Multi-active-degree-of-freedom tendon-driven robot dexterous hand

Abstract

The invention discloses a multi-active-degree-of-freedom tendon-driven robot dexterous hand which comprises a palm which comprises a palm frame and a plurality of palm knuckles; the fingers are connected to the palm through the palm knuckles, each finger comprises a plurality of knuckles, and each knuckle comprises a knuckle body and a tendon rope guiding mechanism; the plurality of groups of tendon ropes are respectively arranged on the plurality of fingers, and each group of tendon ropes comprises a plurality of tendon ropes; the driving unit is fixed on the palm frame; the adjacent knuckles of each finger and the plurality of fingers and the plurality of palm knuckles are connected through tough elements to form a plurality of interphalangeal joints; each tendon rope on each finger penetrates through the corresponding tendon rope guiding mechanism and is connected with the driving unit, and the driving unit drives the corresponding finger to conduct stretching-buckling movement and abduction-adduction movement through the tendon ropes.

Description

Technical Field

[0001] This invention relates to the field of robot end effector technology, and in particular to a multi-degree-of-freedom tendon-driven robot dexterous hand based on a rigid-flexible coupling structure, which has high flexibility and compliance. Background Technology

[0002] In recent decades, many research institutions at home and abroad have made remarkable achievements in the design and control of robot dexterous hands in order to simulate the functions of the human hand. However, they have not been able to simultaneously achieve the three indicators of high flexibility, compliance, and compactness. Dexterous hands using external motors and tendon-driven methods can easily achieve human-like flexibility and compliance, approaching 20 active degrees of freedom, but have low compactness and versatility. Integrated dexterous hands based on built-in micro motors and linkage-driven methods achieve a certain degree of flexibility, about 6-16 active degrees of freedom, but lack compliance, i.e., adaptability, and have weak impact resistance. Summary of the Invention

[0003] In view of this, the present invention proposes a multi-active-degree-of-freedom tendon-driven robot dexterous hand based on a rigid-flexible coupling structure, which has high flexibility and compliance. It aims to solve the problem that existing dexterous hands cannot simultaneously achieve flexibility, compliance and compactness, so as to provide a robot end effector that can highly simulate the grasping operation function and adaptive capability of human hand.

[0004] To address the above problems, the present invention proposes the following technical solution: A multi-DOF tendon-driven robotic dexterous hand includes: a palm comprising a palm frame and multiple palmar phalanges; multiple fingers connected to the palm via the multiple palmar phalanges, each finger comprising multiple phalanges, each phalange comprising a phalanx body and a tendon ligament guiding mechanism; multiple sets of tendon ligaments distributed on the multiple fingers, each set of tendon ligaments comprising multiple tendon ligaments; a drive unit fixed to the palm frame; adjacent phalanges of each finger, and the multiple fingers and the multiple palmar phalanges, are connected by flexible elements to form multiple interphalangeal joints; each tendon ligament on each finger passes through the corresponding tendon ligament guiding mechanism and is connected to the drive unit, and the drive unit drives the corresponding finger to perform extension-flexion and abduction-adduction movements via the tendon ligaments.

[0005] Furthermore, the plurality of palmar phalanges includes a first palmar phalanx, a second palmar phalanx, a third palmar phalanx, a fourth palmar phalanx, and a fifth palmar phalanx; the plurality of fingers includes five fingers: the index finger, the middle finger, the ring finger, the little finger, and the thumb. Each finger includes a first phalanx, a second phalanx, and a third phalanx. The first phalanx of the thumb, the first phalanx of the index finger, the first phalanx of the middle finger, the first phalanx of the ring finger, and the first phalanx of the little finger are respectively connected by ligaments to the first palmar phalanx, the second palmar phalanx, the third palmar phalanx, the fourth palmar phalanx, and the fifth palmar phalanx, forming the first interphalangeal joint of the thumb, the index finger, the middle finger, the ring finger, and the little finger, respectively. The second phalanx of each finger is connected to its first phalanx by ligaments to form its second interphalangeal joint, and the third phalanx of each finger is connected to its second phalanx by ligaments to form its third interphalangeal joint.

[0006] Furthermore, the first interphalangeal joint adopts a ball-and-socket structure, which is a three-degree-of-freedom joint including extension-flexion, abduction-adduction, and external rotation-internal rotation; the second interphalangeal joint and the third interphalangeal joint both adopt a pin-like structure, which are single-degree-of-freedom joints of extension-flexion.

[0007] Furthermore, the tendon ligament guiding mechanism for each finger includes: a first phalanx tendon ligament guiding portion located in the middle of the first phalanx of each finger, a second phalanx tendon ligament guiding portion located in the middle of the second phalanx of each finger, and a third phalanx tendon ligament guiding portion located at the distal end of the third phalanx of each finger; the first phalanx tendon ligament guiding portion of each finger is provided with guide holes for tendon ligaments to pass through at the proximal and distal ends on the palmar radial and palmar ulnar sides; the second phalanx tendon ligament guiding portions of the thumb and index finger are respectively provided with connecting posts at the proximal ends on the palmar radial sides that connect with the corresponding phalanx bodies; the second phalanx tendon ligament guiding portions of the middle, ring, and little fingers are respectively provided with connecting posts at the proximal ends on the palmar ulnar sides that connect with the corresponding phalanx bodies.

