A high-degree-of-freedom direct-drive robotic dexterity hand for complex intramanual operations

Abstract

This application relates to the field of robotics, providing a high-degree-of-freedom direct-drive robotic dexterous hand for complex intramanual operations, including a palm structure, finger structure, and metacarpophalangeal joint structure. The metacarpophalangeal joints integrate three independent degrees of freedom (MCP): flexion / extension, oscillation, and axial rotation. Each degree of freedom is equipped with an independent direct-drive unit to achieve mechanical decoupling, effectively reducing motion control complexity. The fingers adopt a three-segment serial architecture (proximal, middle, and distal phalanges), with each interphalangeal joint employing an independent direct-drive design. The palm is divided into two relatively rotatable parts, with continuous stepless adjustment of the opening and closing angle achieved through a side-mounted direct-drive pivot. An active palmar opposition degree of freedom is set at the base of the thumb, arranged at an angle. This application employs a fully distributed independent direct-drive architecture, improving finger posture adjustment accuracy, palm configuration adaptability, and multi-finger collaborative operation capabilities. It can stably complete complex operations such as continuous object rotation and intramanual repositioning, and is suitable for humanoid robots, precision assembly, and other fields.

Description

Technical Field

[0001] This application relates to the field of robotics, and more specifically to a high-degree-of-freedom direct-drive robotic dexterity hand for complex intramanual operations. Background Technology

[0002] With the continuous development of robotics, intelligent control, and artificial intelligence, the application scenarios of robot systems have gradually expanded from traditional industrial fields to service robots, human-computer interaction, remote operation, medical assistance, and autonomous operation in complex environments. In these application scenarios, robot end effectors not only need to complete basic object grasping tasks but also need to possess fine manipulation capabilities similar to a human hand, enabling functions such as object posture adjustment, continuous rotation, intra-hand repositioning, and complex contact operations. Compared to traditional gripping manipulators, dexterous robot hands, with their multi-joint, multi-degree-of-freedom structural design, can simulate the movement patterns of a human hand, achieving more flexible grasping and manipulation functions. Therefore, high-degree-of-freedom robot dexterous hands have become one of the important research directions in the field of robot end effectors.

[0003] Several typical robotic dexterous hand structures have been proposed in existing technologies, such as the Allegro Hand, Leap Hand, and Shadow Hand. These dexterous hands generally employ a multi-finger serial structure, with metacarpophalangeal joints, proximal interphalangeal joints, and distal interphalangeal joints on each finger. Multiple drive units are configured to achieve finger flexion and grasping movements, as well as a certain degree of spatial motion. Some dexterous hands incorporate flexion-extension and pivoting degrees of freedom at the metacarpophalangeal joints to expand the range of motion of the fingers. The palm often uses a one-piece rigid structure as the mounting support for the fingers, while the thumb is mounted on the side of the palm via a fixed base, working in conjunction with the other fingers to complete grasping actions.

[0004] However, existing robotic dexterous hands generally lack active rotational degrees of freedom around the finger axis in their metacarpophalangeal joints, and mostly employ coupled transmission schemes. Significant mechanical coupling exists between different degrees of freedom, resulting in limited finger spatial posture adjustment capabilities and making it difficult to stably perform complex intramanual operations such as continuous object rotation and high-precision posture adjustments. Simultaneously, existing dexterous hands often employ fixed, rigid palm structures, and the thumb base lacks an active opposition degree of freedom. This prevents the palm shape from actively adapting to objects of different sizes and shapes, and the insufficient coordination between the thumb and other fingers further limits the complex operational performance and scene adaptability of dexterous hands. Summary of the Invention

[0005] This application addresses the problems of existing robotic dexterous hands generally lacking active rotational freedom around the finger axis in the metacarpophalangeal joints and mostly adopting fixed rigid palm structures, with the thumb base lacking active palm-opposition freedom. It provides a high-degree-of-freedom direct-drive robotic dexterous hand for complex intra-hand operations, including a palm structure, at least one set of finger structures, and a metacarpophalangeal joint structure. The metacarpophalangeal joint structure is located between the palm structure and the root of the finger structure; The metacarpophalangeal joint structure includes an MCP flexion-extension structure, an MCP swing structure, and an MCP axial rotation structure. The fixed side of the MCP flexion-extension structure is fixed relative to the palm structure, and the output side of the MCP flexion-extension structure rotates about the laterally extending flexion-extension axis. The fixed side of the MCP swing structure is fixedly connected to the output side of the MCP flexion-extension structure and moves synchronously with the MCP flexion-extension structure. The output side of the MCP swing structure rotates around a swing axis that intersects with the flexion-extension axis. The fixed side of the MCP axial rotation structure is fixedly connected to the output side of the MCP swing structure and moves synchronously with the MCP swing structure. The output side of the MCP axial rotation structure rotates around a rotation axis extending longitudinally along the finger. The root of the finger structure is fixedly connected to the output side of the MCP axial rotation structure; The MCP bending and stretching structure, the MCP swinging structure, and the MCP axial rotation structure are each equipped with an independent drive unit. Each drive unit is fixed on the fixed side component of the corresponding structure, and the output end of the drive unit is fixedly connected to the rotation shaft of the corresponding structure.

[0006] In one feasible implementation, the metacarpophalangeal joint structure further includes an MCP support base and an MCP mounting structure; The MCP support base is fixedly connected to the finger mounting side surface of the palm structure through the MCP mounting structure. The MCP flexion-extension structure includes an MCP flexion-extension drive unit, an MCP flexion-extension connecting frame, and an MCP flexion-extension rotating shaft. The MCP flexion-extension connector is fixedly installed on the surface of the MCP support base away from the palm structure. The MCP flexion-extension pivot is transversely inserted into the internal cavity of the MCP flexion-extension connecting frame, and its axis forms the flexion-extension axis. The MCP flexion-extension drive unit is fixedly installed on the lateral side of the MCP flexion-extension connecting frame, and its output shaft is coaxially and fixedly connected to one end of the MCP flexion-extension rotating shaft. The MCP swing structure includes an MCP swing drive unit, an MCP swing connecting frame, and an MCP swing rotating shaft. The lower part of the MCP swing connection frame is fixedly connected to the MCP flexion-extension shaft and rotates synchronously around the flexion-extension axis with the MCP flexion-extension shaft. The MCP swing shaft passes through the upper part of the MCP swing connecting frame, and its axis intersects the flexion and extension axis in space to form a swing axis. The MCP swing drive unit is fixedly installed on the side of the MCP swing connecting frame, and its output shaft is coaxially and fixedly connected to one end of the MCP swing rotating shaft. The MCP axial rotation structure includes an MCP rotation drive unit, an MCP rotation mounting base, and an MCP rotation shaft. The lower part of the MCP rotary mounting base is fixedly connected to the MCP swing shaft and rotates synchronously around the swing axis with the MCP swing shaft. The MCP rotating shaft is inserted longitudinally through the inside of the MCP rotating mounting base along the finger, and its axis forms the rotation axis. The MCP rotary drive unit is fixedly installed inside the MCP rotary mounting base, and its output shaft is coaxially and fixedly connected to the proximal end of the MCP rotary shaft. The root of the finger structure is fixedly connected to the distal end face of the MCP rotating shaft.

[0007] In one feasible implementation, the finger structure includes, in the longitudinal direction, a proximal phalanx segment, a middle phalanx segment, a distal phalanx segment, a proximal interphalangeal joint structure, and a distal interphalangeal joint structure. The proximal interphalangeal joint structure connects the distal end of the proximal phalanx to the proximal end of the middle phalanx. The distal interphalangeal joint structure connects the distal end of the middle phalanx to the proximal end of the distal phalanx. The root of the proximal phalanx is fixedly connected to the output side of the MCP axial rotation structure.

