Multi-active-dof tendon-driven robotic hand

Abstract

The application discloses a multi-active-degree tendon-driven robot dexterous hand, which comprises a palm, a plurality of palm joints, a plurality of fingers, a plurality of tendon groups and a driving unit.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of robot end effector, and particularly relates to a multi-active-degree-of-freedom tendon-driven robot dexterous hand based on rigid-flexible coupling structure and having high flexibility and compliance. BACKGROUND

[0002] In recent decades, in order to simulate the function of human hand, many research institutions at home and abroad have made outstanding achievements in the design and control of robot dexterous hand, but have not been able to achieve the three indicators of high flexibility, compliance and compactness at the same time. The dexterous hand adopting the mode of external motor and tendon driving is easy to realize the flexibility and compliance close to human hand, and has about 20 active degrees of freedom, but has low compactness and universality; and the integrated dexterous hand based on the mode of built-in micro motor and linkage driving realizes a certain flexibility, about 6-16 active degrees of freedom, but lacks compliance, that is, self-adaptability, and has weak impact resistance. SUMMARY

[0003] In view of this, the present application provides a multi-active-degree-of-freedom tendon-driven robot dexterous hand based on rigid-flexible coupling structure and having high flexibility and compliance, aiming to solve the problem that the existing dexterous hand cannot simultaneously consider flexibility, compliance and compactness, so as to provide a robot end effector capable of highly simulating the grasping operation function and self-adaptive ability of human hand.

[0004] In order to solve the above problems, the present application provides the following technical scheme:

[0005] A multi-active-degree-of-freedom tendon-driven robot dexterous hand, comprising: a palm comprising a palm frame and a plurality of palm joints; a plurality of fingers connected to the palm through the plurality of palm joints respectively, each finger comprising a plurality of joints, each joint comprising a joint body and a tendon rope guide mechanism; a plurality of tendon ropes arranged in the plurality of fingers respectively, each tendon rope comprising a plurality of tendon ropes; a driving unit fixed on the palm frame; a flexible element is connected between adjacent joints of each finger and between the plurality of fingers and the plurality of palm joints, forming a plurality of interdigital joints; each tendon rope on each finger passes through the corresponding tendon rope guide mechanism and is connected with the driving unit, and the driving unit drives the corresponding finger to perform extension-flexion movement and abduction-adduction movement through the tendon rope.

[0006] Further, the plurality of metacarpal joints comprises a first metacarpal joint, a second metacarpal joint, a third metacarpal joint, a fourth metacarpal joint and a fifth metacarpal joint; the plurality of fingers comprises five fingers, i.e. an index finger, a middle finger, a ring finger, a little finger and a thumb, each of which comprises 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 connected to the first metacarpal joint, the second metacarpal joint, the third metacarpal joint, the fourth metacarpal joint and the fifth metacarpal joint respectively by ligaments to form 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 the first phalanx thereof by a ligament to form the second interphalangeal joint thereof, and the third phalanx of each finger is connected to the second phalanx thereof by a ligament to form the third interphalangeal joint thereof.

[0007] Further, the first interphalangeal joint adopts a ball-and-socket type structure and 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 type structure and are single-degree-of-freedom joints of extension-flexion.

[0008] Further, the tendon guide mechanism of each finger comprises a first phalanx tendon guide part located at the middle of the first phalanx of each finger, a second phalanx tendon guide part located at the middle of the second phalanx of each finger, and a third phalanx tendon guide part located at the distal end of the third phalanx of each finger; the first phalanx tendon guide part of each finger is provided with a guide hole for the tendon to pass through at the proximal end and the distal end of the radial side and the ulnar side of the palmar side; the proximal end of the radial side of the second phalanx tendon guide part of the thumb and the index finger is respectively provided with a connecting column connected to the corresponding phalanx body; the proximal end of the ulnar side of the palmar side of the second phalanx tendon guide part of the middle finger, the ring finger and the little finger is respectively provided with a connecting column connected to the corresponding phalanx body.