[0008] Furthermore, each finger is driven by a set of tendon cords. The set of tendon cords corresponding to the index finger includes: a radial flexor tendon cord, the tail end of which is fixed to the connecting post between the tendon cord guide portion of the second phalanx of the index finger and the phalanx body of the second phalanx; the head end passes through a guide hole on the radial side of the palmar side of the tendon cord guide portion of the first phalanx of the index finger, and around a reversing post on the radial side of the palmar side of the second palmar phalanx before connecting to the first motor of the drive unit; an ulnar flexor tendon cord, the tail end of which is fixed to the connecting post between the tendon cord guide portion of the third phalanx of the index finger and the phalanx body of the third phalanx; the head end passes through guide holes on the ulnar side of the tendon cord guide portions of the second and first phalanxes of the index finger, and around a reversing post on the ulnar side of the palmar side of the second palmar phalanx before connecting to the second motor of the drive unit; and an extensor tendon cord, including: for realizing the first flexor tendon of the index finger... The index finger comprises a non-elastic main body with interphalangeal joint extension, a first elastic part located on the dorsal side of the second interphalangeal joint for extending the second interphalangeal joint, and a second elastic part located on the dorsal side of the third interphalangeal joint for extending the third interphalangeal joint. The tail end of the non-elastic main body is located at the proximal end of the dorsal side of the first phalanx and is fixed to a connecting post between the tendon guide portion of the first phalanx and the phalanx body of the first phalanx. The head end passes through a guide hole on the dorsal side of the second palmar phalanx and around a reversing post on the dorsal side of the second palmar phalanx before being connected to a third motor of the drive unit. The two ends of the first elastic part are respectively connected to the distal end of the dorsal side of the first phalanx and the dorsal side of the second phalanx. The two ends of the second elastic part are respectively connected to the dorsal side of the second phalanx and the dorsal side of the third phalanx.

[0009] Furthermore, the first elastic portion of the index finger is a first elastic line of the index finger, which bypasses the connecting post between the tendon cord guiding portion of the first phalanx of the index finger and the phalanx body of the first phalanx of the index finger, and connects end to end at the connecting post between the tendon cord guiding portion of the second phalanx of the index finger and the phalanx body of the second phalanx of the index finger; the second elastic portion of the index finger is a second elastic line of the index finger, which bypasses the connecting post between the tendon cord guiding portion of the second phalanx of the index finger and the phalanx body of the second phalanx of the index finger, and connects end to end at the connecting post between the tendon cord guiding portion of the third phalanx of the index finger and the phalanx body of the third phalanx of the index finger.

[0010] Furthermore, the three sets of tendon cords corresponding to the middle finger, the ring finger, and the little finger have the same structure and connection method, and the three sets of tendon cords differ from the one set of tendon cords of the index finger only in the following connection method: the tail end of the radial flexor tendon cord of the three sets of tendon cords is fixed to the connecting post between the tendon cord guide part of the third phalanx of the corresponding finger and the phalanx body of the third phalanx, and the tail end of the ulnar flexor tendon cord of the three sets of tendon cords is fixed to the connecting post between the tendon cord guide part of the second phalanx of the corresponding finger and the phalanx body of the second phalanx.

[0011] Further, the set of tendon cords corresponding to the thumb includes: a radial flexor tendon cord for the thumb, the tail end of which is located on the palmar radial side of the tendon cord guide portion of the second phalanx of the thumb, and fixed to the connecting post between the tendon cord guide portion of the second phalanx of the thumb and the phalanx body of the second phalanx of the thumb; the head end passes through the guide hole on the palmar radial side of the tendon cord guide portion of the first phalanx of the thumb, and after passing around the reversing post on the palmar radial side of the first palmar phalanx, it is connected to the fourth motor of the drive unit; and a ulnar flexor tendon cord for the thumb, the tail end of which is located on the palmar ulnar side of the tendon cord guide portion of the third phalanx of the thumb, and fixed to the third phalanx of the thumb. The first end of the tendon cord guide section, located on the connecting post between the tendon cord guide section of the thumb's third phalanx and the phalanx body of the thumb, passes through a guide hole on the palmar-ulnar side of the tendon cord guide section of the thumb's second phalanx and the tendon cord guide section of the thumb's first phalanx, and then connects to the fifth motor of the drive unit after passing around the reversing post on the palmar-ulnar side of the first palmar phalanx; the thumb radial extensor tendon cord includes: a non-elastic thumb body portion for achieving extension and abduction of the thumb's first interphalangeal joint, a first elastic thumb portion located on the dorsal side of the thumb's second interphalangeal joint for achieving extension of the thumb's second interphalangeal joint, and a portion located on the dorsal side of the thumb's third interphalangeal joint... A second elastic part of the thumb for extending the third interphalangeal joint of the thumb; wherein: the tail end of the non-elastic main body of the thumb is located at the proximal end of the dorsal side of the tendon cord guiding part of the first phalanx of the thumb, and is fixed on the radial connecting post between the tendon cord guiding part of the first phalanx of the thumb and the phalanx body of the first phalanx of the thumb; the head end passes through the guide hole on the radial side of the dorsal side of the first palmar phalanx, and after passing around the reversing post on the radial side of the dorsal side of the first palmar phalanx, it is connected to the sixth motor of the drive unit; the two ends of the first elastic part of the thumb are respectively connected to the distal end of the dorsal side of the first phalanx of the thumb and the dorsal side of the second phalanx of the thumb; The two ends of the second elastic part of the thumb are respectively connected to the dorsal side of the second phalanx of the thumb and the dorsal side of the third phalanx of the thumb; the ulnar extensor tendon of the thumb has its tail end located on the dorsal side of the tendon guide part of the second phalanx of the thumb, and is fixed to the ulnar side connecting post between the tendon guide part of the second phalanx of the thumb and the phalanx body of the second phalanx of the thumb. Its head end passes through the connecting post at the distal and proximal ends of the ulnar side of the dorsal side of the tendon guide part of the first phalanx of the thumb, then passes through the guide hole on the ulnar side of the dorsal side of the first palmar phalanx, and passes through the reversing post on the ulnar side of the dorsal side of the first palmar phalanx before being connected to the seventh motor of the drive unit.

