Three-degree-of-freedom decoupling wrist

Abstract

The invention discloses a three-degree-of-freedom decoupling wrist, and relates to the technical field of humanoid wrist robots, the three-degree-of-freedom decoupling wrist comprises a static platform base, a pointing motion branch, a middle rotation branch, a movable platform, a guide wheel assembly and a driving rope assembly, the pointing motion branch comprises a pitching supporting seat, a deflection supporting seat, a pitching driving wheel, a deflection driving wheel and a connecting rod assembly; the middle rotary branch is mounted between the static platform base and the movable platform; the guide wheel assembly is installed on the static platform base. The driving rope assembly comprises a first driving rope, a second driving rope and a third driving rope, and the driving rope assembly is suitable for being connected between the guide wheel assembly and the pointing movement branch in a winding mode; the decoupling wrist is suitable for rotating and rotating for a whole circle in the three-degree-of-freedom movement direction by driving the rope assembly. The three-degree-of-freedom decoupling wrist is simple and compact in structure and free of singular shapes and positions in a working space, the axes of all the joints intersect at one point, and rotary motion of the wrist is easier to achieve.

Description

Technical Field

[0001] The invention relates to the technical field of humanoid wrist robots, and in particular to a three-degree-of-freedom decoupling wrist. Background Art

[0002] The humanoid wrist is an important component of the humanoid manipulator, which is responsible for simulating the flexible movements of the human hand, including rotation, bending and swinging. The design of the wrist directly affects the operating accuracy, adaptability and flexibility of the robot arm. When performing complex tasks such as fine assembly, surgical assistance or human-computer interaction, a highly bionic wrist can provide a range of motion and control similar to that of a human hand, thereby greatly improving the performance of the robot arm.

[0003] The Chinese invention patent with publication number CN107351064A discloses a two-degree-of-freedom parallel humanoid wrist, which uses two semicircular arc-shaped follower pointing rods. The motor drives the semicircular arc pointing rods through gears to achieve two-degree-of-freedom movement of the mechanism, which is free, flexible and high in precision. However, the friction and wear between the rods are serious, the service life is short, and it is difficult to fix the cable to install the actuator at the end.

[0004] The Chinese invention patent with publication number CN117773995A discloses a three-degree-of-freedom robot wrist, which includes a slewing mechanism, a differential drive mechanism and a differential transmission mechanism. The robot wrist has the characteristics of flexible range of motion, strong load capacity and compact structure. However, it has a large mass and it is difficult to install the end effector through cables, which is not convenient for high-speed movement.

[0005] The Chinese invention patent with publication number CN214724204U discloses a rope-driven wrist module based on a three-degree-of-freedom serial-parallel hybrid mechanism. The wrist module consists of a three-degree-of-freedom serial-parallel module and a drive-control integrated module. The three-degree-of-freedom serial-parallel module includes a spherical pure rolling parallel mechanism and a tension amplification mechanism. The spherical pure rolling parallel mechanism realizes the two-degree-of-freedom spherical motion of the wrist. The lower platform of the parallel mechanism is designed as a rotational degree of freedom, thereby forming a serial-parallel hybrid mechanism, and the tension amplification mechanism ensures that the mechanism is lightweight without losing stiffness; the drive-control integrated module is used to integrate the motor, driver and controller to form an independent electromechanical system; by combining the advantages of rope drive and modularization, the design has the advantages of light weight, reconfigurability and good flexibility. The proposed serial-parallel hybrid mechanism has the same degree of freedom configuration as a real wrist, and can realize highly realistic human-like wrist motion. However, the hybrid structure has too many connecting rods, a complex structure, and cannot complete a full-circle rotation. The mathematical model of the forward and inverse solutions is complex, which is not conducive to control.

[0006] Comprehensive analysis shows that the existing humanoid wrists have the following problems: First: it is difficult to achieve a full rotation, or to achieve a full rotation, various drivers need to work together, the control is complex, and the accuracy is poor; Second: the existing wrist transmission mechanism is complex and heavy, which is not conducive to lightweight design; Third: Most of the existing wrists cannot achieve closed-loop rope drive, and the drive system is complicated; Fourth: The existing wrist cannot simultaneously meet the advantages of three-axis rotation, easy full-circle rotation, closed-loop rope drive, simple mathematical model, etc., and there will be obvious shortcomings in application. Summary of the invention

[0007] In view of this, and in response to the technical problems existing in the prior art, the purpose of the present invention is to provide a three-degree-of-freedom decoupled wrist that has a simple and compact structure, and three sets of drive ropes that can achieve three-degree-of-freedom rotation, a large wrist rolling motion space, and a full-circle rotation motion.

[0008] In order to solve the above problems, the technical solution of the present invention provides a three-degree-of-freedom decoupling wrist, comprising: static platform base; Moving platform; A pointing motion branch is arranged above the static platform base, and the pointing motion branch comprises a pitch support seat, a deflection support seat, a pitch driving wheel, a deflection driving wheel and a connecting rod assembly, wherein the pitch support seat and the deflection support seat are both fixedly connected to the static platform base; the pitch driving wheel is connected to the pitch support seat via a first rotating pair, and the deflection driving wheel is connected to the deflection support seat via a second rotating pair; An intermediate rotary branch is installed between the static platform base and the dynamic platform; A guide wheel assembly is mounted on the static platform base; A driving rope assembly, comprising a first driving rope, a second driving rope and a third driving rope for driving the same joint in a closed loop in pairs, wherein the driving rope assembly is suitable for winding and connecting between the guide wheel assembly, the directional motion branch and the intermediate rotation branch; The decoupled wrist is suitable for rotation and full rotation in three degrees of freedom movement directions through the drive rope assembly.