[0008] In one feasible implementation, the proximal interphalangeal joint structure includes a PIP drive unit, a PIP connector, and a PIP pivot. The proximal end of the PIP connector is fixedly connected to the distal end of the proximal phalanx, and the distal end of the PIP connector is correspondingly engaged with the proximal end of the middle phalanx. The PIP pivot is laterally inserted inside the PIP connector, and the proximal end of the middle phalanx is fixedly connected to the PIP pivot. The PIP drive unit is fixed to the side of the PIP connector, and its output end is coaxially and fixedly connected to the PIP shaft. The distal interphalangeal joint structure includes a DIP drive unit, a DIP connector, and a DIP pivot. The proximal end of the DIP connector is fixedly connected to the distal end of the middle phalanx, and the distal end of the DIP connector is correspondingly engaged with the proximal end of the distal phalanx. The DIP pivot is laterally inserted inside the DIP connector, and the proximal end of the distal phalanx is fixedly connected to the DIP pivot. The DIP drive unit is fixed to the side of the DIP connector, and its output end is coaxially and fixedly connected to the DIP shaft.

[0009] In one feasible implementation, the palm structure includes a first palm, a second palm, a palm connection structure, and a palm driving structure. The first palm portion is arranged in the upper region of the palm structure, and the second palm portion is arranged in the lower region of the palm structure; The palm connection structure is connected between the lower edge of the first palm and the upper edge of the second palm, forming a rotating joint of the first palm relative to the second palm; The palm drive structure is installed in the adjacent area of ​​the first palm and the second palm, with its fixed side fixedly connected to the second palm and its output side fixedly connected to the first palm.

[0010] In one feasible implementation, the palm connection structure includes a palm connection pivot. The palm-connecting pivot extends along the width of the palm and passes through the lower edge of the first palm and the upper edge of the second palm. The palm drive structure is fixed to the side of the second palm near the palm connecting shaft, and its output shaft is coaxially and fixedly connected to the palm connecting shaft. The first palm and the connecting shaft rotate synchronously, so that the included angle between the first palm and the second palm can be continuously adjusted.

[0011] In one feasible implementation, the finger structure includes a thumb, and a thumb root structure is provided between the thumb and the palm structure; The fixed side of the thumb root structure is fixedly connected to the thumb mounting side of the palm structure, and the output side of the thumb root structure is fixedly connected to the root of the thumb. The axis of rotation of the thumb root structure is inclined toward the palm.

[0012] In one feasible implementation, the thumb root structure includes a thumb additional degree-of-freedom structure, which includes a thumb drive unit, a thumb connecting base, a thumb rotation shaft, and a thumb connector. The thumb connecting base is fixedly connected to the thumb mounting side surface of the palm structure; The thumb rotation shaft passes through the inside of the thumb connecting base; One end of the thumb connector is fixedly connected to the thumb rotation shaft, and the other end is fixedly connected to the base of the thumb; The thumb drive unit is fixed to the side of the thumb connecting base, and its output end is coaxially and fixedly connected to the thumb rotation shaft.

[0013] In one feasible implementation, the finger structure further includes a fingertip structure; The fingertip structure is fixedly installed on the front end face of the distal phalanx; The fingertip structure has a nail structure at its front, and the outer surface of the nail structure extends forward and protrudes from the fingertip surface.

[0014] One feasible implementation also includes a driving structure; The drive structure is composed of the metacarpophalangeal joint structure, the joints of the finger structure, the palm structure, and the drive unit corresponding to the thumb root structure. Each drive unit is fixedly installed on the fixed side component of the corresponding structure, and the output end of the drive unit is fixedly connected to the rotating shaft of the corresponding structure.

[0015] As described above, this application provides a high-degree-of-freedom direct-drive dexterous hand for complex intramanual manipulation. Through the coordinated operation of a multi-degree-of-freedom metacarpophalangeal joint structure, an actively variable palm structure, an enhanced thumb-palm opposition structure, and a fully direct-drive distributed drive system, it solves problems such as insufficient degrees of freedom in the metacarpophalangeal joints and lack of axial rotation capability in robotic hands. This improves the spatial posture adjustment capability of the fingers, the configurational adaptability of the palm, the collaborative operation capability of multiple fingers, and the overall motion control precision. It can better support advanced manipulation tasks such as continuous object rotation, fine posture adjustment, and complex intramanual repositioning. It can be widely applied in humanoid robots, dexterous assembly, and precision manipulation, possessing significant engineering application value and promising prospects for technological promotion. Attached Figure Description

[0016] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the implementation of the invention and, together with the description, serve to explain the principles of the embodiments of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0017] Figure 1 This is a schematic diagram of the overall structure of a high-degree-of-freedom direct-drive robot dexterous hand for complex intramanual operations, as shown in an embodiment of this application. Figure 2This is a schematic diagram of the finger structure shown in the embodiments of this application; Figure 3 This is a schematic diagram of the initial state structure of the metacarpophalangeal joint structure shown in the embodiments of this application; Figure 4 This is a schematic diagram of the rotational state of the metacarpophalangeal joint structure shown in the embodiments of this application; Figure 5 This is a schematic diagram of the unfolded state of the palm structure shown in the embodiments of this application; Figure 6 This is a schematic diagram of the palm structure in the closed state shown in the embodiments of this application; Figure 7 This is a schematic diagram of the thumb's open state structure shown in an embodiment of this application; Figure 8 This is a schematic diagram of the thumb in an opposing palmar position as shown in an embodiment of this application.

[0018] Figure label: 2-Palm structure; 3-Finger structure; 4-Metacarpophalangeal joint structure; 5-Proximal interphalangeal joint structure; 6-Distal interphalangeal joint structure; 7-Base structure of thumb; 8-Fingertip structure; 9-Drive structure; 21-First palm; 22-Second palm; 23-Palm connection structure; 24-Palm drive structure; 31-Index finger; 32-Middle finger; 33-Ring finger; 34-Thumb; 41-MCP flexion-extension structure; 42-MCP swing structure; 43-MCP axial rotation structure; 44-MCP support base; 45-MCP mounting structure; 51-PIP drive unit; 52-PIP connector; 53-PIP pivot; 61-DIP drive unit; 62-DIP connector; 63-DIP pivot; 71-Thumb additional degree of freedom structure; 81-Nail structure; 231-Palm connecting pivot; 411-MCP flexion-extension drive unit; 412-MCP flexion-extension connecting frame; 413-MCP flexion-extension pivot; 421-MCP swing drive unit; 422-MCP swing connecting frame; 423-MCP swing pivot; 431-MCP rotation drive unit; 432-MCP rotation mounting base; 433-MCP rotation pivot; 711-Thumb drive unit; 712-Thumb connecting base; 713-Thumb rotation shaft; 714-Thumb connector. Detailed Implementation

[0019] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that the embodiments of the invention will be more comprehensive and complete, and will fully convey the concept of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a full understanding of how embodiments of the invention are carried out.

[0020] Current robotic dexterous hands typically possess only a single degree of flexion-extension at their metacarpophalangeal joints, or only a simple left-right swinging degree, resulting in limited overall motion capabilities. Most structures lack truly decoupled multi-degree-of-freedom designs, particularly lacking rotational freedom around the finger axis, leading to insufficient finger posture adjustment in space. Furthermore, traditional metacarpophalangeal joint structures often employ coupled transmission schemes, exhibiting significant mechanical coupling between different degrees of freedom. This easily leads to complex motion control, error accumulation, and decreased control accuracy, making it difficult to support complex intra-hand operations such as continuous object rotation and intra-hand repositioning.

[0021] To address the aforementioned problems, this embodiment provides a high-degree-of-freedom direct-drive robotic dexterous hand for complex intramanual operations, referring to... Figure 1 As shown, the hand includes a palm structure 2, at least one set of finger structures 3, and a metacarpophalangeal joint structure 4. The number of finger structures 3 can be set to multiple sets, with each set of finger structures 3 installed at different positions on the palm structure 2 via corresponding metacarpophalangeal joint structures 4, forming a multi-finger collaborative grasping architecture. The number of finger structures 3 can be adjusted according to actual application needs, for example, set to three, four, or more sets. For example, if there are four sets of finger structures 3, they may include the index finger 31, middle finger 32, ring finger 33, and thumb 34. This embodiment does not limit this to a single type. The palm structure 2 serves as the basic support base for the entire dexterous hand, supporting all finger structures and drive components, and undertaking the load transfer function during grasping and manipulation.