[0012] Furthermore, the first elastic portion of the thumb is a first elastic line of the thumb, which bypasses the connecting post between the tendon guide portion of the first phalanx of the thumb and the phalanx body of the first phalanx of the thumb, and connects end to end at the connecting post between the tendon guide portion of the second phalanx of the thumb and the phalanx body of the second phalanx of the thumb; the second elastic portion of the thumb is a second elastic line of the thumb, which bypasses the connecting post between the tendon guide portion of the second phalanx of the thumb and the phalanx body of the second phalanx of the thumb, and connects end to end at the connecting post between the tendon guide portion of the third phalanx of the thumb and the phalanx body of the third phalanx of the thumb.

[0013] Furthermore, the palm is made of aluminum alloy and is manufactured using selective laser melting technology; the multiple fingers are integrally formed using multi-material fused deposition modeling technology, wherein the main body of the finger joint is made of polyethylene terephthalate and the tendon ligament guiding mechanism is made of thermoplastic polyurethane.

[0014] The multi-DOF tendon-driven robotic dexterous hand provided by this invention connects multiple fingers to the palm via the knuckles, forming interphalangeal joints using ligaments. Multiple sets of tendon cords, guided by a drive unit and passing through a specific tendon cord guidance mechanism, drive the finger movements, forming a complete rigid-flexible coupling structure system. This technical solution combines the precise guidance and stable support of a rigid joint structure with the passive adaptation and energy storage and release characteristics of ligaments and elastic tendon cords. This allows the dexterous hand to buffer external impacts through the deformation of flexible components, achieving excellent compliance and impact resistance. Simultaneously, the multiple independent tendon cords designed for each finger and their precise placement paths ensure that each knuckle can be independently and precisely controlled, achieving up to 20 active degrees of freedom. This gives the dexterous hand high flexibility, enabling it to reproduce complex human hand movements. Furthermore, the integrated design of the drive unit built into and fixed to the palm frame, and the integrated design of the knuckle body and tendon cord guidance mechanism, significantly improves space utilization, making the overall hand structure simpler and more compact, with dimensions and weight close to that of a human hand. Ultimately, through the synergistic effect of the aforementioned technical features, the present invention successfully achieves three performance indicators that are difficult to balance simultaneously in the prior art: high flexibility, high compliance, and high compactness. Attached Figure Description

[0015] Figure 1 This is a front view of the overall structure of the dexterous hand of the multi-degree-of-freedom tendon-driven robot according to an embodiment of the present invention.

[0016] Figure 2 This is a rear view of the overall structure of the dexterous hand of the multi-degree-of-freedom tendon-driven robot according to an embodiment of the present invention.

[0017] Figure 3 This is a right view of the overall structure of the dexterous hand of a multi-degree-of-freedom tendon-driven robot according to an embodiment of the present invention.

[0018] Figure 4 This is a top view of the overall structure of the dexterous hand of the multi-degree-of-freedom tendon-driven robot according to an embodiment of the present invention. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments and examples, but this is not intended to limit the scope of protection of the present invention.

[0020] The present invention aims to provide a specific implementation of a dexterous hand for a multi-degree-of-freedom tendon-driven robot. Its core lies in achieving high flexibility, high compliance, and high compactness of the dexterous hand through a rigid-flexible coupling structural design (combining a rigid phalanx body with flexible ligaments and elastic tendon ropes) and an optimized multi-tendon rope transmission path.

[0021] like Figure 1 As shown, the multi-degree-of-freedom tendon-driven robot dexterous hand provided in this embodiment of the invention includes: a palm 1, five fingers (index finger 2, middle finger 3, ring finger 4, little finger 5, thumb 6), multiple ligaments 7, multiple tendon cords 8, and a drive unit 9; the palm 1 includes a palm frame 11, a first palmar phalanx 12, a second palmar phalanx 13, a third palmar phalanx 14, a fourth palmar phalanx 15, and a fifth palmar phalanx 16; each finger includes three phalanges, and each phalanx includes a phalanx body and a tendon cord guiding mechanism; adjacent phalanges of each finger, as well as the five fingers and the aforementioned five palmar phalanges, are connected by ligaments to form multiple interphalangeal joints; the tendon cord guiding mechanism is used to constrain and guide the tendon cord path, and each tendon cord on each finger passes through the corresponding tendon cord guiding mechanism and is connected to the corresponding motor in the drive unit, and the corresponding motor drives the corresponding finger to perform extension-flexion and abduction-adduction movements through the tendon cord. The multiple motors included in the drive unit 9 are all fixed to the palm frame 11, realizing a built-in motor design.