[0009] Preferably, the connecting rod assembly comprises a first connecting rod, a second connecting rod, a third connecting rod and a fourth connecting rod, wherein: The first connecting rod and the second connecting rod are connected via a third rotational pair; the second connecting rod and the third connecting rod are connected via a fourth rotational pair; the third connecting rod and the fourth connecting rod are connected via a fifth rotational pair; The first connecting rod is fixedly connected to the yaw driving wheel through a transmission shaft, the third connecting rod is fixedly connected to the moving platform, and the fourth connecting rod is fixedly connected to the pitch driving wheel through a transmission shaft; The fourth rotational pair and the fifth rotational pair are both located on the third connecting rod, and an angle is formed between the fourth rotational pair and the fifth rotational pair.

[0010] Preferably, the intermediate slewing branch comprises a base flange, a slewing driving wheel, a slewing connecting flange and a universal joint, wherein: The universal hinge is composed of a universal hinge lower fork, a universal hinge upper fork and a universal hinge center block; The base flange is fixedly connected to the static platform base, the base flange is connected to the rotary drive wheel through a sixth rotation pair, and the rotary drive wheel is fixedly connected to the universal joint lower fork; The direction of the sixth rotation pair is perpendicular to the static platform base, and the sixth rotation pair is suitable for full-circle rotation; The universal hinge upper fork passes through the center of the moving platform and is connected to the moving platform via a seventh rotation pair.

[0011] Preferably, the first rotating pair, the second rotating pair, the third rotating pair, the fourth rotating pair, the fifth rotating pair, the sixth rotating pair and the seventh rotating pair converge at one point, and the intersection center coincides with the rotation center of the universal joint; the first rotating pair and the second rotating pair both maintain a horizontal fixed direction.

[0012] Preferably, the guide wheel assembly comprises a first guide wheel group, a second guide wheel group, a third guide wheel group and a fourth guide wheel group; The fifth pulley and the ninth pulley as well as the sixth pulley and the tenth pulley are symmetrically arranged at two ends of the first guide wheel group; The thirteenth pulley and the fifteenth pulley as well as the fourteenth pulley and the sixteenth pulley are symmetrically arranged at both ends of the second guide wheel group; The seventh pulley and the eleventh pulley as well as the eighth pulley and the twelfth pulley are symmetrically arranged at both ends of the third guide wheel group; The third pulley and the fourth pulley are symmetrically arranged at both ends of the fourth guide wheel group, and the fourth guide wheel group is connected to the static platform base through a guide wheel base.

[0013] Preferably, the static platform base is an inverted U-shaped structure, and the first crossbeam and the second crossbeam run through the middle of the inverted U-shaped structure, the first crossbeam is mounted on the first guide wheel group and the second guide wheel group is mounted on the second crossbeam.

[0014] Preferably, the starting ends of the two first drive ropes are fixedly connected to the knotting hole of the pitch drive wheel, and the other ends respectively pass downward through the first wire hole and the second wire hole of the static platform base, pass around from under the sixth pulley and the tenth pulley, and then pass around from above the fifth pulley and the ninth pulley respectively, and pass through the first guide wheel group; the ends of the two first drive ropes extend downward in a front-to-rear symmetrical manner to be connected to the output end of the first drive member.

[0015] Preferably, the starting ends of the two second drive ropes are fixedly connected to the knotting hole of the deflection drive wheel, and the other ends pass through the third wire hole and the fourth wire hole on the static platform base respectively, pass around from under the fourteenth pulley and the sixteenth pulley, and then pass around from above the thirteenth pulley and the fifteenth pulley respectively, and pass through the second guide wheel group; the ends of the two second drive ropes extend downward in a front-to-rear symmetrical manner to be connected to the output end of the second drive member.

[0016] Preferably, the starting ends of the two third drive ropes are wound and fixedly connected to the knotting hole of the rotary drive wheel, and the other ends pass through the third pulley and the fourth pulley on the fourth guide wheel group, and then pass through the fifth wire hole and the sixth wire hole on the static platform base respectively, and then pass around from under the eighth pulley and the twelfth pulley respectively, and pass around from above the seventh pulley and the eleventh pulley and pass through the third guide wheel group respectively; the ends of the two third drive ropes extend downward in a front-to-rear symmetrical manner to be connected to the output end of the third drive member.

[0017] Preferably, the universal hinge lower fork and the universal hinge upper fork are provided with through holes along the long rod direction, and the universal hinge center block is provided with a through hole suitable for passing cables.

