Modular rope-driven anthropomorphic dexterous hand with joint motion decoupling structure

Abstract

The application discloses a modular rope-driven anthropomorphic dexterous hand with joint motion decoupling structure, which comprises a palm and five fingers, each finger being an independent modular structure and comprising a distal phalanx, a middle phalanx, a proximal phalanx and a metacarpal bone, and DIP, PIP and MCP joints connecting the phalanges. A key guide point of a driving rope path of the DIP joint is arranged at a center position of a rolling surface of the MCP joint, so that the length of the driving rope path of the DIP joint is not affected when the MCP joint moves, and complete decoupling of the MCP joint movement and the DIP joint driving is realized. A single finger has four degrees of freedom, i.e. three flexing and one side swinging, and the five fingers have a total of 20 degrees of freedom. The application realizes complete decoupling of joint movement, adopts a modular design, has a compact structure, is convenient to maintain and expand functions, and realizes natural flexing movement and passive recovery of anthropomorphism through coupling of a rope path and a recovery rope path, so that the control precision and movement stability are improved.

Description

Technical Field

[0001] This invention belongs to the field of robotics technology, and in particular relates to a modular rope-driven humanoid dexterous hand with a joint motion decoupling structure. Background Technology

[0002] As an important branch of robotic end effectors, humanoid dexterous hands aim to mimic the structure and movement functions of the human hand to achieve flexible and stable grasping and manipulation of diverse objects. In recent years, with the deepening application of robotics technology in fields such as industrial automation, medical rehabilitation, and service robots, higher requirements have been placed on the number of degrees of freedom, actuation methods, structural compactness, flexibility, and control precision of dexterous hands.

[0003] Currently, the driving methods for humanoid dexterous hands are mainly divided into three types: motor-driven, hydraulic-driven, and rope-driven. Among them, rope-driven methods have become one of the mainstream design solutions for high-degree-of-freedom dexterous hands due to their advantages of allowing the drive unit to be placed far away from the actuator, reducing the hand's weight, and facilitating multi-degree-of-freedom movements. However, existing rope-driven humanoid dexterous hands still have the following technical problems in terms of structural design and motion decoupling:

[0004] 1. Most existing rope-driven bionic dexterous hands have low degrees of freedom, lacking the freedom of lateral movement of the four fingers. High-degree-of-freedom rope-driven dexterous hands, on the other hand, integrate the drive components into the forearm, resulting in a bulky design. High-degree-of-freedom rope-driven bionic dexterous hands cannot simultaneously achieve both compactness and dexterity.

[0005] 2. In existing rope-driven dexterous hands, the flexion movements of the MCP joint and DIP joint are coupled, which has always been a technical bottleneck restricting control accuracy and operational stability. Specifically, the tendon rope driving the distal joint (such as the DIP or PIP joint) must cross the proximal joint (such as the MCP joint). In traditional revolute joint structures, when the MCP joint undergoes flexion or extension, the envelope path length of the tendon rope at the joint changes with the rotation angle. This change in the physical path leads to unintended "parasitic displacement" in the distal joint, i.e., severe coupled motion. Summary of the Invention

[0006] The purpose of this invention is to provide a modular rope-driven anthropomorphic dexterous hand with a joint motion decoupling structure to solve the above-mentioned technical problems.

[0007] To solve the above-mentioned technical problems, the specific technical solution of the present invention for a modular rope-driven anthropomorphic dexterous hand with a joint motion decoupling structure is as follows:

[0008] A modular, rope-driven anthropomorphic dexterous hand with a joint motion decoupling structure includes a palm and five fingers. Each finger is an independent modular structure, including a distal phalanx, middle phalanx, proximal phalanx, and metacarpal bone, as well as joint structures connecting each phalanx. The distal and middle phalanxes are connected by a DIP joint, the middle and proximal phalanxes by a PIP joint, and the proximal phalanx and metacarpal bone by an MCP joint. The distal, middle, and proximal phalanxes and metacarpal bones are connected by tendon-wire transmission. The key guide point of the drive rope path of the DIP joint is set at the center of the rolling surface of the MCP joint, so that the movement of the MCP joint does not affect the length of the drive rope path of the DIP joint, achieving complete decoupling between the movement of the MCP joint and the drive of the DIP joint.

