically mounted on the other side are the second left guide wheel 511 and the second right guide wheel 513. The two fixed wheel fixing rope ends 5112 are installed between the first left guide wheel 5113 and the first right guide wheel 5114. Symmetrically extending L-shaped brackets from both sides of the circular surface of the fixed wheel 515, the first rotating guide wheel 5110 is fixed by a shoulder and an open retaining ring.

[0059] The fixed wheel 515 has a multi-step shaft end with a first-step shoulder that is fixed to the axial movement of the inner ring of the first bearing with a retaining circlip. The outer ring of the bearing is fixed to the follower wheel 516 through a hole with a retaining circlip. The outer ring of the follower wheel 516 has two symmetrically designed stepped surfaces with cylindrical grooves for wiring. The outer ring of the follower wheel 516 has a fan-shaped groove with two stepped shafts extending from the bottom plane of the fan-shaped groove, which respectively fix the first guide wheel 512 and the second guide wheel 514 of the follower wheel with different diameters.

[0060] Similarly, the inner ring of the follower wheel 516 has a cylindrical groove for wiring, and a fan-shaped groove with a stepped shaft extending from the bottom plane of the fan-shaped groove for fixing the third guide wheel 5111 of the follower wheel. In terms of position, the semi-circular guide grooves of the first left guide wheel 5113 and the first right guide wheel 5114 of the fixed wheel are tangent to the semi-cylindrical guide groove of the inner ring of the follower wheel 516.

[0061] Similarly, the semi-circular guide grooves of the second left guide wheel 511 and the second right guide wheel 513 of the fixed wheel are tangent to the semi-circular guide groove of the inner ring of the follower wheel 516.

[0062] The fixed wheel 515 has a multi-step shaft end, the second step shaft shoulder is fixed to the shaft with a snap ring to fix the axial movement of the inner ring of the second bearing. The outer ring of the bearing is fixed to the driving wheel 517 through the hole with a snap ring. The first left guide wheel 518 and the first right guide wheel 519 of the driving wheel are symmetrically installed on one side of the annular groove of the driving wheel 517, and the second left guide wheel 5115 and the second right guide wheel 5116 of the driving wheel are symmetrically installed on the other side.

[0063] In terms of positional relationship, the semi-circular guide grooves of the first left guide wheel 518 and the first right guide wheel 519 of the driving wheel are tangent to the position of the semi-circular guide groove of the inner ring of the follower wheel 516.

[0064] Similarly, the semi-circular guide grooves of the second left guide wheel 5115 and the second right guide wheel 5116 of the driving wheel are tangent to the semi-cylindrical guide groove of the inner ring of the follower wheel 516. The two driving wheel fixing rope ends 5120 are installed between the first left guide wheel 518 and the first right guide wheel 519 of the driving wheel. Four cylindrical platforms extend from the annular groove of the driving wheel 517, and threaded holes are opened at their upper ends for fixing to the differential mechanism 52.

[0065] The specific rope winding method is as follows: The left 5121 and right 5122 ends of the two first wire ropes are symmetrically fixed to the fixed rope end 5112 of the fixed wheel, then pass around the cylindrical groove on the outer stepped surface of the follower wheel 516, and after being guided by the first guide wheel 512 of the follower wheel, they pass around the cylindrical groove on the outer stepped surface of the follower wheel 516, and the other ends of the ropes are symmetrically fixed to the fixed rope end 5120 of the driving wheel.

[0066] The two second wire ropes, left 543 and right 544, are transmitted through the second Bowden conduit 540 to the threaded end on the fixed end of the forearm 4. After being guided by the first left guide wheel 5113 and the first right guide wheel 5114 of the fixed wheel, they are symmetrically wound around the cylindrical groove on the outer ring of the follower wheel 516. After being guided by the second guide wheel 514 of the follower wheel, they are further wound around the cylindrical groove on the outer ring of the follower wheel 516. After being guided by the first left guide wheel 518 and the first right guide wheel 519 of the drive wheel, they reach the other end of the rope.