[0018] Compared with the prior art, the present invention has the following beneficial effects: 1. The three-degree-of-freedom decoupling wrist in this application realizes the three-degree-of-freedom motion decoupling through its unique structural design, wherein the layout of the static platform base, pointing motion branch, intermediate rotation branch and moving platform and other components is reasonable and compact, and the pitch support seat and the deflection support seat are both fixedly connected to the static platform base, ensuring the stability of the pointing motion branch; the intermediate rotation branch is installed between the static platform base and the moving platform, effectively connecting and supporting the two, so that the entire wrist structure maintains good rigidity and reliability during the movement process, reducing the motion error and failure risk caused by structural deformation or loosening, which is conducive to long-term stable operation in harsh working environments; the pointing motion branch includes two driving wheels for pitch and deflection, and is connected to the corresponding support seat through the first rotation pair and the second rotation pair respectively, so that the pitch and deflection motion can be carried out independently without interfering with each other. At the same time, the setting of the intermediate rotation branch further enhances the effect of motion decoupling, so that when the wrist performs a full-circle rotation motion, it will not have a coupling effect on the pitch and deflection motion, so that the wrist can accurately control the movement in the three degrees of freedom directions, meeting the requirements of motion accuracy for complex operation tasks. With the help of the drive rope assembly and the guide wheel assembly installed on the static platform base, the decoupled wrist can rotate and make a full rotation in the three-degree-of-freedom motion direction. This design allows the wrist to have greater flexibility in movement, cover a wider range of motion, adapt to the operation requirements of different angles and positions, and can easily reach and operate target objects in different spatial positions and postures, improving the flexibility and efficiency of operations. The use of the drive rope assembly provides a simple and effective way to drive the wrist. By controlling the winding and release of the drive rope, the pointing motion branch can be accurately driven to achieve full-circle rotation of the pitch, yaw, and intermediate rotation branches, and the structure of the drive system is relatively simple, which is easy to integrate with the control system.

[0019] 2. The lightweight pulley-driven three-degree-of-freedom decoupled wrist based on the intersection of rotating shafts has three degrees of freedom and is driven by three pairs of closed-loop ropes. The drive system is simple and the structure is lightweight. The parallel mechanism design is adopted with fewer rods and a simple structure, which enhances the stiffness of the wrist and gives it better operational stability and balance. The special rotation branch design allows the other branches to be fixed when the wrist realizes rotational motion, thereby improving the posture capability of the wrist. A long cable can pass through the middle of the wrist, which is conducive to the installation of the end effector and ensures the aesthetics and safety of the overall mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the three-dimensional structure of the three-degree-of-freedom decoupling wrist in an embodiment of the present invention; Figure 2 It is a schematic diagram of the front structure of a three-degree-of-freedom decoupling wrist in an embodiment of the present invention; Figure 3It is a schematic diagram of the back structure of a three-degree-of-freedom decoupling wrist in an embodiment of the present invention; Figure 4 It is a structural schematic diagram of a static platform base in an embodiment of the present invention; Figure 5 Schematic diagram of the structure of the rotary motion branch in an embodiment of the present invention.

[0021] Description of reference numerals: 1-static platform base; 2-pointing motion branch; 3-rotational motion branch; 4-moving platform; a-pitch support seat; b-yaw support seat; c-base flange; d-slewing drive wheel; e-slewing connection flange; f-universal hinge lower fork; g-universal hinge center block; h-universal hinge upper fork; L1-first connecting rod; L2-second connecting rod; L3-third connecting rod; L4-fourth connecting rod; R1-first rotation pair; R2-second rotation pair; R3-third rotation pair; R4-fourth rotation pair; R5-fifth rotation pair; R6-sixth rotation pair; R7-seventh rotation pair; U-universal hinge; Z1-first guide wheel group; Z2-second guide wheel group; Z3-third guide wheel group; Z4-fourth guide wheel group; S1-first drive rope; S2-second drive rope; S3-third drive rope; P1-pitch drive wheel; P2-yaw drive wheel; P3-third pulley; P4-fourth pulley; P5-fifth pulley; P6-sixth pulley; P7-seventh pulley; P8-eighth pulley; P9-ninth pulley; P10-tenth pulley; P11-eleventh pulley; P12-twelfth pulley; P13-thirteenth pulley; P14-fourteenth pulley; P15-fifteenth pulley; P16-sixteenth pulley; K1-first wire hole; K2-second wire hole; K3-third wire hole; K4-fourth wire hole; K5-fifth wire hole; K6-sixth wire hole; H1-first beam; H2-second beam. DETAILED DESCRIPTION

[0022] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, it can also be the internal connection of two components, it can be a wireless connection, or it can be a wired connection. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0024] See also Figure 1-5 As shown, an embodiment of the present invention provides a three-degree-of-freedom decoupling wrist, which includes a static platform base 1, a pointing motion branch 2, an intermediate rotation branch 3, a moving platform 4, a guide wheel assembly and a drive rope assembly, wherein: The static platform base 1 is the fixed part of the entire structure, and the dynamic platform 4 is used to carry lightweight connecting rods and guide wheels to reduce inertia and improve dynamic response speed.

