A tendon-driven dexterous hand finger with metacarpophalangeal joint motion decoupling

Abstract

The application discloses a tendon-driven dexterous hand finger with metacarpophalangeal joint motion decoupling, wherein the flexion-extension rotary joint and the side swing rotary joint of the tendon-driven dexterous hand finger are both bidirectional rotary structures controlled by a rope; the side swing rotary joint is a rolling engagement structure formed by two toothed plate components, the two toothed plate components are both provided with a rope guide wheel, the two rope guide wheels are used for guiding and outputting a flexion-extension driving rope of the flexion-extension rotary joint and a side swing driving rope of the side swing rotary joint, the winding directions of the flexion-extension driving rope on the two rope guide wheels are opposite, and the two free ends of the side swing driving rope are staggered arranged through the rope guide wheels; after the scheme is adopted, the transmission chain links of the side swing motion and the flexion-extension motion are decoupled, the effective length change of the flexion-extension driving rope caused by the side swing motion is completely compensated in geometry, the effective length of the flexion-extension chain link is kept constant at any side swing angle, and the motion stability and the repeat positioning performance of the dexterous hand finger under multi-posture and multi-load conditions are improved.

Description

Technical Field

[0001] This invention relates to the technical field of dexterous hand fingers, and particularly to a tendon-driven dexterous hand finger with decoupling of metacarpophalangeal joint movement. Background Technology

[0002] In the fields of embodied intelligence and robotic manipulation, dexterous hand fingers are key execution units for achieving precise grasping, in-hand manipulation, and complex contact interactions. Compared to rigid grippers, dexterous hand fingers need to achieve multi-degree-of-freedom motion, high output force, and controllability within a limited space, while maintaining stable and repeatable motion performance under disturbances and load variations. Existing drive solutions mainly include linkage drives, direct drives, and chord drives. Direct drives and linkage drives have the advantages of high transmission stiffness and clearer control modeling, but their mechanisms are complex and their size increases significantly with the increase of degrees of freedom. Chord drives can place the drive source remotely, completing force / displacement transmission through flexible chords, and have advantages such as lightweight and flexible layout, thus being widely used in highly integrated dexterous hand systems.

[0003] In chord actuation, joint actuation methods mainly include unidirectional actuation (single chord with a rebound element) and antagonistic actuation (double chords with opposing traction). Among them, antagonistic actuation can achieve bidirectional controllable output and maintain tension through pretension to reduce gaps and suppress switching impact and hysteresis; at the same time, the equivalent stiffness and damping can be adjusted through tension distribution, which is beneficial to improving the stability of the joint under multiple loads and disturbances, thus having significant advantages in engineering implementation.

[0004] However, chord-driven fingers are essentially multi-joint systems that traverse multiple joints: the same chord often crosses multiple joints and is guided around them. Proximal joint rotation alters the chord envelope geometry and path, resulting in additional effective length changes, which are then superimposed on the distal joint link as "passive traction," forming inter-joint coupling. This coupling can lead to undesirable linkages, output force drift with posture, and control mapping that is highly sensitive to friction and assembly errors, significantly increasing calibration and control costs. For parallel axis links, the coupling term can be suppressed to some extent through feedforward compensation and calibration; however, when the axes are not parallel, compensation and target traction tend to counteract each other, amplifying the error. Therefore, in antagonistic systems, two chords may simultaneously relax or tighten, making it difficult to maintain tension within the effective window, significantly reducing stability and controllability. Thus, deterministic decoupling at the structural level is needed to ensure that the effective length of the distal driving chord does not change at any angle of proximal joint rotation.

[0005] Taking a common finger configuration as an example, the metacarpophalangeal joints have flexion-extension and lateral swing degrees of freedom, while the interphalangeal joints provide flexion-extension degrees of freedom. The flexion-extension axes of the metacarpophalangeal joints are parallel to those of the interphalangeal joints, while the lateral swing axis of the metacarpophalangeal joints is not parallel to other flexion-extension axes. Therefore, lateral swing introduces additional length changes and coupling into the flexion-extension link, easily leading to an imbalance in the tension of the antagonistic tendons and chordae tendons. Existing solutions often reduce the coupling amplitude by walking the rope close to the axis, but this is usually an approximate reduction and it is difficult to establish a strict decoupling relationship at the geometric level within the effective range of lateral swing. Therefore, it is still difficult to fundamentally eliminate the influence of lateral swing on the flexion-extension link.

[0006] In summary, existing solutions for the kinematic coupling problem of lateral swing and flexion-extension degrees of freedom in chord-driven dexterous hands still lack a method that can achieve deterministic decoupling at the structural geometry level. Therefore, it is necessary to propose a chord-driven dexterous hand finger design with decoupling of metacarpophalangeal joint motion. This design should geometrically compensate for the additional effective length of the chords involved in flexion-extension movements caused by lateral swing, thereby maintaining a constant effective length of the flexion-extension link at any lateral swing angle and achieving complete decoupling of the lateral swing and flexion-extension motion transmission links. Summary of the Invention

[0007] The purpose of this invention is to provide a chord-driven dexterity hand finger with decoupled metacarpophalangeal joint movement, so as to solve the motion coupling problem between the lateral swing and flexion-extension movements of the metacarpophalangeal joint in the chord-driven dexterity hand finger.

[0008] To address the aforementioned technical problems, this invention provides a tendon-driven dexterity hand finger with decoupled metacarpophalangeal joint movement. The flexion-extension rotation joint and lateral rotation joint of the tendon-driven dexterity hand finger are both bidirectional rotational structures controlled by rope drive. The lateral rotation joint is a rolling meshing structure formed by two toothed plate components. Each of the two toothed plate components is equipped with a guide wheel. The two guide wheels guide and output the flexion-extension drive rope of the flexion-extension rotation joint and the lateral rotation drive rope of the lateral rotation joint. The flexion-extension drive rope is wound in opposite directions on the two guide wheels, and the two free ends of the lateral rotation drive rope are staggered and guided by the guide wheels.