[0022] like Figure 1 and Figure 2As shown, the first metacarpophalangeal joint 12 of the palm 1 and the first phalanx 61 of the thumb 6 are connected by a ligament 74 to form the first interphalangeal joint of the thumb 6. The ligament 74 passes through a through-hole on the proximal end of the first phalanx 61 and the first metacarpophalangeal joint 12. Through-holes are also provided at the proximal end of the second phalanx 62 of the thumb 6 and the distal end of the first phalanx 61 for the ligament to pass through. The first phalanx 61 and the second phalanx 62 are connected by a ligament 75 to form the second interphalangeal joint of the thumb 6. Similarly, the second phalanx 62 and the third phalanx 63 are connected by a ligament 76 to form the third interphalangeal joint of the thumb 6. Likewise, the second metacarpophalangeal joint 13 of the palm 1 and the first phalanx 21 of the index finger 2 are connected by a ligament 71 to form the first interphalangeal joint of the index finger 2; the first phalanx 21 and the second phalanx 22 are connected by a ligament 72 to form the second interphalangeal joint of the index finger 2; and the second phalanx 22 and the third phalanx are connected by a ligament 73 to form the third interphalangeal joint of the index finger 2. The design and connection of the interphalangeal joints of the middle finger (3), ring finger (4), and little finger (5) are the same as those of the index finger (2), and will not be repeated here. Each of the first interphalangeal joints adopts a ball-and-socket structure, which is a three-degree-of-freedom joint including extension-flexion, abduction-adduction, and external rotation-internal rotation; while the second and third interphalangeal joints adopt a pin-like structure, which is a single-degree-of-freedom joint of extension-flexion.

[0023] In some exemplary embodiments, the ligaments of each interphalangeal joint are three parallel high molecular weight polyethylene fishing lines. Accordingly, the size of the reserved through hole should ensure that the three fishing lines can slide freely. In one embodiment of the present invention, a through hole with a diameter of about 2 mm is reserved. The two ends of the ligament are connected end to end after passing through the corresponding through hole, thereby connecting and constraining adjacent phalanges to form an interphalangeal joint.

[0024] In this embodiment of the invention, each phalanx of each finger includes a phalanx body and a tendon ligament guiding mechanism. The tendon ligament guiding mechanism of each finger is located in the middle of the first phalanx, the middle of the second phalanx, and the distal end of the third phalanx. Specifically, the tendon ligament guiding portion of the first phalanx has guide holes at its proximal and distal ends on the radial and ulnar sides of the palmar side for the tendon ligament to pass through. In particular, the tendon ligament guiding portions of the second phalanx of the thumb and index finger do not have guide holes at their proximal and distal ends on the radial side of the palmar side; instead, they have a connecting post at the proximal end that connects to the phalanx body. The tendon ligament guiding portions of the second phalanx of the middle, ring, and little fingers do not have guide holes at their proximal and distal ends on the ulnar side of the palmar side; instead, they have a connecting post at the proximal end that connects to the phalanx body.

[0025] Please refer to Figure 1Taking the index finger (2) as an example, the four fingers excluding the thumb have the following structures: the first phalanx (21) includes a phalanx body (211) and a tendon ligament guiding portion (212); the second phalanx (22) includes a phalanx body (221) and a tendon ligament guiding portion (222); and the third phalanx (23) includes a phalanx body (231) and a tendon ligament guiding portion (232). Please also refer to... Figure 2 A set of tendon cords for index finger transmission includes: a radial flexor tendon cord 81, an ulnar flexor tendon cord 82, and an extensor tendon cord 83. The radial flexor tendon cord 81 is knotted and sintered after its tail end wraps around the connecting post between the second phalanx tendon cord guide portion 222 and the phalanx body 221. Its head end passes through the guide hole on the radial side of the first phalanx tendon cord guide portion 212, and around the reversing post on the radial side of the second palmar phalanx 13 before connecting to the motor 91. The ulnar flexor tendon cord 82 is knotted and sintered after its tail end wraps around the connecting post between the third phalanx tendon cord guide portion 232 and the phalanx body 231. Its head end passes through the guide holes on the ulnar and palmar sides of the second phalanx tendon cord guide portion 222 and the first phalanx tendon cord guide portion 212, and around the reversing post on the ulnar and palmar sides of the second palmar phalanx 13 before connecting to the motor 92. The index finger extensor tendon cord 83 includes: a non-elastic main body portion 831 for extending the first interphalangeal joint of the index finger, a first elastic cord 832 located on the dorsal side of the second interphalangeal joint of the index finger for extending the second interphalangeal joint of the index finger, and a second elastic cord 833 located on the dorsal side of the third interphalangeal joint of the index finger for extending the third interphalangeal joint of the index finger. The tail end of the non-elastic main body portion 831 is knotted and sintered after wrapping around the connecting post between the first interphalangeal tendon cord guide portion 212 and the interphalangeal body 211. The head end passes through the guide hole on the dorsal side of the second palmar interphalangeal joint 13, and after passing around the reversing post on the dorsal side of the second palmar interphalangeal joint 13, it is connected to the motor 93. The two ends of the first elastic line 832 are respectively connected to the distal dorsal side of the first phalanx of the index finger and the dorsal side of the second phalanx of the index finger. Specifically, the first elastic line 832 passes around the connecting post between the tendon cord guiding portion 212 of the first phalanx and the phalanx body 211, and connects end to end at the connecting post between the tendon cord guiding portion 222 of the second phalanx and the phalanx body 221. The two ends of the second elastic line 833 are respectively connected to the dorsal side of the second phalanx of the index finger and the dorsal side of the third phalanx of the index finger. Specifically, the second elastic line 833 passes around the connecting post between the tendon cord guiding portion 222 of the second phalanx and the phalanx body 221, and connects end to end at the connecting post between the tendon cord guiding portion 232 of the third phalanx and the phalanx body 231.

