A tendon-driven dexterous hand with metacarpal adduction and finger extension / retraction locking functions

Abstract

This invention relates to a tendon-driven dexterous hand with metacarpal adduction and finger extension / retraction locking functions. It includes a thumb connected to a thumb base, an index and middle finger connected to a first metacarpal base, a ring finger connected to a second metacarpal base, and a little finger connected to a third metacarpal base. Both the second and third metacarpal bases are driven to rotate by a coordinating adduction device mounted on a palm rest base. This coordinating adduction device drives the second and third metacarpal bases to simultaneously adduct towards the palm, causing the ring and little fingers to form a palmar arch-like enveloping posture. As can be seen from the above technical solution, this invention, by setting a coordinating adduction device to drive the second and third metacarpal bases to coordinatingly adduct towards the palm, and making the adduction angle of the third metacarpal base greater than that of the second metacarpal base, thereby causing the ring and little fingers to form a palmar arch-like enveloping posture, improves the ability to adhere to cylinders, spheres, and irregular objects and enhances grasping stability.

Description

Technical Field

[0001] This invention relates to the field of robotic dexterous hands, and more specifically to a tendon-driven dexterous hand with metacarpal adduction and finger extension / retraction locking functions. Background Technology

[0002] As an important form of robotic end effector, dexterous hands can perform operations such as gripping, pinching, and enveloping grasping through the coordinated movement of multiple fingers. They have high application value in humanoid robots, service robots, rehabilitation assistive devices, and industrial sorting. Tendon-driven dexterous hands can place the actuators in the palm, wrist, or forearm area and transmit traction force to each finger joint through tendon cords, which helps to reduce the load on the fingertips and achieve multi-degree-of-freedom integration.

[0003] Existing tendon-driven dexterous hands are primarily designed around the degrees of freedom of finger flexion and extension, lateral movement, and thumb opposition, while the palm or metacarpal areas often employ relatively fixed support structures. When grasping cylinders, spheres, or irregular objects, the ring and little finger sides struggle to effectively converge towards the palm according to the object's shape, resulting in insufficient palm envelope adjustment capabilities. This can negatively impact the degree of contact between the fingers and the object's surface and grasping stability. For example, patents CN202211084475.4 and CN202520829468.5, while improving hand envelope adjustment capabilities through structures such as thumb palm, secondary palm deflection, or little finger module flipping, mainly adjust the posture of the entire palm area or individual finger modules. They do not incorporate differentiated and coordinated adduction structures for the fourth and fifth metacarpal bones, making it difficult to form a palmar arch-like envelope posture.

[0004] Furthermore, the effective contact length of the fingers in some dexterous hands is relatively fixed. When facing objects of different sizes, they mainly rely on the joint flexion angle to adapt, which limits the envelope contact range. For example, patents CN 202011349706.0 and CN202280071414.6, while improving finger linkage, simplified actuation, or position holding through elastic telescopic components or stopping mechanisms, do not combine the adjustment of the effective contact length with locking in the extended and retracted positions, making it difficult to achieve stable adjustment of the effective contact length. In some thumb structures, the passive compliance ability of the fingertip is insufficient when contacting complex curved surfaces or subjected to external forces, easily leading to insufficient contact area or unstable local contact. Therefore, existing dexterous hands still have room for improvement in areas such as coordinated adduction of the fourth and fifth metacarpal bones, adjustment and stable locking of the effective contact length of the fingers, thumb posture adjustment and contact compliance, centralized actuation arrangement, and tendon and ligament traction guidance. Summary of the Invention

[0005] The purpose of this invention is to provide a tendon-driven dexterous hand with metacarpal adduction and finger extension / retraction locking functions, in order to improve the problems of insufficient adjustment ability of metacarpal region envelope shape, inconvenient adjustment of effective finger contact length, insufficient thumb posture adjustment and fingertip contact compliance ability, and relatively complex drive layout and wiring management in existing dexterous hands.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: including a thumb connected to a thumb base, an index finger and a middle finger connected to a first metacarpal base, a ring finger connected to a second metacarpal base, and a little finger connected to a third metacarpal base; and also including a palm support base, wherein the upper and lower ends of the thumb base are respectively hinged to the first metacarpal base and the palm support base, the first metacarpal base is fixed on the palm support base, and the second metacarpal base and the third metacarpal base are respectively rotatably connected to the palm support base, and both the second metacarpal base and the third metacarpal base are driven to rotate by a cooperating adduction device provided on the palm support base; The aforementioned coordinated retraction device includes an upper housing and a lower housing that are arranged in opposition. A gear transmission mechanism is provided between the upper housing and the lower housing. The gear transmission mechanism includes a motor, a drive gear, a first output gear, a second output gear that meshes with the first output gear through a connecting gear, and an intermediate gear set connecting the drive gear and the second output gear. The number of teeth on the first output gear is greater than that on the second output gear. The gear shafts of the first output gear and the second output gear are fixedly connected to the second metacarpal seat and the third metacarpal seat, respectively. A first angle sensor is connected to the second output gear. The motor drives the first output gear and the second output gear to rotate synchronously in the same direction through the transmission of the drive gear, the intermediate gear set, and the connecting gear, thereby driving the second metacarpal seat and the third metacarpal seat to retract synchronously towards the palm side, so that the ring finger and the little finger form a palmar arch-like enveloping posture. The thumb, index finger, middle finger, ring finger, and little finger are flexed by a thumb flexion drive mechanism, an index finger flexion drive mechanism, a middle finger flexion drive mechanism, a ring finger flexion drive mechanism, and a little finger flexion drive mechanism, respectively. The structure of each drive mechanism is the same, including a first drive motor, a first drive disk, and a flexion tendon rope. One end of the flexion tendon rope is wrapped around and fixed to the first drive disk, and the other end of the flexion tendon rope is fixed to the distal phalanx of each finger through a channel inside each finger.

[0007] The thumb comprises a distal phalanx, a middle phalanx, and a proximal phalanx that are rotatably connected in sequence. The distal phalanx and the middle phalanx are rotatably connected by a first joint axis, and the middle phalanx and the proximal phalanx are rotatably connected by a second joint axis. The proximal phalanx is connected to the thumb base through a thumb metacarpal connecting arm. The middle phalanx and the proximal phalanx are respectively provided with a first thread guide block and a second thread guide block. The middle phalanx is hinged to the first joint axis at an arc-shaped groove at the end of the middle phalanx, and the first joint axis can slide within the arc-shaped groove. The index, middle, ring, and little fingers have the same structure, each comprising a distal phalanx, an intermediate phalanx, and a proximal phalanx that are rotatably connected in sequence. The distal and intermediate phalanxes are rotatably connected via a third joint axis, and the intermediate and proximal phalanxes are rotatably connected via a fourth joint axis. The proximal phalanx is connected to a palmar-finger connector on a corresponding metacarpal bone base via a palmar-finger connector. The distal phalanx is provided with a third guide block, and the proximal phalanx is provided with a fourth guide block. The outer surfaces of the distal and intermediate phalanxes are connected by a first return spring, and the outer surfaces of the intermediate and proximal phalanxes are connected by a second return spring. The first and second return springs are used to achieve extension and return of the index, middle, ring, and little fingers after flexion.

[0008] The upper and lower ends of the thumb base are respectively provided with a first connecting shaft and a second connecting shaft. The axes of the first connecting shaft and the second connecting shaft are matched, and the first connecting shaft and the second connecting shaft are rotatably connected to the first metacarpal base and the palm support base, respectively. The thumb base is also provided with a first winding groove opened along its circumference. The thumb base is connected to the thumb rotation drive mechanism, which includes a second drive motor, a second drive disk, and a thumb rotation tendon rope. The middle section of the thumb rotation tendon rope is fixed on the second drive disk, and the two ends of the thumb rotation tendon rope pass around the second drive disk and enter from both sides of the first winding groove. The two ends of the thumb rotation tendon rope are fixed to the first winding groove.