[0067] The ends of the two third steel wire ropes, left 541 and right 542, are transmitted through the second Bowden conduit 540 to the threaded ends on the fixed end of the forearm 4. After being guided by the second left guide wheel 511 and the second right guide wheel 513 of the fixed wheel, they symmetrically wind around the cylindrical grooves of the inner ring of the follower wheel 516. After being guided by the third guide wheel 5111 of the follower wheel, they wind around the cylindrical grooves of the inner ring of the follower wheel 516. After passing through the second left guide wheel 5115 and the second right guide wheel 5116 of the driving wheel, they reach the other end of the rope. The second steel wire ropes left 543 and right 544, together with the third steel wire ropes left 541 and right 542, are used to drive the deflection and rotation of the differential mechanism 52, thereby realizing the movement of the second and third degrees of freedom of the wrist joint.

[0068] The left and right ends of the two fourth steel wire ropes (551 and 552) are transmitted through the second Bowden conduit 540 to the threaded ends on the fixed end of the forearm 4. After passing through the first self-rotating guide wheel 5110, they cross and are wound upwards / downwards onto the cylindrical surface of the drive wheel 517, and the rope ends are fixed through openings on both sides of the drive wheel 517. The left and right fourth steel wire ropes (551 and 552) are used to drive the rotation of the drive wheel 517, thereby realizing the first degree of freedom of the wrist joint.

[0069] The rotation decoupling principle of the rotation decoupling mechanism 51 is as follows: One end of the first wire rope (left 5121, right 5122) is fixed to the fixed end 5112 of the fixed pulley. After passing the first guide wheel 512, the other end is fixed to the fixed end 5120 of the driving pulley. Thus, through the connection of the first wire rope (left 5121, right 5122), the fixed pulley 515, the follower wheel 516, and the driving pulley 517 form a standard movable pulley system. The fixed end 5112 of the fixed pulley is kept fixed. The driving pulley 517, driven by the fourth wire rope (left 551, right 552), moves... r 1* ω The speed of clockwise / counterclockwise rotation will drive the second wire rope left 543 and the second wire rope right 544 to generate r 2* ω *Δ t The change in rope length will cause the left 541 of the third wire rope and the right 542 of the third wire rope to produce... r 3* ω *Δ t The rope length changes; under the action of the characteristics of the movable pulley, the follower pulley 516... r n * ω / 2( n =1,2,3) rotate in the same direction at speeds in the same direction; the ropes on both sides of the first guide wheel 512, the second guide wheel 514, and the third guide wheel 5111 shorten in the same direction of rotation, with a shortening amount of 2* r n * ω / 2*Δ t = r n * ω *Δ t ( n =1,2,3), which cancels out the changes in the length of the second and third wire ropes caused by the rotation of the drive wheel 517. Therefore, while the drive wheel 517 rotates, the output ends of the second and third wire ropes remain unchanged.

[0070] The first absolute encoder mounting base 5117 extends four legs and is fixedly connected to the drive wheel 517. The rotating side 5118 of the first absolute encoder is fixedly connected to the top of the third step of the multi-step shaft of the fixed wheel 515 via set screws. The magnetic base 5119 of the first absolute encoder is fitted into the first absolute encoder mounting base 5117 and fixedly connected by bolts. There is a certain gap between the rotating side 5118 of the first absolute encoder and the magnetic base 5119 of the first absolute encoder, which is not limited to 0.8mm. This electrical component is used to measure the rotation angle of the self-rotation decoupling mechanism 51 in real time.

[0071] Specifically, the differential mechanism 52 includes a differential rotation shaft 523, a differential rotation shaft sleeve 525, a differential rotation shaft outer fixing seat 524, a first differential deflection base 521, a second differential deflection base 526, a differential rotating wheel 527, a second rotation guide wheel 528, a bearing end cover 522, a second absolute encoder mounting seat 5210, a second absolute encoder magnetic seat 5211, a second absolute encoder rotating side 5212, and a third absolute encoder 529.

