Straight line driving active twenty-two degrees of freedom humanoid five-finger dexterous hand

Abstract

The present disclosure provides a linear drive active twenty-two degree of freedom humanoid five-fingered dexterous hand, comprising a palm unit, a wrist unit and a thumb, an index finger, a middle finger, a ring finger and a little finger arranged on the palm unit; the wrist unit is connected with the palm unit; the thumb, the index finger, the middle finger, the ring finger and the little finger each have four active degrees of freedom, and the wrist unit has two active degrees of freedom, so that the humanoid five-fingered dexterous hand has twenty-two active degrees of freedom; each active degree of freedom of the humanoid five-fingered dexterous hand is configured with an independent linear drive assembly to convert linear push-pull motion into rotation of a corresponding joint output, and the driving stroke of any two active degrees of freedom is independent of each other. In this embodiment, the linear drive assembly can be used to replace tendon, connecting rod, synchronous belt or gear set transmission, which can improve transmission efficiency and response speed and realize the effect of simulating a human hand.

Description

Technical Field

[0001] This disclosure relates to the field of robotics, and more particularly to a linearly driven, active 22-DOF humanoid five-fingered dexterous hand. Background Technology

[0002] Humanoid dexterous hands are robotic end effectors that closely resemble human hands in shape, degrees of freedom, and manipulative capabilities. They can perform tasks such as grasping, pinching, palm striking, tool manipulation, and adapting to complex curved surfaces. They can be applied to humanoid robots, teleoperated robots, industrial service robots, prostheses, and equipment for working in hazardous environments.

[0003] Current anthropomorphic dexterous hands commonly employ chord actuation, linkage actuation, gear actuation, synchronous belt actuation, or underactuated mechanisms. Chord actuation allows actuators to be positioned outside the palm or wrist, but the chords are prone to slackness, wear, pretension changes, and transmission lag. Furthermore, the complex wiring of multiple chords in the palm and wrist makes maintenance difficult. Underactuated mechanisms reduce the number of actuators, but the distal joints are usually coupled with the proximal joints, making independent control of each joint's degree of freedom difficult.

[0004] For a highly flexible, humanoid five-fingered dexterous hand, it is necessary to arrange a sufficient number of actuators within the limited size envelope of the human hand, while also ensuring that each phalanx and joint maintains a skeletal proportion and pivot position close to that of the human hand. If traditional rotary motors, gear sets, or linkage mechanisms are used, it can easily lead to increased structural dimensions at the joints, tortuous force transmission paths, or reduced output efficiency. If tendon-tethered remote drives are used, problems such as wiring, decoupling, and pre-tensioning maintenance will be introduced.

[0005] Therefore, a new humanoid five-fingered dexterous hand structure is needed to achieve twenty-two active degrees of freedom within a humanoid size, and to directly drive each joint output component through independent linear drive components, so as to reduce intermediate transmission links and improve control independence, response speed and mechanical reliability.

[0006] Existing dexterous hands often stack the wrist, palm, and fingers as relatively independent mechanical modules. The actuators, joints, and palm support structures may not conform to the continuous kinematic chain relationship of the human wrist, palm, and fingers, which can easily lead to bloated structures, insufficient posture coverage, insufficient thumb-palm support, and insufficient multi-finger coordination stability.

[0007] In existing dexterous hands, the palm is typically used primarily as a fixed mounting base for the fingers and actuators. The palmar contour is relatively fixed and fails to fully simulate the supporting role of the thenar eminence in thumb opposition and grasping. When the thumb needs to form an opposition with different fingers or manipulate objects of different shapes, the fixed palm cannot actively change its palmar support shape, limiting the achievable gestures and stable contact area.

[0008] Furthermore, existing dexterous hands often employ rigid shells or rigid connection structures near the metacarpophalangeal joints. When the metacarpophalangeal joints flex and extend, the rigid palmar surface is difficult to deform continuously with the joint movement, easily creating a suspended area between the palm and the object. This prevents the palm from fully utilizing its functions of enveloping and grasping and adapting to irregular object shapes. Summary of the Invention

[0009] To address the aforementioned technical problems, this disclosure provides the following technical solutions: In a first aspect, a linearly driven, active 22-DOF humanoid five-fingered dexterous hand is provided, comprising a palm unit, a wrist unit, and a thumb, index finger, middle finger, ring finger, and little finger disposed in the palm unit; the wrist unit is connected to the palm unit; the thumb, index finger, middle finger, ring finger, and little finger each have four active degrees of freedom, and the wrist unit has two active degrees of freedom, so that the humanoid five-fingered dexterous hand has 22 active degrees of freedom; Each active degree of freedom of the humanoid five-fingered dexterous hand is equipped with an independent linear drive component to convert linear push-pull motion into rotation of the corresponding joint output component, and the drive stroke of any two active degrees of freedom is independent of each other.

[0010] In one embodiment, the four active degrees of freedom of the thumb include one lateral swing degree of freedom, two flexion and extension degrees of freedom, and one opposition rotation degree of freedom, the opposition rotation degree of freedom being used to drive the thumb to perform opposition movement relative to the palm unit.

[0011] In one embodiment, the index finger, the middle finger, the ring finger, and the little finger each include a proximal phalanx, a middle phalanx, and a distal phalanx; the proximal phalanx refers to the phalanx closest to the palm unit; the distal phalanx refers to the phalanx furthest from the palm unit; and the middle phalanx refers to the phalanx located between the proximal phalanx and the distal phalanx. Each of the index finger, middle finger, ring finger, and little finger has four active degrees of freedom, including one lateral swing degree of freedom located at the base of the finger and three flexion and extension degrees of freedom arranged sequentially along the extension direction of the finger.