[0025] The pointing motion branch 2 is used to process pitch and yaw. The pointing motion branch 2 in this embodiment is arranged above the static platform base 1. The pointing motion branch 2 includes a pitch support seat a, a yaw support seat b, a pitch driving wheel P1, a yaw driving wheel P2 and a connecting rod assembly. The pitch support seat a and the yaw support seat b are both fixedly connected to the static platform base 1; the pitch driving wheel P1 is connected to the pitch support seat a through a first rotation pair R1, and the yaw driving wheel P2 is connected to the yaw support seat b through a second rotation pair R2; The intermediate rotating branch 3 adopts an independent structure to allow the moving platform 4 to rotate a full circle. As a preferred mode of this embodiment, the intermediate rotating branch 3 is installed between the static platform base 1 and the moving platform 4, allowing 360° continuous rotation through the center axis of the moving platform 4, thereby expanding the working space and being suitable for scenarios requiring full-circle operations; the guide wheel assembly is installed on the static platform base 1 to help reduce friction on the drive rope and ensure the correct path of the rope to avoid interference and wear problems with other components.

[0026] The driving rope assembly includes a first driving rope S1, a second driving rope S2 and a third driving rope S3 that drive the same joint in a closed loop. Each degree of freedom is coordinated by two driving ropes to achieve rotation by differential means, and the driving rope assembly is suitable for winding and connecting between the guide wheel assembly and the pointing motion branch 2. The driving rope assembly is wound through the guide wheel, and the driving part is placed on the base, which reduces the mass of the moving parts and improves the dynamic performance. In addition, the use of driving ropes and guide wheels can reduce the complexity of the mechanical structure, making the wrist lighter and more responsive.

[0027] The decoupled wrist is suitable for rotation and full rotation in three degrees of freedom movement directions through the drive rope assembly.

[0028] Therefore, the decoupled wrist achieves efficient decoupling and flexible movement of three degrees of freedom through a split branch structure and rope drive, and has the advantages of both lightweight and full-circle rotation. The decoupling of pitch, yaw and rotation motion is achieved through discrete directional motion branches (pitch, yaw) and intermediate rotation branches, combined with closed-loop control of three sets of drive ropes. Each degree of freedom is controlled by an independent drive wheel and drive rope, which reduces motion coupling and simplifies the kinematic model. Paired closed-loop drive ropes (such as S1 / S2 drive pitch, S3 drive rotation) achieve precise angle adjustment through differential tensioning / relaxation, avoiding the cumulative error of traditional series mechanisms. Rope drive provides flexibility, suitable for human-machine collaboration or precision operation, and the guide wheel assembly optimizes the rope path and reduces friction loss.

[0029] Compared with traditional drive methods such as gears and connecting rods, the drive rope assembly has higher transmission efficiency and lower friction loss. At the same time, it avoids the manufacturing and assembly difficulties brought by complex mechanical transmission structures, reduces costs, improves system reliability and maintainability, and facilitates precise motion control and real-time adjustment to adapt to different work tasks and requirements.

[0030] Specifically, see Figure 2 As shown, the connecting rod assembly includes a first connecting rod L1, a second connecting rod L2, a third connecting rod L3 and a fourth connecting rod L4, wherein: The first link L1 is connected to the second link L2 via a third rotation pair R3; the second link L2 is connected to the third link L3 via a fourth rotation pair R4; the third link L3 is connected to the fourth link L4 via a fifth rotation pair R5; The first link L1 is fixedly connected to the yaw drive wheel P2 through a transmission shaft, the third link L3 is fixedly connected to the moving platform 4, and the fourth link L4 is fixedly connected to the pitch drive wheel P1 through a transmission shaft; The fourth rotational pair R4 and the fifth rotational pair R5 are both located on the third connecting rod L3, and an angle is formed between the fourth rotational pair R4 and the fifth rotational pair R5.

[0031] Specifically in this embodiment, the first link L1 obtains power from the yaw drive wheel P2, transmits it to the second link L2 through the third rotation pair R3, then to the third link L3 through the fourth rotation pair R4, and finally to the moving platform 4 and the pitch drive wheel P1 through the fifth rotation pair R5. In this way, the multi-link structure can separate the yaw and pitch motions to reduce coupling. The angle between the rotation pairs can help decompose the motion direction, such as independently controlling the yaw and pitch. The four-bar linkage (L1-L4) can amplify the small angle change of the drive wheel into a large range of motion of the moving platform through the rotation pairs in series, thereby improving the flexibility of the joints; the link assembly forms a folding structure through multiple rotation pairs (R3-R5), which can be retracted in the non-working state to reduce space occupation; when unfolded, the range of motion is expanded through the angle design (R4 and R5); the angle between the fourth rotation pair R4 and the fifth rotation pair R5 (such as orthogonal or specific angle) can further separate the transmission paths of the yaw and pitch motions to reduce motion interference.

[0032] Therefore, the four-bar linkage achieves physical decoupling of yaw and pitch motion through multi-stage revolute series + angle design, combining the force efficiency of rigid transmission with the flexibility of rope drive, but needs to balance the error accumulation of multiple joints and dynamic performance limitations. Further combined with high-precision manufacturing, lightweight materials and intelligent control algorithms, its practicality in precision operation scenarios can be significantly improved.