[0009] The thumb metacarpal connecting arm is a U-shaped structure formed by the joining of a first arm body and a second arm body. The open ends of the thumb metacarpal connecting arm are located on the front and rear sides of the thumb base and are rotatably connected to the thumb base through a base connecting shaft. The non-open end of the thumb metacarpal connecting arm is fixedly connected to the proximal phalanx of the thumb. The thumb base is provided with a slot for installing a second angle sensor, and the inner ring of the second angle sensor is fixedly connected to the base connecting shaft. One end of the base connecting shaft is fixed to the inner surface of the first arm body, and the other end of the base connecting shaft passes through the circular shaft hole on the thumb base and the inner ring of the second angle sensor in sequence and is fixedly connected to the shaft hole on the second arm body. A second winding groove is opened on the inner surface of the second arm body along the circumference of the base connecting shaft. The thumb metacarpal connecting arm is connected to the thumb swing drive mechanism. The thumb swing drive mechanism includes a third drive motor, a third drive disk, and a thumb swing tendon rope. The middle section of the thumb swing tendon rope is fixed on the third drive disk. The two ends of the thumb swing tendon rope pass around the third drive disk and enter from both sides of the second winding groove. The two ends of the thumb swing tendon rope are fixed to the second winding groove.

[0010] The thumb is provided with a passive compliant reset mechanism to achieve thumb extension reset after flexion. The passive compliant reset mechanism includes a first link, a second link, a first spring, and a second spring. One end of the first link is hinged to the distal phalanx of the thumb via a first axis, and the other end of the first link is hinged to one end of the second link via a second axis. The other end of the second link is hinged to the proximal phalanx of the thumb via a third axis. One end of the first spring is fixed to a first joint axis, and the other end of the first spring is fixed to a fourth axis fixed on the middle phalanx of the thumb. One end of the second spring is fixed to a second axis, and the other end of the second spring is fixed to a fifth axis on the proximal phalanx of the thumb.

[0011] The palm and finger connector includes a base body and a cover plate that cooperates with the base body. The cover plate has a raised ear structure on top, and a wire-passing roller is connected to the ear. The inner surface of the base body that is close to the cover plate has a wire-passing hole. The palmar finger connector is connected between the base and the cover plate, and the palmar finger connector is rotatably connected to the proximal phalanx via a sixth axis. The front end and rear end of the palmar finger connector are respectively provided with a first limiting post and a second limiting hole. The first limiting post is positioned in conjunction with the first limiting hole on the cover plate, and the second limiting hole is positioned in conjunction with the second limiting post on the base. A torsion spring is sleeved on the sixth axis, and the two ends of the torsion spring are fixed to the palmar finger connector and the proximal phalanx, respectively.

[0012] The middle joints of the index, middle, ring, and little fingers are all retractable joints. Each middle joint includes a joint body and a joint outer cylinder that slides with the joint body. A third return spring is provided between the bottom of the joint body and the bottom of the joint outer cylinder. The joint body is rotatably connected to the distal joint, and the joint outer cylinder is rotatably connected to the proximal joint. The joint outer cylinder has a slide rail along the length of the middle joint. The joint body has a slider that cooperates with the slide rail at a corresponding position. The slide rail has a positioning post, and the slider has an oblong groove that cooperates with the positioning post. The oblong groove is oriented in the same direction as the slide rail.

[0013] The knuckle body and the knuckle outer tube are locked and unlocked by an electromagnetic locking mechanism. The electromagnetic locking mechanism includes an electromagnetic coil and a first locking member and a second locking member symmetrically arranged on both sides of the electromagnetic coil. The first locking member and the second locking member have the same structure, each including a sleeve and a movable block disposed inside the sleeve and slidingly engaged with the sleeve. The movable block is cylindrical in shape, with a spring fixed at one end near the electromagnetic coil and a fixing pin at the other end away from the electromagnetic coil. A magnet is disposed inside the movable block. The sleeves of the first locking member and the second locking member are respectively provided with a first coil cover and a second coil cover at the ends near the electromagnetic coil. The knuckle body has a through hole for accommodating the electromagnetic locking mechanism. The first coil cover and the through hole are integrally formed, and a cavity for accommodating the electromagnetic coil is formed between the first coil cover and the second coil cover. The left and right sides of the knuckle outer tube are respectively provided with fixing holes that cooperate with the fixing pin. Two sets of fixing holes are arranged along the vertical direction of the knuckle outer tube.

[0014] The second metacarpal seat is rotatably connected to the palm support base via the first support arm. The first support arm is L-shaped in general. The horizontal section of the first support arm is provided with a first positioning hole. The first positioning hole cooperates with the first positioning pin provided on the lower housing to rotate. The vertical section of the first support arm is provided with a connector that is fixed to the second metacarpal seat. The palm support base is provided with a recess that cooperates with the vertical section of the first support arm to limit the rotation angle of the second metacarpal seat. The lower end of the third metacarpal seat extends to a horizontal plate surface, on which a second positioning hole is provided. The second positioning hole cooperates with a second positioning pin provided on the lower housing to rotate. The third metacarpal seat is connected to the second output gear through a second support arm.

[0015] The index finger, ring finger, and little finger are also connected to the index finger lateral swing drive mechanism, the ring finger lateral swing drive mechanism, and the little finger lateral swing drive mechanism, respectively, to realize the left and right swing of the index finger, ring finger, and little finger. The index finger lateral swing drive mechanism, the ring finger lateral swing drive mechanism, and the little finger lateral swing drive mechanism have the same structure, each including a fourth drive motor, a fourth drive disk, and a lateral swing tendon rope. The middle section of the lateral swing tendon rope is fixed on the fourth drive disk, and the two ends of the lateral swing tendon rope pass through the palm-finger connector and are fixed to the two side walls of the proximal phalanx, respectively.

[0016] The beneficial effects of this invention are as follows: First, the present invention sets up a cooperative retraction device, which uses a gear transmission structure to drive the second and third metacarpal bases to retract towards the palm side in a cooperative manner, and makes the retraction angle of the third metacarpal base greater than that of the second metacarpal base, thereby enabling the ring finger and little finger to form a palmar arch-like enveloping posture, improving the ability to fit and grasp cylinders, spheres and irregular objects.

[0017] Secondly, by setting an electromagnetic locking mechanism, the present invention allows the knuckle body to extend or retract relative to the knuckle outer tube, thereby adjusting the effective contact length of the finger. At the same time, by controlling the energization and de-energization of the knuckle body and the knuckle outer tube through an electromagnetic coil, the knuckle body maintains stability in both the extended and retracted positions, improving the dexterous hand's ability to envelop objects of different sizes and its grasping stability.

[0018] Third, by setting up a thumb flexion drive mechanism, a thumb rotation drive mechanism, and a passive compliant reset mechanism, the present invention can adjust the palmar opposition posture of the thumb relative to other fingers, and when the distal phalanx of the thumb contacts an object and is subjected to external force, it produces a restricted and recoverable posture change, thereby making the thumb tip present a compliant and adaptive contact posture, increasing its fit with the object surface, and improving the stability of palmar opposition gripping and grasping curved or irregular objects.