[0009] Furthermore, the MCP joint has two degrees of freedom of movement: flexion and lateral movement. The DIP and PIP joints each have one degree of flexion of movement. Each finger has four degrees of freedom, for a total of 20 degrees of freedom across all five fingers. Further, the DIP joint is a rolling joint, consisting of a first rolling surface at the lower end of the distal phalanx and a second rolling surface at the upper end of the middle phalanx. The two rolling surfaces are interlocking arcuate structures that maintain contact during movement. Four slots are formed on the two rolling surfaces, and a tendon cord is inserted into these slots and wound in a crisscross pattern to form four interlocking rope strands, with two strands wound in a clockwise and two in a counter-clockwise direction.

[0010] Furthermore, the MCP joint is a rolling joint, including a joint shaft and a pair of bearings mounted on the lateral swing axis of the joint shaft. The outer ring of the joint shaft has a fourth rolling surface, and the lower end near the phalanx has a third rolling surface. The fourth rolling surface and the third rolling surface cooperate with each other. The two rolling surfaces have an arc structure and are also provided with slots. The embedded cross ropes ensure that the two rolling surfaces always remain in contact during joint movement. The outer ring of the bearing is embedded in the lateral swing axis of the metacarpal bone to support the lateral swing movement of the finger.

[0011] Furthermore, the guide point of the drive rope path of the DIP joint is cylindrical pin fourteen in the proximal phalanx and cylindrical pin nine in the MCP joint; the cylindrical pin fourteen is located at the center of the third rolling surface at the lower end of the proximal phalanx, and the cylindrical pin nine is located at the center of the fourth rolling surface of the bearing one, so that the length of the drive rope path of the DIP joint between the two guide points remains constant when the MCP joint moves, thus achieving complete decoupling between the movement of the MCP joint and the flexion movement of the DIP joint.

[0012] Furthermore, one end of the drive rope of the DIP joint is fixed to the cylindrical pin one of the distal phalanx, passes sequentially around the cylindrical pins five and six in the middle phalanx, the cylindrical pins seven and eight in the proximal phalanx, and the cylindrical pins fourteen and nine located at the center of the rolling surface of the MCP joint, enters the metacarpal bone, passes around the pulleys on the cylindrical pins eleven and four, and finally connects to the drive element.

[0013] Furthermore, a coupling rope path is provided between the DIP joint and the PIP joint. The coupling rope path is a closed cross rope path structure, including two tendon ropes, which are led out from the distal phalanx, pass through tendon sheath one in the middle phalanx and tendon sheath two in the proximal phalanx respectively, and are fixed at the same fixed point in the proximal phalanx, so that the flexion movement of the DIP joint and the PIP joint presents a coupled movement pattern.

[0014] Furthermore, the movement of the MCP joint is differentially controlled by two tendon ropes. The two tendon ropes are symmetrically arranged on the left and right. One end of each tendon rope is fixed to a cylindrical pin seven near the phalanx, and the other end is guided through the tendon sheath in the metacarpal bone and connected to the drive element. When the two tendon ropes are contracted and released in the same direction, flexion movement is achieved; when they are contracted and released in opposite directions, lateral swing movement is achieved; when they are contracted and released in combination, a compound movement of flexion and lateral swing is achieved.

[0015] Furthermore, the PIP joint is equipped with a recovery spring, one end of which is fixed to the cylindrical pin two of the middle phalanx and the other end is fixed to the cylindrical pin three of the proximal phalanx, for passive recovery of the PIP and DIP joints; the MCP joint is equipped with a proximal phalanx flexion movement recovery rope, one end of which is fixed to the cylindrical pin seven of the proximal phalanx, passes sequentially around the cylindrical pin eight, cylindrical pin fourteen, cylindrical pin nine, cylindrical pin ten, and the cylindrical pin twelve of the metacarpal bone, and connects to the tension spring two, the other end of which is fixed to the cylindrical pin thirteen of the metacarpal bone, for passive recovery of the MCP joint.