[0009] In one embodiment, the tendon-driven dexterous hand fingers include a distal phalanx module, a proximal phalanx module, and a metacarpophalangeal joint module that are rotatably connected in sequence; both rotatable connections of the proximal phalanx module are flexion-extension rotation joints, and the two flexion-extension rotation joints are respectively connected and fixed to the non-endpoint portions of the two flexion-extension drive ropes; the metacarpophalangeal joint module is provided with two toothed plate components.

[0010] In one embodiment, both free ends of the flexion-extension drive rope are wound into the same side of one guide rope wheel and out the same side in the opposite direction from the other guide rope wheel, and the two flexion-extension drive ropes are wound in opposite directions on the two guide rope wheels.

[0011] In one embodiment, the proximal phalanx module is provided with a guide mechanism; the flexion-extension drive rope connected to the distal phalanx module is first guided by the guide mechanism, and then guided out by the two guide wheels.

[0012] In one embodiment, the guiding mechanism includes two guide bushings arranged in a separated and opposite manner between the two flexion-extension rotation joints. The opposing portions of the two guide bushings are used to abut against the flexion-extension drive rope to guide the output of the flexion-extension drive rope.

[0013] In one embodiment, the metacarpophalangeal joint module further includes two oppositely arranged fixed end caps, with two toothed plate members provided between the two fixed end caps. The two fixed end caps are rotatably connected to the two toothed plate members to form two positioning rotation joints. The two positioning rotation joints are respectively arranged coaxially with the two guide rope wheels.

[0014] In one embodiment, one of the two toothed plate components is a first toothed plate component, which includes two separate opposing support plates and two separate opposing first toothed plates; the two support plates are disposed between the two first toothed plates, and both support plates are rotatably connected to the proximal phalanx module to form the flexion-extension rotation joint, and the two support plates are respectively connected and fixed to the two free ends of the lateral swing drive rope; the two first toothed plates are rotatably connected to the two fixed end caps to form the positioning rotation joint, the guide rope wheel is provided between the two first toothed plates, and the two first toothed plates mesh with the other toothed plate component to form a rolling meshing structure.

[0015] In one embodiment, the two free ends of the lateral swing drive rope first pass over the opposite sides of the two guide rope wheels in a parallel and opposite manner, and then connect and fix them to the two support plates in an alternating manner from one of the guide rope wheels.

[0016] In one embodiment, one of the two toothed plate components is a second toothed plate component, which includes two separate and opposite second toothed plates; the two second toothed plates are rotatably connected to the two fixed end caps to form the positioning rotation joint, the guide rope wheel is provided between the two second toothed plates, and the two second toothed plates mesh with the other toothed plate component to form a rolling meshing structure.

[0017] In one embodiment, the guide rope wheel is provided with multiple annular grooves arranged along its axial direction. The multiple annular grooves are arranged around the peripheral wall of the guide rope wheel and are used to position and guide the flexion drive rope and the lateral swing drive rope.

[0018] The beneficial effects of this invention are as follows:

[0019] (1) The present invention introduces motion decoupling design at the metacarpophalangeal joint module. Through geometric constraints and symmetrical compensation of transmission path, the effective length change of the flexion-extension drive tendon caused by the lateral swing motion of the metacarpophalangeal joint is deterministically canceled within the effective rotation angle range. This fundamentally avoids the limitation that traditional routing optimization or local guidance schemes can only approximately weaken the coupling terms and are difficult to achieve decoupling relationship in the whole domain.

[0020] (2) The present invention achieves complete decoupling between the lateral swing degree of freedom and the flexion-extension drive link, so that the flexion-extension control mapping remains consistent under different lateral swing postures, significantly reducing phenomena such as undesired joint linkage and output torque drift with posture, thereby improving the stability and repeatability of finger movements under multiple postures, multiple loads and complex contact disturbances.

[0021] (3) Since the decoupling relationship is determined and established at the structural geometry level, the dependence of the present invention on the control side feedforward compensation and high-precision parameter calibration is significantly reduced. At the same time, the sensitivity of the system to non-ideal factors such as friction, assembly error and tendon wear is reduced, thereby reducing the debugging cost and improving the robustness and consistency of long-term operation.

[0022] (4) The present invention can set up a standardized universal installation interface in the metacarpophalangeal joint module and realize the modular packaging of the finger unit, so that the finger can be quickly assembled, disassembled and replaced as an independent module; during maintenance, upgrade and iterative manufacturing, the assembly positioning and transmission alignment relationship can be quickly reconstructed, reducing repeated debugging time and improving the maintainability, scalability and engineering implementation efficiency of the dexterous hand system. Attached Figure Description

[0023] To more clearly illustrate the technical solution of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of the structure provided in an embodiment of the present invention;

[0025] Figure 2 yes Figure 1 Schematic diagram of the flexion-extension drive rope layout Figure 1 ;

[0026] Figure 3 yes Figure 1 Schematic diagram of flexion-extension drive rope layout Figure 2 ;

[0027] Figure 4 yes Figure 1A schematic diagram of the side swing drive rope layout;

[0028] Figure 5 yes Figure 1 A schematic diagram of the metacarpophalangeal joint module structure;

[0029] Figure 6 yes Figure 1 A schematic diagram of the guide rope wheel structure.

[0030] The attached figures are labeled as follows:

[0031] 110. Flexion-extension rotation joint; 111. Flexion-extension drive rope; 120. Lateral swing rotation joint; 121. Lateral swing drive rope; 130. Positioning rotation joint;

[0032] 200. Metacarpophalangeal joint module; 210. Toothed plate component; 211. First toothed plate; 212. Second toothed plate; 213. Support plate; 220. Guide rope pulley; 221. Annular groove; 230. Fixed end cap;

[0033] 300. Proximal knuckle module; 310. Guide mechanism; 311. Guide bushing;

[0034] 400. Distal knuckle module; 410. Quick-release fingertip; 420. Distal knuckle base. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0036] This invention provides a tendon-driven dexterous hand finger with decoupled metacarpophalangeal joint movement, the first embodiment of which is, for example... Figures 1 to 6 As shown, the flexion-extension rotation joint 110 and the lateral rotation joint 120 of the tendon-wire driven dexterous hand are both bidirectional rotational structures controlled by rope drive. The lateral rotation joint 120 is a rolling meshing structure formed by two toothed plate members 210. Both toothed plate members 210 are provided with guide rope wheels 220. The two guide rope wheels 220 are used to guide the flexion-extension drive rope 111 of the flexion-extension rotation joint 110 and the lateral rotation drive rope 121 of the lateral rotation joint 120. The flexion-extension drive rope 111 is wound in opposite directions on the two guide rope wheels 220, and the two free ends of the lateral rotation drive rope 121 are staggered and guided by the guide rope wheels 220.