[0019] Fourth, all the flexion drive mechanism, lateral swing drive mechanism, thumb rotation drive mechanism and thumb swing drive mechanism of the present invention are implemented by tendon rope binding, and all drive mechanisms are uniformly set in the drive mechanism fixed bracket, which helps to reduce the drive load on the finger tip and palm finger activity area and reduce the weight of the moving parts; at the same time, the centralized arrangement facilitates the binding, guidance and maintenance of tendon rope, and improves the overall structure compactness and assembly convenience. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the present invention. Figure 1 ; Figure 2 This is a schematic diagram of the structure of the present invention. Figure 2 ; Figure 3 This is a schematic diagram of the structure of the thumb of the present invention. Figure 1 ; Figure 4 This is a schematic diagram of the structure of the thumb of the present invention. Figure 2 ; Figure 5 yes Figure 4 A schematic diagram of the decomposed structure; Figure 6 This is a schematic diagram of the connection between the distal phalanx of the thumb and the proximal phalanx of the thumb in this invention; Figure 7 This is a schematic diagram of the structure of the second arm of the thumb in this invention; Figure 8 This is a diagram of the tendon cord winding of the thumb in this invention; Figure 9 This is a schematic diagram of the palm support base of the present invention. Figure 1 ; Figure 10This is a schematic diagram of the palm support base of the present invention. Figure 2 ; Figure 11 This is a schematic diagram showing the connection between the palm support base, the synergistic adduction device, the second metacarpal base, and the third metacarpal base of the present invention. Figure 1 ; Figure 12 This is a schematic diagram showing the connection between the palm support base, the synergistic adduction device, the second metacarpal base, and the third metacarpal base of the present invention. Figure 2 ; Figure 13 This is a schematic diagram of the structure of the second metacarpal seat of the present invention; Figure 14 yes Figure 13 A schematic diagram of the decomposed structure; Figure 15 This is a schematic diagram of the structure of the third metacarpal seat of the present invention; Figure 16 This is a schematic diagram of the structure of the first metacarpal seat of the present invention. Figure 1 ; Figure 17 This is a schematic diagram of the structure of the first metacarpal seat of the present invention. Figure 2 ; Figure 18 This is a schematic diagram of the cover plate of the present invention; Figure 19 This is a schematic diagram of the structure of the collaborative retraction device of the present invention; Figure 20 This is a schematic diagram of the internal structure of the collaborative retraction device of the present invention. Figure 1 ; Figure 21 This is a schematic diagram of the internal structure of the collaborative retraction device of the present invention. Figure 2 ; Figure 22 This is a schematic diagram of the structure of the index finger of the present invention. Figure 1 ; Figure 23 This is a schematic diagram of the structure of the index finger of the present invention. Figure 2 ; Figure 24 yes Figure 23 A schematic diagram of the decomposed structure; Figure 25 This is a cross-sectional view of the index finger of the present invention; Figure 26 This is a schematic diagram of the palm and finger connector of the present invention. Figure 1 ; Figure 27 This is a schematic diagram of the palm and finger connector of the present invention. Figure 2 ; Figure 28 This is a schematic diagram of the palm and finger connector of the present invention. Figure 3 ; Figure 29 This is a schematic diagram of the structure of the knuckle body of the present invention. Figure 1 ; Figure 30 This is a schematic diagram of the structure of the knuckle body of the present invention. Figure 2 ; Figure 31 This is a schematic diagram of the structure of the finger joint outer tube of the present invention. Figure 1 ; Figure 32 This is a schematic diagram of the structure of the finger joint outer tube of the present invention. Figure 2 ; Figure 33 This is a schematic diagram of the slide rail structure of the present invention; Figure 34 This is a schematic diagram of the electromagnetic locking mechanism of the present invention; Figure 35 This is a schematic diagram of the structure of the movable block and magnet of the present invention; Figure 36 This is a cross-sectional view of the electromagnetic locking mechanism of the present invention. Figure 37 This is the arrangement of the various driving mechanisms in this invention. Figure 1 ; Figure 38 This is the second arrangement of the various driving mechanisms in this invention; Figure 39 This is a schematic diagram of the structure of each driving mechanism of the thumb in this invention; Figure 40 This is a diagram showing the thumb flexion state of the present invention; Figure 41 This is a diagram showing the five fingers in flexed position according to the present invention; Figure 42 This is a diagram showing the state of the ring finger and little finger working together to retract inward, as described in this invention.

[0021] The reference numerals in the above figures are as follows: Thumb 1, distal phalanx of thumb 11, intermediate phalanx of thumb 12, first thread guide block 121, arc groove 122, proximal phalanx of thumb 13, second thread guide block 131, first joint axis 14, second joint axis 15, thumb metacarpal connecting arm 16, first arm body 161, second arm body 162, base connecting shaft 163, shaft hole 164, second winding groove 165, second angle sensor 17, passive compliant reset mechanism 18, first connecting rod 181, second connecting rod 182, first spring 183, second spring 184, first shaft 185, second shaft 186, third shaft 187, fourth shaft 188, fifth shaft 189, index finger 2, distal phalanx 21, third thread guide block 211, intermediate phalanx 22. Knuckle body 221. Knuckle outer cylinder 222. Fixing hole 2221. Third return spring 223. Slide rail 224. Slider 225. Positioning post 226. Waist-shaped groove 227. Electromagnetic locking mechanism 228. Electromagnetic coil 2281. Sleeve 2282. Moving block 2283. Spring 2284. Fixing pin 2285. First coil cover 2286. Second coil cover 2287. Magnet 2288. Through hole 229. Proximal knuckle 23. Fourth wire guide block 231. Third joint shaft 24. Fourth joint shaft 25. Palm-finger connector 26. Sixth shaft 261. First limiting post 262. Second limiting hole 263. Torsion spring 264. First return spring 27. Second return spring 28. Middle finger 3. Limiting sidewall 301. Unnamed finger 4. Little finger; 5. Palm support base; 6. Recess; 63. Cooperative retraction device; 7. Upper housing; 71. Lower housing; 72. First positioning pin; 721. Second positioning pin; 722. Motor; 73. Drive gear; 74. First output gear; 75. Output key; 751. Connecting sleeve; 752. Second output gear; 76. First angle sensor; 77. Intermediate gear set; 78. Connecting gear; 79. Thumb flexion drive mechanism; 8A. Index finger flexion drive mechanism; 8B. Middle finger flexion drive mechanism; 8C. Ring finger flexion drive mechanism; 8D. Little finger flexion drive mechanism; 8E. Thumb rotation drive mechanism; 8F. Thumb swing drive mechanism; 8G. Index finger lateral swing drive mechanism; 8H. Ring finger lateral swing drive mechanism; 8J. Little finger lateral swing drive mechanism; 8K. First drive motor; 801. First drive... Moving disc 802, flexion tendon cord 803, second drive motor 804, second drive disc 805, thumb rotation tendon cord 806, third drive motor 807, third drive disc 808, thumb swing tendon cord 809, fourth drive motor 810, fourth drive disc 811, lateral swing tendon cord 812, drive mechanism fixing bracket 9, thumb base 10, first connecting shaft 101, second connecting shaft 102, first winding groove 103, slot 104, circular shaft hole 105, first metacarpal seat 20, seat body 201, cover plate 202, thread guide roller 203, thread guide hole 204, first limiting hole 205, second limiting post 206, second metacarpal seat 30, first support arm 301, first positioning hole 302, connector head 303, third metacarpal seat 40.Second positioning hole 401, second support arm 402. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings: like Figure 1 , Figure 2 The illustrated tendon-driven dexterous hand with metacarpal adduction and finger extension / retraction locking functions includes a thumb 1 connected to a thumb base 10, an index finger 2 and a middle finger 3 connected to a first metacarpal base 20, a ring finger 4 connected to a second metacarpal base 30, and a little finger 5 connected to a third metacarpal base 40; it also includes a palm support base 6 and a drive mechanism fixing bracket 9 connected below the palm support base 6. Figure 9 , Figure 10 As shown, the palm support base 6 includes a cover 61 connected to the drive mechanism fixing bracket 9 and a connecting seat 62 integrally formed with the cover 61. The cover 61 has a hollow structure for the tendon cord wiring of each drive mechanism. The connecting seat 62 is used to connect the thumb base 10, the first metacarpal seat 20, the first metacarpal seat 20 and the second metacarpal seat 30, etc. Preferably, the tendon cord exposed to the outside of the present invention is fitted with a gathering tube to facilitate wiring.