[0016] Furthermore, the fingers are fixed to the palm via a detachable connection structure, and the ends of the tendons are centrally connected to the drive unit inside the palm, facilitating quick finger replacement and functional expansion.

[0017] The modular rope-driven anthropomorphic dexterous hand with a joint motion decoupling structure of the present invention has the following advantages:

[0018] High motion decoupling: By designing the DIP joint and MCP joint as rolling joints and setting the key guide point of the drive rope path at the center of the rolling circle, the motion of the MCP joint and the drive of the DIP joint are completely decoupled from the motion of the DIP joint from the geometric principle, eliminating the parasitic displacement problem in the traditional rope drive structure and improving the control accuracy.

[0019] High reliability and flexibility: The use of cross-rope fixed rolling joints improves joint stability and load-bearing capacity; the instantaneous rotation center of the rolling joint dynamically shifts with the joint angle. This characteristic allows the knuckle to produce richer spatial pose changes during flexion than traditional fixed-axis hinges, effectively expanding the accessible working space of the fingertip.

[0020] Compact structure and high degree of freedom density: Utilizing a modular design, 20 degrees of freedom are integrated within the palm and fingers, eliminating the need for external drive components. The overall structure is compact, making it suitable for applications sensitive to size and weight, such as intelligent prostheses and service robots. Furthermore, the modular design allows for individual finger removal and replacement, reducing maintenance costs and downtime.

[0021] The movement is highly human-like: the rope path is coupled through the DIP and PIP joints, so that the finger flexion movement conforms to the natural coupling law of human fingers; the two rope differential drive through the MCP joint realizes the compound movement of flexion and lateral swing, making the movement flexible and natural.

[0022] The recovery mechanism is well integrated: through the cooperation of tension springs and recovery ropes, passive recovery of DIP and MCP joints is achieved, eliminating the need to set up elastic elements for each direction of movement and simplifying the internal structure of the finger. Attached Figure Description

[0023] Figure 1 Axonometric view of the finger;

[0024] Figure 2 A schematic diagram of the various modules of the finger;

[0025] Figure 3 A diagram of finger joints;

[0026] Figure 4 This is a diagram showing the position of the finger cylindrical pin;

[0027] Figure 5a This is a schematic diagram of the rolling surface of a DIP rolling joint;

[0028] Figure 5b A schematic diagram of the cross rope path at the rolling joint;

[0029] Figure 6 Schematic diagram of the rope path driving the flexion movement of the DIP joint;

[0030] Figure 7 This is a schematic diagram of the cross rope path for DIP and PIP joint coupling;

[0031] Figure 8 A schematic diagram of the rope path for recovery of proximal phalangeal flexion movement;

[0032] Figure 9 Schematic diagram of the rope path driving the movement of the MCP joint;

[0033] Note: The blue lines in the diagram represent the rope path;

[0034] Explanation of markings in the diagram: 1. Distal phalanx; 2. Middle phalanx; 3. Proximal phalanx; 4. Metacarpal bone; 5. DIP joint; 6. PIP joint; 7. MCP joint; 71. Joint axis; 711. Fourth rolling surface; 72. Bearing 1; 9. Bearing 2; 11. First rolling surface; 12. Tendon sheath 1; 13. Tendon sheath 2; 14. Tension spring 2; 15. Restoration tension spring; 21. Second rolling surface; 31. Third rolling surface; 101. Cylindrical pin one; 102. Cylindrical pin two; 103. Cylindrical pin three; 104. Cylindrical pin four; 105. Cylindrical pin five; 106. Cylindrical pin six; 107. Cylindrical pin seven; 108. Cylindrical pin eight; 109. Cylindrical pin nine; 1010. Cylindrical pin ten; 1011. Cylindrical pin eleven; 1012. Cylindrical pin twelve; 1013. Cylindrical pin thirteen; 1014. Cylindrical pin fourteen. Detailed Implementation

[0035] To better understand the purpose, structure, and function of this invention, the following detailed description, in conjunction with the accompanying drawings, provides a modular rope-driven humanoid dexterous hand with a joint motion decoupling structure.