[0037] The aforementioned flexion-extension rotation joint 110 and lateral swing rotation joint 120 are formed by rotating connections of different components, for example, from... Figures 1 to 5It is understood that in this embodiment, the tendon-driven dexterous hand fingers are configured to include a distal phalanx module 400, a proximal phalanx module 300, and a metacarpophalangeal joint module 200 that are rotatably connected in sequence. The two rotatable connection points of the proximal phalanx module 300 are both flexion-extension rotation joints 110, and the two flexion-extension rotation joints 110 are respectively connected and fixed to the non-endpoint parts of the two flexion-extension drive ropes 111. The metacarpophalangeal joint module 200 is provided with two toothed plate components 210.

[0038] At this point, the tendon-driven dexterous hand is composed of a distal phalanx module 400, a proximal phalanx module 300, and a metacarpophalangeal joint module 200, which are sequentially hinged from the distal end to the proximal end. The modules are connected coaxially or nearly coaxially through rotating support components to form a continuous and stable motion link.

[0039] The distal phalanx module 400 refers to the combination of a quick-release fingertip 410 and a distal phalanx base 420, which are detachably connected by a fixing pin. The quick-release fingertip 410 can be replaced with an end structure with different curvature, material or friction characteristics according to the actual grasping task requirements. For example, it can be a rigid finger bone covered with silicone, a flexible 3D printed structure or a composite structure with a tactile sensing layer.

[0040] The proximal phalanx module 300 is formed by fixing two side plates together with fasteners such as studs, and the interphalangeal joint rotation support and the metacarpophalangeal joint flexion-extension rotation support are assembled at corresponding positions; the two flexion-extension rotation joints 110 are respectively located at the connection between this module and the distal phalanx module 400, and at the connection between this module and the metacarpophalangeal joint module 200; the rotation shaft of the flexion-extension rotation joint 110 is a cylindrical pin shaft, a needle roller bearing shaft, or a deep groove ball bearing shaft, and its specific form is set according to the load, accuracy and space constraints.

[0041] The non-endpoint portions (such as the middle sections) of the two flexion-extension drive ropes 111 are respectively connected and fixed to the two flexion-extension rotation joints 110. This means that after the flexion-extension drive rope 111 passes over the guide rope wheel 220 or the guide bushing 311, the middle part of its rope body is fixed to the corresponding rotation joint by a set screw, pressure plate or embedded clamping structure. This connection method allows the flexion-extension drive rope 111 to move synchronously with the rotating component during the joint rotation, thereby converting the winding and unwinding action of the drive source into joint angular displacement.

[0042] The metacarpophalangeal joint module 200 is the core structural unit that supports and integrates the two toothed plate components 210. The two toothed plate components 210 are arranged vertically opposite each other and are connected by meshing gear teeth to form a rolling fit relationship. The relative rotation axis of the two toothed plate components 210 is the lateral swing rotation axis of the metacarpophalangeal joint. This axis is not parallel to the axes of the two aforementioned flexion-extension rotation joints 110, and is usually arranged orthogonally or approximately orthogonally.

[0043] The above setup achieves a modular, hierarchical, and well-defined mechanical configuration: the distal phalanx module 400 is responsible for end-effector interaction and interphalangeal flexion-extension response; the proximal phalanx module 300 serves as a relay anchoring platform for the flexion-extension drive rope 111 and supports two flexion-extension rotation joints 110; and the metacarpophalangeal joint module 200 serves as the physical carrier for the decoupling core mechanism, integrating two toothed plate components 210 and their matching guide rope wheel 220, support structure, and lateral swing drive interface. This three-level modular architecture provides a deterministic spatial channel for the flexion-extension drive rope 111 to enter the decoupling region across the joints.

[0044] The flexion-extension rotation joint 110 is a rotational connection structure formed between the distal phalanx module 400 and the proximal phalanx module 300, and between the proximal phalanx module 300 and the metacarpophalangeal joint module 200, used to realize the flexion and extension movements of the distal phalanx module 400 and the proximal phalanx module 300. The flexion-extension rotation joint 110 is a structure that realizes bidirectional controllable rotation by using a pair of antagonistically arranged flexion-extension drive ropes 111. The flexion-extension drive ropes 111 are high-modulus flexible tendon ropes, such as polyaramid fiber ropes or stainless steel wire ropes, with both ends connected to an external drive source, and the basic tension is maintained by pre-tensioning to suppress gaps and hysteresis. The flexion-extension drive ropes 111 do not disengage from the groove of the guide rope pulley 220 during movement, and their effective length change is determined only by the amount of winding and unwinding of the drive source.

[0045] The lateral swing rotation joint 120 is a relative rotation structure formed between two toothed plate components 210 inside the metacarpophalangeal joint module 200. Its rotation axis is perpendicular to the axis of the flexion-extension rotation joint 110 and is used to realize the adduction and abduction movements of the metacarpophalangeal joint module 200. The lateral swing rotation joint 120 is a structure that realizes bidirectional controllable rotation by using two antagonistic lateral swing drive ropes 121 (for example, it can be two antagonistic lateral swing drive ropes 121, or the two free ends of the lateral swing drive rope 121 can be antagonistically arranged). The lateral swing drive rope 121 is a flexible tendon rope of the same material as or different material from the flexion-extension drive rope 111, and its tension can be independently adjusted to adapt to different lateral swing loads.

[0046] Both toothed plate components 210 are provided with incomplete gear tooth profiles that mesh with each other. The tooth profile profile is in the form of an involute, circular arc or cycloid, and the meshing method is external meshing. The two toothed plate components 210 achieve pure rolling constraint through the rolling contact of the gear teeth, suppressing the rope path deviation and uncertainty caused by sliding friction.