[0023] Furthermore, such as Figures 3-8 As shown, the thumb 1 includes a distal phalanx 11, a middle phalanx 12, and a proximal phalanx 13 that are rotatably connected in sequence. The distal phalanx 11 and the middle phalanx 12 are rotatably connected by a first joint axis 14. The end of the middle phalanx 12 is provided with an arc-shaped groove 122. The first joint axis 14 is confined within the arc-shaped groove 122 and can slide within the groove of the arc-shaped groove 122. That is, the arc-shaped groove 122 restricts the relative range of motion of the distal phalanx 11. The first middle phalanx 12 and the proximal phalanx 13 are rotatably connected by a second joint axis 15. The proximal phalanx 13 is connected to the thumb base 10 through a thumb metacarpal connecting arm 16.

[0024] Furthermore, the thumb metacarpal connecting arm 16 is a U-shaped structure formed by the mating of the first arm body 161 and the second arm body 162. The open ends of the thumb metacarpal connecting arm 16 are located on the front and rear sides of the thumb base 10 and are rotatably connected to the thumb base 10 via the base connecting shaft 163, meaning that the thumb metacarpal connecting arm 16 is rotatable relative to the thumb base 10. Specifically, the non-open end of the thumb metacarpal connecting arm 16 is fixedly connected to the proximal phalanx 13 of the thumb. The thumb base 10 is provided with a slot 104 for installing the second angle sensor 17, and the inner ring of the second angle sensor 17 is fixedly connected to the base connecting shaft 163. The second angle sensor 17 is used to detect the rotation angle of the thumb metacarpal connecting arm 16 relative to the thumb base 10. In this embodiment, one end of the base connecting shaft 163 is fixed to the inner surface of the first arm body 161, and the other end of the base connecting shaft 163 passes through the circular shaft hole 105 on the thumb base 10 and the inner ring of the second angle sensor 17 in sequence, and is fixedly connected to the shaft hole 164 on the second arm body 162. The inner surface of the second arm body 162 is provided with a second winding groove 165 along the circumference of the base connecting shaft 163.

[0025] Furthermore, the second winding groove 165 in the thumb metacarpal connecting arm 16 is connected to the thumb swing drive mechanism 8G, which drives the thumb metacarpal connecting arm 16 to rotate axially along the base connecting shaft 163. The thumb swing drive mechanism 8G includes a third drive motor 807, a third drive disk 808, and a thumb swing tendon 809. The specific routing of the thumb swing tendon 809 is as follows: the middle section of the thumb swing tendon 809 is fixed on the third drive disk 808, and both ends of the thumb swing tendon 809 are led out through the third drive disk 808 and enter the wiring channel inside the palm support base 6, and then enter from both sides of the second winding groove 165. The two ends of the thumb swing tendon 809 are fixed to the second winding groove 165.

[0026] When the third drive motor 807 rotates forward, it drives the third drive disc 808 to rotate clockwise. At this time, the thumb swing tendon rope 809 pulls the thumb metacarpal connecting arm 16 to rotate counterclockwise around the base connecting shaft 163. The thumb metacarpal connecting arm 16 swings downward, driving the entire thumb 1 to swing downward. Conversely, the thumb metacarpal connecting arm 16 swings upward.

[0027] In this embodiment, the second angle sensor 17 is a rotary angle position sensor, model SVO1A103AEA01R00. The base connecting shaft 163 is a D-shaped shaft that matches the inner ring shape of the second angle sensor 17. The two ends of the D-shaped shaft are fixed to the first arm 161 and the second arm 162, respectively. The inner ring of the second angle sensor 17 is fixed on the D-shaped shaft, which can rotate within the circular shaft hole 105.

[0028] Furthermore, a first thread guide block 121 and a second thread guide block 131 are respectively provided on the middle phalanx 12 and the proximal phalanx 13 of the thumb. The first thread guide block 121 and the second thread guide block 131 are integrally formed with the middle phalanx 12 and the proximal phalanx 13 of the thumb, respectively. In this embodiment, the first thread guide block 121 and the second thread guide block 131 are both hollow columnar structures with V-shaped guide grooves. The first thread guide block 121 and the second thread guide block 131 have arc-shaped guide surfaces to change the routing direction of the flexor tendon cord 803 and reduce routing friction.

[0029] Furthermore, the upper and lower ends of the thumb base 10 are hinged to the first metacarpal base 20 and the palm support base 6, respectively. Specifically, the upper and lower ends of the thumb base 10 are respectively provided with a first connecting shaft 101 and a second connecting shaft 102. The axes of the first connecting shaft 101 and the second connecting shaft 102 are matched. The first connecting shaft 101 and the second connecting shaft 102 are rotatably connected to the first metacarpal base 20 and the palm support base 6, respectively. The thumb base 10 is also provided with a first winding groove 103 opened along its circumference. The first winding groove 103 is connected to the thumb rotation drive mechanism 8F. The thumb rotation drive mechanism 8F drives the thumb base 10 to rotate along the central axis direction of the first connecting shaft 101 and the second connecting shaft 102.

[0030] Furthermore, the thumb rotation drive mechanism 8F includes a second drive motor 804, a second drive disk 805, and a thumb rotation tendon 806. The specific routing of the thumb rotation tendon 806 is as follows: the middle section of the thumb rotation tendon 806 is fixed on the second drive disk 805, and both ends of the thumb rotation tendon 806 are led out through the second drive disk 805 and enter the wiring channel inside the palm support base 6, and then enter from both sides of the first winding groove 103, and the two ends of the thumb rotation tendon 806 are fixed to the first winding groove 103 respectively.

[0031] When the second drive motor 804 rotates clockwise, it drives the second drive disc 805 to rotate clockwise. The thumb rotation tendon 806 pulls the thumb base 10 to rotate counterclockwise. At this time, the thumb base 10 drives the thumb 1 to rotate towards the palm side around the central axis of the first connecting shaft 101 and the second connecting shaft 102, forming a palm-facing posture of the thumb 1. Conversely, the thumb base 10 rotates towards the back of the hand to form an unfolded and reset posture.

[0032] Furthermore, such as Figure 39As shown, the thumb 1 flexes via a thumb flexion drive mechanism 8A fixed to the drive mechanism mounting bracket 9. The thumb flexion drive mechanism 8A includes a first drive motor 801, a first drive disc 802, and a flexion tendon cord 803. The specific path of the flexion tendon cord 803 is as follows: one end of the flexion tendon cord 803 is wrapped around and fixed to the first drive disc 802; the other end of the flexion tendon cord 803 passes sequentially through the thread passages inside the palm support base 6 and the thumb base 10, then through the second thread guide block 131 and into the thread passage inside the proximal phalanx 13 of the thumb, then through the first thread guide block 121 and into the thread passage inside the middle phalanx 12 of the thumb, and finally into the thread passage inside the distal phalanx 11 of the thumb and is knotted and fixed at the tethering hole at the distal end of the distal phalanx 11.

[0033] When the first drive motor 801 rotates forward, it drives the first drive disc 802 to rotate clockwise, tightening the flexion tendon rope 803 and pulling the distal phalanx 11, the middle phalanx 12, and the proximal phalanx of the thumb to flex in coordination, thereby achieving the flexion of the thumb 1.

[0034] Furthermore, the extension and reset of the thumb after flexion is achieved by a passive compliant reset mechanism 18 provided on the thumb 1. The passive compliant reset mechanism 18 includes a first link 181, a second link 182, a first spring 183, and a second spring 184. One end of the first link 181 is hinged to the distal phalanx 11 of the thumb via a first shaft 185, and the other end of the first link 181 is hinged to one end of the second link 182 via a second shaft 186. The other end of the second link 182 is hinged to the proximal phalanx 13 of the thumb via a third shaft 187. One end of the first spring 183 is fixed to a first joint shaft 14, and the other end of the first spring 183 is fixed to a fourth shaft 188 fixed on the middle phalanx 12 of the thumb. One end of the second spring 184 is fixed to the second shaft 186, and the other end of the second spring 184 is fixed to a fifth shaft 189 on the proximal phalanx 13 of the thumb.