[0009] Further, each finger is driven by a set of tendons, wherein the set of tendons corresponding to the index finger comprises: an index finger radial side flexor tendon, the tail end of which is fixed on the connecting column between the index finger second knuckle tendon guide portion and the knuckle body of the index finger second knuckle, the head end of which is connected to the first motor of the driving unit after passing through the guide hole on the palmar radial side of the index finger first knuckle tendon guide portion and bypassing the reversing column on the palmar radial side of the second palm knuckle; an index finger ulnar side flexor tendon, the tail end of which is fixed on the connecting column between the index finger third knuckle tendon guide portion and the knuckle body of the index finger third knuckle, the head end of which is connected to the second motor of the driving unit after passing through the guide hole on the palmar ulnar side of the index finger second knuckle tendon guide portion and the index finger first knuckle tendon guide portion and bypassing the reversing column on the palmar ulnar side of the second palm knuckle; an index finger finger extension tendon, which comprises: an index finger non-elastic main body portion for realizing the extension of the index finger first interphalangeal joint, an index finger first elastic portion located on the dorsal side of the index finger second interphalangeal joint for realizing the extension of the index finger second interphalangeal joint, and an index finger second elastic portion located on the dorsal side of the index finger third interphalangeal joint for realizing the extension of the index finger third interphalangeal joint; the tail end of the index finger non-elastic main body portion is located at the proximal end of the dorsal side of the index finger first knuckle and is fixed on the connecting column between the index finger first knuckle tendon guide portion and the knuckle body of the index finger first knuckle, the head end of which is connected to the third motor of the driving unit after passing through the guide hole on the dorsal side of the second palm knuckle and bypassing the reversing column on the dorsal side of the second palm knuckle; the two ends of the index finger first elastic portion are respectively connected to the dorsal side of the index finger first knuckle and the dorsal side of the index finger second knuckle; the two ends of the index finger second elastic portion are respectively connected to the dorsal side of the index finger second knuckle and the dorsal side of the index finger third knuckle.

[0010] Further, the index finger first elastic portion is an index finger first elastic wire, which is connected head to tail at the connecting column between the index finger first knuckle tendon guide portion and the knuckle body of the index finger first knuckle and at the connecting column between the index finger second knuckle tendon guide portion and the knuckle body of the index finger second knuckle; the index finger second elastic portion is an index finger second elastic wire, which is connected head to tail at the connecting column between the index finger second knuckle tendon guide portion and the knuckle body of the index finger second knuckle and at the connecting column between the index finger third knuckle tendon guide portion and the knuckle body of the index finger third knuckle.

[0011] Further, the three sets of tendons corresponding to the middle finger, the ring finger and the little finger have the same structure and connection configuration, and the three sets of tendons and the set of tendons of the index finger only differ in the connection configuration as follows: the tail end of the radial side flexor tendon of the three sets of tendons is fixed on the connecting column between the third knuckle tendon guide portion and the knuckle body of the corresponding finger; the tail end of the ulnar side flexor tendon of the three sets of tendons is fixed on the connecting column between the second knuckle tendon guide portion and the knuckle body of the corresponding finger.

[0012] Further, the tendon set corresponding to the thumb includes: a thumb radial flexor tendon, a tail end of which is located at a radial side of a palm side of a second metacarpal tendon guide part of the thumb, and is fixed on a connecting column between the second metacarpal tendon guide part of the thumb and a metacarpal body of the second metacarpal of the thumb, a head end of which is connected to a fourth motor of the driving unit after passing through a guide hole of a radial side of a palm side of the first metacarpal tendon guide part of the thumb and bypassing a reversing column of the radial side of the palm side of the first metacarpal; a thumb ulnar flexor tendon, a tail end of which is located at an ulnar side of a palm side of a third metacarpal tendon guide part of the thumb, and is fixed on a connecting column between the third metacarpal tendon guide part of the thumb and a metacarpal body of the third metacarpal of the thumb, a head end of which is connected to a fifth motor of the driving unit after passing through guide holes of an ulnar side of a palm side of the second metacarpal tendon guide part of the thumb and the first metacarpal tendon guide part of the thumb and bypassing a reversing column of the ulnar side of the palm side of the first metacarpal; a thumb radial extensor tendon, including: a non-elastic main body part of the thumb for realizing extension and abduction of a first interphalangeal joint of the thumb, a first elastic part of the thumb for realizing extension of a second interphalangeal joint of the thumb located at a dorsal side of the second interphalangeal joint of the thumb, and a second elastic part of the thumb for realizing extension of a third interphalangeal joint of the thumb located at a dorsal side of the third interphalangeal joint of the thumb; wherein: a tail end of the non-elastic main body part of the thumb is located at a dorsal proximal end of the first metacarpal tendon guide part of the thumb, and is fixed on a radial connecting column between the first metacarpal tendon guide part of the thumb and a metacarpal body of the first metacarpal of the thumb, a head end of which is connected to a sixth motor of the driving unit after passing through a guide hole of a dorsal radial side of the first metacarpal, and bypassing a reversing column of the dorsal radial side of the first metacarpal; two ends of the first elastic part of the thumb are connected to a dorsal distal end of the first metacarpal of the thumb and a dorsal side of the second metacarpal of the thumb respectively; two ends of the second elastic part of the thumb are connected to a dorsal side of the second metacarpal of the thumb and a dorsal side of the third metacarpal of the thumb respectively; a thumb ulnar extensor tendon, a tail end of which is located at a dorsal side of the second metacarpal tendon guide part of the thumb, and is fixed on an ulnar connecting column between the second metacarpal tendon guide part of the thumb and a metacarpal body of the second metacarpal of the thumb, a head end of which is connected to a seventh motor of the driving unit after passing through a guide hole of an ulnar side of a dorsal side of the first metacarpal tendon guide part of the thumb, and bypassing a reversing column of the ulnar side of the dorsal side of the first metacarpal.