[0047] The guide rope wheel 220 is located at the corresponding position of the two toothed plate components 210, and its axis is parallel to the lateral swing rotation axis. It is used to axially limit and radially support the bending and stretching drive rope 111 and the lateral swing drive rope 121.

[0048] The two bending drive ropes 111 are wound in opposite directions on the two guide rope pulleys 220. When the two bending drive ropes 111 are wound into the upper guide rope pulley 220 from the near side and out from the far side, they are wound into the lower guide rope pulley 220 from the far side and out from the near side, thus forming a cross-symmetrical "figure-eight" winding path. This winding method makes the effective length change of the two bending drive ropes 111 at the upper guide rope pulley 220 equal in magnitude and opposite in direction to the change at the lower guide rope pulley 220.

[0049] For example, when the lateral swing rotation causes the upper guide rope wheel 220 to move downwards and the lower guide rope wheel 220 to move upwards, the bending and stretching drive rope 111 shortens by ΔL in the section around the upper guide rope wheel 220 and lengthens by ΔL in the section around the lower guide rope wheel 220, with the total effective length change being zero. This geometric compensation relationship does not depend on the specific value of the lateral swing angle. As long as the two guide rope wheels 220 maintain synchronous opposite displacement, the decoupling effect can be maintained throughout the entire lateral swing motion range.

[0050] The two free ends of the lateral swing drive rope 121 are guided by the guide rope wheel 220 and arranged in an alternating manner: one free end of the lateral swing drive rope 121 passes around one side of the upper guide rope wheel 220 and connects to the support plate 213 of the upper toothed plate component 210, and the other free end of the lateral swing drive rope 121 passes around the opposite side of the upper guide rope wheel 220 and connects to the other support plate 213 of the upper toothed plate component 210. The two are arranged in a staggered manner in space. This alternating arrangement ensures that the torques applied by the two free ends of the lateral swing drive rope 121 to the two toothed plate components 210 are in the same direction and the line of action of the resultant force passes through the lateral swing rotation center, thereby ensuring the symmetry and stability of the lateral swing drive. The connection point position and preload of the lateral swing drive rope 121 are set according to the required lateral swing stiffness and response speed.

[0051] Through the above technical solution, the present invention achieves the following: when the metacarpophalangeal joint module 200 undergoes lateral swinging motion, the two toothed plate components 210 undergo pure rolling, driving the two guide rope wheels 220 to synchronously generate spatial displacement; because the flexion-extension drive rope 111 is wound in opposite directions on the two guide rope wheels 220, the effective length changes in the upper and lower winding paths cancel each other out, keeping the total effective length of the flexion-extension drive link constant; thus, the lateral swinging motion will not cause tension fluctuations in the flexion-extension drive rope 111, avoiding the risk of the antagonistic rope being slack or tight at the same time, ensuring that the flexion-extension control mapping remains consistent under any lateral swinging posture; at the same time, the staggered arrangement of the lateral swinging drive rope 121 and the rolling meshing of the two toothed plate components 210 work together to ensure symmetrical traction and torque balance of the lateral swinging motion, improving the overall motion stability and repeatability positioning accuracy.

[0052] like Figure 2 and Figure 3As shown, in an embodiment of the present invention, both free ends of the flexion-extension drive rope 111 are wound into the same side of one guide rope wheel 220 and out of the same side of the other guide rope wheel 220 in the opposite direction, and the winding directions of the two flexion-extension drive ropes 111 on the two guide rope wheels 220 are opposite.

[0053] The two free ends of the flexion-extension drive rope 111 are respectively connected to an external drive source, and the flexion-extension direction is switched by the tension difference between release and release. The flexion-extension drive rope 111 can be a stainless steel wire rope, a polymer fiber rope, or a coated synthetic fiber tendon rope, and its diameter can be set according to the actual output force and spatial constraints.

[0054] "Entering from the same side of a guide sheave 220" means that both free ends of the flexion-extension drive rope 111 enter the corresponding annular groove 221 from the proximal or distal side of the upper guide sheave 220 (or the lower guide sheave 220) in the same orientation. For example, they both enter from the proximal side in a clockwise tangential direction, or both enter from the distal side in a counterclockwise tangential direction. This orientation consistency ensures that the initial wrap angle of the two ropes is symmetrical, providing a reference for subsequent mirror winding.

[0055] "Waving out from the same side in the opposite direction of the other guide rope wheel 220" means that when the two free ends of the flexion-extension drive rope 111 wrap around the other guide rope wheel 220, they both emerge from the side that is spatially mirrored with the side into which it wraps. For example, when both ropes wrap around from the near end of the upper guide rope wheel 220, they both emerge from the far end of the lower guide rope wheel 220. The "same side in the opposite direction" does not mean that the absolute orientation is the same, but rather that in the relative arrangement of the two guide rope wheels 220, their exit positions are centrally symmetrical or axially symmetrical about the pivot axis of the metacarpophalangeal joint, thus ensuring that the two winding paths are geometrically mirrored.

[0056] "The two bending drive ropes 111 are wound in opposite directions on the two guide rope pulleys 220" means that if one bending drive rope 111 forms a clockwise wrap angle on the upper guide rope pulley 220 and a counterclockwise wrap angle on the lower guide rope pulley 220, then the other bending drive rope 111 will form a counterclockwise wrap angle on the upper guide rope pulley 220 and a clockwise wrap angle on the lower guide rope pulley 220.

[0057] Through the above technical solution, the present invention achieves the following: when the metacarpophalangeal joint module 200 undergoes lateral swinging motion, the two guide rope wheels 220 generate a definite relative displacement due to the rolling meshing of the toothed plate component 210, resulting in the effective length change of the flexion-extension drive rope 111 in the section wound around the upper guide rope wheel 220 being equal in magnitude and opposite in direction to the effective length change in the section wound around the lower guide rope wheel 220; since the two winding paths are strictly mirror symmetrical and the winding directions are opposite, this cancellation relationship holds true at any lateral swinging angle, thereby ensuring that the effective length of the flexion-extension drive link remains constant at the structural level, eliminating the residual coupling error introduced by the asymmetry of the winding, and improving the manufacturing consistency and batch stability of the decoupling performance.