[0012] In one embodiment, a set of tail-to-tail linear drive components is provided at the base of each of the index finger, middle finger, ring finger and little finger; the set of tail-to-tail linear drive components are used to drive the lateral swing degree of freedom and the flexion and extension degree of freedom of the corresponding finger.

[0013] In one embodiment, the linear drive assembly includes a frameless torque motor, a ball screw, an output end, a rolling slider, and a raceway; the frameless torque motor drives the ball screw to move, the ball screw drives the output end to perform linear push-pull motion, the output end cooperates with the rolling slider, and the rolling slider cooperates with the raceway to drive the corresponding joint output component to rotate.

[0014] In one embodiment, the output end of the linear drive assembly has a wrap-around groove; the wrap-around groove is a semi-circular groove or an arc-shaped groove; the rolling slider and the raceway form a rolling friction engagement, so that the linear drive assembly converts linear motion into rotation of the corresponding joint output component through the rolling slider and the raceway.

[0015] In one embodiment, the linear drive components of each active degree of freedom are arranged in the direction of the extension of the humanoid skeleton of the finger and are arranged within the outer envelope of the corresponding phalanx or metacarpal bone; the wrist unit, the palm unit and the five fingers together form a continuous bionic kinematic chain.

[0016] In one embodiment, the linear drive assembly is arranged along a direction close to the action line of the biomimetic muscle or tendon, and drives the corresponding joint output component to rotate in a manner that simulates muscle traction joint. This allows the linear push-pull direction of the linear drive assembly to form a constrained force transmission path with the corresponding joint rotation direction through a wrap-around groove, a rolling slider, and a raceway, thereby reducing transmission offset and ineffective lateral force components.

[0017] In one embodiment, the wrist unit includes a universal joint structure and two linear drive components; the output ends of the two linear drive components respectively cooperate with different force-bearing parts of the universal joint structure, and the two linear drive components drive the universal joint structure to rotate around two different directions through their respective linear push-pull movements, so as to realize two degrees of freedom wrist movement of the palm unit relative to the forearm connection end, and provide a proximal posture basis for five-finger grasping, palm opposition and enveloping grasping.

[0018] The active degrees of freedom of the thumb, index finger, middle finger, ring finger, little finger, and wrist unit are directly driven by the pointing drive unit.

[0019] In one embodiment, the palm unit includes a palm base and a movable thenar eminence located on one side of the base of the thumb; the palm base forms a mid-palm support structure for supporting a linear drive module for the five fingers, and together with the wrist unit provides proximal support for the output force and posture adjustment of the five fingers; The movable thenar eminence can move relative to the palm base to change the support shape of the palm side of the palm unit; when the thumb performs an opposition movement, the movable thenar eminence forms a support surface facing the palm center to contact the object being manipulated, thereby expanding the opposition posture range of the thumb and the effective gripping area of ​​the palm unit.

[0020] In one embodiment, a force sensor or a mounting portion for mounting a force sensor is provided at the fingertip of at least one of the thumb, index finger, middle finger, ring finger, and little finger.

[0021] In one embodiment, the palm unit further includes a flexible palm area disposed at at least one metacarpophalangeal joint. The flexible palm area is made of an elastomeric material and spans between the palm base and the root of the corresponding finger. The flexible palm area is configured to undergo stretching and wrinkling deformation with the flexion and extension movements of the corresponding metacarpophalangeal joint to form a flexible contact surface that changes with the posture of the metacarpophalangeal joint. During the grasping process, it conforms to the outer surface of the grasped object to increase the contact area between the palm unit and the grasped object, assist in the envelope grasping, and adapt to the shape of different grasped objects.

[0022] The technical solutions provided by the embodiments of this disclosure may include the following beneficial effects: The linearly driven active 22-DOF humanoid five-finger dexterous hand provided in this embodiment includes a palm unit, a wrist unit, and a thumb, index finger, middle finger, ring finger, and little finger disposed in the palm unit; the wrist unit is connected to the palm unit; the thumb, index finger, middle finger, ring finger, and little finger each have four active degrees of freedom, and the wrist unit has two active degrees of freedom, so that the humanoid five-finger dexterous hand has 22 active degrees of freedom; each active degree of freedom of the humanoid five-finger dexterous hand is equipped with an independent linear drive component to convert linear push-pull motion into rotation of the corresponding joint output component, and the drive stroke of any two active degrees of freedom is independent of each other. In this embodiment, a linear drive assembly can be used to replace the tendon cord, connecting rod, synchronous belt or gear set transmission, which can reduce tendon cord slack, wear, hysteresis, pretension changes and maintenance problems caused by complex wiring; or, compared with worm gear, gear set or multi-stage linkage transmission, this method has a more direct force transmission path, which can reduce transmission offset and ineffective lateral force, and can improve transmission efficiency and response speed.

[0023] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings.

[0025] Figure 1 This is a schematic diagram of the overall structure of a linearly driven active 22-DOF humanoid five-fingered dexterous hand according to an embodiment of this disclosure.

[0026] Figure 2 This is a schematic diagram showing the distribution of the twenty-two active degrees of freedom in an embodiment of this disclosure.