[0033] Specifically, see Figure 1 , 2 As shown, the middle slewing branch 3 includes a base flange c, a slewing driving wheel d, a slewing connecting flange e and a universal joint U, wherein: The universal joint U is composed of a universal joint lower fork f, a universal joint upper fork h and a universal joint center block g. The universal joint of this structure has good rigidity and stability, and can effectively reduce deformation and shaking in the process of transmitting motion and force, thereby ensuring the posture stability of the moving platform 4 during the movement, and avoiding problems such as decreased motion accuracy or jitter of the moving platform 4 caused by the unstable structure of the universal joint itself, thereby improving the stability and motion accuracy of the entire system during operation.

[0034] The base flange c is fixedly connected to the static platform base 1, providing a stable support foundation for the entire intermediate slewing branch 3. The base flange c is connected to the slewing drive wheel d through the sixth rotation pair R6, and the slewing drive wheel d is fixedly connected to the universal joint lower fork f, so that the slewing drive wheel d can achieve a stable and smooth full-circle rotation, thereby driving the universal joint lower fork f fixed thereto to perform a corresponding rotation action; the entire intermediate slewing branch 3 has a certain load capacity, and can withstand the inertial force, gravity and other forces generated by the moving platform 4 and the various loads carried thereon during the movement process, ensuring the normal operation of the system under load. The direction of the sixth rotation pair R6 is perpendicular to the static platform base 1, and the sixth rotation pair R6 is suitable for full-circle rotation.

[0035] The fork h on the universal hinge passes through the center of the moving platform 4 and is connected to the moving platform 4 through the seventh rotation pair R7. Such a structure enables the moving platform 4 to flexibly change its posture and direction according to actual needs under the action of the universal hinge U, and realize multi-degree-of-freedom movement. The connection and transmission between the various components of the entire intermediate rotary branch 3 are relatively coherent during the movement process, which effectively ensures the flexibility and coherence of the movement and can adapt to complex and changeable working scenes and movement requirements.

[0036] Therefore, the base flange c, the rotary drive wheel d, the rotary connecting flange e and the universal hinge U and other components are not only arranged compactly and reasonably, but also connected to each other by means of rotating pairs, etc., which not only meets the requirements of motion transmission, but also saves space to a certain extent, so that the entire intermediate rotary branch 3 can realize complex rotary motion and posture adjustment functions in a limited space, which is conducive to the miniaturization and lightweight design of the overall equipment and improves space utilization.

[0037] Specifically, see Figure 1 , 2 As shown, the first rotation pair R1, the second rotation pair R2, the third rotation pair R3, the fourth rotation pair R4, the fifth rotation pair R5, the sixth rotation pair R6 and the seventh rotation pair R7 converge at one point, and the intersection center coincides with the rotation center of the universal joint U; the first rotation pair R1 and the second rotation pair R2 both maintain a horizontal fixed direction.

[0038] Therefore, this layout greatly improves the accuracy of the entire mechanism movement. During the movement process, the rotation of each revolving pair can be performed around the same center, avoiding the accumulation of motion errors caused by relative position deviations between different revolving pairs, making the movement coordination between various components more accurate and coordinated, and being able to achieve complex and precise motion trajectories and posture changes, meeting the needs of high-precision operations or motion control.

[0039] The first rotation pair R1 and the second rotation pair R2 both maintain a horizontal fixed direction, providing a stable horizontal reference for the movement of the entire mechanism. When the mechanism is running, these two horizontal rotation pairs can ensure that the horizontal movement or posture adjustment of the components connected to them is deterministic and consistent, which helps to maintain the movement coordination of the entire mechanism in the horizontal plane, avoid problems such as mechanism jitter and offset caused by uncontrolled or uncoordinated horizontal movement, and further improve the stability and accuracy of the mechanism movement.

[0040] The intersection structure of the revolving pair assembly allows the forces in all directions to be concentrated and transmitted to the intersection center, and then the force is effectively transmitted and dispersed through the universal joint U. This force transmission method allows the various revolving pairs to share the force when the entire mechanism is under load, avoiding problems such as wear, deformation or damage caused by excessive force on a single revolving pair, thereby improving the load capacity of the mechanism and enabling it to adapt to working scenarios with larger loads.

[0041] Due to the intersection of the revolving pairs and the reasonable layout of the universal joints, the mechanism has good stability during movement. The mutual constraints and synergy between the revolving pairs enable the mechanism to quickly adjust its posture and return to a stable working state when subjected to external interference forces or load changes, reducing adverse effects such as vibration and shaking caused by the instability of the mechanism, and ensuring the reliability and stability of the mechanism during long-term operation.

[0042] Specifically, see Figure 1 , 2 As shown, the guide wheel assembly includes a first guide wheel group Z1, a second guide wheel group Z2, a third guide wheel group Z3 and a fourth guide wheel group Z4, wherein: The fifth pulley P5 and the ninth pulley P9 as well as the sixth pulley P6 and the tenth pulley P10 are symmetrically arranged at both ends of the first guide wheel group Z1; The thirteenth pulley P13 and the fifteenth pulley P15 as well as the fourteenth pulley P14 and the sixteenth pulley P16 are symmetrically arranged at both ends of the second guide wheel group Z2; The seventh pulley P7 and the eleventh pulley P11 as well as the eighth pulley P8 and the twelfth pulley P12 are symmetrically arranged at both ends of the third guide wheel group Z3; The third pulley P3 and the fourth pulley P4 are symmetrically arranged at both ends of the fourth guide wheel group Z4, and the fourth guide wheel group Z4 is connected to the static platform base 1 through a guide wheel base.

