A coupled adaptive underactuated biomimetic dexterous hand finger

Abstract

The application discloses a coupled adaptive underactuated bionic dexterous manipulator finger and relates to the technical field of manipulator fingers.The manipulator finger comprises a finger connecting base, a knuckle assembly and a driving assembly.The knuckle assembly comprises a distal knuckle, a middle knuckle and a proximal knuckle which are connected in sequence and cooperate with each other.The driving assembly comprises a side swing-flexion module and a grabbing driving module, and the side swing-flexion module and the grabbing driving module each comprise a multi-stage connecting rod structure.The side swing-flexion module and the grabbing driving module are used for driving the knuckle assembly to complete a specified action.The manipulator finger effectively improves the passive adaptive capacity of the finger, realizes more natural enveloping grabbing, and makes the finger have a larger grabbing space while keeping simple and compact structure.

Description

Technical Field

[0001] This invention generally relates to the field of robotic hand finger technology, and specifically to a coupled adaptive underactuated bionic dexterous robotic hand finger. Background Technology

[0002] In recent years, with the rapid development of robotics technology, robotic hands, as an important component of robots, have seen continuous improvements in function and performance, and their application areas have gradually expanded from the initial manufacturing sector to non-manufacturing sectors. Currently popular biomimetic dexterous robotic hands, by mimicking the structure and movement of human or other biological hands, can not only achieve more natural and flexible operations but also complete more complex tasks, showing broad application prospects.

[0003] Among common rigid dexterous hands, those based on linkage-driven mechanisms constitute a significant portion. Hands developed based on this mechanism facilitate joint movement in desired directions by combining multiple links, offering advantages such as bidirectional joint control, robustness, and ease of manufacturing and maintenance. However, this mechanism struggles to achieve multi-degree-of-freedom motion and requires a large workspace. Furthermore, the in-hand manipulation of multi-finger linkage robotic hands is often limited by the range of finger postures, hindering precise and flexible grasping of objects. To address these limitations, we propose a coupled adaptive underactuated bionic dexterous manipulator finger. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a coupled adaptive underactuated bionic dexterous manipulator finger.

[0005] This invention proposes a coupled adaptive underactuated bionic dexterous manipulator finger, comprising:

[0006] A finger connecting base forms a mounting surface, which is used to support the interlocking knuckle assembly and drive assembly;

[0007] The knuckle assembly includes: a distal knuckle, a mid knuckle, and a proximal knuckle that cooperate with each other and are connected in sequence; wherein the proximal knuckle is located on the side closer to the finger connection base;

[0008] The drive assembly is connected to the knuckle assembly; the drive assembly includes a lateral swing-flexion-extension module and a gripping drive module, and both the lateral swing-flexion-extension module and the gripping drive module are structures composed of multiple links. The lateral swing-flexion-extension module and the gripping drive module cooperate with each other to drive the knuckle assembly to complete a specified action.

[0009] The lateral swing-flexion-extension module includes: a first drive link connected to both sides of the end of the proximal phalanx away from the middle phalanx; the gripping drive module includes: two second drive links movably connected to the ends of the proximal phalanx and the middle phalanx that are close to each other, and two third drive links movably connected to the distal phalanx.

[0010] According to the technical solution provided by the present invention, the lateral swing-flexion module includes at least two sets of lateral swing-flexion units connected by transmission, as well as a rotating seat and a ball joint connecting rod connected to the two lateral swing-flexion units.

[0011] The rotating seat is disposed on the top of the finger connecting base, and the rotating seat includes two rotating ends, which are respectively rotatably connected to different lateral swing-flexion-extension units; one end of the proximal phalanx is rotatably disposed in the middle of the ball joint; the two lateral swing-flexion-extension units can synchronously drive the proximal phalanx to move through the rotating seat and the ball joint.

[0012] According to the technical solution provided by the present invention, the lateral swing-flexion-extension unit includes:

[0013] A front slider is disposed on the finger connecting base, and the front sliders included in the two side swing-flexion-extension units are parallel and correspondingly disposed along a first direction; the front slider can slide along the first direction;

[0014] The first double-headed joint bearing rod is rotatably mounted on the top of the front slider, and the ends of the first double-headed joint bearing rods contained in the two side swing-flexion units that are away from the front slider are respectively rotatably connected to the two ends of the ball joint connecting rod.

[0015] One end of each of the two first drive links is rotatably connected to the body of the ball joint, and the other end of each is rotatably connected to one of the rotating ends of the rotating seat; the two first drive links are located on both sides of the proximal phalanx at the rotation connection point of the ball joint.

[0016] A first driving member is rotatably connected to the front slider, and the first driving member is used to drive the front slider to reciprocate along the first direction.

[0017] According to the technical solution provided by the present invention, the gripping drive module includes a first gripping drive unit and a second gripping drive unit connected by transmission, and a fixed-length rod cooperating with the two gripping drive units. The first gripping drive unit, the second gripping drive unit and the fixed-length rod are all connected to a first ball shaft.