[0027] Figure 3 This is a schematic diagram of a linear drive assembly according to an embodiment of the present disclosure and its transmission principle for converting linear motion into joint rotation.

[0028] Figure 4 This is a schematic diagram of the thumb structure, joint composition, and four active degrees of freedom according to an embodiment of the present disclosure.

[0029] Figure 5 This is a schematic diagram of the structure, joint composition, and four active degrees of freedom of the index finger according to an embodiment of this disclosure. The middle finger, ring finger, and little finger adopt corresponding structures.

[0030] Figure 6 This is a schematic diagram of the tail-to-tail arrangement structure and motion state of the dual linear drive assembly at the base of the finger according to an embodiment of this disclosure.

[0031] Figure 7 This is a schematic diagram showing the correspondence between the arrangement of the finger bionic skeleton, joint positions, and simulated muscle action paths in an embodiment of this disclosure.

[0032] Figure 8 This is a schematic diagram of a wrist dual-degree-of-freedom structure according to an embodiment of the present disclosure.

[0033] Figure 9 This is a schematic diagram showing the location of the movable thenar eminence and the flexible palm area at the metacarpophalangeal joint in an embodiment of this disclosure.

[0034] Figure 10 This is a schematic diagram of a typical humanoid gesture and operating posture formed by the cooperation of multiple active degrees of freedom in an embodiment of this disclosure.

[0035] Figure 11 This is a schematic diagram illustrating the motion process and gripping posture of forming a special multi-finger envelope grip on a spherical object according to an embodiment of the present disclosure. Detailed Implementation

[0036] This disclosure describes multiple technical solutions with different concepts. Each concept has one or more embodiments, and different concepts can be combined to form more embodiments. Those skilled in the art, after reading this disclosure, can combine different concepts to obtain new technical solutions, and these new technical solutions should also fall within the scope of this disclosure.

[0037] The technical solutions of these different concepts will be introduced in turn below. Some concepts may appear in multiple technical solutions of different concepts. For these concepts, this disclosure will explain them when they first appear and will not repeat them in the following text.

[0038] To address the aforementioned technical problems, this disclosure provides a linearly driven, active 22-DOF humanoid five-fingered dexterous hand. (See also...) Figure 1 The device includes a palm unit 100, a wrist unit 700, and thumb 200, index finger 300, middle finger 400, ring finger 500, and little finger 600 disposed on the palm unit 100. The wrist unit 700 is connected to the palm unit 100 and is located away from one end of each of the aforementioned fingers. The thumb 200, index finger 300, middle finger 400, ring finger 500, and little finger 600 each have four active degrees of freedom, and the wrist unit 700 has two active degrees of freedom, giving the humanoid five-fingered dexterous hand twenty-two active degrees of freedom. Each active degree of freedom of the humanoid five-fingered dexterous hand is equipped with an independent linear drive component to convert linear push-pull motion into rotation of the corresponding joint output component, and the drive stroke of any two active degrees of freedom is independent of each other. In this embodiment, the wrist unit 700, the palm unit 100, and the five fingers constitute a continuous bionic kinematic chain, enabling the bionic design to simultaneously cover proximal posture adjustment, palm support deformation, and distal phalangeal active movement.

[0039] It should be noted that the active degree of freedom of a finger refers to the independent joint movement achieved through the conscious control and active contraction of its own muscles, as opposed to passive degree of freedom (which is generated by external force and cannot be actively performed by the muscles themselves). Each independent axis of rotation is counted as one degree of freedom. Based on this, the active degree of freedom in this disclosure refers to the rotation of the corresponding joint output component around a certain axis of rotation caused by the linear push-pull motion of the linear drive component, which is considered an active degree of freedom.

[0040] In this embodiment, the active degrees of freedom of the humanoid five-fingered dexterous hand are allocated as follows: the four active degrees of freedom of the thumb 200 include one lateral swing degree of freedom, two flexion and extension degrees of freedom, and one opposition rotation degree of freedom. The index finger 300, middle finger 400, ring finger 500, and little finger 600 each include a proximal phalanx, a middle phalanx, and a distal phalanx (not shown in the figure); the proximal phalanx refers to the phalanx close to the palm unit 100; the distal phalanx refers to the phalanx far from the palm unit 100; the middle phalanx refers to the phalanx located between the proximal and distal phalanxes; each of the four active degrees of freedom of the index finger 300, middle finger 400, ring finger 500, and little finger 600 includes one lateral swing degree of freedom located at the base of the finger and three flexion and extension degrees of freedom arranged sequentially along the extension direction of the finger.

[0041] In this embodiment, see Figure 2 The humanoid five-fingered dexterous hand has twenty-two active degrees of freedom, R1-R22.

[0042] R1 and R2 correspond to the active degrees of freedom of the wrist unit 700 around the first rotation direction (parallel to the x-axis) and the second rotation direction (parallel to the z-axis), respectively.

[0043] R3 to R6 correspond to the lateral swing degree of the little finger 600 around the second rotation direction (parallel to the z-axis) and the three flexion and extension degrees of freedom around the first rotation direction, respectively.

[0044] R7 to R10 correspond to the lateral swing degree of the ring finger 500 about the second rotation direction (parallel to the z-axis) and the three flexion and extension degrees of freedom about the first rotation direction.

[0045] R11 to R14 correspond to the lateral swing degree of the middle finger 400 around the second rotation direction (parallel to the z-axis) and the three flexion and extension degrees of freedom around the first rotation direction.