[0043] Specifically, the guide wheel assembly can effectively guide and constrain the rope through the symmetrical arrangement of multiple guide wheel groups and pulleys, so that it moves along a predetermined path. The symmetrically arranged pulleys can ensure that the rope is evenly stressed when entering and exiting the guide wheel assembly, reducing problems such as deviation and jitter caused by uneven stress, thereby improving the stability of the entire transmission system. The pulleys on different guide wheel groups can guide ropes from different directions respectively, so that the rope can flexibly change the direction of movement in all directions, realize complex motion transmission and conversion, and meet the requirements for motion flexibility in different application scenarios.

[0044] The fourth guide wheel group Z4 is connected to the static platform base 1 through the guide wheel base, which provides a stable support foundation for the entire guide wheel assembly, so that the guide wheel assembly can maintain a relatively static position during operation, further enhancing the stable guiding effect on the rope and avoiding problems such as reduced transmission accuracy or transmission medium disorder caused by the shaking of the guide wheel assembly itself.

[0045] In addition, this symmetrical arrangement of the guide wheel assembly is compact and reasonable in spatial layout. The various guide wheel groups and pulleys are distributed in a relatively concentrated area, making full use of the limited space and reducing the overall volume occupied by the guide wheel assembly. This is conducive to the miniaturization design of the entire transmission system or equipment, and is particularly suitable for application scenarios with strict requirements on spatial dimensions.

[0046] Specifically, see Figure 1 , 2 As shown, the stationary platform base 1 is an inverted U-shaped structure, which has high stability. The middle of the inverted U-shaped structure crosses the first crossbeam H1 and the second crossbeam H2, providing sufficient space for the installation of the guide wheel group without taking up too much additional space. In this embodiment, the first crossbeam H1 is installed with the first guide wheel group Z1 and the second guide wheel group Z2, and the second crossbeam H2 is installed with the third guide wheel group Z3 and the fourth guide wheel group Z4, which not only further enhances the rigidity and strength of the stationary platform base 1, so that the entire stationary platform base 1 can withstand large loads and various external forces, but also provides a stable support foundation for the guide wheel group and other related components installed thereon, reduces the problems of component position offset or working failure caused by deformation or shaking of the stationary platform base 1, and improves the reliability of the entire system during operation.

[0047] The first crossbeam H1 and the second crossbeam H2 are respectively equipped with guide wheel groups. This layout allows the weight and working load of the guide wheel groups to be evenly distributed to various parts of the base, avoiding the occurrence of excessive local stress, further enhancing the bearing capacity and stability of the entire structure, and helping to extend the service life of the equipment.

[0048] Therefore, by installing the guide wheel groups on the first crossbeam H1 and the second crossbeam H2 respectively, the moving parts or transmission media can be effectively guided and constrained so that they move along a predetermined path. The different guide wheel groups cooperate with each other to achieve complex motion trajectories and conversion of motion directions, ensure the stability and accuracy of the moving parts or transmission media during the movement, and improve the motion performance and work efficiency of the entire system. Since the guide wheel group is installed on a relatively fixed crossbeam, its position and posture are relatively stable, which can provide consistent guidance for the moving parts or transmission media, avoiding problems such as motion errors or uncoordinated motion caused by the unstable position of the guide wheel group, making the movement of the entire system more coordinated and smooth, which is conducive to improving product quality and production efficiency.

[0049] Specifically, see Figure 1 , 2 As shown in Figures 3 and 4, the starting ends of the two first driving ropes S1 are fixedly connected to the knotted holes of the pitch driving wheel P1, ensuring a reliable connection between the first driving rope S1 and the pitch driving wheel P1, effectively converting the rotational motion of the pitch driving wheel P1 into the linear motion of the first driving rope S1, and providing an accurate starting point and motion source for the entire transmission process. The other ends of the two first driving ropes S1 respectively pass downward through the first wire hole K1 and the second wire hole K2 of the static platform base 1, and guide and limit the first driving ropes S1, so that the first driving ropes S1 can move along a predetermined path, avoiding the first driving ropes S1 from swinging and winding randomly during the movement, ensuring the accuracy of the movement of the first driving ropes S1, and also reducing the transmission error and failure risk caused by the unstable path of the first driving ropes S1. The two first drive ropes S1 pass under the sixth pulley P6 and the tenth pulley P10, and then pass over the fifth pulley P5 and the ninth pulley P9 respectively, and pass through the first guide wheel group Z1. The ends of the two first drive ropes S1 extend downward in a front-to-rear symmetrical manner to connect with the output end of the first drive member, thereby further accurately guiding and adjusting the movement of the first drive ropes S1. The pulley can change the movement direction of the first drive rope S1, and under the action of the pulley and the guide wheel group, the first drive rope S1 can maintain a stable tensioned state, ensuring its smoothness and accuracy during movement, so that the first drive rope S1 can accurately transmit power to the output end of the first drive member, thereby improving the movement accuracy and reliability of the entire transmission system.