[0072] One side of the differential rotation shaft 523 is fixedly connected to the simplified humanoid hand 6 by bolts, and the other side is sequentially fitted with a first deep groove ball bearing, a differential rotation shaft sleeve 525, and a second deep groove ball bearing. The outer fixing seat 524 of the differential rotation shaft has a groove, and the outer side of the bearing is fitted into the groove by two differential rotation shaft outer fixing seats 524 overlapping each other. After the two differential rotation shaft outer fixing seats 524 overlap each other, a multi-step shaft is formed on the left and right sides. The axial movement of the inner side of the third deep groove ball bearing is fixed on the stepped shaft on both sides by the first stepped shaft shoulder and a shaft retaining circlip. The outer side of the third deep groove ball bearing is fixed to the differential rotating wheel 527 by a hole retaining circlip. Further, the axial movement of the inner side of the fourth deep groove ball bearing is fixed by the second stepped shaft shoulder and a shaft retaining circlip. The outer side of the fourth deep groove ball bearing is fixed to the first differential deflection base 521 and the second differential deflection base 526 by the bearing end cover 522.

[0073] The second absolute encoder mounting base 5210 extends four legs and is fixedly connected to the outer fixing base 524 of the differential rotation shaft. The rotating side 5212 of the second absolute encoder is interference-fitted with the top end of the differential rotation shaft 523. The magnetic base 5211 of the second absolute encoder is fitted into the second absolute encoder mounting base 5210 and fixedly connected by bolts. There is a certain gap between the rotating side 5212 of the second absolute encoder and the magnetic base 5211 of the second absolute encoder, which is not limited to 0.8mm. This electrical component is used to measure the rotation angle of the differential mechanism 52 in real time.

[0074] The third absolute encoder 529 is fixed to the inside of the multi-step shaft formed on the left and right sides after the outer fixing seats 524 of the two differential rotating shafts are closed together by its own shaft shoulder. The groove on its rotating side is engaged with the corresponding boss on the bearing end cover 522. This electrical component is used to measure the deflection rotation angle in the differential mechanism 52 in real time.

[0075] The specific rope winding method is as follows: The two second steel wire ropes (left 543, right 544) and the two third steel wire ropes (left 541, right 542) pass through the rotation decoupling mechanism 51 and then cross over to the two differential rotating wheels 527, with the rope ends fixed through openings on both sides of the differential rotating wheels 527. There are four fifth steel wire ropes 5213, one end of which is connected to both sides of the two differential rotating wheels 527, and the other end, after being guided by the second rotation guide wheel 528 on the outer fixing seat 524 of the differential rotation shaft, cross over to the opening on the second stepped shaft of the differential rotation shaft 523, with the rope end fixed.

[0076] When the third wire rope (left 541) and the second wire rope (right 544), or the second wire rope (left 543) and the third wire rope (right 542) are pulled in the same direction and at the same speed, the second degree of freedom of the wrist joint produces a deflection motion, but no rotational motion. When the third wire rope (left 541) and the second wire rope (right 544), or the second wire rope (left 543) and the third wire rope (right 542) are pulled in opposite directions at the same speed, the third degree of freedom of the wrist joint produces a rotational motion, but no deflection motion. When the third wire rope (left 541) and the second wire rope (right 544), or the second wire rope (left 543) and the third wire rope (right 542) are pulled at different speeds, both the second and third degrees of freedom of the wrist joint will operate, coupling to generate deflection and rotational motions.

[0077] More specifically, the three degrees of freedom of movement corresponding to the human wrist joint are: When the fourth steel wire rope left 551 or the fourth steel wire rope right 552 driven by the second joint module 55 is pulled, the active wheel 517 will generate a counterclockwise or clockwise rotation of the first degree of freedom of the wrist joint, and drive the differential mechanism 52 and the humanoid simplified hand 6 to rotate synchronously to simulate the rotation of the human wrist.

[0078] When the third steel wire rope 541 (left) and the second steel wire rope 544 (right) or the second steel wire rope 543 (left) and the third steel wire rope 542 (right) driven by the first joint module 54 are pulled in the same direction and at the same speed, the second degree of freedom of the wrist joint produces a deflection motion to simulate the pitching and flexing motion of the human wrist.