[0046] R15 to R18 correspond to the lateral swing degree of the index finger 300 around the second rotation direction (parallel to the z-axis) and the three flexion and extension degrees of freedom around the first rotation direction.

[0047] R19~R22 correspond to the thumb's 200 degrees of freedom of palmar rotation around the third rotation direction (parallel to the y-axis), lateral swing around the second rotation direction (parallel to the z-axis), and two degrees of freedom of flexion and extension around the first rotation direction (parallel to the x-axis).

[0048] See also Figure 2 The lateral swing degree of freedom is the swing motion in the xoy plane; the flexion-extension degree of freedom is the rotational motion in the yoz plane; the palm rotation degree of freedom is used to drive the thumb to perform palm-to-palm motion relative to the palm unit, that is, rotational motion in the xoz plane.

[0049] In one embodiment, each of the active degrees of freedom R1 to R22 is equipped with an independent linear drive component, and the drive stroke of any active degree of freedom does not depend on the drive stroke of other active degrees of freedom. In this embodiment, each active degree of freedom can be adjusted independently, avoiding the posture limitation problem caused by the coupling between the distal and proximal joints in underactuated fingers; and, through coordinated control, it can also form thumb-opposition, multi-finger pinching, enveloping grasp, and complex wrist postures.

[0050] In one embodiment, each active degree of freedom is implemented using a linear drive assembly with the same transmission principle. The structure of the linear drive assembly and its operation in converting linear motion into joint rotation will be described first, followed by an explanation of the arrangement and function of this linear drive assembly in the thumb, the other four fingers, and the wrist unit. See [link to documentation]. Figure 3 Each active degree of freedom is equipped with an independent linear drive assembly 800. The linear drive assembly 800 includes a frameless torque motor 801, a ball screw 802, an output end 803, a wrap-around slot 804, a rolling slider 805, a raceway 806, and a joint output component 807. The frameless torque motor 801 and the ball screw 802 form a linear drive module, which is used to convert the rotational output of the frameless torque motor 801 into linear push-pull motion of the output end 803.

[0051] In this embodiment, a wrap-around groove 804 is disposed at the output end 803. The wrap-around groove 804 can be a semi-circular groove or an arc-shaped groove. The wrap-around groove 804 contacts and engages with the rolling slider 805. When the output end 803 performs a linear push-pull motion, the wrap-around groove 804 pushes the rolling slider 805 to move along the raceway 806. In one example, a rolling friction engagement is formed between the rolling slider 805 and the raceway 806. The raceway 806 is connected to or integrally formed with the corresponding joint output component. When the rolling slider 805 moves along the raceway 806, the rolling slider 805 applies a force to the raceway 806, thereby driving the corresponding joint output component 807 to rotate around the joint axis.

[0052] Based on the above, the wrap-around groove 804, the rolling slider 805, and the raceway 806 constitute a rolling motion conversion mechanism between the output end 803 of the linear drive assembly 800 and the joint output component 807. This mechanism enables two degrees of freedom movement of the finger joint, namely, the sliding and rotation of the finger joint along the joint surface, causing the joint output component to rotate around the joint axis. Compared to worm gears, gear sets, or multi-stage linkages, this method provides a more direct force transmission path, reduces transmission offset and ineffective lateral force components, and the rolling friction in the contact pair reduces friction loss, improving transmission efficiency and response speed.

[0053] See also Figure 3The rolling slider 805 is connected to the output end 803 of the linear drive assembly via a wrap-around groove 804. The wrap-around groove 804 at least partially surrounds the rolling slider 805 to ensure that the rolling slider 805 tracks the movement of the output end 803. A raceway 806 is provided with a limiting groove to prevent the rolling slider 805 from disengaging or deviating in a direction perpendicular to its rolling direction. The rolling slider 805 rolls in engagement with the raceway 806. On the component fixedly connected to the joint output member 807, the rolling slider 805 rolls in engagement with the raceway 806.

[0054] The principle behind this rolling motion conversion mechanism, which converts linear push-pull motion into joint rotation, is as follows: When the linear drive assembly 800 outputs linear push-pull motion, the rolling slider 805 rolls or moves in a restricted manner along the raceway 806 under the combined constraint of the wrap-around groove 804 and the raceway 806, and applies a force deviating from its rotation axis to the joint output member 807, causing the joint output member 807 to rotate around the corresponding joint axis. Thus, the rolling motion conversion mechanism can convert the linear motion of the linear drive assembly into the rotational output of the corresponding joint output member 807.

[0055] In this embodiment, the rolling slider 805 and the raceway 806 are in rolling contact, which can reduce frictional resistance and transmission lag compared to the sliding fit of the groove. Since the groove shape of the raceway 806 can form a lateral constraint on the rolling slider 805, it can reduce the lateral movement, derailment and jamming of the rolling slider 805 when subjected to eccentric load, thereby improving the stability of the joint output and the repeatability of the positioning accuracy.

[0056] In this embodiment, unlike the structure that pulls the distal joint through tendons, each active degree of freedom is independently driven by the corresponding linear drive component 800, and the linear drive component 800 is arranged within the outer envelope of the corresponding phalanx, metacarpal or wrist structure.

[0057] In one embodiment, the thumb 200 has four active degrees of freedom: one lateral swing degree of freedom, two flexion-extension degrees of freedom, and one opposition rotation degree of freedom. The thumb 200 can adjust the fingertip orientation through the lateral swing and opposition rotation degrees of freedom, and can bend and extend through the two flexion-extension degrees of freedom, thereby achieving opposition contact with the index, middle, ring, or little finger.