[0050] Thus, from the pitch driving wheel P1 to the output end of the first driving member, the first driving rope S1 is transmitted through a plurality of pulleys and guide wheel groups, and this transmission method can effectively transmit and distribute the driving force. During the transmission process, the pulley plays a role in supporting and changing the direction of the force, so that the driving force can be accurately transmitted to the target position along the predetermined path, reducing the loss and waste of force and improving the transmission efficiency.

[0051] In addition, the first drive rope S1 passes through the wire hole of the static platform base 1 and detours between various pulleys and guide wheel groups, making full use of the space, making the transmission path of the first drive rope S1 more compact and simple, reducing the redundant length and unnecessary bending of the first drive rope S1 in space, avoiding space waste and interference problems caused by the first drive rope S1 being too long or arranged unreasonable, which is conducive to realizing the miniaturization and compact design of the entire equipment and improving space utilization.

[0052] Specifically, see Figure 1 , 2 As shown in Figures 3 and 4, the starting ends of the two second drive ropes S2 are fixedly connected to the knotted hole of the deflection drive wheel P2, and the other ends pass through the third wire hole K3 and the fourth wire hole K4 on the static platform base 1, respectively, pass under the fourteenth pulley P14 and the sixteenth pulley P16, and then pass over the thirteenth pulley P13 and the fifteenth pulley P15, and pass through the second guide wheel group Z2; the ends of the two second drive ropes S2 extend downward in a front-to-rear symmetrical manner to be connected to the output end of the second drive member.

[0053] In the embodiment of the present invention, two second drive ropes S2 are transmitted from the deflection drive wheel P2 to the output end of the second drive member through a plurality of pulleys and a guide wheel group. This transmission method can effectively transmit and distribute the driving force. During the transmission process, the pulley plays a role in supporting and changing the direction of the force, so that the driving force can be accurately transmitted to the target position along a predetermined path, reducing the loss and waste of force and improving the transmission efficiency. The front-to-back symmetrical arrangement of the two second drive ropes S2 makes the forces on the two second drive ropes S2 relatively uniform during the transmission process, avoiding problems such as increased wear of the drive ropes or unstable transmission due to uneven force, further improving the reliability and durability of the transmission system, and also ensuring that the force transmission is more stable and accurate, which is conducive to improving the operating efficiency and performance of the entire system.

[0054] Specifically, see Figure 1 , 2As shown in Figures 3 and 4, the starting ends of the two third drive ropes S3 are wound and fixedly connected to the knotting hole of the rotary drive wheel d, and the other ends pass through the third pulley P3 and the fourth pulley P4 on the fourth guide wheel group Z4, and then pass through the fifth wire hole K5 and the sixth wire hole K6 on the static platform base 1 respectively, and then pass under the eighth pulley P8 and the twelfth pulley P12 respectively, and pass over the seventh pulley P7 and the eleventh pulley P11 respectively and pass through the third guide wheel group Z3; the ends of the two third drive ropes S3 extend downward in a front-to-rear symmetrical manner to be connected to the output end of the third drive member.

[0055] The arrangement and connection mode of the third driving rope S3 enable the third driving rope S3 to be well integrated and coordinated with other components such as the rotary driving wheel, the static platform base 1, the pulley, the guide wheel group and the third driving member, etc. The various components form an organic whole through the third driving rope S3, realizing the coordinated work and motion transmission between the various components, and improving the integration and reliability of the entire system.

[0056] The transmission process of the third drive rope S3 is coordinated with the motion control of the entire system. By controlling the rotation of the rotary drive wheel, the movement speed and position of the third drive rope S3 can be accurately adjusted, thereby achieving precise control of the output end of the third drive component, so that the entire system can operate stably and reliably according to predetermined working requirements and motion laws, meeting the requirements for system motion accuracy and coordination in different application scenarios.

[0057] Specifically, see Figure 1 As shown, the universal hinge lower fork f and the universal hinge upper fork h have through holes along the long rod direction, so that the cables can be arranged along the hinge axis to avoid excessive bending or winding of the cables during movement. The universal hinge center block g has a through hole and is suitable for passing the cables. The through hole of the universal hinge center block g allows the cables to move freely without being affected by the rotation of the joint. In this way, the cables can bend with the movement of the universal hinge U, but will not be twisted, extending the service life.

[0058] Although the present invention is disclosed as above, the protection scope of the present invention is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the present invention, and these changes and modifications will fall within the protection scope of the present invention.

Claims

1. A three-degree-of-freedom decoupling wrist, characterized in that: include: static platform base; Moving platform; A pointing motion branch is arranged above the static platform base, and the pointing motion branch comprises a pitch support seat, a deflection support seat, a pitch driving wheel, a deflection driving wheel and a connecting rod assembly, wherein the pitch support seat and the deflection support seat are both fixedly connected to the static platform base; the pitch driving wheel is connected to the pitch support seat via a first rotating pair, and the deflection driving wheel is connected to the deflection support seat via a second rotating pair; An intermediate rotary branch is installed between the static platform base and the dynamic platform; A guide wheel assembly is mounted on the static platform base; A driving rope assembly, comprising a first driving rope, a second driving rope and a third driving rope for driving the same joint in a closed loop in pairs, wherein the driving rope assembly is suitable for winding and connecting between the guide wheel assembly, the directional motion branch and the intermediate rotation branch; The decoupled wrist is suitable for rotating and making a full revolution in three degrees of freedom motion directions through the drive rope assembly.