[0035] When the tip of the distal phalanx 11 of the thumb 1 contacts an object and is subjected to an external force, the first joint axis 14 on the distal phalanx 11 can slide along the arcuate groove 122 under the push of the external force, producing an adaptive posture change within the range defined by the arcuate groove 122. The first spring 183 and the second spring 184 undergo elastic deformation, and after the external force decreases or disappears, they cooperate with the first connecting rod 181 and the second connecting rod 182 to drive the distal phalanx 11 of the thumb to complete the extension and reset. During the reset process, the first drive motor 801 cooperates in releasing the wire. Thus, the passive compliant reset mechanism 18 can form a recoverable passive compliance when contacting an object, improving the adhesion between the tip of the thumb 1 and the surface of the object.

[0036] Furthermore, the first metacarpal seat 20 is fixed on the palm support base 6 to support and connect the index finger 2 and the ring finger 3. The second metacarpal seat 30 and the third metacarpal seat 40 are rotatably connected to the palm support base 6, and both the second metacarpal seat 30 and the third metacarpal seat 40 are driven to rotate by the cooperating adduction device 7 provided on the palm support base 6.

[0037] Furthermore, such as Figure 19 , Figure 20 , Figure 21 As shown, the collaborative retraction device 7 includes an upper housing 71 and a lower housing 72 that are fitted together. A gear transmission mechanism is provided between the upper housing 71 and the lower housing 72. The gear transmission mechanism includes a motor 73, a drive gear 74, a first output gear 75, a second output gear 76 that meshes with the first output gear 75 through a connecting gear 79, and an intermediate gear set 78 connecting the drive gear 74 and the second output gear 76. Specifically, when the motor 73 rotates forward, the drive gear 74, through the transmission of the intermediate gear set 78 and the connecting gear 79, causes the first output gear 75 and the second output gear 76 to rotate synchronously in the same direction, driving the second metacarpal base 30 and the third metacarpal base 40 to retract synchronously towards the palm, so that the ring finger 4 and the little finger 5 form a palmar arch-like enveloping posture. The upper housing 71 and the lower housing 72 are fixedly connected, and a mounting cavity for accommodating the gear transmission mechanism is formed between them. Each gear in the gear transmission mechanism is rotatably mounted between the upper housing and the lower housing through a corresponding support shaft. A first angle sensor 77 is connected to the second output gear 76. The first angle sensor 77 is used to detect the rotation angle of the second output gear 76.

[0038] In this invention, the number of teeth of the first output gear 75 is greater than that of the second output gear 76, so that the output rotation angle of the second output gear 76 is greater than that of the first output gear 75. Preferably, the ratio of the number of teeth of the first output gear 75 to the second output gear 76 is 2.5:1, that is, the transmission ratio of the first output gear 75 to the second output gear 76 is 1:2.5.

[0039] Furthermore, the gear shafts of the first output gear 75 and the second output gear 76 are fixedly connected to the second metacarpal seat 30 and the third metacarpal seat 40, respectively. Specifically, an output key 751 is coaxially connected to the upper end of the first output gear 75. The output key 751 is fixedly connected to the second metacarpal seat 30 through a connecting sleeve 752. The inner wall of the connecting sleeve 752 is provided with a keyway that mates with the output key 751. The connecting sleeve 752 is fixedly connected to the output key 751 and the connecting part below the second metacarpal seat 30, respectively. The first output gear 75 drives the output key 751 to rotate synchronously, and the output key 751 drives the connecting sleeve 752 to rotate, thereby driving the second metacarpal seat 30 to rotate. The connection method of the second output gear 76 is the same as that of the first output gear 75, and will not be described again here.

[0040] When motor 73 rotates forward, the drive gear 74 rotates with the output shaft of motor 73 and transmits power to the second output gear 76 and the first output gear 75 through the intermediate gear set 78 meshing with it. These gears, via output keys, drive the second metacarpal base 30 and the third metacarpal base 40 to retract inward toward the palm. Because the output angle of the second output gear 76 is greater than that of the first output gear 75, the rotation angle of the third metacarpal base 40 is greater than the retraction angle of the second metacarpal base 30 during the retraction process. As a result, the ring finger 4 and little finger 5 can retract relative to the palm base 6 toward the palm, changing the palm area from a relatively open state to a palmar arch-like state, thereby improving the ability to envelop and conform to cylinders, spheres, and irregular objects. Conversely, the ring finger 4 and little finger 5 return to their open state.

[0041] Furthermore, such as Figure 11 , Figure 12 , Figure 13 , Figure 14 , Figure 15 As shown, the second metacarpal seat 30 is rotatably connected to the palm support base 6 via a first support arm 301. The first support arm 301 is generally L-shaped. The horizontal section of the first support arm 301 is provided with a first positioning hole 302, which cooperates with a first positioning pin 721 provided on the lower housing 72 for rotation. The vertical section of the first support arm 301 is provided with a connector 303 fixed to the second metacarpal seat 30. The palm support base 6 is provided with a recess 63 that cooperates with the vertical section of the first support arm 301 to limit the rotation angle of the second metacarpal seat 30. That is, when the second metacarpal seat 30 unfolds and returns to its original position, the first support arm 301 contacts the recess 63 and forms a stop, thereby limiting the return limit position of the second metacarpal seat 30 and preventing the second metacarpal seat 30 from over-unfolding and returning to its original position. The lower end of the third metacarpal seat 40 extends to a horizontal plate surface, on which a second positioning hole 401 is provided. The second positioning hole 401 cooperates with the second positioning pin 722 provided on the lower housing 7 to rotate. The third metacarpal seat 40 is connected to the second output gear 76 through the second support arm 402.

[0042] Furthermore, such as Figure 22 , Figure 23 , Figure 24 , Figure 25As shown, the index finger 2, middle finger 3, ring finger 4, and little finger 5 have the same structure, each including a distal phalanx 21, an intermediate phalanx 22, and a proximal phalanx 23 that are rotatably connected in sequence. The distal phalanx 21 and the intermediate phalanx 22 are rotatably connected by a third joint axis 24, and the intermediate phalanx 22 and the proximal phalanx 23 are hinged by a fourth joint axis 25. The proximal phalanx 23 is connected to a palmar-finger connector on the corresponding metacarpal bone seat through a palmar-finger connector 26. The distal phalanx 21 is provided with a third thread guide block 211, and the proximal phalanx 23 is provided with a fourth thread guide block 231. The outer surfaces of the distal phalanx 21 and the intermediate phalanx 22 are connected by a first return spring 27, and the outer surfaces of the intermediate phalanx 22 and the proximal phalanx 23 are connected by a second return spring 28. The first return spring 27 and the second return spring 28 are used to realize the extension and return of the index finger 2, middle finger 3, ring finger 4, and little finger 5 after flexion.

[0043] Furthermore, such as Figure 16 , Figure 17 , Figure 18 As shown, the metacarpophalangeal connector includes a base 201 and a cover plate 202 that mates with the base 201. The base 201 is integrally formed with the first metacarpal base 20. A raised ear-shaped structure is provided on the top of the cover plate 202. A wire-passing roller 203 is connected to the ear-shaped structure. A wire-passing hole 204 is provided on the inner surface of the base 201 that is close to the cover plate 202. Figure 26 , Figure 27 , Figure 28 As shown, the palmar finger connector 26 is connected between the base 201 and the cover plate 202, and the palmar finger connector 26 and the proximal phalanx 23 are rotatably connected through the sixth shaft 261. The front end and rear end of the palmar finger connector 26 are respectively provided with a first limiting post 262 and a second limiting hole 263. The first limiting post 262 is positioned in cooperation with the first limiting hole 205 on the cover plate 202, and the second limiting hole 263 is positioned in cooperation with the second limiting post 206 on the base 201. A torsion spring 264 is sleeved on the sixth shaft 261, and the two ends of the torsion spring 264 are respectively fixed to the palmar finger connector 26 and the proximal phalanx 23.