[0013] Further, the first elastic part of the thumb is a first elastic line of the thumb, which passes around a connecting column between the first knuckle tendon guide part and the knuckle body of the first knuckle of the thumb, and connects at the connecting column between the second knuckle tendon guide part and the knuckle body of the second knuckle of the thumb.

[0014] Further, the palm is made of aluminum alloy material and is formed by selective laser melting technology; the plurality of fingers are integrally formed by multi-material fused deposition molding technology, wherein the knuckle body is made of polyethylene terephthalate material, and the tendon guide mechanism is made of thermoplastic polyurethane material.

[0015] The multi-active degree of freedom tendon-driven robot dexterous hand provided by the application connects a plurality of fingers to the palm through knuckles of the palm, forms interdigital joints through ligaments, and drives finger movement through a plurality of groups of tendons passing through specific tendon guide mechanisms and pulled by driving units, thereby constituting a complete rigid-flexible coupling structure system. The technical solution combines the accurate guidance and stable support of the rigid joint structure, and the passive adaptation and energy storage and release characteristics of the ligament and elastic tendon, so that the dexterous hand can be buffered through the deformation of the flexible component when subjected to external force impact, thereby realizing excellent compliance and impact resistance. At the same time, the plurality of independent tendons designed for each finger and the accurate layout path thereof ensure that each knuckle can be independently and accurately controlled, realize up to 20 active degrees of freedom, and endow the dexterous hand with high flexibility, which can reproduce complex operation movements of the human hand. In addition, the arrangement mode of the driving unit built-in and fixed in the palm frame, and the integrated design of the knuckle body and the tendon guide mechanism significantly improve the space utilization, so that the whole hand structure is more simple and compact, and the size and weight are close to those of the human hand. Finally, through the synergistic effect of the above technical features, the application successfully achieves the three performance indicators of high flexibility, high compliance and high compactness, which are difficult to balance in the prior art. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 is the overall structure front view of the multi-active degree of freedom tendon-driven robot dexterous hand of the embodiment of the application.

[0017] Figure 2 is the overall structure rear view of the multi-active degree of freedom tendon-driven robot dexterous hand of the embodiment of the application.

[0018] Figure 3 is the overall structure right view of the multi-active degree of freedom tendon-driven robot dexterous hand of the embodiment of the application.

[0019] Figure 4 is the overall structure of the multi-active degree of freedom tendon-driven robot dexterous hand of the embodiment of the present application. DETAILED DESCRIPTION

[0020] The present application will be further described in detail below in combination with the drawings and specific embodiments, but not as a limitation to the scope of protection of the present application.

[0021] The embodiment of the present application aims to provide a specific implementation of a multi-active degree of freedom tendon-driven robot dexterous hand, the core of which is to realize high flexibility, high compliance and high compactness of the dexterous hand through rigid-flexible coupling structure design (combination of rigid knuckle body and flexible ligament, elastic tendon rope) and optimized multi-tendon rope transmission path.

[0022] As shown in Figure 1 The multi-active degree of freedom tendon-driven robot dexterous hand provided by the embodiment of the present application includes a palm 1, five fingers (index finger 2, middle finger 3, ring finger 4, little finger 5, and thumb 6), multiple ligaments 7, multiple tendon ropes 8, and a driving unit 9. The palm 1 includes a palm frame 11, a first palm knuckle 12, a second palm knuckle 13, a third palm knuckle 14, a fourth palm knuckle 15, and a fifth palm knuckle 16. Each finger includes three knuckles, and each knuckle includes a knuckle body and a tendon rope guide mechanism. The adjacent knuckles of each finger and the five fingers and the above-mentioned five palm knuckles are connected by ligaments to form multiple interphalangeal joints. The tendon rope guide mechanism is used to constrain and guide the tendon rope path. Each tendon rope on each finger passes through the corresponding tendon rope guide mechanism and is connected with the corresponding motor in the driving unit, and the corresponding motor drives the corresponding finger to perform extension-flexion movement and abduction-adduction movement through the tendon rope. Among them, the multiple motors contained in the driving unit 9 are fixed on the palm frame 11, realizing the built-in motor design.