[0058] like Figure 1 and Figure 2 As shown, in an embodiment of the present invention, the proximal phalanx module 300 is provided with a guide mechanism 310; and the flexion-extension drive rope 111 connected to the distal phalanx module 400 is first guided by the guide mechanism 310, and then guided out by the two guide rope wheels 220.

[0059] The guide mechanism 310 provided on the proximal phalanx module 300 is a mechanical structure used to spatially constrain and calibrate the path of the flexion-extension drive rope 111, so as to guide the flexion-extension drive rope 111 into the metacarpophalangeal joint module 200 along a predetermined spatial direction, and finally guide it out through the two guide rope wheels 220.

[0060] The flexion-extension drive rope 111 first passes through the guide mechanism 310. This passage process enables the flexion-extension drive rope 111 to obtain initial spatial positioning and tension pre-steady state, eliminating the disturbance of the rope entry angle caused by the swing angle change of the distal phalanx module 400 during the flexion and extension of the interphalangeal joint. After being constrained by the guide mechanism 310, the exit direction of the flexion-extension drive rope 111 points to the area where the two guide rope wheels 220 are located in the metacarpophalangeal joint module 200.

[0061] Through the above technical solution, the present invention achieves the following: when the distal phalanx module 400 undergoes flexion and extension movements, the guide mechanism 310 applies a pre-rigid constraint to the flexion and extension drive rope 111, ensuring that it has a stable rope entry posture and spatial position before entering the metacarpophalangeal joint module 200; this stable input condition ensures the consistency of the winding starting point, envelope length, and relative tension distribution of the flexion and extension drive rope 111 on the two guide rope wheels 220, thereby ensuring that the "winding direction opposite" relationship defined by the present invention is strictly established within the entire motion envelope; thus avoiding the disruption of the geometric compensation relationship between the two guide rope wheels 220 caused by the movement of the interphalangeal joint, so that the flexion and extension drive link can still maintain a constant effective length under any lateral swing angle of the metacarpophalangeal joint, thereby supporting the continuous and reliable realization of the metacarpophalangeal joint motion decoupling function defined by the present invention.

[0062] like Figure 1 and Figure 2 As shown, in an embodiment of the present invention, the guide mechanism 310 includes two guide bushings 311. The two guide bushings 311 are arranged in a separate and opposite manner between two flexion-extension rotation joints 110. The opposite parts of the two guide bushings 311 are used to abut against the flexion-extension drive rope 111 to guide the output of the flexion-extension drive rope 111.

[0063] The guide bushing 311 refers to a rigid sleeve structure with a hollow cylindrical or elliptical cylindrical inner cavity. Its outer diameter can be set according to the installation space of the proximal finger module 300, and its inner diameter can be set according to the diameter of the adapted flexion and extension drive rope 111 and the allowable envelope tolerance.

[0064] The opposing portions of the two guide bushings 311 are used to abut against the bending and stretching drive rope 111. This means that the ends of the two guide bushings 311 that are close to each other have a smooth-transition inner chamfer or arc surface. This area constitutes the guide working surface that contacts the bending and stretching drive rope 111. This structure can provide a stable radial reaction force when the bending and stretching drive rope 111 undergoes slight deflection or vibration, suppressing its lateral movement and torsion, and ensuring that the rope path is always within the preset plane.

[0065] The contact relationship between the guide bushing 311 and the bending and stretching drive rope 111 is a non-tight mechanical contact, without applying axial clamping force, and the trajectory constraint is achieved only through geometric limit; its material can be stainless steel, aluminum alloy, engineering plastic (such as PEEK or PA66) or surface-hardened copper alloy, in order to take into account the requirements of wear resistance, rigidity and lightweight.

[0066] Through the above technical solution, the present invention achieves the following: before the flexion-extension drive rope 111 is led out from the distal phalanx module 400, passes through the proximal phalanx module 300 and enters the metacarpophalangeal joint module 200, it is first clamped and limited by two separately arranged guide bushings 311, so that it maintains a stable spatial orientation and posture in the transition section between the two flexion-extension rotation joints 110; this structure replaces flexible guides or complex slide rails with the geometric constraints of rigid bushings, which significantly improves the structural rigidity and long-term operational stability while ensuring the guiding accuracy; since its arrangement is located between the two flexion-extension rotation joints 110 and is directly integrated into the two side plates of the proximal phalanx module 300, it does not need to occupy additional axial space or change the original hinge relationship, thus achieving a high degree of integration between the guiding function and the modular structure.

[0067] like Figure 1 , Figure 4 and Figure 5 As shown, in an embodiment of the present invention, the metacarpophalangeal joint module 200 further includes two oppositely arranged fixed end caps 230, and two toothed plate members 210 are provided between the two fixed end caps 230. The two fixed end caps 230 are rotatably connected to the two toothed plate members 210 to form two positioning rotation joints 130. The two positioning rotation joints 130 are respectively arranged coaxially with the two guide rope wheels 220.

[0068] The fixed end cap 230 is a plate-shaped structural component made of rigid metal or engineering plastic. Its outline can be set to rectangle, circle or polygon according to the overall spatial constraints of the metacarpophalangeal joint module 200. The two fixed end caps 230 are arranged opposite each other, and their spacing can be adapted according to the thickness of the two toothed plate components 210, the meshing clearance and the installation space of the rotating support component. The specific dimensions can be set according to the actual situation. The fixed end cap 230 is provided with through holes or bearing mounting seats for mounting the metacarpophalangeal joint side swing rotating support component. The support component is a rolling bearing, sliding bearing or spherical bearing. Its inner ring is matched with the rotating shaft part of the toothed plate component 210, and its outer ring is interference-fitted with the through hole or mounting seat of the fixed end cap 230 or locked by fasteners, thereby realizing the rotational connection between the fixed end cap 230 and the toothed plate component 210.