[0079] When the third steel wire rope 541 (left) and the second steel wire rope 544 (right) or the second steel wire rope 543 and the third steel wire rope 542 (right) driven by the first joint module 54 are pulled in opposite directions at the same speed, the wrist joint's third degree of freedom generates a rotational motion, first rotating 90°. Subsequently, when the third steel wire rope 541 (left) and the second steel wire rope 544 (right) or the second steel wire rope 543 and the third steel wire rope 542 (right) driven by the first joint module 54 are pulled in the same direction at the same speed, the wrist joint's second degree of freedom generates a yaw motion, simulating the yaw motion of the human wrist.

[0080] Tensioning solutions for rope ends fixed to shoulder, elbow, and wrist joints include, but are not limited to, bolt-slider tensioning solutions, tension / compression spring tensioning solutions, disc spring tensioning solutions, and temperature-controlled spring tensioning solutions.

[0081] The basic principles, main features and beneficial effects of the present invention have been described above. Any changes, modifications, substitutions and variations made to the implementation methods without departing from the principles and spirit of the present invention shall fall within the scope of the claims of the present invention.

Claims

1. A modular seven-DOF rope-driven humanoid robotic arm, characterized in that: It includes a three-degree-of-freedom parallel attitude-adjusting rope-driven humanoid shoulder joint (1), and the upper arm (2) is connected to the output end of the three-degree-of-freedom parallel attitude-adjusting rope-driven humanoid shoulder joint (1). The first winding disc (15) is fixedly connected to the shoulder joint base (11), and the first winding disc (15), the second winding disc (16), and the third winding disc (17) are nested in sequence; the first revolute joint (110), the second revolute joint (19), and the third revolute joint (18) are all provided with D-shaped holes in the middle of their discs, and the first winding disc (15), the second winding disc (16), and the third winding disc (17) are respectively provided with D-shaped shafts and shaft shoulders on their upper sides, which are fixedly connected to the first revolute joint (110), the second revolute joint (19), and the third revolute joint (18); the first revolute joint (110), the second revolute joint (19), and the third revolute joint (18) are provided with L-shaped brackets on their upper sides, and bearing positioning shafts are provided on the L-shaped brackets. The intersection of the axes of the three bearing positioning shafts is the center of rotation of the human-like shoulder joint; the moving platform (112) moves up and down. Three lugs extend from each side. The upper lug is T-shaped, and the lower lug has a bearing positioning hole. The L-shaped brackets on the upper side of the first rotary joint (110), the second rotary joint (19), and the third rotary joint (18) are connected to the three lugs on the lower side of the moving platform (112) through three rotary joint connecting rods (111) to form three branches of the parallel 3-RRR mechanism. The other side of the shoulder joint steering connector (113) is fixedly connected to the upper arm (2). The upper side of the shoulder joint base (11) has three positioning holes for the shoulder joint modules (10) evenly opened. The three shoulder joint modules (10) are fixed on the shoulder joint base (11) respectively. The first winding motor output shaft (12), the second winding motor output shaft (13), and the third winding motor output shaft (14) are fixedly connected to the three shoulder joint modules (10) in sequence. A tension-amplified constant torque constant stiffness rope-driven humanoid elbow joint (3) is installed at the output end of the upper arm (2), a forearm (4) is installed at the output end of the tension-amplified constant torque constant stiffness rope-driven humanoid elbow joint (3), a self-rotation decoupling differential rope-driven humanoid wrist joint (5) is installed at the output end of the forearm (4), and a simplified humanoid hand (6) is installed at the output end of the self-rotation decoupling differential rope-driven humanoid wrist joint (5). The self-rotation decoupling differential rope-driven humanoid wrist joint (5) includes a self-rotation decoupling mechanism (51) and a differential mechanism (52), and is driven by a differential rope driven by a steel wire rope in the joint. The self-rotation decoupling mechanism (51) and the differential mechanism (52) achieve flexible drive and transmission between the first joint module (54), the second joint module (55) and the corresponding degree of freedom through the combination of the second Bowden cable (540), the wire rope and the guide wheel; The self-rotation decoupling mechanism (51) includes a fixed wheel (515), a first left guide wheel of the fixed wheel (5113), a first right guide wheel of the fixed wheel (5114), a second left guide wheel of the fixed wheel (511), a second right guide wheel of the fixed wheel (513), a fixed rope end of the fixed wheel (5112), a follower wheel (516), a first guide wheel of the follower wheel (512), a second guide wheel of the follower wheel (514), a third guide wheel of the follower wheel (5111), a driving wheel (517), a first left guide wheel of the driving wheel (518), a first right guide wheel of the driving wheel (519), a second left guide wheel of the driving wheel (5115), a second right guide wheel of the driving wheel (5116), a fixed rope end of the driving wheel (5120), a first self-rotating guide wheel (5110), a first absolute encoder mounting base (5117), a first absolute encoder rotating side (5118), a first absolute encoder magnetic base (5119), a first steel wire rope, and a fourth steel wire rope; The fixed wheel (515) serves as the base. The annular boss end of the fixed wheel (515) is fixed to the forearm (4) by bolts. The first left guide wheel (5113) and the first right guide wheel (5114) of the fixed wheel are symmetrically installed on one side of the annular boss end of the fixed wheel (515), and the second left guide wheel (511) and the second right guide wheel (513) of the fixed wheel are symmetrically installed on the other side. The two fixed wheel fixing rope ends (5112) are installed in the middle of the first left guide wheel (5113) and the first right guide wheel (5114). The two fixed wheels have L-shaped brackets symmetrically extending from both sides of the circular vertical surface of the fixed wheel (515), and the first self-rotating guide wheel (5110) is fixed by the shaft shoulder and the open retaining ring. The first stepped shoulder of the multi-step shaft end of the fixed wheel (515) is fixed to the axial movement of the inner ring of the first bearing with a circlip. The outer ring of the bearing is fixed to the follower wheel (516) through the hole with a circlip. The outer ring of the follower wheel (516) has two stepped surfaces symmetrically designed, and cylindrical grooves are opened on the stepped surfaces. The outer ring of the follower wheel (516) has a fan-shaped groove, and two stepped shafts extend from the bottom plane of the groove to fix the first guide wheel (512) and the second guide wheel (514) of the follower wheel with different diameters respectively. The inner ring of the follower wheel (516) has a cylindrical groove; the inner ring of the follower wheel (516) has a fan-shaped groove, and a stepped shaft extends from the bottom plane of the fan-shaped groove to fix the third guide wheel (5111) of the follower wheel; the semi-circular guide grooves of the first left guide wheel (5113) and the first right guide wheel (5114) of the fixed wheel are tangent to the semi-cylindrical guide groove of the inner ring of the follower wheel (516).