[0022] The metacarpophalangeal joint structure 4 is located between the palm structure 2 and the root of the finger structure 3 to transmit motion between the palm structure 2 and the finger structure 3, while providing multi-degree-of-freedom motion support for the finger structure 3. The metacarpophalangeal joint structure 4 includes an MCP flexion-extension structure 41, an MCP swing structure 42, and an MCP axial rotation structure 43. The three are arranged in a layered manner from the palm side to the finger side along the motion transmission direction, forming a multi-layered nested series kinematic chain structure to achieve the layer-by-layer superposition of multiple degrees of freedom of motion, and finally output the composite motion to the finger structure 3.

[0023] The fixed side of the MCP flexion-extension structure 41 is fixed relative to the palm structure 2, and the output side of the MCP flexion-extension structure 41 rotates about the flexion-extension axis extending laterally. In one embodiment, the flexion-extension axis can extend along the width direction of the palm to ensure that the flexion-extension movement of the finger structure 3 is within the longitudinal plane of the finger, which meets the movement requirements of conventional grasping actions; in another embodiment, the flexion-extension axis can also be arranged with a slight inclination angle according to the overall configuration of the palm to adapt to specific finger opening angle requirements.

[0024] The MCP flexion-extension structure 41 is the basic motion level of the metacarpophalangeal joint structure 4, located on the side of the entire kinetic chain closest to the palm structure 2. It provides the finger structure 3 with flexion-extension capabilities in the forward and backward directions, enabling the finger structure 3 to perform basic bending and extension movements, achieving initial gripping and release of objects. At the same time, the fixed side of the MCP flexion-extension structure 41 remains relatively fixed to the palm structure 2, providing a stable mounting base for the upper swing and rotation structures, ensuring the stiffness and stability of motion transmission.

[0025] The fixed side of the MCP swing structure 42 is fixedly connected to the output side of the MCP flexion-extension structure 41 and moves synchronously with the MCP flexion-extension structure 41. The output side of the MCP swing structure 42 rotates around a swing axis that intersects the flexion-extension axis. In one embodiment, the swing axis and the flexion-extension axis can be arranged in a spatially perpendicular intersecting form to improve the degree of motion decoupling between the two degrees of freedom at the structural level and reduce the possibility of motion interference. In another embodiment, the swing axis and the flexion-extension axis can also adopt a non-perpendicular intersecting angle to adapt to specific finger swing range requirements.

[0026] The MCP swing structure 42 is an intermediate motion level of the metacarpophalangeal joint structure 4, superimposed on the flexion-extension degrees of freedom. It provides the finger structure 3 with lateral swing motion capability, allowing the finger structure 3 to adjust its relative position within the plane of the palm to adapt to grasping objects of different widths and shapes, thus improving the adaptability of multi-finger coordination to a certain extent. Since the fixed side of the MCP swing structure 42 moves synchronously with the output side of the MCP flexion-extension structure 41, the motion of the swing degree of freedom can be completely superimposed on the flexion-extension degrees of freedom. This allows the finger structure 3 to perform swing motion simultaneously while completing flexion-extension movements, achieving posture adjustment in a two-dimensional plane without relying on other mechanisms for motion compensation.

[0027] The fixed side of the MCP axial rotation structure 43 is fixedly connected to the output side of the MCP swing structure 42 and moves synchronously with the MCP swing structure 42. The output side of the MCP axial rotation structure 43 rotates around the rotation axis extending longitudinally along the finger. As the end motion level of the metacarpophalangeal joint structure 4, the MCP axial rotation structure 43 is superimposed on the two degrees of freedom of flexion and extension and swing. It is used to provide the finger structure 3 with the ability to actively rotate around its own axis, so that the finger structure 3 can actively adjust the spatial orientation of the contact surface while maintaining the clamping contact, thereby changing the contact posture with the object and providing a motion basis for complex operations such as continuous rotation of the object and intra-hand repositioning.

[0028] The root of finger structure 3 is fixedly connected to the output side of MCP axial rotation structure 43. Therefore, the motion output of MCP flexion-extension structure 41, MCP swing structure 42, and MCP axial rotation structure 43 can be transmitted to finger structure 3 layer by layer, driving finger structure 3 to complete the corresponding spatial posture changes. The motion of the three degrees of freedom is independent of each other and can be superimposed and coordinated, which can be combined to form different finger postures according to task requirements, adapting to diverse operation scenarios.

[0029] The MCP flexion-extension structure 41, MCP swing structure 42, and MCP axial rotation structure 43 are each equipped with independent drive units. Each drive unit is fixed to the fixed-side component of its corresponding structure, and the output end of the drive unit is fixedly connected to the rotation shaft of the corresponding structure. Each drive unit can use a direct-drive element, with the driving force acting directly on the corresponding rotation shaft without the need for an intermediate transmission mechanism, thus reducing transmission backlash and transmission error. This independent drive configuration allows for mechanical decoupling between the three degrees of freedom. The movement of a single degree of freedom will not mechanically interfere with the movement of other degrees of freedom, thereby reducing the complexity of motion control, minimizing the accumulation of control errors, and improving the motion control accuracy and response speed of the entire metacarpophalangeal joint structure 4 to a certain extent. Simultaneously, the design of fixing the drive unit to the fixed-side component avoids torsional fatigue of the wiring caused by repeated rotation of the drive unit with the moving side, improving the reliability and service life of the electrical connection.

[0030] The robotic dexterous hand provided in this embodiment addresses the problems of insufficient degrees of freedom in the metacarpophalangeal joints, lack of axial rotation capability, and severe mechanical coupling between degrees of freedom in existing technologies. By integrating three independent degrees of freedom—flexion, extension, and axial rotation—into the metacarpophalangeal joints and employing an independently driven configuration, it effectively expands the spatial range of motion of the fingers, enhances the active adjustment capability of finger posture, and reduces the control difficulty caused by motion coupling. Compared to traditional dexterous hands with single or dual degrees of freedom metacarpophalangeal joints, the dexterous hand in this embodiment can better support complex operations such as continuous object rotation, fine posture adjustment, and intra-hand repositioning, thereby improving the operational flexibility and task adaptability of the dexterous hand to a certain extent.

[0031] In some embodiments of this application, reference is made to Figure 3 and Figure 4 As shown, the metacarpophalangeal joint structure 4 also includes an MCP support base 44 and an MCP mounting structure 45. The MCP support base 44 is fixedly connected to the finger mounting side surface of the palm structure 2 via the MCP mounting structure 45.

[0032] The MCP flexion-extension structure 41 includes an MCP flexion-extension drive unit 411, an MCP flexion-extension connecting frame 412, and an MCP flexion-extension rotating shaft 413. The MCP flexion-extension connecting frame 412 is fixedly installed on the surface of the MCP support base 44 away from the palm structure 2. In one embodiment, the MCP flexion-extension connecting frame 412 can adopt an integrally molded frame structure, with an internal cavity to accommodate the rotating shaft and support walls on both sides to improve its structural rigidity and reduce deformation under load. The MCP flexion-extension rotating shaft 413 is transversely inserted into the internal cavity of the MCP flexion-extension connecting frame 412, and its axis constitutes the flexion-extension axis. In one embodiment, the two ends of the MCP flexion-extension rotating shaft 413 can be rotatably engaged with the support walls on both sides of the MCP flexion-extension connecting frame 412 through bearing assemblies to reduce frictional resistance during rotation, improve smoothness of movement, and withstand radial and axial loads.

[0033] The MCP flexion-extension drive unit 411 is fixedly installed on the lateral side of the MCP flexion-extension connecting frame 412, and its output shaft is coaxially and fixedly connected to one end of the MCP flexion-extension rotating shaft 413. When the MCP flexion-extension drive unit 411 is running, the output torque directly drives the MCP flexion-extension rotating shaft 413 to rotate around its own axis, thereby driving the upper structure to complete the flexion-extension action synchronously. Since the MCP flexion-extension drive unit 411 is fixed on the MCP flexion-extension connecting frame 412, which is a fixed side component, the drive unit itself does not rotate with the moving side. Therefore, it can avoid repeated bending and twisting of the drive circuit with joint movement, which improves the reliability and service life of the electrical connection to a certain extent.