[0069] The two positioning rotary joints 130 are rotary pairs composed of a fixed end cap 230, a support member, and a toothed plate member 210. Their rotation center line is the geometric axis of rotation of the toothed plate member 210 around its own axis. This rotation center line is determined after assembly and does not shift with load or attitude changes. The two positioning rotary joints 130 are respectively arranged coaxially with the two guide pulleys 220. This means that the rotation axis of each guide pulley 220 coincides with the rotation center line of its corresponding toothed plate member 210. That is, the guide pulley 220 is directly installed on the extension of the rotating shaft of the toothed plate member 210, or is rigidly connected to the rotating shaft of the toothed plate member 210 through a transition bushing, key connection, interference fit, etc., thereby ensuring that the guide pulley 220 always maintains a spatial relationship consistent with the rolling meshing motion axis during the rotation of the toothed plate member 210.

[0070] Through the above technical solution, the present invention achieves the following: the fixed end cap 230 provides a stable radial and axial constraint reference for the two toothed plate components 210, so that they do not wobble or deflect during lateral rolling; the positioning rotation joint 130 serves as the rotation support point of the toothed plate component 210 and also as the installation reference axis of the guide rope wheel 220, so that the rolling meshing motion axis and the guide axis of the guide rope wheel 220 are structurally forced to be unified; thus, when the metacarpophalangeal joint module 200 laterally swings, the guide rope wheel 220 rotates synchronously and coaxially with the toothed plate component 210, ensuring that the winding path of the flexion and extension drive rope 111 on the two guide rope wheels 220 always meets the geometric conditions of "opposite winding directions" and "staggered arrangement", thereby supporting the technical effect of motion decoupling achieved by the rolling meshing structure and the guide rope wheel 220 in the present invention.

[0071] like Figure 1 , Figure 4 and Figure 5As shown, in an embodiment of the present invention, one of the two toothed plate components 210 is a first toothed plate component. The first toothed plate component includes two separate opposing support plates 213 and two separate opposing first toothed plates 211. The two support plates 213 are disposed between the two first toothed plates 211. Both support plates 213 are rotatably connected to the proximal phalanx module 300 to form a flexion-extension rotation joint 110, and the two support plates 213 are respectively connected and fixed to the two free ends of the side swing drive rope 121. The two first toothed plates 211 are rotatably connected to the two fixed end caps 230 to form a positioning rotation joint 130. A guide rope wheel 220 is provided between the two first toothed plates 211, and the two first toothed plates 211 mesh with the other toothed plate component 210 to form a rolling meshing structure.

[0072] The first toothed plate component refers to a composite toothed plate structure that integrates support, transmission, guidance and meshing functions; it is made of metal materials (such as aluminum alloy, stainless steel) or high-strength engineering plastics (such as PEEK, carbon fiber reinforced nylon) through precision machining or injection molding; the spatial relative positional relationship between the components is determined by the rigid constraints of the structure and does not rely on additional fasteners to maintain the stability of the geometric relationship during the movement.

[0073] The two support plates 213 are thin-walled plate-like structures with rectangular, trapezoidal, or arc-shaped cross sections. The two support plates 213 are parallel to each other and symmetrically arranged along the flexion-extension axis of the metacarpophalangeal joint. Their inner surfaces are provided with through holes or bearing mounting positions that match the corresponding support shafts on the proximal phalanx module 300, for assembling the flexion-extension rotation support of the metacarpophalangeal joint, thereby forming the flexion-extension rotation joint 110. The axis of the flexion-extension rotation joint 110 coincides with the flexion-extension rotation axis of the proximal phalanx module 300, ensuring coaxiality of motion transmission. The outer ends of the two support plates 213 are provided with rope fixing structures, such as countersunk threaded holes, U-shaped grooves, or clamping bosses, for connecting and fixing to the two free ends of the side-swing drive rope 121. The side-swing drive rope 121 is a stainless steel wire rope, a polymer fiber rope, or a covered Kevlar rope. The connection method can be knot fixing, thread crimping, heat shrink tubing locking, or special rope clamping.

[0074] The two first toothed plates 211 are incomplete gear plates. The two first toothed plates 211 are symmetrically arranged along the plane of the support plate 213 and have space to accommodate the guide rope wheel. The central area of ​​the two first toothed plates 211 is provided with a through shaft hole for cooperating with the rotating support (such as a miniature deep groove ball bearing or a self-lubricating bushing) on ​​the fixed end cover 230, so as to form a positioning rotating joint 130 together with the two fixed end covers 230. The axis of the positioning rotating joint 130 is consistent with the theoretical rotation center of the side swing rotating joint 120 to ensure that there is no eccentric slippage during rolling meshing.

[0075] Through the above technical solution, the present invention achieves the following: when the lateral swing drive rope 121 pulls the two support plates 213, the support plates 213 drive the first toothed plate component to deflect around the axis of the positioning rotation joint 130; this deflection is transformed into the reverse deflection of the other toothed plate component 210 through the pure rolling meshing between the first toothed plate 211 and the second toothed plate 212, thereby driving the metacarpophalangeal joint to complete the lateral swing motion; while the flexion-extension rotation joint 110 formed by the support plate 213 and the proximal phalanx module 300 is not affected by this lateral swing motion, and its axial position and rotational degree of freedom remain unchanged, thereby ensuring the physical isolation and functional decoupling of the flexion-extension and lateral swing motion links at the structural level.

[0076] like Figure 4 As shown, in an embodiment of the present invention, the two free ends of the side swing drive rope 121 are first arranged to pass over the opposite sides of the two guide rope wheels 220 in a parallel and opposite manner, and then connected and fixed to the two support plates 213 from one guide rope wheel 220 in an alternating manner.

[0077] The two free ends of the side swing drive rope 121 can refer to two independent tendon ropes with the same pretension force and material properties, which are drawn from the same drive source, or they can be the two free ends of the same continuous tendon rope; its material can be high-modulus polyethylene fiber, aramid fiber or stainless steel wire rope, and its diameter can be set according to the actual load and space constraints.

[0078] "The two free ends are parallel to each other and have a constant distance before entering the area of ​​the guide rope wheel 220, and they are simultaneously cut in from the side of the two guide rope wheels 220 facing each other (i.e., the opposite side); for example, one free end cuts in from the right surface of the guide rope wheel 220 and the other free end cuts in from the left surface of the guide rope wheel 220. The two ends have symmetrical rope entry angles, consistent wrap angles, and uniform initial tension distribution. This arrangement can ensure that the two free ends have geometric symmetry and consistent force before the toothed plate component 210 laterally rolls.