[0044] Furthermore, such as Figure 29 , Figure 30 , Figure 31 , Figure 32 , Figure 33As shown, the middle phalanges 22 of the index finger 2, middle finger 3, ring finger 4, and little finger 5 are all retractable phalanges. The middle phalange 22 includes a phalange body 221 and a phalange outer cylinder 222 that slides with the phalange body 221. A third return spring 223 is provided between the bottom of the phalange body 221 and the bottom of the phalange outer cylinder 222. The phalange body 221 is rotatably connected to the distal phalange 21, and the phalange outer cylinder 222 is rotatably connected to the proximal phalange 23. The phalange outer cylinder 222 is provided with a slide rail 224 along the length direction of the middle phalange 22. The phalange body 221 is provided with a slider 225 that cooperates with the slide rail 224 at a corresponding position. Through the sliding cooperation between the slider 225 and the slide rail 224, the distal phalange 21 can extend or retract along the length direction of the phalange with the phalange body 221. Preferably, the slide rail 224 is provided with a positioning post 226, and the slider 225 is provided with a waist-shaped groove 227 that cooperates with the positioning post 226. The direction of the waist-shaped groove 227 is consistent with the direction of the slide rail 224. The positioning post 226 is engaged in the waist-shaped groove 227 to guide the extension and retraction of the knuckle body 221. At the same time, when the knuckle body 221 moves to the extension limit position or the retraction limit position, the end of the waist-shaped groove 227 abuts against the positioning post 226, thereby limiting the extension and retraction stroke of the knuckle body 221 relative to the knuckle outer cylinder 222.

[0045] Furthermore, such as Figure 34 , Figure 35 , Figure 36 As shown, the knuckle body 221 and the knuckle outer cylinder 222 are locked and unlocked by an electromagnetic locking mechanism 228. The electromagnetic locking mechanism 228 includes an electromagnetic coil 2281 and a first locking member and a second locking member symmetrically arranged on both sides of the electromagnetic coil 2281. The first locking member and the second locking member have the same structure, each including a sleeve 2282 and a moving block 2283 disposed inside the sleeve 2282 and slidingly engaged with the sleeve 2282. The moving block 2283 is cylindrical in shape, with a spring 2284 fixed at one end near the electromagnetic coil 2281 and a fixing pin 2285 at the other end away from the electromagnetic coil 2281. 3 has a magnet 2288 inside. The sleeves 2282 of the first locking member and the second locking member have a first coil cover 2286 and a second coil cover 2287 respectively at the end near the electromagnetic coil 2281. The finger joint body 221 has a through hole 229 for accommodating the electromagnetic locking mechanism 228. The first coil cover 2286 and the through hole 229 are integrally formed. A cavity for accommodating the electromagnetic coil 2281 is formed between the first coil cover 2286 and the second coil cover 2287. The left and right sides of the finger joint outer cylinder 222 are respectively provided with fixing holes 2221 that cooperate with the fixing pin 2285. Two sets of fixing holes 2221 are arranged along the vertical direction of the finger joint outer cylinder 222.

[0046] When the electromagnetic coil 2281 is energized, it attracts the magnet 2288, causing the moving blocks 2283 in the first and second locking components to move towards the electromagnetic coil 2281 against the elastic force of the spring 2284. At this time, the fixing pin 2285 disengages from the fixing hole 2221 on the knuckle outer cylinder 222, and the knuckle body 221 exits the locked position. When the knuckle body 221 reaches the extended or retracted position, the electromagnetic coil 2281 is de-energized, and the moving block 2283 enters the corresponding fixing hole 2221 under the action of the spring 2284, thereby locking the knuckle body 221 relative to the knuckle outer cylinder 222, thus restricting the sliding of the knuckle body 221.

[0047] Taking the index finger 2 as an example, during the extension and retraction of the index finger 2, the electromagnetic coil 2281 is first energized, causing the fixing pin 2285 to disengage from the fixing hole 2221. Subsequently, the flexion tendon rope in the index finger flexion drive mechanism 8B pulls the phalanx body 221 to extend along the phalanx outer cylinder 222. When the phalanx body 221 reaches the extended position, the electromagnetic coil 2281 is de-energized, and the fixing pin 2285 enters the fixing hole 2221, maintaining the locking between the phalanx body 221 and the phalanx outer cylinder 222. When retraction is required, the electromagnetic coil 2281 is energized again to release the lock. After the flexion tendon rope is released, the third return spring 223 drives the phalanx body 221 to retract. After the phalanx body 221 retracts to the position, the electromagnetic coil 2281 is de-energized, and the fixing pin 2285 enters the fixing hole 2221, thus locking the phalanx body 221 and the phalanx outer cylinder 222. When the phalanx body 221 is in the extended locked state or the retracted locked state, the flexion tendon rope can still continue to pull the index finger 2 to perform flexion movements.

[0048] Furthermore, the index finger 2, middle finger 3, ring finger 4 and little finger 5 respectively achieve the flexion action of each finger through the index finger flexion drive mechanism 8B, the middle finger flexion drive mechanism 8C, the ring finger flexion drive mechanism 8D and the little finger flexion drive mechanism 8E. The above drive mechanisms have the same structure as the thumb flexion drive mechanism 8A. Slightly different is the direction of the flexor tendon cords in the index finger 2, middle finger 3, ring finger 4, and little finger 5, which differs from that in the thumb 1. Taking the index finger as an example, the direction of the flexor tendon cord 803 on the index finger 2 is as follows: one end of the flexor tendon cord 803 is wrapped around and fixed to the first drive disc 802. The other end of the flexor tendon cord 803 passes through the thread passages inside the palm support base 6 and the first metacarpal base 20, then through the thread passage hole 204 on the base 201, then around the thread roller 203 and into the thread passage channel inside the proximal phalanx 23. It then passes through the fourth thread guide wheel 231 into the thread passage channel inside the middle phalanx 22, and finally passes through the third thread guide wheel 211 into the thread passage channel inside the proximal phalanx 21 and is knotted and fixed at the tethering hole at the distal end of the distal phalanx 21. The direction of the flexor tendon cord 803 corresponding to the middle finger 3, ring finger 4, and little finger 5 is the same as that of the index finger, and will not be described again here. The extension and return of the index finger 2, middle finger 3, ring finger 4, and little finger 5 after flexion are achieved by the torsion spring 264, the first return spring 27, and the second return spring 28.

[0049] Furthermore, such as Figure 37 , Figure 38 As shown, the index finger 2, ring finger 4, and little finger 5 are also connected to the index finger lateral swing drive mechanism 8H, the ring finger lateral swing drive mechanism 8J, and the little finger lateral swing drive mechanism 8K, respectively, to realize the left and right swing of the index finger 2, ring finger 4, and little finger 5. The index finger lateral swing drive mechanism 8H, the ring finger lateral swing drive mechanism 8J, and the little finger lateral swing drive mechanism 8K have the same structure, each including a fourth drive motor 810, a fourth drive disk 811, and a lateral swing tendon rope 812. The middle section of the lateral swing tendon rope 812 is fixed on the fourth drive disk 811, and the two ends of the lateral swing tendon rope 812 pass through the palm-finger connector 26 and are fixed to the two side walls of the proximal phalanx 23, respectively.

[0050] Taking the index finger as an example, the middle section of the lateral swing tendon 812 is fixed to the fourth drive disc 811. The two ends of the lateral swing tendon 812 enter the thread channel inside the metacarpophalangeal connector 26 through the thread channel inside the first metacarpal seat 20, and are then fixed to the two side walls of the proximal phalanx 23. The clockwise or counterclockwise rotation of the fourth drive disc 811 causes the index finger 2 to deflect to the left or right, respectively.