[0018] One end of the fixed-length rod is rotatably connected to the first ball shaft, and the other end is rotatably connected to the ball head connecting rod; a first buffer is provided at the end of the fixed-length rod connected to the ball head connecting rod.

[0019] According to the technical solution provided by the present invention, the first grasping driving unit includes:

[0020] A rear slider is disposed on the finger connecting base; the extension direction of the rear slider is parallel to the extension direction of the front slider, and it is located between the two front sliders and in a different plane from the front sliders; a second ball bearing is rotatably disposed on the top of the rear slider;

[0021] The second double-headed spherical bearing rod has one end rotatably connected to the first ball shaft and the other end rotatably connected to the second ball shaft.

[0022] The fourth drive link has one end rotatably mounted on the first ball shaft, and its other end is connected to two second drive links via a first pin.

[0023] The two second drive links are rotatably connected to the two ends of the first pin; the other end of the two second drive links is also rotatably connected to the second pin; the ends of the middle phalanx and the proximal phalanx that are close to each other are rotatably connected to the rod body of the second pin, and the rotatable connection points of the two second drive links and the second pin are located on both sides of the middle phalanx and the proximal phalanx.

[0024] The second driving member is rotatably connected to the rear slider and is used to drive the rear slider to reciprocate along the first direction.

[0025] According to the technical solution provided by the present invention, at least two lugs are provided at the end of the distal phalanx near the middle phalanx; one of the lugs is rotatably connected to the end of the middle phalanx away from the proximal phalanx by a third pin.

[0026] The second gripping drive unit includes: a fourth pin shaft rotatably connected to another lug, the fourth pin shaft being connected to one end of a third drive link, and the other end of the third drive link being rotatably connected to a first ball shaft; wherein, the connection points of the two third drive links and the first ball shaft are located on both sides outside the connection points of the fourth drive link, the second double-headed joint bearing rod, and the fixed-length rod with the first ball shaft.

[0027] According to the technical solution provided by the present invention, the finger connection base includes: a main frame, the main frame being used to install the first driving member and the second driving member; a guide frame is also provided on the top of the main frame, the guide frame including guide segments corresponding to the front slider and the rear slider, each guide segment being slidably connected to the corresponding front slider and the rear slider via a slider and a slide rail, the extension direction of the slide rail being the first direction.

[0028] According to the technical solution provided by the present invention, a second buffer is also provided at the connection between the second drive link and the middle finger joint.

[0029] In summary, this technical solution specifically discloses a coupled adaptive underactuated bionic dexterous manipulator finger, comprising: a finger connecting base, the finger connecting base forming a mounting surface for supporting mutually cooperating knuckle components and a drive component; the knuckle component includes: a distal knuckle, a mid knuckle, and a proximal knuckle that cooperate with each other and are connected in sequence; wherein, the proximal knuckle is located on the side closer to the finger connecting base; the drive component is connected to the knuckle component; the drive component includes: a lateral swing-flexion-extension module and a grasping drive module, and both the lateral swing-flexion-extension module and the grasping drive module are structures composed of multiple links, which are used to drive the knuckle component to complete a specified action; the lateral swing-flexion-extension module includes first drive links connected to both sides of the proximal knuckle at the end away from the mid knuckle; the grasping drive module includes two second drive links that are movably connected to the ends of the proximal knuckle and the mid knuckle that are close to each other, and two third drive links that are movably connected to the distal knuckle.

[0030] Existing finger mechanisms face challenges in terms of freedom of movement and sufficient workspace, resulting in poor grasping accuracy and flexibility in handling complex tasks. This invention addresses these issues by dividing the knuckle assembly into distal, mid, and proximal knuckles, structurally mimicking the knuckle distribution of a human finger and providing a foundation for precise multi-degree-of-freedom movement. Furthermore, the drive assembly utilizes a lateral swing-flexion / extension module and a linkage structure within the grasping drive module, connecting to each knuckle for precise multi-degree-of-freedom motion control, simulating the human finger. This achieves a more natural envelope grasping motion while maintaining a simple and compact structure, thus providing a larger grasping space. Attached Figure Description

[0031] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0032] Figure 1 This is an isometric view of the structure of the present invention.

[0033] Figure 2This is a side view of the first embodiment of the present invention.

[0034] Figure 3 This is a side view of the second embodiment of the present invention.

[0035] Figure 4 This is a partial exploded view of the side-swing-flexion module of the present invention.

[0036] Figure 5 This is a schematic diagram showing the cooperation between the second drive link and the second buffer component of the present invention.

[0037] Figure 6 This is a front view of the structure of the present invention.

[0038] Figure 7 This is a first schematic diagram of the grasping operation of the present invention.

[0039] Figure 8 This is a second schematic diagram of the grasping operation of the present invention.

[0040] Figure 9 This is a first schematic diagram of the side-swing condition of the present invention.

[0041] Figure 10 This is a second schematic diagram of the side-swing condition of the present invention.