2. The modular seven-degree-of-freedom rope-driven humanoid robotic arm according to claim 1, characterized in that: Tension amplification constant torque constant stiffness rope drive humanoid elbow joint (3), self-rotation decoupling differential rope drive humanoid wrist joint (5) are flexibly driven by steel wire ropes guided by the main Bowden tube (7); The main Bowden conduit (7) includes the first Bowden conduit (32) and the second Bowden conduit (540); The tension amplification constant torque constant stiffness rope-driven anthropomorphic elbow joint (3) includes a first set of steel wire ropes (31), a first Bowden conduit (32), a fixed end of the elbow joint (33), a double-end connector (34), a stepped double-layer pulley at the moving end (35), a moving end of the elbow joint (36), a pulley seat at the moving end (37), a guide wheel at the fixed end (38), a small pulley at the fixed end (39), a second set of steel wire ropes (310), a large pulley at the fixed end (311), a tension plate (312), a central shaft at the moving end (313), a rotating side of the absolute encoder (314), a magnetic seat of the absolute encoder (315), a central shaft at the fixed end (316), a coupling rope (317), and a joint module (318). The four sides of the elbow joint fixed end (33) are fixed to one side of the upper arm (2). Two first Bowden tubes (32) threading ends and two rope knot fixing ends are provided on its upper side. Two protruding pentagonal bearing support platforms are provided on its lower side. Each support platform is equipped with a four-step shaft. The shoulders of the four-step shaft and the open retaining rings are respectively fixed with eight small fixed end pulleys (39) of the same diameter used as rope winding guides. One end with a quarter-circle arc plane perpendicular to the four-sided plane side of the elbow joint fixing end (33) extends out of the four-sided plane side and, through the joint action of the shoulders of the two stepped shafts and the open retaining ring, fixes two large fixed end pulleys (311) of different diameters used as rope guides. The other end with the quarter-circle arc plane side has a circular groove at the center of the arc and is evenly provided with eight threaded holes. The two fixed end central shafts (316) are fixed to the left and right end faces of the other end with the quarter-circle arc plane side of the elbow joint fixing end (33) by bolts. The fixed end central shaft (316) is connected to the shaft retaining spring through the shoulder of the stepped shaft and fixes the inner side of two deep groove ball bearings of the same diameter and a third deep groove ball bearing of different diameter in the axial direction. The outer side of the two deep groove ball bearings of the same diameter is axially fixed to the fixed end guide wheel (38) through the hole retaining spring.