[0051] The middle finger 3 of this invention does not have a lateral swing drive mechanism. In order to avoid the middle finger 3 from lateral swinging due to eccentric force when flexing and grasping, this invention forms a limiting sidewall 301 on the palm-finger connecting seat corresponding to the middle finger 3. The limiting sidewall 301 is located on both sides of the proximal phalanx of the middle finger 3 and is abutted against the sides of the proximal phalanx to limit the lateral swing space of the proximal phalanx of the middle finger 3 in the left and right directions. At the same time, the limiting sidewall 301 does not restrict the flexion and extension movement of the proximal phalanx of the middle finger 3.

[0052] When grasping objects, the dexterous hand of this invention can select different action combinations according to the size, shape, and grasping method of the object. When grasping regular small objects, the thumb 1 can be used in conjunction with the index finger 2 or middle finger 3 to complete the gripping. When grasping larger objects or when it is necessary to increase the coverage area, the middle joints of the index finger 2, middle finger 3, ring finger 4, and little finger 5 can be extended and locked first, and then the flexion grasping can continue. When grasping cylindrical, spherical, or irregular objects, the ring finger 4 and little finger 5 can be formed into a palmar arch-like enveloping posture by the cooperative adduction device 7, and then the flexion of the index finger 2, middle finger 3, ring finger 4, and little finger 5, as well as the adduction and flexion of the thumb 1, can be used to complete the grasping.

[0053] In this invention, each drive motor can also be a servo motor capable of outputting rotation angle according to angle commands. Each servo motor's output end is equipped with a drive disc for tightening or releasing the corresponding tendon cable. In this invention, the electromagnetic coil, angle sensor, motor, and servo motor are electrically connected to the control unit. The control unit and power supply unit can be located near the palm support base 6 or the drive mechanism fixing bracket 9, and connected to the aforementioned electrical components via wires, flexible cables, or connectors. This embodiment only describes the connection relationship between the control unit, power supply unit, and electrical connection structure and the various execution and detection components, without limiting their specific circuit configurations, component models, or wiring methods.

[0054] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A tendon-driven dexterous hand with metacarpal adduction and finger extension / retraction locking functions, characterized in that: It includes a thumb (1) connected to a thumb base (10), an index finger (2) and a middle finger (3) connected to a first metacarpal base (20), a ring finger (4) connected to a second metacarpal base (30), and a little finger (5) connected to a third metacarpal base (40); it also includes a palm support base (6), the upper and lower ends of the thumb base (10) are respectively hinged to the first metacarpal base (20) and the palm support base (6), the first metacarpal base (20) is fixed on the palm support base (6), the second metacarpal base (30) and the third metacarpal base (40) are respectively rotatably connected to the palm support base (6), and the second metacarpal base (30) and the third metacarpal base (40) are both driven to rotate by a coordinating adduction device (7) provided on the palm support base (6); The cooperative retraction device (7) includes an upper housing (71) and a lower housing (72) that are mated together. A gear transmission mechanism is provided between the upper housing (71) and the lower housing (72). The gear transmission mechanism includes a motor (73), a drive gear (74), a first output gear (75), a second output gear (76) that meshes with the first output gear (75) through a connecting gear (79), and an intermediate gear set (78) that connects the drive gear (74) and the second output gear (76). The first output gear (75) has a greater number of teeth than the second output gear (76). The gear shaft of gear (75) and the gear shaft of the second output gear (76) are fixedly connected to the second metacarpal seat (30) and the third metacarpal seat (40) respectively. The second output gear (76) is connected to a first angle sensor (77). The motor (73) drives the first output gear (75) and the second output gear (76) to rotate synchronously in the same direction through the transmission of the drive gear (74), the intermediate gear set (78) and the connecting gear (79), which drives the second metacarpal seat (30) and the third metacarpal seat (40) to move inward toward the palm side synchronously, so that the ring finger (4) and the little finger (5) form a palmar arch-like enveloping posture. The thumb (1), index finger (2), middle finger (3), ring finger (4) and little finger (5) respectively achieve the flexion action of each finger through the thumb flexion drive mechanism (8A), index finger flexion drive mechanism (8B), middle finger flexion drive mechanism (8C), ring finger flexion drive mechanism (8D) and little finger flexion drive mechanism (8E). The above drive mechanisms have the same structure, each including a first drive motor (801), a first drive disk (802) and a flexion tendon rope (803). One end of the flexion tendon rope (803) is wrapped around the first drive disk (802) and fixed thereto, and the other end of the flexion tendon rope (803) is fixed to the distal phalanx of each finger through the channel inside each finger.

2. The tendon-driven dexterous hand with metacarpal adduction and finger extension / retraction locking functions according to claim 1, characterized in that: The thumb (1) includes a distal phalanx (11), a middle phalanx (12), and a proximal phalanx (13) connected in sequence. The distal phalanx (11) and the middle phalanx (12) are rotatably connected by a first joint axis (14). The middle phalanx (12) and the proximal phalanx (13) are rotatably connected by a second joint axis (15). The proximal phalanx (13) is connected to the thumb base (10) by a thumb metacarpal connecting arm (16). The middle phalanx (12) and the proximal phalanx (13) are respectively provided with a first thread guide block (121) and a second thread guide block (131). The middle phalanx (12) and the first joint axis (14) are hinged at an arc-shaped groove (122) at the end of the middle phalanx (12). The first joint axis (14) can slide within the arc-shaped groove (122). The index finger (2), middle finger (3), ring finger (4), and little finger (5) have the same structure, each including a distal phalanx (21), an intermediate phalanx (22), and a proximal phalanx (23) that are rotatably connected in sequence. The distal phalanx (21) and the intermediate phalanx (22) are rotatably connected by a third joint axis (24), and the intermediate phalanx (22) and the proximal phalanx (23) are hinged by a fourth joint axis (25). The proximal phalanx (23) is connected to a palmar-finger connector on the corresponding metacarpal bone seat through a palmar-finger connector (26). The distal phalanx (21) and the proximal phalanx (23) are connected by a palmar-finger connector (26). A third wire guide block (211) is provided on the phalanx (21), and a fourth wire guide block (231) is provided on the proximal phalanx (23); the outer side of the distal phalanx (21) and the middle phalanx (22) are connected by a first return spring (27), and the outer side of the middle phalanx (22) and the proximal phalanx (23) are connected by a second return spring (28). The first return spring (27) and the second return spring (28) are used to realize the extension and return of the index finger (2), middle finger (3), ring finger (4) and little finger (5) after flexion.

3. The tendon-driven dexterous hand with metacarpal adduction and finger extension / retraction locking functions according to claim 1, characterized in that: The upper and lower ends of the thumb base (10) are respectively provided with a first connecting shaft (101) and a second connecting shaft (102). The axes of the first connecting shaft (101) and the second connecting shaft (102) are matched, and the first connecting shaft (101) and the second connecting shaft (102) are rotatably connected to the first metacarpal base (20) and the palm support base (6) respectively. The thumb base (10) is also provided with a first winding groove (103) opened along its circumference. The thumb base (10) is connected to the thumb rotation drive mechanism (8F). The thumb rotation drive mechanism (8F) includes a second drive motor (804), a second drive disk (805), and a thumb rotation tendon rope (806). The middle section of the thumb rotation tendon rope (806) is fixed on the second drive disk (805). The two ends of the thumb rotation tendon rope (806) pass through the second drive disk (805) and enter from both sides of the first winding groove (103). The two ends of the thumb rotation tendon rope (806) are fixed to the first winding groove (103).