[0026] Therefore, based on the aforementioned finger joint and phalanx design, the index finger achieves five degrees of freedom (including four active degrees of freedom) through the combined action of three tendon ropes and their guiding mechanisms via three motors. Specifically, motors 91 and 92 drive the first interphalangeal joint to flex via the radial flexor tendon rope 81 and the ulnar flexor tendon rope 82, while motor 93 drives the first interphalangeal joint to extend via the non-elastic main body 831 of the extensor tendon rope 83. When motor 93 restricts the flexion of the first interphalangeal joint via the non-elastic main body 831 of the extensor tendon rope 83, motor 91 drives the second interphalangeal joint to flex via the radial flexor tendon rope 81, and the second interphalangeal joint is extended by the first elastic line 832. When motor 91... When the second interphalangeal joint is flexed to its limit position by the radial flexor tendon rope 81 of the index finger, the third interphalangeal joint can be further flexed by the motor 92 through the ulnar flexor tendon rope 82 of the index finger, and the third interphalangeal joint is extended by the second elastic line 833; when the first interphalangeal joint is restricted by the non-elastic main body 831 of the extensor tendon rope 83 of the index finger by the motor 93, the first interphalangeal joint is abducted by the motor 91 through the radial flexor tendon rope 81 of the index finger, and the first interphalangeal joint is adducted by the motor 92 through the ulnar flexor tendon rope 82 of the index finger.

[0027] The tendon pathways and working principles of the middle finger (3), ring finger (4), and little finger (5) are similar to those of the index finger (2), except that the fixing points of the radial and ulnar flexor tendons are opposite to those of the index finger (2). Specifically, the three sets of tendons corresponding to the middle finger (3), ring finger (4), and little finger (5) have the same structure and connection method, and these three sets of tendons differ from the one set of tendons on the index finger only in their connection method (see reference). Figure 1 and Figure 2 The radial flexor tendon cords of the three sets of tendon cords are fixed to the connecting post between the tendon cord guide portion of the third phalanx of the corresponding finger and the phalanx body of the third phalanx. The ulnar flexor tendon cords of the three sets of tendon cords are fixed to the connecting post between the tendon cord guide portion of the second phalanx of the corresponding finger and the phalanx body of the second phalanx. Similarly, the middle finger 3, ring finger 4, and little finger 5 are each driven by 3 motors in a similar manner to the index finger 2, achieving 5 degrees of freedom (including 4 active degrees of freedom).

[0028] Please refer to Figure 3 and Figure 4The set of tendon cords corresponding to the thumb 6 includes: the radial flexor tendon cord 84, the ulnar flexor tendon cord 85, the radial extensor tendon cord 86, and the ulnar extensor tendon cord 87. The tail end of the radial flexor tendon cord 84 is tied and fixed by wrapping it around the connecting post between the second phalanx tendon cord guide portion 622 and the phalanx body 621. The head end passes through the guide hole on the radial side of the first phalanx tendon cord guide portion 612, and passes around the reversing post on the radial side of the first palmar phalanx 12 before being connected to the motor 94. The tail end of the thumb ulnar flexor tendon rope 85 is tied and sintered after wrapping around the connecting post between the third phalanx tendon rope guide part 632 and the phalanx body 631. The head end passes through the guide round hole on the palmar and ulnar sides of the second phalanx tendon rope guide part 622 and the first phalanx tendon rope guide part 612, and then passes around the reversing round post on the palmar and ulnar sides of the first palmar phalanx 12 before being connected to the motor 95.

[0029] refer to Figure 3 The thumb radial extensor tendon cord 86 includes: a non-elastic main body 861 for extending and abducting the first interphalangeal joint of the thumb; a first elastic cord 862 located on the dorsal side of the second interphalangeal joint of the thumb for extending the second interphalangeal joint of the thumb; and a second elastic cord 863 located on the dorsal side of the third interphalangeal joint of the thumb for extending the third interphalangeal joint of the thumb. The tail end of the non-elastic main body 861 is knotted and sintered after wrapping around the connecting post on the radial side between the first interphalangeal tendon cord guide portion 612 and the interphalangeal body 611. The head end passes through a guide hole on the radial side of the dorsal side of the first palmar interphalangeal joint 12, and after passing around a reversing post on the radial side of the dorsal side of the first palmar interphalangeal joint 12, it is connected to the motor 96. The two ends of the first elastic cord 862 are respectively connected to the distal dorsal side of the first phalanx of the thumb and the dorsal side of the second phalanx of the thumb. Specifically, the first elastic cord 862 passes around the connecting post between the tendon cord guiding portion 612 of the first phalanx and the phalanx body 611, and connects end to end at the connecting post between the tendon cord guiding portion 622 of the second phalanx and the phalanx body 621. The two ends of the second elastic cord 863 are respectively connected to the dorsal side of the second phalanx of the thumb and the dorsal side of the third phalanx of the thumb. Specifically, the second elastic cord 863 passes around the connecting post between the tendon cord guiding portion 622 of the second phalanx and the phalanx body 621, and connects end to end at the connecting post between the tendon cord guiding portion 632 of the third phalanx and the phalanx body 631. The tail end of the thumb ulnar extensor tendon rope 87 is wrapped around the ulnar connecting post between the second phalanx tendon rope guide part 622 and the phalanx body 621, then knotted and sintered for fixation. The head end passes through the connecting post at the distal and proximal ends of the dorsal ulnar side of the first phalanx tendon rope guide part 612, then passes through the guide hole on the dorsal ulnar side of the first palmar phalanx 12, and after passing around the reversing post on the dorsal ulnar side of the first palmar phalanx 12, it is connected to the motor 97.