2. The three-degree-of-freedom decoupling wrist according to claim 1, characterized in that: The connecting rod assembly comprises a first connecting rod, a second connecting rod, a third connecting rod and a fourth connecting rod, wherein: The first connecting rod and the second connecting rod are connected via a third rotational pair; the second connecting rod and the third connecting rod are connected via a fourth rotational pair; the third connecting rod and the fourth connecting rod are connected via a fifth rotational pair; The first connecting rod is fixedly connected to the yaw driving wheel through a transmission shaft, the third connecting rod is fixedly connected to the moving platform, and the fourth connecting rod is fixedly connected to the pitch driving wheel through a transmission shaft; The fourth rotational pair and the fifth rotational pair are both located on the third connecting rod, and an angle is formed between the fourth rotational pair and the fifth rotational pair.

3. The three-degree-of-freedom decoupling wrist according to claim 2, characterized in that: The intermediate slewing branch comprises a base flange, a slewing driving wheel, a slewing connecting flange and a universal joint, wherein: The universal hinge is composed of a universal hinge lower fork, a universal hinge upper fork and a universal hinge center block; The base flange is fixedly connected to the static platform base, the base flange is connected to the rotary drive wheel through a sixth rotation pair, and the rotary drive wheel is fixedly connected to the universal joint lower fork; The direction of the sixth rotation pair is perpendicular to the static platform base, and the sixth rotation pair is suitable for full-circle rotation; The universal hinge upper fork passes through the center of the moving platform and is connected to the moving platform via a seventh rotation pair.

4. The three-degree-of-freedom decoupling wrist according to claim 3, characterized in that: The first rotating pair, the second rotating pair, the third rotating pair, the fourth rotating pair, the fifth rotating pair, the sixth rotating pair and the seventh rotating pair converge at one point, and the center of convergence coincides with the rotation center of the universal joint; the first rotating pair and the second rotating pair both maintain a horizontal fixed direction.

5. The three-degree-of-freedom decoupling wrist according to claim 4, characterized in that: The guide wheel assembly includes a first guide wheel group, a second guide wheel group, a third guide wheel group and a fourth guide wheel group; The fifth pulley and the ninth pulley as well as the sixth pulley and the tenth pulley are symmetrically arranged at two ends of the first guide wheel group; The thirteenth pulley and the fifteenth pulley as well as the fourteenth pulley and the sixteenth pulley are symmetrically arranged at both ends of the second guide wheel group; The seventh pulley and the eleventh pulley as well as the eighth pulley and the twelfth pulley are symmetrically arranged at both ends of the third guide wheel group; The third pulley and the fourth pulley are symmetrically arranged at both ends of the fourth guide wheel group, and the fourth guide wheel group is connected to the static platform base through a guide wheel base.

6. The three-degree-of-freedom decoupling wrist according to claim 5, characterized in that: The static platform base is an inverted U-shaped structure, with the first crossbeam and the second crossbeam running through the middle of the inverted U-shaped structure, the first crossbeam is mounted with the first guide wheel group and the second guide wheel group, and the second crossbeam is mounted with the third guide wheel group and the fourth guide wheel group.

7. The three-degree-of-freedom decoupling wrist according to claim 5, characterized in that: The starting ends of the two first drive ropes are fixedly connected to the knotting holes of the pitch drive wheels, and the other ends respectively pass downward through the first wire hole and the second wire hole of the static platform base, pass under the sixth pulley and the tenth pulley, and then pass over the top of the fifth pulley and the ninth pulley respectively, and pass through the first guide wheel group; the ends of the two first drive ropes extend downward in a front-to-rear symmetrical manner to be connected to the output end of the first drive member.

8. The three-degree-of-freedom decoupling wrist according to claim 5, characterized in that: The starting ends of the two second drive ropes are fixedly connected to the knotting hole of the deflection drive wheel, and the other ends pass through the third wire hole and the fourth wire hole on the static platform base respectively, pass under the fourteenth pulley and the sixteenth pulley, and then pass over the thirteenth pulley and the fifteenth pulley respectively, and pass through the second guide wheel group; the ends of the two second drive ropes extend downward in a front-to-rear symmetrical manner to be connected to the output end of the second drive member.

9. The three-degree-of-freedom decoupling wrist according to claim 6, characterized in that: The starting ends of the two third drive ropes are wound and fixedly connected to the knotting hole of the rotary drive wheel, and the other ends pass through the third pulley and the fourth pulley on the fourth guide wheel group, and then pass through the fifth wire hole and the sixth wire hole on the static platform base respectively, and then pass under the eighth pulley and the twelfth pulley respectively, and pass over the seventh pulley and the eleventh pulley respectively and pass through the third guide wheel group; the ends of the two third drive ropes extend downward in a front-to-rear symmetrical manner to be connected to the output end of the third drive member.

10. The three-degree-of-freedom decoupling wrist according to claim 4, characterized in that: The universal joint lower fork and the universal joint upper fork are provided with through holes along the long rod direction, and the universal joint center block is provided with a through hole suitable for passing cables.

Images