[0036] like Figure 1 , Figure 2 As shown, this embodiment provides a modular rope-driven humanoid dexterous hand with a joint motion decoupling structure, including a palm and five fingers. Each finger is an independent modular structure that can be assembled and replaced individually. Each finger includes a distal phalanx 1, a middle phalanx 2, a proximal phalanx 3, and a metacarpal bone 4, as well as a joint structure connecting the phalanges.

[0037] Specifically, the distal phalanx 1 and the middle phalanx 2 are connected by the DIP joint 5 (distal interphalangeal joint), the middle phalanx 2 and the proximal phalanx 3 are connected by the PIP joint 6 (proximal interphalangeal joint), and the proximal phalanx 3 and the metacarpal bone 4 are connected by the MCP joint 7 (metacarpophalangeal joint). The MCP joint 7 has two degrees of freedom: flexion and lateral movement. The DIP joint 5 and the PIP joint 6 each have one degree of freedom of flexion, meaning each finger has four degrees of freedom, for a total of 20 degrees of freedom across the five fingers.

[0038] like Figure 3 , Figure 5a , Figure 5b As shown, this embodiment provides a detailed description of the specific structure of the joint.

[0039] DIP, PIP, and MCP joint structures:

[0040] The DIP joint 5 is a rolling joint, consisting of a first rolling surface 11 at the lower end of the distal phalanx 1 and a second rolling surface 21 at the upper end of the middle phalanx 2. The two rolling surfaces are interlocking arc-shaped structures that maintain contact during movement. Four grooves are formed on the two rolling surfaces, and a tendon cord is inserted into these grooves and wound in a crisscross pattern to form four interlocking rope strands. These four strands are wound in two forward and two reverse directions to fix the rolling joint, ensuring that the two rolling surfaces remain in contact during joint movement, thereby improving the joint's stability and load-bearing capacity. Because the rope strands form a bidirectional cross constraint on the rolling surfaces, the joint can not only withstand flexion loads but also effectively resist lateral and torsional forces, making the rolling joint less prone to displacement or dislocation under external loads, thus enhancing the stiffness and reliability of the fingers when grasping objects.

[0041] The MCP joint 7 is also a rolling joint. Furthermore, the MCP joint 7 includes a joint shaft 71 and a pair of bearings 72 mounted on the lateral swing axis of the joint shaft. The outer ring of the joint shaft 71 has a fourth rolling surface 711, and the lower end near the phalanx 3 has a third rolling surface 31. The fourth rolling surface 711 and the third rolling surface 31 cooperate with each other. Both rolling surfaces have an arc-shaped structure and grooves, with embedded cross-shaped ropes to ensure that the two rolling surfaces remain in contact during joint movement. The outer ring of the bearings 72 is embedded in the lateral swing axis of the metacarpal bone 4 to support the lateral swing movement of the fingers.

[0042] Traditional hinge joints have a fixed axis of rotation, restricting the movement trajectory of each finger joint to an arc path within a single plane, resulting in relatively limited space accessible to the fingertip. In this invention, both the DIP joint 5 and the MCP joint 7 are rolling joints. These rolling joints are coupled via cross-path cables, providing a non-rigid, flexible coupling. The movement of the rolling joint is determined by the arc geometry of the two rolling surfaces, and its instantaneous rotation center dynamically shifts with changes in the joint angle. This variable instantaneous center characteristic allows for richer spatial pose changes during flexion. In the MCP joint of this invention, the cooperation between the rolling surfaces and the cross-path cables enables the proximal phalanx to roll smoothly during flexion rather than rotate around a fixed axis, providing a better motion transmission path for subsequent phalanges and effectively expanding the fingertip's workspace. This is particularly suitable for grasping various irregularly shaped objects (such as clothing and soft medical supplies), reducing joint friction, lowering control complexity, and increasing freedom of movement. By designing different surface radii, curvature variation patterns, and contact surface shapes, the angle-driving force relationship and the coupling motion patterns between joints can be customized. For example, the arcuate parameters of the first and second rolling surfaces of the DIP joint can be optimized according to bionic requirements, enabling the relative movement between the distal and middle phalanges to better conform to the actual movement characteristics of human fingers. The MCP rolling joint of this invention not only serves the core innovation of "MCP and DIP motion decoupling," but also, through its designable geometric characteristics, provides dexterous hands with a better movement space and more natural flexion behavior, further enhancing the overall performance of the anthropomorphic dexterous hand.