[0023] As shown in Figure 1 and Figure 2As shown, the first metacarpal phalangeal joint of the thumb 6 is formed by the connection between the first metacarpal phalange 12 of the palm 1 and the first phalange 61 of the thumb 6 with a ligament 74 passing through the through-hole on the proximal end of the first phalange 61 and the proximal end of the first metacarpal phalange 12; the proximal end of the second phalange 62 of the thumb 6 and the distal end of the first phalange 61 are also provided with through-holes for the ligament to pass through, and the first phalange 61 and the second phalange 62 are connected by a ligament 75 to form the second interphalangeal joint of the thumb 6; similarly, the second phalange 62 and the third phalange 63 are connected by a ligament 76 to form the third interphalangeal joint of the thumb 6. Similarly, the first metacarpal phalangeal joint of the index finger 2 is formed by the connection between the first metacarpal phalange 13 of the palm 1 and the first phalange 21 of the index finger 2 with a ligament 71 passing through the through-hole; the first phalange 21 and the second phalange 22 are connected by a ligament 72 to form the second interphalangeal joint of the index finger 2; the second phalange 22 and the third phalange are connected by a ligament 73 to form the third interphalangeal joint of the index finger 2. The design and connection method of the interphalangeal joints of the middle finger 3, the ring finger 4 and the little finger 5 are the same as those of the index finger 2, and will not be described again. Each first interphalangeal joint adopts a spherical socket-like structure, which is a three-degree-of-freedom joint including extension-flexion, abduction-adduction and external rotation-internal rotation; and the second interphalangeal joint and the third interphalangeal joint adopt a pin-like structure, which is a single-degree-of-freedom joint of extension-flexion.

[0024] In some exemplary embodiments, the ligament of each interphalangeal joint is three high-molecular-weight polyethylene fishing lines arranged side by side, and the size of the reserved through-hole should ensure that the three fishing lines can slide freely. In an embodiment of the present application, a through-hole with a diameter of about 2 mm is reserved; after passing through the corresponding through-hole, the two ends of the ligament are connected end to end, thereby connecting and constraining the adjacent phalanges to form the interphalangeal joint.

[0025] In an embodiment of the present application, each phalange of each finger includes a phalange body and a tendon guide mechanism, and the tendon guide mechanisms of each finger are located in the middle of the first phalange, the middle of the second phalange, and the distal end of the third phalange of the finger. Among them, the tendon guide part of the first phalange is provided with a guide round hole for the tendon to pass through at the proximal end and the distal end of the radial side and the ulnar side of the palmar side; in particular, the proximal end and the distal end of the radial side of the tendon guide part of the second phalange of the thumb and the index finger are not provided with a guide round hole, but a connecting column connected with the phalange body is arranged at the proximal end; and the proximal end and the distal end of the ulnar side of the palmar side of the tendon guide part of the second phalange of the middle finger, the ring finger and the little finger are not provided with a guide round hole, but a connecting column connected with the phalange body is arranged at the proximal end.

[0026] Please refer to Figure 1, the four fingers except the thumb are taken the index finger 2 as an example, the first phalanx 21 includes a phalanx body 211 and a first phalanx tendon sheath guiding part 212, the second phalanx 22 includes a phalanx body 221 and a second phalanx tendon sheath guiding part 222, and the third phalanx 23 includes a phalanx body 231 and a third phalanx tendon sheath guiding part 232. Please refer to Figure 2 The set of tendons for the index finger transmission includes an index finger radial flexor tendon 81, an index finger ulnar flexor tendon 82, and an index finger finger extensor tendon 83. The tail end of the index finger radial flexor tendon 81 is knotted and sintered after winding around the connecting column between the second phalanx tendon sheath guiding part 222 and the phalanx body 221, and the head end is connected with the motor 91 after passing through the guiding circular hole on the palmar radial side of the first phalanx tendon sheath guiding part 212 and bypassing the reversing cylinder on the palmar radial side of the second palm phalanx 13. The tail end of the index finger ulnar flexor tendon 82 is knotted and sintered after winding around the connecting column between the third phalanx tendon sheath guiding part 232 and the phalanx body 231, and the head end is connected with the motor 92 after passing through the guiding circular hole on the palmar ulnar side of the second phalanx tendon sheath guiding part 222 and the first phalanx tendon sheath guiding part 212 and bypassing the reversing cylinder on the palmar ulnar side of the second palm phalanx 13. The index finger finger extensor tendon 83 includes a non-elastic main part 831 for realizing the extension of the first interphalangeal joint of the index finger, a first elastic wire 832 located on the dorsal side of the second interphalangeal joint of the index finger for realizing the extension of the second interphalangeal joint of the index finger, and a second elastic wire 833 located on the dorsal side of the third interphalangeal joint of the index finger for realizing the extension of the third interphalangeal joint of the index finger. The tail end of the non-elastic main part 831 is knotted and sintered after winding around the connecting column between the first phalanx tendon sheath guiding part 212 and the phalanx body 211, and the head end is connected with the motor 93 after passing through the guiding circular hole on the dorsal side of the second palm phalanx 13 and bypassing the reversing cylinder on the dorsal side of the second palm phalanx 13. The two ends of the first elastic wire 832 are connected to the dorsal side of the first phalanx of the index finger and the dorsal side of the second phalanx of the index finger respectively, specifically, the first elastic wire 832 bypasses the connecting column between the first phalanx tendon sheath guiding part 212 and the phalanx body 211, and the connecting column between the second phalanx tendon sheath guiding part 222 and the phalanx body 221 is connected head to tail. The two ends of the second elastic wire 833 are 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 respectively, specifically, the second elastic wire 833 bypasses the connecting column between the second phalanx tendon sheath guiding part 222 and the phalanx body 221, and the connecting column between the third phalanx tendon sheath guiding part 232 and the phalanx body 231 is connected head to tail.