4. The tendon-driven dexterous hand with metacarpal adduction and finger extension / retraction locking functions according to claim 2, characterized in that: The thumb metacarpal connecting arm (16) is a U-shaped structure formed by the first arm body (161) and the second arm body (162). The open ends of the thumb metacarpal connecting arm (16) are located on the front and rear sides of the thumb base (10) and are rotatably connected to the thumb base (10) through the base connecting shaft (163). The non-open end of the thumb metacarpal connecting arm (16) is fixedly connected to the proximal phalanx (13) of the thumb. The thumb base (10) is provided with a slot (104) for installing the second angle sensor (17), and the inner ring of the second angle sensor (17) is fixedly connected to the base connecting shaft (163). One end of the base connecting shaft (163) is fixed to the inner surface of the first arm body (161), and the other end of the base connecting shaft (163) passes through the circular shaft hole (105) on the thumb base (10) and the inner ring of the second angle sensor (17) in sequence, and is fixedly connected to the shaft hole (164) on the second arm body (162). The inner surface of the second arm body (162) is provided with a second winding groove (165) along the circumference of the base connecting shaft (163). The thumb metacarpal connecting arm (16) is connected to the thumb swing drive mechanism (8G). The thumb swing drive mechanism (8G) includes a third drive motor (807), a third drive disk (808), and a thumb swing tendon rope (809). The middle section of the thumb swing tendon rope (809) is fixed on the third drive disk (808). The two ends of the thumb swing tendon rope (809) pass through the third drive disk (808) and enter from both sides of the second winding groove (165). The two ends of the thumb swing tendon rope (809) are fixed to the second winding groove (165).

5. The tendon-driven dexterous hand with metacarpal adduction and finger extension / retraction locking functions according to claim 1, characterized in that: The thumb (1) is provided with a passive compliant reset mechanism (18), which is used to realize the extension reset of the thumb (1) after flexion. The passive compliant reset mechanism (18) includes a first link (181), a second link (182), a first spring (183), and a second spring (184). One end of the first link (181) is hinged to the distal phalanx (11) of the thumb through a first shaft (185), and the other end of the first link (181) is connected to one end of the second link (182). The second link (182) is hinged to the second axis (186), and the other end of the second link (182) is hinged to the proximal phalanx (13) of the thumb via the third axis (187); one end of the first spring (183) is fixed to the first joint axis (14), and the other end of the first spring (183) is fixed to the fourth axis (188) fixed on the middle phalanx (12) of the thumb; one end of the second spring (184) is fixed to the second axis (186), and the other end of the second spring (184) is fixed to the fifth axis (189) on the proximal phalanx (13) of the thumb.

6. The tendon-driven dexterous hand with metacarpal adduction and finger extension / retraction locking functions according to claim 2, characterized in that: The palm and finger connector includes a base (201) and a cover plate (202) that cooperates with the base (201). The cover plate (202) has a raised ear structure on its upper part. A wire passing roller (203) is connected to the ear. A wire passing hole (204) is provided on the inner surface of the base (201) that is close to the cover plate (202). The palm-finger connector (26) is connected between the base (201) and the cover plate (202), and the palm-finger connector (26) and the proximal phalanx (23) are rotatably connected through the sixth shaft (261). The front end and the rear end of the palm-finger connector (26) are respectively provided with a first limiting post (262) and a second limiting hole (263). The first limiting post (262) is positioned in cooperation with the first limiting hole (205) on the cover plate (202), and the second limiting hole (263) is positioned in cooperation with the second limiting post (206) on the base (201). A torsion spring (264) is sleeved on the sixth shaft (261), and the two ends of the torsion spring (264) are fixed to the palm-finger connector (26) and the proximal phalanx (23) respectively.

7. The tendon-driven dexterous hand with metacarpal adduction and finger extension / retraction locking functions according to claim 1, characterized in that: The middle knuckles (22) of the index finger (2), middle finger (3), ring finger (4), and little finger (5) are all retractable knuckles. Each middle knuckle (22) includes a knuckle body (221) and a knuckle outer cylinder (222) that slides with the knuckle body (221). A third return spring (223) is provided between the bottom of the knuckle body (221) and the bottom of the knuckle outer cylinder (222). The knuckle body (221) is rotatably connected to the distal knuckle (21), and the knuckle outer cylinder (222) is connected to... The proximal phalanx (23) is rotatably connected. The outer cylinder (222) of the phalanx is provided with a slide rail (224) along the length of the middle phalanx (22). The phalanx body (221) is provided with a slider (225) that cooperates with the slide rail (224) at the corresponding position. The slide rail (224) is provided with a positioning post (226). The slider (225) is provided with a waist-shaped groove (227) that cooperates with the positioning post (226). The setting direction of the waist-shaped groove (227) is consistent with the direction of the slide rail (224).

8. The tendon-driven dexterous hand with metacarpal adduction and finger extension / retraction locking functions according to claim 7, characterized in that: The knuckle body (221) and the knuckle outer cylinder (222) are locked and unlocked by an electromagnetic locking mechanism (228). The electromagnetic locking mechanism (228) includes an electromagnetic coil (2281) and a first locking member and a second locking member symmetrically arranged on both sides of the electromagnetic coil (2281). The first locking member and the second locking member have the same structure, each including a sleeve (2282) and a moving block (2283) disposed inside the sleeve (2282) and slidingly engaged with the sleeve (2282). The moving block (2283) is cylindrical in shape, with a spring (2284) fixed at one end near the electromagnetic coil (2281) and a fixing pin (2285) at the other end away from the electromagnetic coil (2281). The moving block (2283) contains a The magnet (2288), the sleeves (2282) of the first locking member and the second locking member are respectively provided with a first coil cover (2286) and a second coil cover (2287) at the end near the electromagnetic coil (2281), the finger body (221) is provided with a through hole (229) for accommodating the electromagnetic locking mechanism (228), the first coil cover (2286) and the through hole (229) are integrally formed, and a cavity for accommodating the electromagnetic coil (2281) is formed between the first coil cover (2286) and the second coil cover (2287), and a fixing hole (2221) that cooperates with the fixing pin (2285) is provided on the left side wall and the right side wall of the finger outer cylinder (222), and two sets of fixing holes (2221) are provided along the vertical direction of the finger outer cylinder (222).

9. The tendon-driven dexterous hand with metacarpal adduction and finger extension / retraction locking functions according to claim 1, characterized in that: The second metacarpal seat (30) is rotatably connected to the palm support base (6) via the first support arm (301). The first support arm (301) is L-shaped in general. The horizontal section of the first support arm (301) is provided with a first positioning hole (302). The first positioning hole (302) is engaged with the first positioning pin (721) provided on the lower housing (72) for rotation. The vertical section of the first support arm (301) is provided with a connector (303) fixed to the second metacarpal seat (30). The palm support base (6) is provided with a recess (63) that engages with the vertical section of the first support arm (301) to limit the rotation angle of the second metacarpal seat (30). The lower end of the third metacarpal seat (40) extends to a horizontal plate surface, on which a second positioning hole (401) is provided. The second positioning hole (401) is engaged with a second positioning pin (722) provided on the lower housing (72) for rotation. The third metacarpal seat (40) is connected to the second output gear (76) through a second support arm (402).

10. The tendon-driven dexterous hand with metacarpal adduction and finger extension / retraction locking functions according to claim 1, characterized in that: The index finger (2), ring finger (4) and little finger (5) are also connected to the index finger lateral swing drive mechanism (8H), the ring finger lateral swing drive mechanism (8J) and the little finger lateral swing drive mechanism (8K) respectively to realize the swing of the index finger (2), ring finger (4) and little finger (5) in the left and right directions. The index finger lateral swing drive mechanism (8H), the ring finger lateral swing drive mechanism (8J) and the little finger lateral swing drive mechanism (8K) have the same structure, each including a fourth drive motor (810), a fourth drive disk (811) and a lateral swing tendon rope (812). The middle section of the lateral swing tendon rope (812) is fixed on the fourth drive disk (811), and the two ends of the lateral swing tendon rope (812) pass through the palm and finger connector (26) and are fixed to the two side walls of the proximal phalanx (23) respectively.

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