[0058] In this embodiment, see Figure 4 The thumb 200 includes a thumb root connector 201, a proximal thumb knuckle 202, and a distal thumb knuckle 203. The thumb root connector 201 is connected to the opposing rotator 204, which drives the rear actuator (i.e., the proximal thumb knuckle 202 and the distal thumb knuckle 203) to rotate relative to the thumb root connector 201, thereby forming the opposing rotational degree of freedom of the thumb 200.

[0059] The proximal phalanx 202 of the thumb is connected to the opposing rotator 204 via a lateral swing joint 205 and a proximal flexion-extension joint 206, thus forming the lateral swing and flexion degrees of freedom of the thumb 200. A distal flexion-extension joint 207 is provided between the proximal phalanx 202 and the distal phalanx 203 of the thumb, and the distal flexion-extension joint 207 and the proximal flexion-extension joint 206 at the base of the thumb constitute two independent degrees of flexion and extension freedom. Through the opposing rotational degree of freedom formed by the opposing rotator 204, the thumb 200 can change the orientation of the fingertip, so that the fingertip or fingertip of the thumb 200 contacts the fingertip or fingertip of other fingers, thereby realizing opposing, lateral pinching, and multi-finger pinching.

[0060] In one embodiment, the index finger 300, middle finger 400, ring finger 500, and little finger 600 each have four active degrees of freedom. Taking the index finger 300 as an example, the index finger 300 includes a proximal phalanx, a middle phalanx, and a distal phalanx, and the four active degrees of freedom of the index finger 300 include lateral flexion-extension at the base of the finger, flexion-extension at the base of the finger, flexion-extension at the middle of the finger, and flexion-extension at the distal end of the finger. The middle finger 400, ring finger 500, and little finger 600 can adopt the same structure as the index finger 300.

[0061] In this embodiment, see Figure 5 Taking the index finger 300 as an example, the index finger 300 includes a base 303, a proximal phalanx 304, a middle phalanx 305, and a distal phalanx 306. The proximal phalanx 304 is connected to the base 303 via a lateral phalanx joint 307 and a flexor-extension joint 308. The middle phalanx 305 is connected to the proximal phalanx 304 via a mid-flexor-extension joint 309. The distal phalanx 306 is connected to the middle phalanx 305 via a distal flexor-extension joint 310. The lateral phalanx joint 307 is used to swing the index finger 300 along the width of the palm. The flexor-extension joints 308, 309, and 310 are used to adjust the flexion and extension postures of the proximal phalanx 304, middle phalanx 305, and distal phalanx 306, respectively. These four joints are driven by independent linear drive components, enabling each phalanx to perform uncoupled active movements.

[0062] It should be noted that the middle finger 400, ring finger 500, and little finger 600 can be achieved using the same or corresponding structure as the index finger 300, which will not be elaborated here.

[0063] In this embodiment, see Figure 6Taking the index finger as an example, each finger has two (or a set) tail-to-tail linear drive components at its base. The tail-to-tail linear drive components consist of a bottom linear drive component 301 and a top linear drive component 302. The bottom linear drive component 301 cooperates with the base 303 to drive the lateral swing freedom of the corresponding finger's base. The top linear drive component 302 cooperates with the actuator, which acts as the middle phalanx of the finger, to drive the flexion and extension freedom of the finger's base. This tail-to-tail arrangement creates a compact drive layout along the length of the metacarpal bones, making the actuator arrangement resemble the extension of the metacarpal and phalangeal bones of the human hand. It also corresponds to the biomimetic requirement that the metacarpophalangeal joints of the fingers typically have two movement directions: flexion / extension and adduction / abduction, thereby reducing interference between actuators and improving the finger base posture adjustment capability.

[0064] In some embodiments, the bodies of two tail-to-tail linear drive components are positioned opposite each other along the metacarpal extension direction of the corresponding fingers, and the output ends of the two linear drive components face opposite directions or different force-bearing positions of the corresponding joints. Thus, independent actuation of both lateral swing and flexion / extension degrees of freedom can be achieved within a limited finger root space.

[0065] It should be noted that the linear drive components are arranged according to the extension direction and joint position of the humanoid skeleton. In particular, two tail-to-tail drive modules are set at the base of each finger, integrating the finger root lateral swing and finger root flexion-extension degrees of freedom within a limited space. This can simulate the length ratio and joint position of the human hand's metacarpal and phalangeal bones, and make the finger root structure correspond to the two-degree-of-freedom movement requirements of metacarpophalangeal joint flexion-extension and lateral swing, making the humanoid five-fingered dexterous hand closer to the human hand in terms of shape, actuator arrangement, and movement.

[0066] In some embodiments, a force sensor or mounting portion for mounting a force sensor is provided at the fingertip of at least one finger. By providing a force sensor at the fingertip, contact forces during grasping or pinching can be detected in order to control the grasping force or protect the object being manipulated.

[0067] In this embodiment, see Figure 7 The five fingers together form a biomimetic skeletal structure 900. Taking the little finger 600 as an example, from the base to the tip, it sequentially forms the biomimetic metacarpal bone extension direction 901, the biomimetic proximal phalanx extension direction 902, the biomimetic middle phalanx extension direction 903, and the biomimetic distal phalanx extension direction 904. Adjacent structural segments respectively form corresponding positions of the metacarpophalangeal joints 905, the proximal interphalangeal joints 906, and the distal interphalangeal joints 907.