[0030] Therefore, based on the aforementioned finger joint and phalanx design, the thumb achieves five degrees of freedom (including four active degrees of freedom) through the combined action of four tendon ropes and their guiding mechanisms via four motors. Specifically, motors 94 and 95 drive flexion of the first interphalangeal joint via the radial flexor tendon rope 84 and the ulnar flexor tendon rope 85, while motors 96 and 97 drive extension of the first interphalangeal joint via the inelastic main body 861 of the radial extensor tendon rope 86 and the ulnar extensor tendon rope 87; motor 96 drives abduction of the first interphalangeal joint via the inelastic main body 861 of the radial extensor tendon rope 86, and motor 97 drives adduction of the first interphalangeal joint via the ulnar extensor tendon rope 87; when motor 96 restricts flexion of the first interphalangeal joint via the inelastic main body 861 of the radial extensor tendon rope 86, motor 94... The second interphalangeal joint is flexed by the radial flexor tendon of the thumb 84 and extended by the first elastic line 862. When the second interphalangeal joint is flexed to its limit by the radial flexor tendon of the thumb 94, the third interphalangeal joint can be further flexed by the ulnar flexor tendon of the thumb 95 and extended by the second elastic line 863. When the flexion of the first and second interphalangeal joints is restricted by the ulnar extensor tendon of the thumb 97, the third interphalangeal joint can be directly flexed by the ulnar flexor tendon of the thumb 95 and extended by the second elastic line 863.

[0031] In some specific embodiments of the present invention, the non-elastic main body of each finger extensor tendon cord is made of the same high molecular weight polyethylene fishing line as the finger flexor tendon cord, while the elastic part is made of thermoplastic polyurethane elastic line. The palm 1 is made of aluminum alloy and manufactured using selective laser melting (SLM) technology; each finger is integrally formed using fused deposition modeling (FDM) technology, wherein the finger joint body is made of polyethylene terephthalate (PETG) and the tendon cord guiding mechanism is made of thermoplastic polyurethane (TPU). However, these are merely exemplary and do not mean that the above-mentioned components of the present invention can only use the materials listed herein. Those skilled in the art can choose other materials with similar properties to replace them as needed, and the present invention does not impose any limitations on this.

[0032] The multi-DOF tendon-driven robot dexterous hand provided in the above embodiments of the present invention combines the advantages of traditional pin joints and humanoid bionic joints, and optimizes the tendon-driven path, thus having the following advantages: 1. This invention can mimic the 25 degrees of freedom of the human hand, with each of the five fingers having 3 degrees of freedom at the first interphalangeal joint, achieving flexibility and suppleness close to that of the human hand, and is highly safe.

[0033] 2. The overall size and weight of the hand are close to those of a human hand, with a length of less than 190 mm, a width of less than 90 mm, and a weight of approximately 500 grams, achieving a highly compact design.

[0034] 3. Based on 16 built-in drive motors (4 motors for the thumb and 3 motors for each of the other four fingers) and tendon-wire transmission, this invention achieves 20 active degrees of freedom. Among them, the abduction-adduction and external rotation-internal rotation degrees of freedom of the first interphalangeal joints of the four fingers and the thumb are coupled, achieving high flexibility, compliance and compactness, that is, achieving a balance of these three indicators.

[0035] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several equivalent substitutions or obvious modifications can be made without departing from the concept of the present invention, and all such modifications, achieving the same performance or purpose, should be considered within the scope of protection of the present invention.

Claims

1. A multi-active-degree-of-freedom tendon-driven robot dexterous hand, characterized in that, include: The palm (1) includes a palm frame (11) and multiple palmar phalanges (12, 13, 14, 15, 16). Multiple fingers (2, 3, 4, 5, 6) are connected to the palm through multiple palmar knuckles. Each finger includes multiple knuckles, and each knuckle includes a knuckle body and a tendon ligament guiding mechanism. Multiple sets of tendon cords (8) are respectively placed on the multiple fingers, and each set of tendon cords contains multiple tendon cords; The drive unit (9) is fixed to the palm frame (11); Each finger is connected to adjacent phalanges by resilient elements, and the multiple fingers are connected to the multiple palmar phalanges to form multiple interphalangeal joints; each tendon cord on each finger passes through the corresponding tendon cord guide mechanism and is connected to the drive unit, which drives the corresponding finger to perform extension-flexion and abduction-adduction movements through the tendon cord.