3. The modular seven-degree-of-freedom rope-driven humanoid robotic arm according to claim 2, characterized in that: The four sides of the elbow joint moving end (36) are fixedly connected to one side of the forearm (4). One end of the four sides of the elbow joint moving end (36) with a quarter-circle arc plane perpendicular to the four sides of the elbow joint moving end (36) extends out of the four sides ... Four threaded holes are evenly arranged on the movable end pulley seat (37), and are fixed to one side of the double-end connector (34) by bolts; the other side of the double-end connector (34) has a bearing hole, which is axially fixed to the outer side of the third deep groove ball bearing on the outer side of the fixed end central shaft (316) by a snap ring through the hole, so as to connect the fixed end (33) of the elbow joint with the movable end (36) of the elbow joint.

4. The modular seven-degree-of-freedom rope-driven humanoid robotic arm according to claim 3, characterized in that: The rotating side (314) of the absolute encoder is fixedly connected to the top of the central shaft (313) of the moving end by a set screw. The magnetic base (315) of the absolute encoder is embedded in the circular groove on one side of the double-end connector and fixedly connected by bolts. There is a certain gap between the rotating side (314) of the absolute encoder and the magnetic base (315) of the absolute encoder. Two wire grooves and two knot holes are opened on the vertical surface of the other end of the elbow joint fixed end (33) with a quarter-circle plane side. Two wire grooves and two knot holes of the same size and position are opened on the vertical surface of the other end of the elbow joint moving end (36) with a quarter-circle plane side. One end of the two coupling ropes (317) is fixed along the wire groove to the knot hole of the elbow joint fixed end (33) and the tension plate (312) on the elbow joint moving end (36) side, respectively. The other end of the two coupling ropes (317) is fixed along the wire groove. The tensioning plate (312) is located on the elbow joint moving end (36) and the elbow joint fixed end (33). The tensioning plate (312) has three holes, and the coupling rope (317) is fixed in one of the holes on both sides of the tensioning plate (312). A long bolt is installed on the bolt hole on the vertical surface of the four sides of the elbow joint fixed end (33). The middle threaded hole of the tensioning plate (312) is connected to the long bolt by thread, and the axial displacement of the tensioning plate (312) is achieved by tightening the bolt, thereby achieving the tensioning of the coupling rope (317). Two sets of steel wire ropes are respectively fixed to the release end and the take-up end of the joint module (318), and are transmitted through the first Bowden tube (32) to the Bowden tube threading end on the elbow joint fixing end (33) and wrapped around the elbow joint.

5. A modular seven-degree-of-freedom rope-driven humanoid robotic arm according to claim 1, characterized in that: The three-degree-of-freedom parallel attitude-adjusting rope-driven humanoid shoulder joint (1) can mimic the three-way posture movement of the ball-and-socket joint in the physiological structure of the human shoulder joint. The three-degree-of-freedom parallel attitude-adjusting rope-driven humanoid shoulder joint (1) includes three RRR branches, which are independently driven by their respective steel wire ropes. The upper arm (2) is a spatial transition between the three-degree-of-freedom parallel attitude-adjusting rope-driven humanoid shoulder joint (1) and the tension-amplified constant torque constant stiffness rope-driven humanoid elbow joint (3). The upper arm (2) forms a mating assembly position at both ends. The tension amplification constant torque constant stiffness rope-driven humanoid elbow joint (3) is a rigid structure with a rolling joint configuration. Its transmission adopts Bowden tube-steel wire rope form to realize tension amplification and constant torque constant stiffness of the elbow joint.