[0068] It should be noted that the length direction, joint hierarchy, and pivot position of each structural segment of the anthropomorphic five-fingered dexterous hand correspond to the positional relationships of the metacarpal bones, proximal phalanges, middle phalanges, distal phalanges, and their respective joints in the human hand. See also... Figure 7, Figure 7 The corresponding indicator line 909 is used to indicate the correspondence between the structural segments and joints of the humanoid five-fingered dexterous hand and the skeletal structure of the human hand, rather than to indicate the mechanical connection structure, so as to facilitate those skilled in the art to understand the solution of this disclosure more clearly.

[0069] In some embodiments, each linear drive component is arranged along a corresponding biomimetic skeletal structure segment, and its axial direction forms a biomimetic muscle action line 908 that approximates the action direction of biomimetic muscles or tendons. The driving method of the linear drive component 800 is analogous to the way human muscles pull joints. Specifically, the linear drive component 800 is arranged along a direction approximating the action line of biomimetic muscles or tendons and generates a linear push-pull force along the direction of the phalanx or metacarpal bone. This linear push-pull force is converted into torque around the joint axis by the wrap-around groove 804, the rolling slider 805, and the raceway 806, thereby driving the adjacent phalanx or wrist component to rotate. The wrap-around groove 804, the rolling slider 805, and the raceway 806 jointly constrain the output path, so that the linear displacement is stably converted into joint rotation, reducing transmission offset and ineffective lateral force, and achieving a large joint rotation range within a small envelope.

[0070] In one embodiment, the wrist unit 700 has two active degrees of freedom: pitch and lateral. Thus, the five fingers have a total of twenty active degrees of freedom, the wrist unit 700 has two active degrees of freedom, and the entire hand has a total of twenty-two active degrees of freedom.

[0071] In this embodiment, see Figure 8 The wrist unit 700 includes a universal joint structure 701, a first wrist linear drive assembly 702, a second wrist linear drive assembly 703, a forearm connector 704, and a palm connector 705. The universal joint structure 701 is disposed between the forearm connector 704 and the palm connector 705, and includes a first rotation axis 706 and a second rotation axis 707 whose rotation directions intersect. The first wrist linear drive assembly 702 and the second wrist linear drive assembly 703 can move synchronously or differentially, causing the universal joint structure 701 to rotate simultaneously around the first rotation axis 706 and the second rotation axis 707, thereby forming a composite wrist posture.

[0072] In some embodiments, the palm unit 100 includes a palm base forming a mid-palm support structure. The mid-palm support structure is used to support the root drive modules of the thumb 200, index finger 300, middle finger 400, ring finger 500, and little finger 600, and together with the wrist unit 700, provides proximal support for the output force, palmar posture, and gripping contact of the five fingers.

[0073] In this embodiment, see Figure 9The palm unit 100 also includes a movable thenar eminence 110. The movable thenar eminence 110 is located on one side of the base of the thumb 200 and is movable relative to the palm base of the palm unit 100.

[0074] The movable thenar eminence 110 is used to change the local contour of the palm on the thumb side, allowing this area to change from a relatively flat state to a supported state that bulges or protrudes towards the palm. When the thumb 200 performs an opposition movement, the movable thenar eminence 110 can change the palm contour and form a support surface located inside or below the base of the thumb 200. This support surface can provide structural support for the thumb 200 and can also serve as the palm contact surface for the palm unit 100 to contact the manipulated object, expanding the contact posture that can be formed between the thumb and other fingers or the manipulated object, thereby reducing the unsupported area between the thumb and the palm, and enabling the thumb 200 to form more opposition, pinching, and gesture postures with the index finger 300, middle finger 400, ring finger 500, or little finger 600.

[0075] In this embodiment, the movable thenar eminence 110 enables the palm unit 100 to participate in the thumb-palm opposition and grasping process, rather than merely serving as a fixed mounting base for each finger. For spherical, cylindrical, or irregularly shaped objects, the movable thenar eminence 110 can change the palm support position according to the grasping posture, increasing the effective contact area between the thumb-side palm and the object, which is beneficial for improving grasping stability, fine motor skills, and human-like posture expression.

[0076] In one embodiment, see further. Figure 9 The palm unit 100 has a flexible palm area 120 at the metacarpophalangeal joint of at least one of the index finger 300, middle finger 400, ring finger 500 and little finger 600. The flexible palm area 120 spans between the palm base and the base of the corresponding finger, and covers or forms at least a portion of the palmar surface of the metacarpophalangeal joint. Figure 9 This is used to illustrate the position of the flexible palm area 120 relative to the palm base and the corresponding finger roots. The specific shape of the flexible palm area 120 can be adapted according to the structural dimensions and range of motion of the metacarpophalangeal joints.

[0077] In this embodiment, the flexible palm region 120 is made of an elastomeric material. The elastomeric material has the properties of being stretchable, bendable, and capable of recovering its deformation. When the corresponding metacarpophalangeal joint undergoes flexion and extension movements, the flexible palm region 120 can elastically deform with the relative movement of the metacarpophalangeal joint to maintain the continuity of the palmar side structure without hindering the movement of the metacarpophalangeal joint; in some embodiments, the elastic deformation includes at least one of stretching, bending, local compression, or wrinkling.