[0034] The MCP swing structure 42 includes an MCP swing drive unit 421, an MCP swing connecting frame 422, and an MCP swing rotating shaft 423. The lower part of the MCP swing connecting frame 422 is fixedly connected to the MCP flexion-extension rotating shaft 413 and rotates synchronously around the flexion-extension axis with the MCP flexion-extension rotating shaft 413. The MCP swing rotating shaft 423 passes through the upper part of the MCP swing connecting frame 422, and its axis intersects the flexion-extension axis in space, forming the swing axis. Similarly, a bearing assembly can be provided between the MCP swing rotating shaft 423 and the MCP swing connecting frame 422 to achieve rotational engagement, reduce friction loss, and improve motion smoothness.

[0035] The MCP swing drive unit 421 is fixedly installed on the side of the MCP swing connecting frame 422, and its output shaft is coaxially fixedly connected to one end of the MCP swing rotating shaft 423. The driving torque output by the MCP flexion-extension drive unit 411 directly acts on the MCP flexion-extension rotating shaft 413, causing the MCP flexion-extension rotating shaft 413 to rotate around the transverse flexion-extension axis. The lower part of the MCP swing connecting frame 422 is fixedly connected to the MCP flexion-extension rotating shaft 413 and rotates synchronously with the shaft; the MCP axial rotation structure 43 and the entire finger structure 3 located above the swing layer both act as upper layer loads and synchronously complete the flexion-extension deflection in the front-back direction with the MCP flexion-extension rotating shaft 413. During the movement, the relative positions of the swing degree of freedom and the axial rotation degree of freedom remain unchanged, and the flexion-extension movement can be executed independently without mechanically coupling and interfering with the motion state of the other two degrees of freedom.

[0036] The MCP axial rotation structure 43 includes an MCP rotation drive unit 431, an MCP rotation mounting base 432, and an MCP rotation shaft 433. The lower part of the MCP rotation mounting base 432 is fixedly connected to the MCP swing shaft 423 and rotates synchronously around the swing axis with the MCP swing shaft 423. The MCP rotation drive unit 431 is fixedly installed inside the MCP rotation mounting base 432, and its output shaft is coaxially fixedly connected to the proximal end of the MCP rotation shaft 433. By internally arranging the MCP rotation drive unit 431, the internal space of the joint can be effectively utilized, the overall volume of the metacarpophalangeal joint structure 4 can be reduced, and the compactness of the dexterous hand structure can be improved.

[0037] The root of finger structure 3 is fixedly connected to the distal end face of MCP rotating shaft 433. When MCP rotating drive unit 431 operates, it directly drives MCP rotating shaft 433 to rotate, thereby causing finger structure 3 to complete axial rotation. Figure 3 and Figure 4 As shown, Figure 3 This represents the initial state of the metacarpophalangeal joint structure. Figure 4 For the rotational state of the metacarpophalangeal joint structure, the axial rotational degree of freedom also adopts an independent direct drive method, and there is no mechanical coupling between it and the flexion, extension and swing degrees of freedom, which further ensures the independence of the three degrees of freedom motion.

[0038] The robotic dexterous hand provided in this embodiment integrates the three-degree-of-freedom drive units onto corresponding fixed components using a support base and stacked connecting frames, achieving fully direct-drive, three-degree-of-freedom decoupled transmission. This structure shortens the transmission path, reduces mechanical backlash and transmission errors, and improves motion control accuracy and response speed. Furthermore, the modular stacked arrangement enhances structural integration and maintainability; individual degree-of-freedom components can be independently disassembled and replaced, reducing the cost of later maintenance and upgrades to some extent.

[0039] In some embodiments of this application, reference is made to Figure 2 As shown, the finger structure 3 includes, in longitudinal direction, a proximal phalanx, a middle phalanx, a distal phalanx, a proximal interphalangeal joint structure 5, and a distal interphalangeal joint structure 6. The root of the proximal phalanx is fixedly connected to the output side of the MCP axial rotation structure 43, and its spatial posture is adjusted synchronously with the three-degree-of-freedom movement of the metacarpophalangeal joint structure 4. In one embodiment, each finger segment can be configured with a hollow cavity structure to accommodate drive components, wiring, and sensing elements, thereby improving the integration and compactness of the finger structure.

[0040] The proximal interphalangeal joint structure 5 connects the distal end of the proximal phalanx to the proximal end of the middle phalanx, enabling flexion and extension movements of the middle phalanx relative to the proximal phalanx. Through the movement of the proximal interphalangeal joint structure 5, the angle between the middle and proximal phalanges can be adjusted, allowing the middle segment of the finger to conform to the side profile of the object, increasing the contact area and stability during grasping. The rotation axis of the proximal interphalangeal joint structure 5 can remain parallel to the flexion and extension axis of the metacarpophalangeal joint structure 4, ensuring that the flexion and extension movements of each finger segment are in the same plane, improving coordination and reducing unnecessary spatial force components.

[0041] The distal interphalangeal joint structure 6 connects the distal end of the middle phalanx to the proximal end of the distal phalanx, enabling flexion and extension movements of the distal phalanx relative to the middle phalanx. Through the movement of the distal interphalangeal joint structure 6, the flexion angle of the distal phalanx can be adjusted, allowing the fingertip to contact the surface at a suitable angle, improving the stability of fingertip contact and the precision of contact force control. The rotation axis of the distal interphalangeal joint structure 6 can also remain parallel to the rotation axis of the proximal interphalangeal joint structure 5, forming a continuous multi-segment flexion-extension kinematic chain, ensuring the smoothness and consistency of the finger flexion process.

[0042] The sequential kinematic chain, comprised of the metacarpophalangeal joint structure 4, the proximal interphalangeal joint structure 5, and the distal interphalangeal joint structure 6, endows finger structure 3 with multiple independent degrees of freedom, enabling continuous posture adjustments from the base to the fingertip. Compared to finger structures with fewer joints, the multi-joint sequential design allows the fingers to better adapt to surfaces with different curvatures and shapes, creating more contact points when grasping irregular objects, thus improving the stability and reliability of the grasp. Simultaneously, the multi-degree-of-freedom finger kinematic chain provides a richer foundation for intramanual manipulation, enabling more complex object posture adjustments in conjunction with the axial rotation and oscillation of the metacarpophalangeal joints, thereby enhancing the flexibility and precision of intramanual manipulation.

[0043] Existing dexterous hands often employ a low-joint or underactuated coupling structure, where each phalanx cannot be independently controlled, resulting in insufficient flexibility in bending and adjusting morphology. This makes it difficult to grasp complex curved objects, and their contact state adjustment capabilities are limited, hindering stable enveloping grasping and precise intramanual manipulation. The robotic dexterous hand provided in this embodiment addresses the problems of limited joint numbers and insufficient surface adaptation capabilities in existing finger structures. By incorporating three segments (proximal, mid, and distal) and two independent interphalangeal joints, a multi-degree-of-freedom serial finger kinematic chain is constructed, effectively improving the finger's bending adjustment capabilities and its ability to adapt to object shapes. Combined with the three-degree-of-freedom motion of the metacarpophalangeal joints, the fingers can achieve flexible posture adjustments in three-dimensional space, enabling both stable grasping and precise intramanual manipulation tasks, thus expanding the application scenarios of dexterous hands.

[0044] Furthermore, existing interphalangeal joints mostly use linkage, rope transmission, or underactuated coupling to achieve movement. The movements of different phalanges are strongly coupled and cannot be controlled independently. In addition, the transmission path is long, the mechanical clearance is large, and the control precision is insufficient. It is difficult to achieve precise fine-tuning of contact force and contact posture, which cannot meet the needs of high-precision operation.