6. The modular seven-degree-of-freedom rope-driven humanoid robotic arm according to claim 1, characterized in that: The forearm (4) is a spatial transition between the tension amplification constant torque constant stiffness rope-driven humanoid elbow joint (3) and the rotation decoupling differential rope-driven humanoid wrist joint (5). The forearm (4) forms a mating assembly position at both ends. The self-rotation decoupled differential rope-driven anthropomorphic wrist joint (5) is a three-degree-of-freedom rope-driven hybrid joint.

7. The modular seven-degree-of-freedom rope-driven humanoid robotic arm according to claim 1, characterized in that: The semi-circular guide grooves of the second left guide wheel (511) and the second right guide wheel (513) of the fixed wheel are tangent to the semi-circular guide groove of the inner ring of the follower wheel (516); The second stepped shaft shoulder of the fixed wheel (515) and the shaft are fixed with a snap ring to prevent the axial movement of the inner ring of the second bearing. The outer ring of the bearing is fixed to the driving wheel (517) through the hole with a snap ring. The first left guide wheel (518) and the first right guide wheel (519) of the driving wheel are symmetrically installed on one side of the annular groove of the driving wheel (517), and the second left guide wheel (5115) and the second right guide wheel (5116) of the driving wheel are symmetrically installed on the other side. The semi-circular guide grooves of the first left guide wheel (518) and the first right guide wheel (519) of the drive wheel are tangent to the semi-circular guide groove of the inner ring of the follower wheel (516); The semi-circular guide grooves of the second left guide wheel (5115) and the second right guide wheel (5116) of the driving wheel are tangent to the semi-circular guide groove of the inner ring of the follower wheel (516); the two driving wheel fixing rope ends (5120) are installed between the first left guide wheel (518) and the first right guide wheel (519) of the driving wheel; four cylindrical platforms extend from the annular groove of the driving wheel (517), and threaded holes are opened at the upper end for fixing with the differential mechanism (52).

8. A modular seven-degree-of-freedom rope-driven humanoid robotic arm according to claim 7, characterized in that: The differential mechanism (52) includes a differential rotation shaft (523), a differential rotation shaft bushing (525), a differential rotation shaft outer fixing seat (524), a first differential deflection base (521), a second differential deflection base (526), ​​a differential rotating wheel (527), a second rotation guide wheel (528), a bearing end cover (522), a second absolute encoder mounting seat (5210), a second absolute encoder magnetic seat (5211), a second absolute encoder rotating side (5212), and a third absolute encoder (529). One side of the differential rotation shaft (523) is fixedly connected to the simplified humanoid hand (6) by bolts, and the other side is sequentially installed with a first deep groove ball bearing, a differential rotation shaft sleeve (525) and a second deep groove ball bearing; the outer fixing seat (524) of the differential rotation shaft has a groove, and the outer side of the bearing is fitted with the groove by the two outer fixing seats (524) of the differential rotation shaft. After the two outer fixing seats (524) of the differential rotation shaft are fitted together, a multi-step shaft is formed on the left and right sides. The axial movement of the inner side of the third deep groove ball bearing is fixed by the first step shaft shoulder and the shaft snap ring on the stepped shaft on both sides, and the outer side of the third deep groove ball bearing is fixed to the differential rotating wheel (527) by the hole snap ring. The second absolute encoder mounting base (5210) extends four legs and is fixedly connected to the outer fixed base (524) of the differential rotation shaft. The rotating side (5212) of the second absolute encoder is interference-fitted with the top end of the differential rotation shaft (523). The magnetic base (5211) of the second absolute encoder is inserted into the second absolute encoder mounting base (5210) and fixedly connected by bolts. There is a certain gap between the rotating side (5212) of the second absolute encoder and the magnetic base (5211) of the second absolute encoder. The third absolute encoder (529) is fixed to the inside of the multi-step shaft formed on the left and right sides after the outer fixing seats (524) of the two differential rotating shafts are closed together by its own shoulder. The groove on its rotating side is fitted with the corresponding boss on the bearing end cover (522).

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