2. The multi-degree-of-freedom tendon-driven robot dexterous hand as described in claim 1, characterized in that, The plurality of palmar phalanges include a first palmar phalanx (12), a second palmar phalanx (13), a third palmar phalanx (14), a fourth palmar phalanx (15), and a fifth palmar phalanx (16). The plurality of fingers include five fingers: index finger (2), middle finger (3), ring finger (4), little finger (5), and thumb (6). Each finger includes a first phalanx, a second phalanx, and a third phalanx. The first phalanx of the thumb, index finger, middle finger, ring finger, and little finger are respectively connected by ligaments to the first palmar phalanx, the second palmar phalanx, the third palmar phalanx, the fourth palmar phalanx, and the fifth palmar phalanx, forming the first interphalangeal joint of the thumb, index finger, middle finger, ring finger, and little finger, respectively. The second phalanx of each finger is connected to its first phalanx by ligaments to form its second interphalangeal joint, and the third phalanx of each finger is connected to its second phalanx by ligaments to form its third interphalangeal joint.

3. The multi-degree-of-freedom tendon-driven robot dexterous hand as described in claim 2, characterized in that, The first interphalangeal joint adopts a ball-and-socket structure and is a three-degree-of-freedom joint including extension-flexion, abduction-adduction, and external rotation-internal rotation; the second and third interphalangeal joints both adopt a pin-like structure and are single-degree-of-freedom joints of extension-flexion.

4. The multi-degree-of-freedom tendon-driven robot dexterous hand as described in claim 2, characterized in that, The tendon cord guiding mechanism of each finger includes: a first phalanx tendon cord guiding portion located in the middle of the first phalanx of each finger, a second phalanx tendon cord guiding portion located in the middle of the second phalanx of each finger, and a third phalanx tendon cord guiding portion located at the distal end of the third phalanx of each finger. The tendon cord guiding portion of the first phalanx of each finger is provided with guide holes at the proximal and distal ends of the palmar radial and palmar ulnar sides for the tendon cord to pass through. The thumb and index finger each have a connecting post at the proximal end of the palmar radial side of the second phalanx tendon guiding portion, which connects to the corresponding phalanx body; the middle finger, ring finger, and little finger each have a connecting post at the proximal end of the palmar ulnar side of the second phalanx tendon guiding portion, which connects to the corresponding phalanx body.

5. The multi-degree-of-freedom tendon-driven robot dexterous hand as described in claim 4, characterized in that, Each finger is driven by a set of tendons, wherein the set of tendons corresponding to the index finger (2) includes: The radial flexor tendon cord (81) of the index finger is fixed at its tail end to the connecting post between the tendon cord guide part (222) of the second phalanx of the index finger and the phalanx body (221) of the second phalanx of the index finger. Its head end passes through the guide hole on the radial side of the palmar side of the tendon cord guide part (212) of the first phalanx of the index finger, and passes around the reversing post on the radial side of the palmar side of the second palmar phalanx (13) before being connected to the first motor (91) of the drive unit. The ulnar flexor tendon cord (82) of the index finger has its tail end fixed to the connecting post between the tendon cord guide part (232) of the third phalanx of the index finger and the phalanx body (231) of the third phalanx of the index finger. Its head end passes through the guide hole on the palmar and ulnar side of the tendon cord guide part (222) and the tendon cord guide part (212) of the first phalanx of the index finger, and passes around the reversing post on the palmar and ulnar side of the second palmar phalanx (13) before being connected to the second motor (92) of the drive unit. The index finger extensor tendon cord (83) includes: a non-elastic main body portion (831) of the index finger for achieving extension of the first interphalangeal joint of the index finger, a first elastic portion (832) of the index finger located on the dorsal side of the second interphalangeal joint of the index finger for achieving extension of the second interphalangeal joint of the index finger, and a second elastic portion (833) of the index finger located on the dorsal side of the third interphalangeal joint of the index finger for achieving extension of the third interphalangeal joint of the index finger. The tail end of the non-elastic main body part (831) of the index finger is located at the proximal end of the dorsal side of the first phalanx of the index finger and is fixed on the connecting post between the tendon cord guiding part (212) of the first phalanx of the index finger and the phalanx body (211) of the first phalanx of the index finger. The head end passes through the guide hole on the dorsal side of the second palmar phalanx (13) and passes around the reversing post on the dorsal side of the second palmar phalanx (13) before being connected to the third motor (93) of the drive unit. The two ends of the first elastic portion (832) of the index finger are respectively connected to the distal end of the dorsal side of the first phalanx of the index finger and the dorsal side of the second phalanx of the index finger; The two ends of the second elastic part (833) of the index finger are respectively connected to the dorsal side of the second phalanx of the index finger and the dorsal side of the third phalanx of the index finger.

6. The multi-degree-of-freedom tendon-driven robot dexterous hand as described in claim 5, characterized in that, The first elastic part (832) of the index finger is the first elastic line of the index finger. The first elastic line of the index finger passes around the connecting post between the tendon cord guiding part (212) of the first phalanx of the index finger and the phalanx body (211) of the first phalanx of the index finger, and connects end to end at the connecting post between the tendon cord guiding part (222) of the second phalanx of the index finger and the phalanx body (221) of the second phalanx of the index finger. The second elastic part (833) of the index finger is the second elastic line of the index finger. The second elastic line of the index finger passes around the connecting post between the tendon cord guiding part (222) of the second phalanx of the index finger and the phalanx body (221) of the second phalanx of the index finger, and connects end to end at the connecting post between the tendon cord guiding part (232) of the third phalanx of the index finger and the phalanx body (231) of the third phalanx of the index finger.