[0027] Therefore, based on the above knuckle and joint design, under the joint action of the three tendon ropes and their tendon rope guide mechanisms, the index finger realizes five degrees of freedom (including four active degrees of freedom) through the three motors. Specifically, the first interphalangeal joint is flexed by the motor 91 and the motor 92 through the index finger radial flexor tendon rope 81 and the index finger ulnar flexor tendon rope 82, and the first interphalangeal joint is extended by the motor 93 through the non-elastic body part 831 of the index finger extensor tendon rope 83; when the first interphalangeal joint is flexed by the motor 93 through the non-elastic body part 831 of the index finger extensor tendon rope 83, the second interphalangeal joint is flexed by the motor 91 through the index finger radial flexor tendon rope 81, and the second interphalangeal joint is extended by the first elastic wire 832; when the second interphalangeal joint is flexed to the limit position by the motor 91 through the index finger radial flexor tendon rope 81, the third interphalangeal joint can be further flexed by the motor 92 through the index finger ulnar flexor tendon rope 82, and the third interphalangeal joint is extended by the second elastic wire 833; when the first interphalangeal joint is flexed by the motor 93 through the non-elastic body part 831 of the index finger extensor tendon rope 83, the first interphalangeal joint is abducted by the motor 91 through the index finger radial flexor tendon rope 81, and the first interphalangeal joint is adducted by the motor 92 through the index finger ulnar flexor tendon rope 82.

[0028] The tendon drive paths and working principles of the middle finger 3, the ring finger 4 and the little finger 5 are similar to those of the index finger 2, except that the tail end fixing positions of the radial flexor tendon ropes and the ulnar flexor tendon ropes are opposite to those of the index finger 2. Specifically, the three groups of tendon ropes corresponding to the middle finger 3, the ring finger 4 and the little finger 5 have the same structure and connection structure, and the three groups of tendon ropes and the group of tendon ropes of the index finger only have the following differences in connection structure (for reference Figure 1 and Figure 2 ): the tail end of the radial flexor tendon rope of the three groups of tendon ropes is fixed on the connecting column between the third knuckle tendon rope guide part and the knuckle body of the corresponding finger, and the tail end of the ulnar flexor tendon rope of the three groups of tendon ropes is fixed on the connecting column between the second knuckle tendon rope guide part and the knuckle body of the corresponding finger. Similarly, the middle finger 3, the ring finger 4 and the little finger 5 also each realize five degrees of freedom (including four active degrees of freedom) through the three motors according to the driving mode similar to the index finger 2.

[0029] Please refer to Figure 3 and Figure 4The tendon group corresponding to the thumb 6 includes the thumb radial flexor tendon 84, the thumb ulnar flexor tendon 85, the thumb radial extensor tendon 86, and the thumb ulnar extensor tendon 87. The tail end of the thumb radial flexor tendon 84 is knotted and sintered after winding around the connecting column between the second knuckle tendon guide part 622 and the knuckle body 621, and the head end is connected to the motor 94 after passing through the guide round hole on the radial side of the first knuckle tendon guide part 612 and bypassing the reversing cylinder on the radial side of the first palm knuckle 12. The tail end of the thumb ulnar flexor tendon 85 is knotted and sintered after winding around the connecting column between the third knuckle tendon guide part 632 and the knuckle body 631, and the head end is connected to the motor 95 after passing through the guide round hole on the ulnar side of the second knuckle tendon guide part 622 and the first knuckle tendon guide part 612, and bypassing the reversing cylinder on the ulnar side of the first palm knuckle 12.

[0030] Reference Figure 3 The thumb radial extensor tendon 86 includes a non-elastic main body part 861 for realizing the extension and abduction of the first interphalangeal joint of the thumb, a first elastic line 862 located on the dorsal side of the second interphalangeal joint of the thumb for realizing the extension of the second interphalangeal joint of the thumb, and a second elastic line 863 located on the dorsal side of the third interphalangeal joint of the thumb for realizing the extension of the third interphalangeal joint of the thumb. The tail end of the non-elastic main body part 861 is knotted and sintered after winding around the connecting column between the first knuckle tendon guide part 612 and the knuckle body 611 on the radial side, and the head end is connected to the motor 96 after passing through the guide round hole on the dorsal side of the first palm knuckle 12 and bypassing the reversing cylinder on the dorsal side of the first palm knuckle 12. The two ends of the first elastic line 862 are connected to the dorsal side of the first phalanx of the thumb and the dorsal side of the second phalanx of the thumb, respectively, and specifically, the first elastic line 862 winds around the connecting column between the first knuckle tendon guide part 612 and the knuckle body 611, and the connecting column between the second knuckle tendon guide part 622 and the knuckle body 621 is connected head to tail. The two ends of the second elastic line 863 are connected to the dorsal side of the second phalanx of the thumb and the dorsal side of the third phalanx of the thumb, respectively, and specifically, the second elastic line 863 winds around the connecting column between the second knuckle tendon guide part 622 and the knuckle body 621, and the connecting column between the third knuckle tendon guide part 632 and the knuckle body 631 is connected head to tail. The tail end of the thumb ulnar extensor tendon 87 is knotted and sintered after winding around the connecting column between the second knuckle tendon guide part 622 and the knuckle body 621 on the ulnar side, and the head end is connected to the motor 97 after passing through the guide round hole on the dorsal side of the first palm knuckle 12 and bypassing the reversing cylinder on the dorsal side of the first palm knuckle 12.