[0043] The PIP joint 6 is a conventional rotary hinge joint, including a pair of bearings 2 9. The inner ring of the bearings 2 9 is fixedly installed on both sides of the distal end of the proximal phalanx 3. The proximal end of the middle phalanx 2 is fitted on the outer ring of the bearings 6 and can rotate around the axis of the bearings 6 under the traction of the tendon chords, thereby realizing the flexion movement of the PIP joint 6.

[0044] DIP joint flexion movement driven by rope path:

[0045] like Figure 4 , Figure 6 As shown, this embodiment provides a detailed description of the drive rope path of the DIP joint 5.

[0046] For ease of description, the numbering of each cylindrical pin in the finger is defined as follows (see...). Figure 4 ):

[0047] Cylindrical pin 101: Located inside the lower part of the distal phalanx 1.

[0048] Cylindrical pin 2 102: Located inside the upper part of the middle finger joint 2.

[0049] Cylindrical pin 3 103: Located above the inner part of the phalanx 3.

[0050] Cylindrical pin 4104: Located above metacarpal bone 4.

[0051] Cylindrical pin 5 (105) and cylindrical pin 6 (106): located inside the lower part of the middle finger joint 2.

[0052] Cylindrical pin 7107: Located below the inner part of the phalanx 3.

[0053] Cylindrical pin 8108: Located in the middle of the inner part of the phalanx 3.

[0054] Cylindrical pin 9109: Located at the center of the rolling surface (fourth rolling surface 711) of the MCP joint inside the joint shaft 71.

[0055] Cylindrical pin 1010: Located inside joint shaft 71

[0056] Cylindrical pin 11 (1011), cylindrical pin 12 (1012), cylindrical pin 13 (1013): located inside metacarpal bone 4.

[0057] Cylindrical pin 141014: Located at the center of the rolling surface (third rolling surface 31) of the MCP joint inside the proximal phalanx 3.

[0058] The DIP joint 5 flexion drive cable (hereinafter referred to as the DIP drive cable) is used to drive the DIP joint 5 to produce flexion movement. For example... Figure 6 As shown, one end of the rope is fixed to the cylindrical pin 101 of the distal phalanx 1, and the other end successively passes over the top of the cylindrical pins 105, 106, and 7, enters the interior of the proximal phalanx 3, passes under the cylindrical pin 8 108 and above the cylindrical pin 14 1014, enters the MCP joint 7, passes over the top of the cylindrical pin 9 109, enters the metacarpal bone 4, passes over the pulleys mounted on the cylindrical pins 11 1011 and 4 104, and finally connects to the drive element (such as a motor-driven take-up reel). A limiting component is provided between the distal phalanx 1 and the middle phalanx 2, so during the tightening of the drive rope, the distal phalanx 1 will only bend inward relative to the middle phalanx 2.

[0059] Since cylindrical pins 14 (1014) and 9 (109) are the arc centers of the two rolling surfaces of the MCP joint 7, the length of the drive rope path passing through cylindrical pins 14 (1014) and 9 (109) remains constant when the MCP joint 7 rolls. Therefore, the flexion motion of the MCP joint 7 does not affect the length of the DIP drive rope path, thus achieving complete decoupling between the motion of the MCP joint 7 and the flexion motion of the DIP joint 6, eliminating the parasitic displacement problem in traditional rope-driven structures. In this embodiment, since the MCP joint 7 adopts a rolling joint structure, its third rolling surface 31 and fourth rolling surface 711 have arc contours, with cylindrical pins 14 (1014) and 9 (109) respectively positioned at their centers. The instantaneous center-of-motion characteristic of the rolling joint allows the rotation center of the proximal phalanx 3 to smoothly shift during flexion, avoiding the rope path length fluctuation caused by axial offset in traditional hinge joints. Based on the geometric characteristics of the rolling joint, the key guide point of the DIP drive rope path is precisely set at the center of the rolling surface, ensuring that the rope path maintains a constant length at any angle of the MCP joint 7. This achieves complete decoupling of the MCP joint motion and the DIP joint drive from the structural root. The backlash-free, low-friction motion provided by the rolling joint further ensures the long-term stability of the decoupling effect, significantly improving the control precision and long-term reliability of the dexterous hand.