[0045] To address this issue, in some embodiments of this application, the proximal interphalangeal joint structure 5 includes a PIP drive unit 51, a PIP connector 52, and a PIP pivot 53. The proximal end of the PIP connector 52 is fixedly connected to the distal end of the proximal phalanx, and the distal end of the PIP connector 52 corresponds to and engages with the proximal end of the middle phalanx. In one embodiment, the PIP connector 52 may employ a fork-shaped connection structure, with its distal end forming two opposing support arms to accommodate the proximal portion of the middle phalanx. The two support arms together support the PIP pivot 53, thereby improving the stability and support stiffness of the connection and reducing the risk of deformation caused by off-center loading. The PIP pivot 53 is laterally inserted inside the PIP connector 52, and the proximal end of the middle phalanx is fixedly connected to the PIP pivot 53.

[0046] The PIP drive unit 51 is fixed to the side of the PIP connector 52, and its output end is coaxially and fixedly connected to the PIP shaft 53. When the PIP drive unit 51 is running, it directly drives the PIP shaft 53 to rotate, causing the middle phalanx to complete flexion and extension movements around the axis of the PIP shaft 53. Since the PIP drive unit 51 is fixed to the PIP connector 52, which is the fixed side, and directly drives the PIP shaft 53 to rotate, there is no need for an intermediate transmission mechanism. Therefore, it can effectively reduce transmission backlash and transmission error, and improve the position control accuracy of the proximal interphalangeal joint. At the same time, the independent drive design allows the movement of the proximal interphalangeal joint to be performed independently of other joints, without mechanical coupling with other degrees of freedom, which facilitates the control system to achieve independent angle and torque control.

[0047] The distal interphalangeal joint structure 6 includes a DIP drive unit 61, a DIP connector 62, and a DIP pivot 63. The proximal end of the DIP connector 62 is fixedly connected to the distal end of the middle phalanx, and the distal end of the DIP connector 62 corresponds to the proximal end of the distal phalanx. Similar to the PIP connector 52, the DIP connector 62 can also adopt a fork-shaped support structure to provide stable rotational support for the distal phalanx, ensuring the joint's load-bearing capacity and smooth movement. The DIP pivot 63 is transversely inserted inside the DIP connector 62, and the proximal end of the distal phalanx is fixedly connected to the DIP pivot 63 to ensure synchronized movement.

[0048] The DIP drive unit 61 is fixed to the side of the DIP connector 62, and its output end is coaxially and fixedly connected to the DIP shaft 63. When the DIP drive unit 61 is running, it directly drives the DIP shaft 63 to rotate, causing the distal phalanx to complete independent flexion and extension movements. The distal interphalangeal joint also adopts an independent direct drive configuration, and its movement is not affected by the movement state of the proximal interphalangeal joint. It can independently adjust the bending angle of the distal phalanx, achieving precise fine-tuning of the fingertip posture.

[0049] Through independently driven proximal interphalangeal joint structure 5 and distal interphalangeal joint structure 6, finger structure 3 can independently adjust the bending angle of each phalanx. When grasping objects of different shapes, the bending angle of the two interphalangeal joints can be adjusted according to the curvature of the object's surface, allowing the finger segments to better conform to the object's contour, increasing the effective contact area and improving grasping stability. When performing fine manipulation tasks, the angle of the distal interphalangeal joint can be adjusted individually to fine-tune the fingertip contact force and contact posture, improving the accuracy of the operation. At the same time, the independent direct drive design also facilitates the deployment of force control algorithms, enabling more precise control of the contact force of each finger segment and avoiding damage to fragile objects during grasping.

[0050] The robotic dexterous hand provided in this embodiment addresses the problems of low control precision and insufficient adjustment flexibility in existing interphalangeal joint coupled transmission systems. It equips each of the two interphalangeal joints with an independent direct-drive unit, achieving independent decoupled control of the flexion and extension movements of each joint. This design not only reduces errors and backlashes introduced by the transmission links, improving the control precision and response speed of joint movements, but also enhances the flexibility of finger posture adjustment, enabling better adaptation to grasping objects of different shapes and sizes. Compared to underactuated fingers with coupled transmission, the finger structure of this embodiment possesses more refined posture adjustment capabilities, providing more precise end-effector support for complex intramanual operations.

[0051] In some embodiments of this application, reference is made to Figure 5 and Figure 6As shown, the palm structure 2 includes a first palm 21, a second palm 22, a palm connecting structure 23, and a palm driving structure 24. The first palm 21 is located in the upper region of the palm structure 2, and the second palm 22 is located in the lower region of the palm structure 2. The first palm 21 and the second palm 22 together constitute the main support base of the dexterous hand, used to install the finger structures and driving components, and at the same time to bear the load transmission function during the grasping process, distributing the external force on the fingers evenly to the entire palm structure.

[0052] The palm-joint structure 23 connects the lower edge of the first palm 21 and the upper edge of the second palm 22, forming a rotating joint between the first palm 21 and the second palm 22. The palm-joint structure 23 provides stable rotational support for the relative movement of the two palm parts, ensuring coaxiality and structural rigidity during movement, preventing swaying or jamming, and also bearing the load transfer function between the two palm parts. Through this rotating joint, the first palm 21 can rotate relative to the second palm 22 around the rotation axis, thereby changing the overall opening angle and spatial configuration of the palm, achieving active adjustment of the palm shape.

[0053] The palm drive structure 24 is installed in the adjacent area between the first palm 21 and the second palm 22. Its fixed side is fixedly connected to the second palm 22, and its output side is fixedly connected to the first palm 21. The palm drive structure 24 is used to output driving torque to drive the first palm 21 to rotate relative to the second palm 22 about the rotation axis of the palm connection structure 23. Since the fixed side of the palm drive structure 24 remains relatively fixed to the second palm 22, and the output side directly acts on the first palm 21, the driving force acts directly on the rotating pair, the transmission path is short, and it can effectively improve the response speed and position control accuracy of the palm movement.

[0054] In one embodiment, the finger structure mounted on the first palm 21 and the finger structure mounted on the second palm 22 can change their relative distance as the two palms rotate relative to each other. Figure 5 As shown, Figure 5 In the unfolded state of the palm structure, when the palm drive structure 24 drives the first palm 21 to rotate away from the second palm 22, the entire palm is in an unfolded state, increasing the distance between the fingers to accommodate larger objects. Simultaneously, it provides ample space for the fingers to close and grasp, facilitating rapid approach to the target object. Figure 6 As shown, Figure 6 In the closed state of the palm structure, when the palm drive structure 24 drives the first palm 21 to rotate towards the second palm 22, the palm as a whole is in a closed state, and each finger synchronously retracts towards the palm area, which can form a more comprehensive grasping space, improve the ability to wrap around objects and the stability of grasping.

[0055] Most existing robotic dexterous hands employ a one-piece, fixed palm structure, meaning the palm shape cannot be actively changed. This results in poor adaptability to objects of different sizes and shapes, making it difficult to effectively enclose large or complex curved objects, leading to insufficient contact area and decreased grasping stability. Furthermore, because the palm cannot move actively, it is difficult to use palm shape changes to assist in completing complex intramanual operations, thus limiting the improvement of the overall operational capabilities of dexterous hands.

[0056] Compared to traditional fixed palm structures, the active, variable-configuration palm in this embodiment can proactively adjust its shape according to the size of the object being grasped and the needs of the task, without relying entirely on finger movements to adapt to different objects. This enhances the environmental adaptability of the dexterous hand to a certain extent. Simultaneously, the active movement of the palm can alter the relative spatial relationships between the fingers, providing additional degrees of freedom for in-hand operations, assisting in object repositioning and posture adjustment, and further enhancing the dexterous hand's complex operational capabilities. When grasping spheres, cylinders, and irregular objects, the palm can actively close to form a contact layout that better conforms to the object's shape, thereby improving overall grasping stability.

[0057] The robotic dexterous hand provided in this embodiment addresses the problems of poor adaptability and inability to assist in-hand operations with existing fixed palms. By dividing the palm into two relatively rotatable parts and configuring independent drive structures, it achieves active adjustment of the palm shape. This design makes the palm itself part of the active motion mechanism, enabling it to coordinate with finger movements. This not only improves the ability to grasp and cover objects of different sizes and enhances grasping stability, but also provides additional motion support for complex in-hand operations, expanding the operational boundaries of the dexterous hand.