[0079] "Connected and fixed to the two support plates 213 in an alternating manner from a guide rope wheel 220" can mean that both free ends are led out to the same guide rope wheel 220 (e.g., the upper guide rope wheel 220) and completed at different positions around the guide rope wheel 220. One free end is connected to the right support plate 213 after being connected to the left side of the guide rope wheel 220, and the other free end is connected to the left support plate 213 after being connected to the right side of the guide rope wheel 220. This alternating winding structure makes the tension forces applied by the two free ends to the two support plates 213 in opposite directions, with coplanar lines of action and equal lever arms, thereby forming a pure torque and driving the first toothed plate component to roll smoothly around its central axis.

[0080] The support plate 213 can be a thin metal plate or a reinforced engineering plastic plate, and its thickness can be set according to the requirements of structural strength and lightweighting. The connection and fixing method between the support plate 213 and the side swing drive rope 121 can be by pressing it into the rope clamp groove on the side of the support plate 213 with a set screw, or by an embedded U-shaped buckle structure, or by melting the rope end into a knot and embedding it into the pre-reserved recess of the support plate 213 and sealing it with a cover plate. The specific form of connection and fixing is not particularly limited in the embodiments of the present invention, as long as the connection rigidity and anti-slip ability can be guaranteed.

[0081] Through the above technical solution, the present invention achieves the following: during the side swing drive process, the two free ends enter the rope in a parallel and opposite manner to ensure the initial tension symmetry, and then pass through the same guide rope wheel 220 to form a pair of tensions with opposite directions and equal lever arms, so that the resultant force applied to the two support plates 213 is zero and the resultant torque is non-zero, thereby generating only a pure rolling drive torque around the central axis, avoiding the introduction of additional bending moment or translation component due to tension offset.

[0082] like Figure 1 , Figure 4 and Figure 5 As shown, in an embodiment of the present invention, one of the two toothed plate components 210 is a second toothed plate component. The second toothed plate component includes two separate and opposite second toothed plates 212. The two second toothed plates 212 are rotatably connected to two fixed end caps 230 to form a positioning rotation joint 130. A guide wheel 220 is provided between the two second toothed plates 212. The two second toothed plates 212 mesh with the other toothed plate component 210 to form a rolling meshing structure.

[0083] Two separate, opposing second toothed plates 212 are arranged parallel to each other in space along the axis of rotation of the metacarpophalangeal joint, and are rotatably connected to two fixed end caps 230 by fasteners. This rotatable connection is achieved by a metacarpophalangeal joint lateral rotation support embedded in the mounting holes of the second toothed plates 212 and the corresponding holes of the fixed end caps 230. The support is a rolling bearing, a sliding bearing, or a bushing structure, and its axis coincides with the axis of rotation of the lateral rotation, so as to ensure that the second toothed plates 212 rotate stably around the fixed end caps 230.

[0084] Two second toothed plates 212 mesh with another toothed plate component 210 to form a rolling meshing structure, wherein the other toothed plate component 210 is the aforementioned first toothed plate component; meshing refers to the two second toothed plates 212 and the two first toothed plates 211 forming a gear meshing pair; the meshing tooth profile is an involute tooth profile, a circular arc tooth profile, or a cycloidal tooth profile, and its module, pressure angle, and number of teeth are set according to the lateral swing motion range, transmission stiffness, and spatial constraint conditions; the rolling meshing structure is configured to a pure rolling non-slip state, that is, the contact point velocity is equal and the relative sliding velocity is zero during the meshing process, thereby suppressing the rope path deviation and uneven wear caused by sliding friction; this rolling meshing relationship is ensured by controlling the installation coaxiality and tooth profile accuracy of the two toothed plate components 210, and their meshing center line coincides with the lateral swing rotation axis, so that the guide rope wheel axis is consistent with the meshing rotation axis, thereby maintaining the constant geometric compensation relationship of the bending and stretching drive rope 111 during the winding process.

[0085] The material of the second toothed plate component is set according to the actual situation, such as aluminum alloy, titanium alloy, engineering plastic (such as PEEK) or stainless steel; its thickness, width and overall stiffness of the toothed plate are matched and designed according to the lateral load, meshing reaction force and variable limit.

[0086] Through the above technical solution, the present invention achieves a mirror-symmetric arrangement of the second toothed plate component and the first toothed plate component in terms of structure, so that the two sets of meshing pairs are completely corresponding in terms of geometry and mechanics. When the metacarpophalangeal joint undergoes lateral swinging motion, the first toothed plate component and the second toothed plate component roll synchronously around a common axis, and the guide rope wheel deflects synchronously with the second toothed plate component. The winding path of the flexion-extension drive rope 111 at the upper and lower guide rope wheels still maintains the "figure-eight cross symmetry" relationship. The effective length changes of the upper and lower winding segments are equal in magnitude and opposite in direction, and the total change is zero. Thus, at the structural level, the lateral swinging motion is completely decoupled from the flexion-extension drive link, improving the bidirectional consistency, repeatability and robustness of motion transmission.

[0087] like Figures 2 to 4 ,as well as Figure 6 As shown, in an embodiment of the present invention, the guide rope wheel 220 is provided with multiple annular grooves 221 arranged along its axial direction. The multiple annular grooves 221 are arranged around the peripheral wall of the guide rope wheel 220, and the multiple annular grooves 221 are used to position and guide the bending and stretching drive rope 111 and the side swing drive rope 121.