[0060] PIP joint flexion movement recovery tension spring:

[0061] like Figure 6 As shown, in order to achieve passive recovery of PIP joint 6, a recovery tension spring 15 is provided at PIP joint 6 in this embodiment.

[0062] One end of the restoring spring 15 is fixed to the cylindrical pin 102 of the middle phalanx 2, and the other end is fixed to the cylindrical pin 103 of the distal phalanx 3. In the default finger position (i.e., extended position), the restoring spring 15 is pre-stretched, providing a certain preload to stabilize the PIP joint 6. When the PIP joint 6 undergoes flexion under external force, the restoring spring 15 is further stretched, storing elastic potential energy; when the driving force is removed, the restoring spring 15 releases the elastic potential energy, providing a restoring force, causing the PIP joint 6 to automatically return to its initial position.

[0063] DIP and PIP joint coupling rope paths:

[0064] like Figure 7 As shown, in order to achieve the natural flexion movement of the human finger, that is, the DIP joint 5 and the PIP joint 6 exhibit a certain coupling relationship during flexion, this embodiment sets up a coupling rope path for the DIP and PIP joints.

[0065] The coupling rope path is a closed-path, cross-rope structure. Specifically, from the fixed point of distal phalanx 1 (e.g. Figure 7Two tendon ropes are drawn out from the red axis in the middle:

[0066] The first tendon cord, guided by the cylindrical pin 101 of the distal phalanx 1, passes through the tendon sheath 12 located inside the middle phalanx 2, then through the tendon sheath 2 13 located inside the proximal phalanx 3, and finally is fixed at the fixation point of the proximal phalanx 3 (e.g., Figure 7 On the blue axis (as shown in the middle);

[0067] The second tendon cord passes through the tendon sheath 12 inside the middle phalanx 2 from above the distal phalanx 1, then emerges from the tendon sheath 23 inside the proximal phalanx 3, and is finally fixed at the same fixation point on the proximal phalanx 3.

[0068] A cross channel is formed within the tendon sheath 12, and the two tendon cords cross to form a mechanism similar to a four-bar linkage. Through this closed cross-cord structure, when the DIP joint 5 flexes, the tendon cords will drive the PIP joint 6 to produce a corresponding flexion movement, and vice versa. This results in the flexion movements of the DIP joint 5 and PIP joint 6 exhibiting a natural coupling movement pattern similar to that of human fingers. The recovery of the DIP joint 5 is synchronously driven by the recovery spring 15.

[0069] MCP joint motion drive rope path:

[0070] like Figure 9 As shown, the movement of the MCP joint 7 is controlled by the coupling of two tendon ropes, achieving two degrees of freedom of movement: flexion and lateral swing.

[0071] Specifically, two tendon ropes are arranged symmetrically on the left and right. One end of each tendon rope is fixed to a cylindrical pin 107 near the phalanx 3, guided by a tendon sheath at the lower part of the metacarpal bone 4, and finally connected to the drive element.

[0072] Its control principle is similar to that of a differential mechanism:

[0073] When the two tendons are simultaneously contracted and released in the same direction and at the same speed, the proximal phalanx 3 produces flexion or extension movements around the MCP joint 7.

[0074] When the two tendons are contracted and released in opposite directions (i.e., one contracted and one released), the proximal phalanx 3 generates a lateral swinging motion around the MCP joint 7.

[0075] By controlling the combination of contraction and extension of the two tendon ropes, a combined flexion and lateral swing movement can be achieved.

[0076] Proximal flexion movement recovery rope route:

[0077] like Figure 8 As shown, in order to achieve passive recovery of MCP joint flexion movement, this embodiment sets up a proximal phalanx flexion movement recovery rope path.