[0058] In some embodiments of this application, the palm connection structure 23 includes a palm connection shaft 231. The palm connection shaft 231 extends along the width direction of the palm and passes through the lower edge of the first palm 21 and the upper edge of the second palm 22. This single-shaft through-type connection design ensures the coaxiality of the rotation of the first palm 21 and the second palm 22, improves the smoothness of movement and the load-bearing capacity of the structure, and avoids rotational jamming caused by off-center loading.

[0059] The palm drive structure 24 is fixed to the side of the second palm 22 near the palm connecting shaft 231, and its output shaft is coaxially and fixedly connected to the palm connecting shaft 231. The first palm 21 rotates synchronously with the palm connecting shaft 231, allowing the included angle between the first palm 21 and the second palm 22 to be continuously adjusted. Existing movable palm structures mostly adopt an external drive combined with gears, connecting rods, and other transmission mechanisms, resulting in a long transmission chain, large mechanical backlash, insufficient control precision, and the external drive mechanism occupies additional external space. In this example, the palm drive structure 24 is arranged on the side of the palm and directly drives the connecting shaft to rotate, eliminating the need for additional gears, connecting rods, and other transmission mechanisms. This effectively simplifies the transmission chain, improves transmission precision, makes the palm structure layout more compact, and reduces the occupation of external space.

[0060] When the palm drive structure 24 is running, the output torque drives the palm connecting shaft 231 to rotate, which in turn drives the first palm 21, which is fixedly connected to the palm connecting shaft 231, to rotate synchronously, realizing continuous stepless adjustment of the angle between the first palm 21 and the second palm 22. In one embodiment, the palm drive structure 24 can use a servo drive element with position feedback, which can realize precise control of the palm rotation angle, thereby accurately adjusting the opening and closing degree of the palm to adapt to different operating needs; at the same time, it can also realize torque mode control, adaptively adjusting the closing force of the palm according to the grasping force state, avoiding excessive clamping and damage to the object.

[0061] The palm adjustment structure, driven by a pivot axis, provides higher control precision and response speed for the opening and closing motion of the palm. It allows for real-time adjustment of the palm shape during grasping, coordinating with finger movements to achieve a comprehensive gripping motion. During in-hand operation, small opening and closing of the palm can also adjust the force applied to the object, assisting in adjusting the object's position and posture, thus improving the smoothness and stability of the operation. Furthermore, the side-mounted direct-drive layout does not occupy internal installation space in the palm and does not affect the arrangement of finger drive components and electrical wiring, facilitating the rational planning of the palm's internal space.

[0062] The robotic dexterous hand provided in this embodiment addresses the problems of complex, poorly compact, and low-precision control in existing movable palm transmission mechanisms. It employs a through-type connection between the rotating shaft and the side-mounted direct-drive unit, achieving direct drive of the palm's opening and closing movements. This design simplifies the transmission structure, reduces transmission backlash and errors, improves the control precision of the palm's movements, and optimizes the spatial layout, enhancing the integration and compactness of the palm structure. This is beneficial for the miniaturization and lightweight design of the dexterous hand.

[0063] In some embodiments of this application, reference is made to Figure 7 and Figure 8As shown, the finger structure 3 includes a thumb 34, and a thumb root structure 7 is disposed between the thumb 34 and the palm structure 2. The fixed side of the thumb root structure 7 is fixedly connected to the thumb mounting side of the palm structure 2, and the output side of the thumb root structure 7 is fixedly connected to the root of the thumb 34. The rotation axis of the thumb root structure 7 is inclined towards the palm.

[0064] In one embodiment, the thumb mounting side can be located in the side region of the palm structure 2, corresponding to the physiological position of the human thumb, to ensure that the thumb 34 can form a relative clamping relationship with other fingers, which conforms to the biomimetic design principle. The thumb root structure 7, as an independent motion mechanism, is located at the root of the kinematic chain of the thumb 34, and is used to drive the entire thumb 34 to rotate as a whole, thereby adjusting the spatial position of the thumb 34 relative to the palm and other fingers, providing the thumb with additional basic degrees of freedom of movement.

[0065] In some embodiments, when the finger structure 3 is configured as four groups, it may include the index finger 31, middle finger 32, ring finger 33, and thumb 34. Since the rotation axis of the thumb root structure 7 is inclined towards the palm, when the thumb root structure 7 drives the thumb 34 to rotate, the thumb 34 can move closer to or further away from the palm, achieving a palm-opening and closing motion similar to that of a human hand. Figure 7 As shown, Figure 7 With the thumb open, the thumb 34 maintains a large distance from other fingers (such as the index finger 31), facilitating the entry of the target object into the grasping area, suitable for approaching and initially aligning large objects; such as Figure 8 As shown, Figure 8 In the palm-opposing position of the thumb, the thumb 34 is drawn towards the palm, forming a relatively closed gripping space with other fingers (such as the index finger 31), which improves the stability and coverage of the grip, making it suitable for fine gripping and complex operation tasks.

[0066] Compared to a thumb structure with a fixed base, this embodiment expands the working space of the thumb 34 by adding additional degrees of freedom at the base, thus improving the relative posture adjustment capability between the thumb and other fingers. When performing fine grasping tasks, the thumb base structure 7 can adjust the overall orientation of the thumb, allowing it to contact the object at a more suitable angle and improving gripping stability. When performing intra-hand manipulation tasks, the thumb base structure 7 can coordinate with the movement of other fingers to actively adjust the support position and contact force, assisting in the posture adjustment and repositioning of the object, thereby improving the overall operational performance of the dexterous hand to a certain extent. Simultaneously, the enhanced palm opposition capability enables the dexterous hand to perform more complex enveloping grasps, improving its adaptability to grasping irregular and curved objects.

[0067] In some embodiments of this application, the thumb root structure 7 includes a thumb additional degree-of-freedom structure 71, which includes a thumb drive unit 711, a thumb connecting base 712, a thumb rotation shaft 713, and a thumb connector 714. The thumb connecting base 712 is fixedly connected to the thumb mounting side surface of the palm structure 2. The thumb rotation shaft 713 passes through the interior of the thumb connecting base 712.

[0068] In one embodiment, the axis of the thumb rotation shaft 713 is inclined toward the palm and can be rotated with the thumb connecting base 712 through the bearing assembly, thereby reducing rotational friction resistance, improving smoothness of movement, and bearing radial and axial loads to ensure the load-bearing capacity of the structure.

[0069] One end of the thumb connector 714 is fixedly connected to the thumb rotation shaft 713, and the other end is fixedly connected to the base of the thumb 34. In one embodiment, the thumb connector 714 can adopt an L-shaped or crank-arm structure, with one end circumferentially fixed to the thumb rotation shaft 713 and the other end fixedly connected to the base end face of the thumb 34, so as to convert the rotational motion of the thumb rotation shaft 713 into the overall swinging motion of the thumb 34; the length and angle of the crank arm can be designed according to the movement range requirements of the thumb to adapt to different workspace requirements.

[0070] The thumb drive unit 711 is fixed to the side of the thumb connecting base 712, and its output end is coaxially and fixedly connected to the thumb rotation shaft 713. When the thumb drive unit 711 is running, it directly drives the thumb rotation shaft 713 to rotate around its own axis, thereby driving the entire thumb 34 to complete the palm-facing swinging motion through the thumb connector 714. This direct-drive method directly applies the driving force to the thumb rotation shaft 713, eliminating the need for intermediate transmission mechanisms. This effectively reduces transmission backlash and errors, improving the control accuracy and response speed of the thumb's palm-facing movement. Furthermore, the side-mounted layout of the drive unit fully utilizes the space on the side of the palm, improving structural integration, avoiding excessive occupation of the palm's internal space, and not affecting the arrangement of other finger drive components.

[0071] Through the above structure, the thumb additional degree of freedom structure 71 can independently drive the thumb 34 to complete the palmar opposition movement. This degree of freedom is independent of the thumb's own metacarpophalangeal joint and interphalangeal joint degrees of freedom, and there is no mechanical coupling. The control system can control the movement of each degree of freedom separately according to task requirements, realizing flexible adjustment of the thumb posture. During grasping, the overall position of the thumb can be quickly adjusted through the root degree of freedom, and the bending movement of the knuckles can be used to achieve stable coverage of the object; during in-hand operation, the supporting force of the thumb can be finely adjusted through the root degree of freedom, and the movement of other fingers can be used to achieve continuous rotation and repositioning of the object.