[0078] When grasping an object, the flexible palm area 120 can undergo compliant deformation under the combined action of finger flexion and the contact force of the object, allowing the palm surface to conform to the local shape of the object being grasped. Compared to a rigid palm surface, the flexible palm area 120 can reduce the suspended area between the palm surface and the object, increase the contact area, and use material deformation to assist in forming an envelope grip; its elastic deformation can also form a local support shape similar to the natural concavity and palmar arch of the human palm, thus adapting to cylindrical, spherical, and irregular objects of different sizes and curvatures.

[0079] In some embodiments, the movable thenar eminence 110 and the flexible palm area 120 together constitute a deformable palm structure. The movable thenar eminence 110 is used to change the palm support shape on the thumb side, and the flexible palm area 120 is used to change the palm shape of the base area of ​​the four fingers as the metacarpophalangeal joints flex and extend. The two work together to form a three-dimensional palm contour that can change with the grip posture, thereby enabling the palm to play a role in support, fit, envelop, and stabilize the grip.

[0080] In this embodiment, see Figure 10 The humanoid five-fingered dexterous hand can display a variety of human-like postures and operational abilities. For example, through the flexion and extension freedom of the five fingers, it can achieve natural opening and clenching of the five fingers; through the 200 degrees of rotational freedom of the thumb and the 300 degrees of flexion and extension freedom of the index finger, it can achieve pinching between the thumb and index finger to form a gesture similar to the OK sign. Figure 10 (Top left corner posture); By moving the thumb (200°) and little finger (60°) in opposite directions, the thumb and little finger can touch each other's palms. Figure 10 (Position in the lower left corner); a three-finger pinch can be achieved through the coordinated movement of the thumb (20°), index finger (30°), and middle finger (40°). Figure 10 (Top right corner posture); a side pinch can be achieved by the lateral coordination of the thumb (20°) and index finger (30°); a comprehensive grasp of cylindrical or irregular objects can be achieved by the coordinated flexion of all five fingers. Figure 10 (Position in the lower right corner). The above posture is used to demonstrate the basic abilities of this disclosure in human-like grasping, pinching, palm-to-palm and gesture expression.

[0081] exist Figure 10 Based on the humanoid poses shown in the examples, see [link / reference]. Figure 11 The humanoid five-fingered dexterous hand can form a special spherical grasping posture that exceeds the conventional activity capabilities of the human hand through the combination of multiple active degrees of freedom, allowing multiple fingers to surround and contact a spherical object from different directions. For example, Figure 11 The first and second gestures on the left in the example use the thumb, ring finger and little finger to grasp the ball; Figure 11 The first and second gestures on the right side of the example involve grasping the first ball using the thumb, ring finger, and movable thenar eminence of the palm, while simultaneously grasping the first ball using the index, middle, and little fingers. Figure 11The exemplified postures demonstrate the posture coverage advantages brought about by the collaboration of twenty-two active degrees of freedom, wrist unit, movable thenar eminence, flexible palm area, and five-finger unit. This enables the humanoid five-finger dexterous hand to not only simulate the conventional operation mode of the human hand, but also to achieve complex envelope grasping and special display postures that are difficult for the human hand to perform naturally.

[0082] Since all twenty-two active degrees of freedom can be independently driven, the humanoid five-fingered dexterous hand can form a rich variety of fingertip trajectories, contact postures, and envelope paths through the combination of the degrees of freedom of each joint. Compared with underactuated fingers that couple distal and proximal joints, this disclosure can perform segmental adjustment of different phalanges, making it easier to achieve precise fingertip contact, segmented envelopes of objects with different curvatures, and special grasping postures, thereby improving adaptability and demonstration capabilities in complex operation scenarios.

[0083] The linearly driven 22-DOF humanoid five-fingered dexterous hand disclosed herein has at least the following beneficial effects: The first and twenty-second degrees of freedom are both active degrees of freedom, which can improve the accuracy of posture control and the ability to combine movements.

[0084] Secondly, each active degree of freedom uses an independent linear drive component to drive the output components of each joint, which can avoid tendon slack, wear and hysteresis, and reduce coupling error and posture restriction problems.

[0085] Third, the wrap-around groove, rolling slider and raceway form a constrained rolling force transmission path, which can reduce transmission offset, ineffective lateral force and friction loss.

[0086] Fourth, the linear drive module is arranged along a direction close to the action line of the biomimetic muscle or tendon, making the force transmission path direct and the mechanical efficiency and reliability high.

[0087] Fifth, the actuators are arranged along the direction of the humanoid skeleton, which is beneficial for integrating high-degree-of-freedom structures within the humanoid size.

[0088] Sixth, the wrist unit provides proximal posture adjustment, the palm base provides mid-palm stability support, the movable thenar eminence and the palmar-finger flexible areas participate in thumb opposition support and simulate palmar soft tissue deformation, respectively, and the five-finger unit linear drive components are arranged along the bionic skeleton and muscle traction path to provide distal fine movement, so that the wrist, palm and fingers form a continuous bionic kinematic chain, improving human-like grasping, pinching, opposition, envelope grasping and gesture expression abilities.

[0089] Seventh, the movable thenar eminence and the flexible palm areas at the metacarpophalangeal joints can respectively provide palm support and palm surface conformal deformation, improving contact area, grip stability, fine manipulation ability, human-like posture expression ability, and adaptability to complex objects.

[0090] Furthermore, although the operations of the methods disclosed herein are described in a specific order in the accompanying drawings, this does not require or imply that these operations must be performed in that specific order, or that all of the operations shown must be performed to achieve the desired result. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps.