[0078] One end of the recovery rope is fixed to the cylindrical pin 7 107 of the proximal phalanx 3, and the other end passes through the tendon sheath inside the proximal phalanx 3, passes under the cylindrical pin 8 108 and above the cylindrical pin 14 1014 in sequence, enters the MCP joint 7, passes above the cylindrical pin 9 109 and below the cylindrical pin 10 1010, enters the metacarpal bone 4, passes above the cylindrical pin 12 1012, and connects to one end of the tension spring 2 14; the other end of the tension spring 2 14 is fixed to the cylindrical pin 13 1013 inside the metacarpal bone 4.

[0079] In the default finger position, tension spring 14 is pre-stretched, providing a certain preload. When the MCP joint 7 flexes under external force, the recovery rope is pulled, and tension spring 14 is further stretched, storing elastic potential energy. When the driving force is removed, tension spring 14 releases its elastic potential energy, pulling the middle phalanx 2 through the recovery rope. Under the action of the coupling ropes of the DIP and PIP joints, the proximal phalanx 3 is simultaneously driven, causing it to automatically return to its initial position in the flexion direction.

[0080] The dexterous hand of this invention adopts a modular design, with each finger being an independent module, including a complete knuckle, joint, tendon ligament, and restoring spring. The finger module is fixed to the palm via a detachable connection structure (such as bolt connection or snap connection), and the ends of the tendon ligament are centrally connected to the drive unit inside the palm.

[0081] When a finger is damaged or needs to be replaced with a different size finger, the faulty finger module can be directly removed and a new module installed, without having to disassemble the entire dexterous hand, significantly reducing maintenance costs and downtime. Furthermore, finger modules with different knuckle lengths, joint stiffness, or actuation methods can be used to quickly expand the dexterous hand's functionality, depending on the application scenario.

[0082] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. A modular rope-driven anthropomorphic dexterous hand with a joint motion decoupling structure, comprising a palm and five fingers, characterized in that: Each finger is an independent modular structure, including the distal phalanx (1), middle phalanx (2), proximal phalanx (3), and metacarpal (4), as well as joint structures connecting each phalanx; the distal phalanx (1) and middle phalanx (2) are connected by a DIP joint (5), the middle phalanx (2) and proximal phalanx (3) are connected by a PIP joint (6), and the proximal phalanx (3) and metacarpal (4) are connected by an MCP joint (7); the distal phalanx (1), middle phalanx (2), proximal phalanx (3), and metacarpal (4) are connected by a tendon cord transmission. The key guide point of the drive rope path of the DIP joint (5) is set at the center of the rolling surface of the MCP joint (7), so that the movement of the MCP joint (7) does not affect the length of the drive rope path of the DIP joint (5), thus achieving complete decoupling between the movement of the MCP joint (7) and the drive of the DIP joint (5).

2. The modular rope-driven anthropomorphic dexterous hand with joint motion decoupling structure according to claim 1, characterized in that: The MCP joint (7) has two degrees of freedom of movement: flexion and lateral swing. The DIP joint (5) and PIP joint (6) each have one degree of freedom of movement of flexion. Each finger has four degrees of freedom, and the five fingers have a total of 20 degrees of freedom.

3. The modular rope-driven anthropomorphic dexterous hand with joint motion decoupling structure according to claim 1, characterized in that: The DIP joint (5) is a rolling joint, consisting of a first rolling surface (11) at the lower end of the distal phalanx (1) and a second rolling surface (21) at the upper end of the middle phalanx (2). The two rolling surfaces are mutually cooperating arc surfaces that can maintain contact during movement. There are four slots on the two rolling surfaces. A tendon rope is embedded in the slot and cross-wound to form four cross ropes connected end to end. The four cross ropes are wound in two forward and two reverse directions.

4. The modular rope-driven anthropomorphic dexterous hand with joint motion decoupling structure according to claim 1, characterized in that: The MCP joint (7) is a rolling joint, including a joint shaft (71) and a pair of bearings (72) mounted on the lateral swing axis of the joint shaft. The outer ring of the joint shaft (71) has a fourth rolling surface (711), and the lower end near the phalanx (3) has a third rolling surface (31). The fourth rolling surface (711) and the third rolling surface (31) cooperate with each other. The two rolling surfaces are arc-shaped and also have slots. The embedded cross ropes keep the two rolling surfaces in contact during joint movement. The outer ring of the bearing (72) is embedded in the lateral swing axis of the metacarpal bone (4) to support the lateral swing movement of the finger.