[0031] Therefore, based on the above phalange and joint design, under the joint action of the four tendon ropes and the tendon rope guide mechanism, the thumb realizes five degrees of freedom (including four active degrees of freedom) through the four motors. Specifically, the first interphalangeal joint is flexed by the motor 94 and the motor 95 through the thumb radial side flexor tendon rope 84 and the thumb ulnar side flexor tendon rope 85, and is extended by the motor 96 and the motor 97 through the non-elastic body part 861 of the thumb radial side extensor tendon rope 86 and the thumb ulnar side extensor tendon rope 87; the first interphalangeal joint is abducted by the motor 96 through the non-elastic body part 861 of the thumb radial side extensor tendon rope 86, and is adducted by the motor 97 through the thumb ulnar side extensor tendon rope 87; when the first interphalangeal joint is flexed by the motor 96 through the non-elastic body part 861 of the thumb radial side extensor tendon rope 86, the second interphalangeal joint is flexed by the motor 94 through the thumb radial side flexor tendon rope 84, and is extended by the first elastic wire 862; when the second interphalangeal joint is flexed to the limit position by the motor 94 through the thumb radial side flexor tendon rope 84, the third interphalangeal joint can be further flexed by the motor 95 through the thumb ulnar side flexor tendon rope 85, and is extended by the second elastic wire 863; when the first and second interphalangeal joints are flexed by the motor 97 through the thumb ulnar side extensor tendon rope 87, the third interphalangeal joint can be directly flexed by the motor 95 through the thumb ulnar side flexor tendon rope 85, and is extended by the second elastic wire 863.

[0032] In some specific embodiments of the present application, the non-elastic body part of each finger extensor tendon rope adopts the same high molecular weight polyethylene fishing line as the flexor tendon rope, and the elastic part adopts a thermoplastic polyurethane elastic wire. The palm 1 is made of aluminum alloy material and is formed by selective laser melting (SLM) technology; each finger is integrally formed by multi-material fused deposition modeling (FDM) technology, in which the phalange body adopts polyethylene terephthalate (PETG) material, and the tendon rope guide mechanism adopts thermoplastic polyurethane (TPU) material. However, these are only exemplary and do not mean that the above-mentioned components of the present application can only use the materials listed here. Those skilled in the art can select other materials with similar properties to replace them as needed, and the present application does not limit this.

[0033] The multi-active degree of freedom tendon-driven robot dexterous hand provided by the above-mentioned embodiments of the present application combines the advantages of traditional pin joints and human-simulating bionic joints, optimizes the tendon driving path, and has the following advantages:

[0034] 1. The present application can simulate the 25 degrees of freedom of the human hand, and the first interphalangeal joint of each of the five fingers has three degrees of freedom, which realizes the flexibility and compliance close to the human hand, and has high safety.

[0035] 2. The size and weight of the whole hand are close to human hand, wherein the length is less than 190mm, the width is less than 90mm, and the weight is about 500g, realizing a highly compact design.

[0036] 3. Based on 16 built-in driving motors (4 motors for the thumb, and 3 motors for each of the other four fingers) and tendon transmission mode, the application realizes 20 active degrees of freedom, wherein the abduction-adduction and external rotation-internal rotation degrees of freedom of the first interphalangeal joint of the thumb and the four fingers are coupled, while realizing high flexibility, compliance and compactness, i.e. realizing the balance of the three indexes.

[0037] The above is a further detailed description of the application in combination with specific preferred embodiments, and the specific implementation of the application cannot be limited to these descriptions. For those skilled in the art to which the application belongs, without departing from the concept of the application, a number of equivalent substitutions or obvious modifications can be made, and the performance or use is the same, which should be regarded as belonging to the protection scope of the application.