[0072] In some embodiments of this application, the finger structure 3 further includes a fingertip structure 8. The fingertip structure 8 is fixedly installed on the front end face of the distal phalanx, serving as the end component of the finger structure 3 that directly contacts the object, and is used to bear contact loads and provide contact friction. The fingertip structure 8 may use the same base material as the distal phalanx, and may also have a flexible contact layer, anti-slip layer, or sensing element on its surface to improve contact performance and environmental awareness; the shape of the fingertip structure 8 may be set as a curved surface with rounded transitions to avoid sharp edges causing damage to the grasped object.

[0073] The fingertip structure 8 has a nail structure 81 at its front, with its outer surface extending forward and protruding from the fingertip surface. The nail structure 81 can be made of a rigid material, and its front end can be designed with a straight or slightly curved edge to simulate the contact characteristics of a human fingernail. The protruding height of the nail structure 81 can be adjusted according to the application scenario, ensuring contact rigidity while avoiding excessive protrusion that could affect the contact effect of conventional grasping. The portion of the nail structure 81 protruding from the fingertip surface can provide additional contact support and force application points when contacting special objects such as object edges, thin sheet objects, and small parts, compensating for the insufficient contact rigidity and poor positioning accuracy of flexible or curved fingertips.

[0074] When performing grasping tasks, for thin, edge-shaped objects, the nail structure 81 can insert into gaps in the object or conform to its edge, providing a more stable gripping force and reducing the risk of slippage. For small parts, the nail structure 81 can provide more precise contact positioning, improving the accuracy of grasping tiny objects. When performing fine manipulation tasks, the nail structure 81 can precisely contact and apply force to the object's minute features, improving the accuracy and stability of the operation. During object rotation and repositioning within the hand, the nail structure 81 can increase the biting force at the contact edge, improving the reliability of contact posture adjustment and preventing operation failure due to contact slippage.

[0075] Compared to traditional purely flexible or purely curved fingertips, the fingertip structure 8 in this embodiment expands the contact scenarios and methods of the fingertip by adding a protruding nail structure 81, improving the ability to manipulate objects with special shapes and enhancing the adaptability and stability of dexterous hands in performing fine manipulation tasks to a certain extent. At the same time, the design of the nail structure 81 is also more in line with the biomimetic design of the human hand, better simulating the operation movements and contact characteristics of the human hand, and improving the naturalness of operation in human-computer interaction scenarios.

[0076] In some embodiments of this application, the dexterous hand further includes a drive structure 9. The drive units corresponding to the metacarpophalangeal joint structure 4, the joints of the finger structure 3, the palm structure 2, and the thumb root structure 7 together constitute the drive structure 9. Each drive unit is fixedly mounted on the fixed side member of the corresponding structure, and the output end of the drive unit is fixedly connected to the rotation shaft of the corresponding structure.

[0077] The drive structure 9 can adopt a distributed independent drive architecture, with each degree of freedom of motion corresponding to at least one independent drive unit, and all drive units together form a complete drive system. Specifically, the flexion, extension, swing, and axial rotation degrees of freedom of the metacarpophalangeal joint structure 4 each correspond to an independent drive unit; the proximal and distal interphalangeal joints of the finger structure 3 each correspond to an independent drive unit; the active adjustment degree of freedom of the palm structure 2 corresponds to an independent drive unit; and the opposition degree of freedom of the thumb root structure 7 corresponds to an independent drive unit. All drive units adopt a direct drive arrangement, with the driving force acting directly on the rotation axis of the corresponding joint, eliminating the need for long-distance transmission mechanisms such as ropes, linkages, and gear sets.

[0078] Since each drive unit is fixed to the fixed side component of the corresponding structure, the drive unit itself does not rotate with the moving side of the joint. Therefore, it can effectively reduce the bending and twisting of the drive circuit, improve the reliability and service life of the electrical connection, and reduce the risk of circuit fatigue damage. At the same time, the independent direct drive configuration completely decouples the motion degrees of freedom at the mechanical level. The movement of a single degree of freedom will not mechanically interfere with other degrees of freedom. The control system can independently control the position, velocity, and torque of each degree of freedom, which greatly reduces the complexity of the control algorithm and improves the control accuracy and response speed.

[0079] This embodiment employs a distributed, modular drive layout, where each degree of freedom's drive component and mechanical structure together form an independent functional module. Each module can be installed, disassembled, maintained, and replaced independently, eliminating the need for large-scale disassembly of the overall structure. This reduces the product's later maintenance costs and upgrade complexity to a certain extent. Simultaneously, the decoupled drive design provides a solid hardware foundation for advanced control strategies such as multi-finger collaborative control, force-position hybrid control, and in-hand operation control, better supporting the execution of complex operational tasks.

[0080] As can be seen from the above embodiments, in actual use, the robot's dexterous hand can sequentially complete the entire action process, including object approach, grasping and covering, hand manipulation, and object release, according to task requirements. During the object approach phase, the palm structure 2 can drive the first palm 21 to unfold via the palm drive structure 24, increasing the distance between the fingers. Simultaneously, the metacarpophalangeal and interphalangeal joints of each finger extend synchronously, expanding the grasping space and facilitating rapid approach to the target object. During the grasping and covering phase, the palm structure 2 gradually closes, causing the fingers to retract towards the palm area. Simultaneously, the metacarpophalangeal and interphalangeal joints of each finger bend in coordination, combined with the opposing action of the thumb 34, so that the fingers and thumb together cover the object surface, forming a stable gripping state. For objects of different shapes, the optimal contact and fit effect can be achieved by adjusting the bending angle of each finger joint, the swing angle of the metacarpophalangeal joints, and the opening and closing degree of the palm, ensuring grasping stability.

[0081] During the hand-operated phase, the contact direction can be adjusted collaboratively by the axial rotational degrees of freedom of the metacarpophalangeal joints of each finger. Combined with the palmar adjustment at the base of the thumb and slight opening and closing of the palm, continuous rotation, fine-tuning of posture, and repositioning of the object can be achieved while maintaining its gripping state, without needing to release the object and re-grasp it, significantly improving operational efficiency and stability. In fine-tuning scenarios, independent fine-tuning of the distal interphalangeal joints, combined with the nail structure 81 of the fingertip structure 8, allows for precise force application and positioning of the object's edges and small features, completing high-precision operation tasks. After the operation is completed, the joints gradually extend, the palm unfolds, the object is released, and the entire operation process is finished.

[0082] Other embodiments of this disclosure will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this disclosure that follow the general principles of this disclosure and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this disclosure are indicated by the following claims.

[0083] It should be understood that this disclosure is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this disclosure is limited only by the appended claims.

Claims

1. A high-degree-of-freedom direct-drive robot dexterous hand for complex intramanual operations, characterized in that, It includes palmar structures (2), at least one set of finger structures (3), and metacarpophalangeal joint structures (4); The metacarpophalangeal joint structure (4) is located between the palm structure (2) and the root of the finger structure (3); The metacarpophalangeal joint structure (4) includes an MCP flexion-extension structure (41), an MCP swing structure (42), and an MCP axial rotation structure (43). The fixed side of the MCP flexion-extension structure (41) is fixed relative to the palm structure (2), and the output side of the MCP flexion-extension structure (41) rotates about the flexion-extension axis that extends laterally. The fixed side of the MCP swing structure (42) is fixedly connected to the output side of the MCP flexion-extension structure (41) and moves synchronously with the MCP flexion-extension structure (41). The output side of the MCP swing structure (42) rotates around the swing axis that is arranged to intersect the flexion-extension axis. The fixed side of the MCP axial rotation structure (43) is fixedly connected to the output side of the MCP swing structure (42) and moves synchronously with the MCP swing structure (42). The output side of the MCP axial rotation structure (43) rotates around the rotation axis extending longitudinally along the finger. The root of the finger structure (3) is fixedly connected to the output side of the MCP axial rotation structure (43); The MCP bending structure (41), the MCP swing structure (42) and the MCP axial rotation structure (43) are each equipped with independent drive units. Each drive unit is fixed on the fixed side component of the corresponding structure, and the output end of the drive unit is fixedly connected to the rotation shaft of the corresponding structure.