5. The modular rope-driven anthropomorphic dexterous hand with joint motion decoupling structure according to claim 4, characterized in that: The guide point of the drive rope of the DIP joint (5) in the proximal phalanx (3) is cylindrical pin fourteen (1014), and the guide point in the MCP joint (7) is cylindrical pin nine (109). The cylindrical pin fourteen (1014) is located at the center of the third rolling surface (31) at the lower end of the proximal phalanx (3), and the cylindrical pin nine (109) is located at the center of the fourth rolling surface (711) of the bearing one (72). This ensures that the length of the drive rope of the DIP joint (5) between the two guide points remains constant when the MCP joint (7) moves, thus achieving complete decoupling between the movement of the MCP joint (7) and the flexion movement of the DIP joint (5).

6. The modular rope-driven anthropomorphic dexterous hand with joint motion decoupling structure according to claim 1, characterized in that: One end of the drive rope of the DIP joint (5) is fixed to the cylindrical pin one (101) of the distal phalanx (1), and passes in sequence around the cylindrical pin five (105) and cylindrical pin six (106) in the middle phalanx (2), the cylindrical pin seven (107) and cylindrical pin eight (108) in the proximal phalanx (3), and the cylindrical pin fourteen (1014) and cylindrical pin nine (109) set at the center of the rolling surface of the MCP joint (7), and after entering the metacarpal bone (4), it passes around the pulleys on the cylindrical pin eleven (1011) and cylindrical pin four (104), and finally connects to the drive element.

7. The modular rope-driven anthropomorphic dexterous hand with joint motion decoupling structure according to claim 1, characterized in that: A coupling rope path is provided between the DIP joint (5) and the PIP joint (6). The coupling rope path is a closed cross rope path structure, including two tendon ropes, which are led out from the distal phalanx (1), pass through the tendon sheath one (12) in the middle phalanx (2) and the tendon sheath two (13) in the proximal phalanx (3), and are fixed at the same fixed point in the proximal phalanx (3), so that the flexion movement of the DIP joint (5) and the PIP joint (6) presents a coupled movement law.

8. The modular rope-driven anthropomorphic dexterous hand with joint motion decoupling structure according to claim 1, characterized in that: The movement of the MCP joint (7) is controlled by the differential movement of two tendon ropes. The two tendon ropes are symmetrically arranged on the left and right. One end of each tendon rope is fixed to the cylindrical pin seven (107) near the phalanx (3), and the other end is guided by the tendon sheath in the metacarpal bone (4) and connected to the drive element. When the two tendon ropes are contracted and released in the same direction, flexion movement is achieved. When they are contracted and released in opposite directions, lateral swing movement is achieved. When they are contracted and released in combination, a compound movement of flexion and lateral swing is achieved.

9. The modular rope-driven anthropomorphic dexterous hand with a joint motion decoupling structure according to claim 6, characterized in that: The PIP joint (6) is provided with a recovery spring (15). One end of the recovery spring (15) is fixed to the second cylindrical pin (102) of the middle phalanx (2), and the other end is fixed to the third cylindrical pin (103) of the proximal phalanx (3), which is used to realize the passive recovery of the PIP joint (6) and the DIP joint (5). The MCP joint (7) is provided with a proximal phalanx flexion movement recovery rope. One end of the recovery rope is fixed to the seventh cylindrical pin (107) of the proximal phalanx (3), and passes through the eighth cylindrical pin (108), the fourteenth cylindrical pin (1014), the ninth cylindrical pin (109), the tenth cylindrical pin (1010), and the twelfth cylindrical pin (1012) of the metacarpal (4) in sequence, and is connected to the second spring (14). The other end of the second spring (14) is fixed to the thirteenth cylindrical pin (1013) of the metacarpal (4), which is used to realize the passive recovery of the MCP joint (7).

10. The modular rope-driven anthropomorphic dexterous hand with joint motion decoupling structure according to claim 1, characterized in that: The fingers and palm are fixed together by a detachable connection structure, and the ends of the tendons are connected to the drive unit inside the palm.

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