Claims

1. A multi-actively-DOF tendon-driven robotic dexterous hand, characterized by, The hand (1) comprises a palm frame (11) and a plurality of palm knuckles (12, 13, 14, 15, 16); a plurality of fingers (2, 3, 4, 5, 6) are connected to the palm respectively through the plurality of palm knuckles, each finger comprises a plurality of knuckles, each knuckle comprises a knuckle body and a tendon guide mechanism; a plurality of tendon groups (8) are arranged in the plurality of fingers respectively, each tendon group comprises a plurality of tendons; a driving unit (9) is fixed on the palm frame (11); adjacent knuckles of each finger and the plurality of palm knuckles are connected by flexible elements to form a plurality of interphalangeal joints; each tendon of each finger passes through the corresponding tendon guide mechanism and is connected to the driving unit, and the driving unit drives the corresponding finger to perform extension-flexion movement and abduction-adduction movement through the tendons; the tendon guide mechanism of each finger comprises a first knuckle tendon guide part located in the middle of the first knuckle of each finger, a second knuckle tendon guide part located in the middle of the second knuckle of each finger, and a third knuckle tendon guide part located at the distal end of the third knuckle of each finger; the first knuckle tendon guide part of each finger is provided with a guide hole for the tendon to pass through at the proximal end and the distal end of the radial side and the ulnar side of the palmar side; the proximal end of the radial side of the palmar side of the second knuckle tendon guide part of the thumb and the index finger is respectively provided with a connecting column connected with the corresponding knuckle body; the proximal end of the ulnar side of the palmar side of the second knuckle tendon guide part of the middle finger, the ring finger and the little finger is respectively provided with a connecting column connected with the corresponding knuckle body; each finger is driven by a tendon group, wherein the tendon group corresponding to the index finger (2) comprises: an index finger radial side finger flexion tendon (81), the tail end of which is fixed on the connecting column between the second knuckle tendon guide part (222) of the index finger and the knuckle body (221) of the second knuckle of the index finger, the head end of which is connected to the first motor (91) of the driving unit after passing through the guide hole of the radial side of the palmar side of the first knuckle tendon guide part (212) of the index finger and bypassing the reversing column of the radial side of the palmar side of the second palm knuckle (13); an index finger ulnar side finger flexion tendon (82), the tail end of which is fixed on the connecting column between the third knuckle tendon guide part (232) of the index finger and the knuckle body (231) of the third knuckle of the index finger, the head end of which is connected to the second motor (92) of the driving unit after passing through the guide holes of the ulnar side of the palmar side of the second knuckle tendon guide part (222) and the first knuckle tendon guide part (212) of the index finger and bypassing the reversing column of the ulnar side of the palmar side of the second palm knuckle (13); an index finger finger extension tendon (83), which comprises an index finger inelastic main part (831) for realizing the extension of the first interphalangeal joint of the index finger, an index finger first elastic part (832) located on the dorsal side of the second interphalangeal joint of the index finger for realizing the extension of the second interphalangeal joint of the index finger, and an index finger second elastic part (833) located on the dorsal side of the third interphalangeal joint of the index finger for realizing the extension of the third interphalangeal joint of the index finger. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The tail end of the index finger non-elastic body part (831) is located at the proximal end of the dorsal side of the first phalanx of the index finger and is fixed on the connecting column between the tendon sheath guide part (212) of the first phalanx of the index finger and the phalanx body (211) of the first phalanx of the index finger, and the head end is connected to the third motor (93) of the driving unit after passing through the guide hole on the dorsal side of the second metacarpal phalanx (13) and bypassing the reversing column on the dorsal side of the second metacarpal phalanx (13); The two ends of the first elastic part (832) of the index finger are connected to the dorsal side of the first phalanx and the dorsal side of the second phalanx of the index finger, respectively; The two ends of the second elastic part (833) of the index finger are connected to the dorsal side of the second phalanx and the dorsal side of the third phalanx of the index finger, respectively.

2. The multi-actively-dof tendon-driven robotic hand of claim 1, wherein, The plurality of metacarpal phalanges includes a first metacarpal phalanx (12), a second metacarpal phalanx (13), a third metacarpal phalanx (14), a fourth metacarpal phalanx (15), and a fifth metacarpal phalanx (16); The plurality of fingers includes five fingers, namely the index finger (2), the middle finger (3), the ring finger (4), the little finger (5), and the thumb (6). 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 connected to the first metacarpal phalanx, the second metacarpal phalanx, the third metacarpal phalanx, the fourth metacarpal phalanx, and the fifth metacarpal phalanx, respectively, to form the first interphalangeal joint of the thumb, the index finger, the middle finger, the ring finger, and the little finger. The second phalanx of each finger is connected to the first phalanx of the finger through a ligament to form the second interphalangeal joint of the finger. The third phalanx of each finger is connected to the second phalanx of the finger through a ligament to form the third interphalangeal joint of the finger.

3. The multi-actively-dof tendon-driven robotic hand of claim 2, wherein, The first interphalangeal joint adopts a spherical socket-like structure and has three degrees of freedom, including extension-flexion, abduction-adduction, and external rotation-internal rotation. The second interphalangeal joint and the third interphalangeal joint both adopt a pin shaft-like structure and have a single degree of freedom, i.e., extension-flexion.