7. The multi-degree-of-freedom tendon-driven robot dexterous hand as described in claim 6, characterized in that, The three sets of tendon cords corresponding to the middle finger (3), the ring finger (4), and the little finger (5) have the same structure and connection, and the three sets of tendon cords differ from the set of tendon cords of the index finger only in the following connection structure: The tail end of the radial flexor tendon of the three sets of tendon ropes is fixed to the connecting post between the tendon rope guide part of the third phalanx of the corresponding finger and the phalanx body of the third phalanx. The tail end of the ulnar flexor tendon of the three sets of tendon ropes is fixed to the connecting post between the tendon rope guide part of the second phalanx of the corresponding finger and the phalanx body of the second phalanx.

8. The multi-degree-of-freedom tendon-driven robot dexterous hand as described in claim 4, characterized in that, The set of tendons corresponding to the thumb (6) includes: The radial flexor tendon cord (84) of the thumb has its tail end located on the radial side of the palmar side of the tendon cord guide part (622) of the second phalanx of the thumb, and is fixed on the connecting post between the tendon cord guide part (622) of the second phalanx of the thumb and the phalanx body (621) of the second phalanx of the thumb. Its head end passes through the guide hole on the radial side of the palmar side of the tendon cord guide part (612) of the first phalanx of the thumb, and passes around the reversing post on the radial side of the palmar side of the first palmar phalanx (12) before being connected to the fourth motor (94) of the drive unit. The ulnar flexor tendon cord (85) of the thumb has its tail end located on the palmar ulnar side of the tendon cord guide portion (632) of the third phalanx of the thumb, and is fixed to the connecting post between the tendon cord guide portion (632) of the third phalanx of the thumb and the phalanx body (631) of the third phalanx of the thumb. Its head end passes through the guide hole on the palmar ulnar side of the tendon cord guide portion (622) of the second phalanx of the thumb and the tendon cord guide portion (612) of the first phalanx of the thumb, and passes around the reversing post on the palmar ulnar side of the first palmar phalanx (12) before being connected to the fifth motor (95) of the drive unit. The radial extensor tendon cord of the thumb (86) includes: a non-elastic main body portion (861) of the thumb for extending and abducting the first interphalangeal joint of the thumb; a first elastic portion (862) of the thumb located on the dorsal side of the second interphalangeal joint of the thumb for extending the second interphalangeal joint of the thumb; and a second elastic portion (863) of the thumb located on the dorsal side of the third interphalangeal joint of the thumb for extending the third interphalangeal joint of the thumb; wherein: the tail end of the non-elastic main body portion (861) is located on the dorsal proximal end of the tendon cord guiding portion (612) of the first phalanx of the thumb and is fixed to the first phalanx of the thumb. The first end of the finger tendon guide portion (612) is connected to the sixth motor (96) of the drive unit after passing through the guide hole on the radial side of the dorsal radial side of the first palmar phalanx (12) and bypassing the reversing post on the radial side of the dorsal radial side of the first palmar phalanx (12); the two ends of the first elastic portion (862) of the thumb are respectively connected to the distal end of the dorsal side of the first phalanx of the thumb and the dorsal side of the second phalanx of the thumb; the two ends of the second elastic portion (863) of the thumb are respectively connected to the dorsal side of the second phalanx of the thumb and the dorsal side of the third phalanx of the thumb. The ulnar extensor tendon cord (87) of the thumb has its tail end located on the dorsal side of the tendon cord guide portion (622) of the second phalanx of the thumb and fixed to the ulnar side connecting post between the tendon cord guide portion (622) of the second phalanx of the thumb and the phalanx body (621) of the second phalanx of the thumb. Its head end passes through the connecting post at the distal and proximal ends of the ulnar side of the dorsal side of the tendon cord guide portion (612) of the first phalanx of the thumb, then passes through the guide hole on the ulnar side of the dorsal side of the first palmar phalanx (12), and passes through the reversing post on the ulnar side of the dorsal side of the first palmar phalanx (12) before being connected to the seventh motor (97) of the drive unit.

9. The multi-degree-of-freedom tendon-driven robot dexterous hand as described in claim 8, characterized in that, The first elastic part of the thumb (862) is the first elastic line of the thumb. The first elastic line of the thumb passes around the connecting post between the tendon cord guiding part (612) of the first phalanx of the thumb and the phalanx body (611) of the first phalanx of the thumb, and connects end to end at the connecting post between the tendon cord guiding part (622) of the second phalanx of the thumb and the phalanx body (621) of the second phalanx of the thumb. The second elastic part (863) of the thumb is the second elastic line of the thumb. The second elastic line of the thumb passes around the connecting post between the tendon cord guiding part (622) of the second phalanx of the thumb and the phalanx body (621) of the second phalanx of the thumb, and connects end to end at the connecting post between the tendon cord guiding part (632) of the third phalanx of the thumb and the phalanx body (631) of the third phalanx of the thumb.

10. The multi-degree-of-freedom tendon-driven robotic dexterous hand as described in any one of claims 1 to 9, characterized in that, The palm (1) is made of aluminum alloy and is manufactured by selective laser melting technology; the multiple fingers (2, 3, 4, 5, 6) are integrally formed by multi-material fused deposition modeling technology, wherein the main body of the finger joint is made of polyethylene terephthalate and the tendon ligament guiding mechanism is made of thermoplastic polyurethane.

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