[0091] While the spirit and principles of this disclosure have been described with reference to several specific embodiments, it should be noted that this disclosure is not limited to the disclosed specific embodiments, and the division of aspects does not imply that features in these aspects cannot be combined for benefit; such division is merely for convenience of expression. This disclosure is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A linearly driven, active 22-DOF humanoid five-fingered dexterous hand, characterized in that, It includes a palm unit, a wrist unit, and a thumb, index finger, middle finger, ring finger, and little finger disposed in the palm unit; the wrist unit is connected to the palm unit; the thumb, index finger, middle finger, ring finger, and little finger each have four active degrees of freedom, and the wrist unit has two active degrees of freedom, so that the anthropomorphic five-fingered dexterous hand has twenty-two active degrees of freedom; Each active degree of freedom of the humanoid five-fingered dexterous hand is equipped with an independent linear drive component to convert linear push-pull motion into rotation of the corresponding joint output component, and the drive stroke of any two active degrees of freedom is independent of each other.

2. The linearly driven active 22-DOF humanoid five-fingered dexterous hand according to claim 1, characterized in that, The four active degrees of freedom of the thumb include one lateral swing degree of freedom, two flexion and extension degrees of freedom, and one opposition rotation degree of freedom. The opposition rotation degree of freedom is used to drive the thumb to perform opposition movement relative to the palm unit.

3. The linearly driven active 22-DOF humanoid five-fingered dexterous hand according to claim 1, characterized in that, The index finger, middle finger, ring finger, and little finger each include a proximal phalanx, a middle phalanx, and a distal phalanx; the proximal phalanx refers to the phalanx closest to the palm unit; the distal phalanx refers to the phalanx furthest from the palm unit; and the middle phalanx refers to the phalanx located between the proximal and distal phalanxes. Each of the index finger, middle finger, ring finger, and little finger has four active degrees of freedom, including one lateral swing degree of freedom located at the base of the finger and three flexion and extension degrees of freedom arranged sequentially along the extension direction of the finger.

4. The linearly driven active 22-DOF humanoid five-fingered dexterous hand according to claim 3, characterized in that, Each of the index finger, middle finger, ring finger, and little finger has a set of tail-to-tail linear drive components at its base; these tail-to-tail linear drive components are used to drive the lateral swing and flexion-extension degrees of freedom of the corresponding finger bases.

5. The linearly driven active 22-DOF humanoid five-fingered dexterous hand according to claim 1, characterized in that, The linear drive assembly includes a frameless torque motor, a ball screw, an output end, a rolling slider, and a raceway; the frameless torque motor drives the ball screw to move, the ball screw drives the output end to perform linear push-pull motion, the output end cooperates with the rolling slider, and the rolling slider cooperates with the raceway to drive the corresponding joint output component to rotate.

6. The linearly driven active 22-DOF humanoid five-fingered dexterous hand according to claim 5, characterized in that, The output end of the linear drive assembly has a wrap-around groove; the wrap-around groove is a semi-circular groove or an arc-shaped groove; the rolling slider and the raceway form a rolling friction fit, so that the linear drive assembly converts linear motion into rotation of the corresponding joint output component through the rolling slider and the raceway.

7. The linearly driven active 22-DOF humanoid five-fingered dexterous hand according to claim 1, characterized in that, Each active degree of freedom linear drive component is arranged in the direction of the extension of the humanoid skeleton of the finger and is placed within the outer envelope of the corresponding phalanx or metacarpal bone; the wrist unit, the palm unit and the five fingers together form a continuous bionic kinematic chain.

8. The linearly driven active 22-DOF humanoid five-fingered dexterous hand according to claim 5, characterized in that, The linear drive assembly is arranged along a direction close to the action line of the biomimetic muscle or tendon, and drives the corresponding joint output component to rotate in a manner that simulates muscle traction joint. The linear push-pull direction of the linear drive assembly and the rotation direction of the corresponding joint are connected by a constrained force transmission path through a wrap-around groove, a rolling slider and a raceway, so as to reduce transmission offset and ineffective lateral force.

9. The linearly driven active 22-DOF humanoid five-fingered dexterous hand according to claim 1, characterized in that, The palm unit includes a palm base and a movable thenar eminence located on one side of the base of the thumb; the palm base forms a mid-palm support structure for supporting the linear drive module of the five fingers, and together with the wrist unit, provides proximal support for the output force and posture adjustment of the five fingers. The movable thenar eminence can move relative to the palm base to change the support shape of the palm side of the palm unit. When the thumb performs an opposition movement, the movable thenar eminence forms a support surface facing the palm side, which is used to contact the object being manipulated, thereby expanding the opposition posture range of the thumb and the effective gripping area of ​​the hand unit.

10. The linearly driven active 22-DOF humanoid five-fingered dexterous hand according to claim 9, characterized in that, The palm unit also includes a flexible palm area disposed at at least one metacarpophalangeal joint. The flexible palm area is made of an elastomeric material and spans between the palm base and the base of the corresponding finger. The flexible palm area is configured to undergo stretching and wrinkling deformation with the flexion and extension movements of the corresponding metacarpophalangeal joint to form a flexible contact surface that changes with the posture of the metacarpophalangeal joint. During the grasping process, it conforms to the outer surface of the object being grasped to increase the contact area between the palm unit and the object being grasped, assist in the envelope grasping, and adapt to the shape of different objects being grasped.

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