[0088] Among them, the guide rope wheel 220 refers to a roller-like component disposed on the two toothed plate components 210 for guiding and outputting the flexion-extension drive rope 111 and the lateral swing drive rope 121. Its structure can be cylindrical or truncated conical. The annular groove 221 is a groove evenly or non-evenly spaced along the axial direction of the guide rope wheel 220. Each annular groove 221 is arranged in a continuous closed circumference around the guide rope wheel 220. The cross-sectional shape of the annular groove 221 can be "V", "U" or arc. Among them, the included angle of the two inclined surfaces of the "V" shaped groove is set according to the diameter and envelope stiffness of the flexion-extension drive rope 111 or the lateral swing drive rope 121 to provide sufficient axial constraint while avoiding excessive radial compressive stress. The groove depth of the annular groove 221 is set according to the diameter of the tendon rope to ensure that the tendon rope does not protrude from the groove opening after being embedded, nor does it reduce the support stiffness of the groove wall due to excessive depth. The number of grooves 221 is set according to the actual number of tendon rope paths required for guidance, which can be 4, 6 or 8. In this embodiment of the invention, 6 grooves can be selected to adapt to the multiple interlacing and winding requirements of the interphalangeal flexion and extension drive rope 111 and the lateral swing drive rope 121. Spacing ribs are provided between each annular groove 221. The width of the spacing ribs is set according to the overall strength of the guide wheel 220 and the reliability of the isolation between the grooves. The guide wheel 220 is made of aluminum alloy, stainless steel or engineering plastic, such as polyoxymethylene (POM) or polyetheretherketone (PEEK), to take into account lightweight, wear resistance and processing accuracy. The guide wheel 220 can be fixed to the toothed plate component 210 by fasteners, or integrally formed with the toothed plate component 210. When the guide wheel 220 and the toothed plate component 210 are set separately, its mounting axis coincides with the rotation axis of the corresponding rotating joint to avoid introducing additional eccentric disturbances.

[0089] Through the above technical solution, the present invention achieves the following: providing independent guide paths for multiple tendon ropes (including flexion-extension drive rope 111 and lateral swing drive rope 121) within a limited space, ensuring that they do not interfere with each other, have clear axial positioning, and stable radial clamping; each tendon rope is constrained within its corresponding annular groove 221, and even when the guide rope wheel 220 undergoes rolling meshing motion with the toothed plate component 210 or is slightly twisted by the pull of the lateral swing drive rope 121, it can still maintain the unchanged winding position relationship; thereby ensuring the physical stability of the "winding direction of the flexion-extension drive rope 111 on the two guide rope wheels 220 is opposite" and "the two free ends of the lateral swing drive rope 121 are guided by the guide rope wheel 220 to be staggered" as defined in the present invention, so that the "figure-eight rope winding" structure does not jump, cross-slot, or fail to wind under long-term reciprocating motion and load changes, thus supporting the continuous and effective operation of the decoupling mechanism of metacarpophalangeal joint flexion-extension and lateral swing motion.

[0090] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A chord-driven dexterity hand finger with decoupled metacarpophalangeal joint movement, characterized in that, The flexion-extension rotation joints and lateral rotation joints of the fingers of the tendon-wire-driven dexterous hand are all bidirectional rotational structures controlled by rope drive. The lateral swing joint is a rolling meshing structure formed by two toothed plate components. Both toothed plate components are provided with guide rope wheels. The two guide rope wheels are used to guide and output the flexion and extension drive rope of the flexion and extension joint and the lateral swing drive rope of the lateral swing joint. The flexion and extension drive ropes are wound in opposite directions on the two guide rope wheels, and the two free ends of the lateral swing drive rope are staggered and guided by the guide rope wheels. The tendon-driven dexterous hand fingers include a distal phalanx module, a proximal phalanx module, and a metacarpophalangeal joint module that are rotatably connected in sequence. Both rotational connections of the proximal phalanx module are flexion-extension rotational joints, and the two flexion-extension rotational joints are respectively connected and fixed to the non-endpoint parts of the two flexion-extension drive ropes; The metacarpophalangeal joint module is provided with two of the aforementioned toothed plate components; Both free ends of the flexion-extension drive rope are wound into the same side of one guide rope wheel and out from the same side in the opposite direction of the other guide rope wheel, and the two flexion-extension drive ropes are wound in opposite directions on the two guide rope wheels. The metacarpophalangeal joint module also includes two oppositely arranged fixed end caps, with two toothed plate components between the two fixed end caps. The two fixed end caps are rotatably connected to the two toothed plate components to form two positioning rotation joints. The two positioning rotation joints are respectively arranged coaxially with the two guide rope wheels. One of the two toothed plate components is a first toothed plate component, which includes two separate and opposite support plates and two separate and opposite first toothed plates; The two support plates are disposed between the two first toothed plates. Both support plates are rotatably connected to the proximal phalanx module to form the flexion-extension rotation joint. The two support plates are respectively connected and fixed to the two free ends of the side swing drive rope. The two first toothed plates are rotatably connected to the two fixed end caps to form the positioning rotation joint, the guide rope wheel is provided between the two first toothed plates, and the two first toothed plates mesh with another toothed plate component to form a rolling meshing structure; The two free ends of the lateral swing drive rope first pass over the opposite sides of the two guide rope wheels in a parallel and opposite manner, and then connect and fix them to the two support plates by staggered winding from one of the guide rope wheels.

2. The tendon-driven dexterity hand finger according to claim 1, characterized in that, The proximal phalanx module is equipped with a guide mechanism; The flexion-extension drive rope connected to the distal phalanx module is first guided by the guide mechanism, and then guided out by the two guide wheels.

3. The tendon-driven dexterity hand finger according to claim 2, characterized in that, The guiding mechanism includes two guide bushings, which are arranged separately and oppositely between the two flexion-extension rotation joints. The opposing portions of the two guide bushings are used to abut against the flexion-extension drive rope to guide the output of the flexion-extension drive rope.

4. The tendon-driven dexterity hand finger according to claim 1, characterized in that, One of the two toothed plate components is a second toothed plate component, the second toothed plate component comprising two separate, opposing second toothed plates; The two second toothed plates are rotatably connected to the two fixed end caps to form the positioning rotation joint. The guide rope wheel is provided between the two second toothed plates. The two second toothed plates mesh with another toothed plate component to form a rolling meshing structure.

5. The tendon-driven dexterity hand finger according to claim 1, characterized in that, The guide rope wheel is provided with multiple annular grooves arranged along its axial direction. The multiple annular grooves are arranged around the peripheral wall of the guide rope wheel and are used to position and guide the bending drive rope and the lateral swing drive rope.

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