2. The high-degree-of-freedom direct-drive robot dexterous hand for complex intramanual operations according to claim 1, characterized in that, The metacarpophalangeal joint structure (4) also includes an MCP support base (44) and an MCP mounting structure (45). The MCP support base (44) is fixedly connected to the finger mounting side surface of the palm structure (2) through the MCP mounting structure (45); The MCP flexion-extension structure (41) includes an MCP flexion-extension drive unit (411), an MCP flexion-extension connecting frame (412), and an MCP flexion-extension rotating shaft (413). The MCP flexion-extension connector (412) is fixedly installed on the side surface of the MCP support base (44) away from the palm structure (2); The MCP flexion-extension pivot (413) is transversely inserted into the internal cavity of the MCP flexion-extension connecting frame (412), and its axis forms the flexion-extension axis. The MCP flexion-extension drive unit (411) is fixedly installed on the lateral side of the MCP flexion-extension connecting frame (412), and its output shaft is coaxially fixedly connected to one end of the MCP flexion-extension rotating shaft (413). The MCP swing structure (42) includes an MCP swing drive unit (421), an MCP swing connecting frame (422), and an MCP swing rotating shaft (423). The lower part of the MCP swing connecting frame (422) is fixedly connected to the MCP flexion-extension rotating shaft (413) and rotates synchronously around the flexion-extension axis with the MCP flexion-extension rotating shaft (413); The MCP swing shaft (423) passes through the upper part of the MCP swing connecting frame (422), and its axis intersects the flexion and extension axis in space to form a swing axis. The MCP swing drive unit (421) is fixedly installed on the side of the MCP swing connecting frame (422), and its output shaft is coaxially fixedly connected to one end of the MCP swing rotating shaft (423). The MCP axial rotation structure (43) includes an MCP rotation drive unit (431), an MCP rotation mounting base (432), and an MCP rotation shaft (433). The lower part of the MCP rotary mounting base (432) is fixedly connected to the MCP swing shaft (423) and rotates synchronously around the swing axis with the MCP swing shaft (423); The MCP rotating shaft (433) is inserted longitudinally along the finger inside the MCP rotating mounting base (432), and its axis forms the rotation axis; The MCP rotary drive unit (431) is fixedly installed inside the MCP rotary mounting base (432), and its output shaft is coaxially fixedly connected to the proximal end of the MCP rotary shaft (433). The root of the finger structure (3) is fixedly connected to the distal end face of the MCP rotating shaft (433).

3. A high-degree-of-freedom direct-drive robot dexterous hand for complex intramanual operations according to claim 1, characterized in that, The finger structure (3) includes, in the longitudinal direction, the proximal phalanx, the middle phalanx, the distal phalanx, the proximal interphalangeal joint structure (5), and the distal interphalangeal joint structure (6). The proximal interphalangeal joint structure (5) connects the distal end of the proximal phalanx to the proximal end of the middle phalanx. The distal interphalangeal joint structure (6) connects the distal end of the middle phalanx to the proximal end of the distal phalanx. The root of the proximal phalanx is fixedly connected to the output side of the MCP axial rotation structure (43).

4. A high-degree-of-freedom direct-drive robot dexterous hand for complex intramanual operations according to claim 3, characterized in that, The proximal interphalangeal joint structure (5) includes a PIP drive unit (51), a PIP connector (52), and a PIP pivot (53). The proximal end of the PIP connector (52) is fixedly connected to the distal end of the proximal phalanx, and the distal end of the PIP connector (52) is correspondingly engaged with the proximal end of the middle phalanx. The PIP pivot (53) is transversely inserted inside the PIP connector (52), and the proximal end of the middle phalanx is fixedly connected to the PIP pivot (53). The PIP drive unit (51) is fixed to the side of the PIP connector (52), and its output end is coaxially fixedly connected to the PIP shaft (53). The distal interphalangeal joint structure (6) includes a DIP drive unit (61), a DIP connector (62), and a DIP pivot (63). The proximal end of the DIP connector (62) is fixedly connected to the distal end of the middle phalanx, and the distal end of the DIP connector (62) is correspondingly engaged with the proximal end of the distal phalanx. The DIP pivot (63) is transversely inserted inside the DIP connector (62), and the proximal end of the distal phalanx is fixedly connected to the DIP pivot (63); The DIP drive unit (61) is fixed to the side of the DIP connector (62), and its output end is coaxially fixedly connected to the DIP shaft (63).

5. A high-degree-of-freedom direct-drive robot dexterous hand for complex intramanual operations according to claim 1, characterized in that, The palm structure (2) includes a first palm (21), a second palm (22), a palm connection structure (23), and a palm drive structure (24). The first palm (21) is arranged in the upper region of the palm structure (2), and the second palm (22) is arranged in the lower region of the palm structure (2); The palm connection structure (23) is connected between the lower edge of the first palm (21) and the upper edge of the second palm (22), forming a rotating pair of the first palm (21) relative to the second palm (22); The palm drive structure (24) is installed in the adjacent area of ​​the first palm (21) and the second palm (22), with its fixed side fixedly connected to the second palm (22) and its output side fixedly connected to the first palm (21).

6. A high-degree-of-freedom direct-drive robot dexterous hand for complex intramanual operations according to claim 5, characterized in that, The palm connection structure (23) includes a palm connection pivot (231); The palm-connecting pivot (231) extends along the width of the palm and passes through the lower edge of the first palm (21) and the upper edge of the second palm (22). The palm drive structure (24) is fixed to the side of the second palm (22) near the palm connecting shaft (231), and its output shaft is coaxially fixedly connected to the palm connecting shaft (231). The first palm part (21) and the palm part connecting shaft (231) rotate synchronously, so that the included angle between the first palm part (21) and the second palm part (22) can be continuously adjusted.

7. A high-degree-of-freedom direct-drive robot dexterous hand for complex intramanual operations according to claim 1, characterized in that, The finger structure (3) includes a thumb (34), and a thumb root structure (7) is provided between the thumb (34) and the palm structure (2). The fixed side of the thumb root structure (7) is fixedly connected to the thumb mounting side of the palm structure (2), and the output side of the thumb root structure (7) is fixedly connected to the root of the thumb (34). The rotation axis of the thumb root structure (7) is arranged inclined toward the palm.

8. A high-degree-of-freedom direct-drive robot dexterous hand for complex intramanual operations according to claim 7, characterized in that, The thumb root structure (7) includes a thumb additional degree of freedom structure (71), which includes a thumb drive unit (711), a thumb connecting base (712), a thumb rotation shaft (713), and a thumb connector (714). The thumb connecting base (712) is fixedly connected to the thumb mounting side surface of the palm structure (2); The thumb rotation shaft (713) passes through the inside of the thumb connecting base (712); One end of the thumb connector (714) is fixedly connected to the thumb rotating shaft (713), and the other end is fixedly connected to the root of the thumb (34); The thumb drive unit (711) is fixed to the side of the thumb connecting base (712), and its output end is coaxially fixedly connected to the thumb rotation shaft (713).

9. A high-degree-of-freedom direct-drive robot dexterous hand for complex intramanual operations according to claim 3, characterized in that, The finger structure (3) also includes a fingertip structure (8); The fingertip structure (8) is fixedly installed on the front end face of the distal phalanx; The fingertip structure (8) has a nail structure (81) at its front, and the outer surface of the nail structure (81) extends forward and protrudes from the fingertip surface.

10. A high-degree-of-freedom direct-drive robot dexterous hand for complex intramanual operations according to claim 8, characterized in that, It also includes the drive structure (9); The driving units corresponding to the metacarpophalangeal joint structure (4), the joints of the finger structure (3), the palm structure (2), and the thumb root structure (7) together constitute the driving structure (9). Each drive unit is fixedly installed on the fixed side component of the corresponding structure, and the output end of the drive unit is fixedly connected to the rotating shaft of the corresponding structure.

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