4. The multi-actively-dof tendon-driven robotic hand of claim 2, wherein, The first elastic part (832) of the index finger is an index finger first elastic wire. The index finger first elastic wire passes around the connecting column between the tendon sheath guide part (212) of the first phalanx of the index finger and the phalanx body (211) of the first phalanx of the index finger and is connected head to tail at the connecting column between the tendon sheath guide 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 an index finger second elastic wire. The index finger second elastic wire passes around the connecting column between the tendon sheath guide part (222) of the second phalanx of the index finger and the phalanx body (221) of the second phalanx of the index finger and is connected head to tail at the connecting column between the tendon sheath guide part (232) of the third phalanx of the index finger and the phalanx body (231) of the third phalanx of the index finger.

5. The multi-actively-dof tendon-driven robotic hand of claim 4, wherein, The three groups of tendons corresponding to the middle finger (3), the ring finger (4), and the little finger (5) have the same structure and connection structure, and the three groups of tendons and the group of tendons of the index finger only differ in the connection structure. Tail ends of the radial side finger flexor tendons of the three groups of tendons are fixed on the connecting columns between the third metacarpal tendon guide portions and the metacarpal bodies of the corresponding fingers, and tail ends of the ulnar side finger flexor tendons of the three groups of tendons are fixed on the connecting columns between the second metacarpal tendon guide portions and the metacarpal bodies of the corresponding fingers.

6. The multi-actively-dof tendon-driven robotic hand of claim 2, wherein, A group of tendons corresponding to the thumb (6) comprises: The thumb radial side finger flexor tendon (84) has its tail end located at the palmar radial side of the second metacarpal tendon guide portion (622) of the thumb, and is fixed on the connecting column between the second metacarpal tendon guide portion (622) and the metacarpal body (621) of the second metacarpal of the thumb, and its head end passes through the guide hole on the palmar radial side of the first metacarpal tendon guide portion (612) of the thumb, and is connected to the fourth motor (94) of the driving unit after passing around the reversing column on the palmar radial side of the first metacarpal (12); The thumb ulnar side finger flexor tendon (85) has its tail end located at the palmar ulnar side of the third metacarpal tendon guide portion (632) of the thumb, and is fixed on the connecting column between the third metacarpal tendon guide portion (632) and the metacarpal body (631) of the third metacarpal of the thumb, and its head end passes through the guide hole on the palmar ulnar side of the second metacarpal tendon guide portion (622) and the first metacarpal tendon guide portion (612) of the thumb, and is connected to the fifth motor (95) of the driving unit after passing around the reversing column on the palmar ulnar side of the first metacarpal (12); The thumb radial side finger flexor tendon (84) has its tail end located at the palmar radial side of the second metacarpal tendon guide portion (622) of the thumb, and is fixed on the connecting column between the second metacarpal tendon guide portion (622) and the metacarpal body (621) of the second metacarpal of the thumb, and its head end passes through the guide hole on the palmar radial side of the first metacarpal tendon guide portion (612) of the thumb, and is connected to the fourth motor (94) of the driving unit after passing around the reversing column on the palmar radial side of the first metacarpal (12); A thumb ulnar digital extensor tendon string (87) has its tail end located on the dorsal side of the thumb second finger joint tendon string guide part (622) and fixed on the connecting column between the thumb second finger joint tendon string guide part (622) and the thumb second finger joint body (621) on the ulnar side, and its head end passes around the connecting column on the dorsal side of the distal end and the proximal end of the thumb first finger joint tendon string guide part (612) on the ulnar side, then passes through the guide hole on the dorsal side of the first palm finger joint (12) on the ulnar side, and is connected to the seventh motor (97) of the driving unit after passing around the reversing column on the dorsal side of the first palm finger joint (12) on the ulnar side.

7. The multi-actively-dof tendon-driven robotic hand of claim 6, wherein, The thumb first elastic part (862) is a thumb first elastic line which passes around the connecting column between the thumb first finger joint tendon string guide part (612) and the thumb first finger joint body (611), and is connected head to tail at the connecting column between the thumb second finger joint tendon string guide part (622) and the thumb second finger joint body (621); The thumb second elastic part (863) is a thumb second elastic line which passes around the connecting column between the thumb second finger joint tendon string guide part (622) and the thumb second finger joint body (621), and is connected head to tail at the connecting column between the thumb third finger joint tendon string guide part (632) and the thumb third finger joint body (631).

8. The multi-actively-dof tendon-driven robotic hand of any one of claims 1 to 7, wherein, The palm (1) is made of aluminum alloy material and is formed by selective laser melting technology; the plurality of fingers (2, 3, 4, 5, 6) are integrally formed by multi-material fused deposition forming technology, wherein the finger joint body is made of polyethylene terephthalate material, and the tendon string guide mechanism is made of thermoplastic polyurethane material.

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