[0042] Figure 11 This is a schematic diagram of the first type of flexion and extension according to the present invention.

[0043] Figure 12 This is a schematic diagram of the second type of flexion and extension according to the present invention.

[0044] Figure 13 This is a partial schematic diagram of the connection of the fixed-length rod of the present invention.

[0045] Numbered in the diagram: 1. Finger connecting base; 2. Distal phalanx; 3. Middle phalanx; 4. Proximal phalanx; 5. First drive link; 6. Second drive link; 61. Wedge; 7. Third drive link; 8. Rotating seat; 81. Rotating end; 9. Ball joint link; 10. Front slider; 11. First double-headed joint bearing rod; 12. First drive component; 121. First motor; 122. First bushing; 123. First lead screw; 13. First ball shaft; 14. Rear slider; 15. Second double-headed joint bearing rod; 16. Fourth drive linkage; 17. First pin; 18. Second pin; 19. Third pin; 20. Second ball joint; 21. Fourth pin; 22. Elastic retaining ring; 23. Fixed length rod; 231. Arc-shaped end; 25. Second drive component; 251. Second motor; 252. Second bushing; 253. Second lead screw; 26. Main frame; 27. Guide frame; 28. Slider; 29. ​​First buffer component; 30. Second buffer component; 301. Arc-shaped track; 31. Lug; 32. Limiting component; 33. Nut; 34. Slide rail. Detailed Implementation

[0046] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0047] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0048] To make the technical solutions of the embodiments of the present invention clearer and easier to understand, the application background of the embodiments of the present invention will be introduced below.

[0049] In recent years, with the rapid development of robotics technology, robotic hands, as an important component of robots, have seen continuous improvements in function and performance, and their application areas have gradually expanded from the initial manufacturing sector to non-manufacturing sectors. Currently popular biomimetic dexterous robotic hands, by mimicking the structure and movement of human or other biological hands, can not only achieve more natural and flexible operations but also complete more complex tasks, showing broad application prospects.

[0050] A good dexterous hand's fingers need to possess characteristics including, but not limited to, high dexterity, good controllability, low cost, and compact structure. However, different types of dexterous hands have their own advantages and disadvantages, which leads to trade-offs in finger performance in existing dexterous hand designs. From the perspective of actuation methods, robotic hands can be divided into fully actuated robotic hands and underactuated robotic hands. To improve joint actuation efficiency, fully actuated robotic hands often place actuators at the finger joints. This design can improve finger dexterity and finger integration. However, this makes the finger's grasping performance too dependent on the quality of the motor, and high-end motors are often expensive, thus increasing the manufacturing cost of the fingers. In addition, because the gaps between dexterous hand fingers are very small, adding sensor control wiring to the fingers inevitably sacrifices some grasping performance and finger compactness. Therefore, to improve finger integration, most current designs choose underactuated methods. For example, in this embodiment of the invention, the motors are centrally located below the finger connecting base, and the fingers are driven to complete the grasping action through a linkage mechanism, thereby reducing manufacturing costs and maintenance difficulty while maintaining the finger's degrees of freedom.

[0051] Among common rigid dexterous hands, those based on linkage-driven mechanisms constitute a significant portion. Hands developed based on this mechanism facilitate joint movement in desired directions by combining multiple links, offering advantages such as bidirectional joint control, robustness, and ease of manufacturing and maintenance. However, this mechanism struggles to achieve a large workspace, and the in-hand manipulation of multi-finger linkage robotic hands is often limited by the range of finger postures achievable when handling objects. Expanding this range of finger postures is crucial for improving the flexibility and versatility of robotic hands in various applications. Furthermore, compared to purely coupled dexterous hands, dexterous hands that can achieve adaptation while being coupled exhibit a clear technological advantage. This is because while purely coupled dexterous hands achieve the linkage of multiple joints, they cannot adaptively adjust according to the shape of the object and the grasping task, resulting in insufficient grasping stability when dealing with objects with complex geometries. Moreover, the fixed-ratio motion coupling between joints can easily lead to internal force accumulation when encountering external resistance, affecting not only grasping accuracy but also potentially causing damage to the mechanism.

[0052] In view of this, to solve the above problems and improve the grasping accuracy, flexibility, and versatility of robotic fingers, please refer to... Figures 1-13 The schematic diagram shown in this embodiment of the present invention relates to a coupled adaptive underactuated bionic dexterous manipulator finger, including:

[0053] Finger connecting base 1, finger connecting base 1 forms a mounting surface, the mounting surface is used to support the interlocking knuckle assembly and drive assembly;

[0054] The knuckle assembly includes: a distal knuckle 2, a middle knuckle 3, and a proximal knuckle 4 that cooperate with each other and are connected in sequence; wherein, the proximal knuckle 4 is located on the side closer to the finger connection base 1;

[0055] The drive assembly is connected to the knuckle assembly; the drive assembly includes: a lateral swing-flexion-extension module and a gripping drive module, and both the lateral swing-flexion-extension module and the gripping drive module are structures composed of multiple links. The lateral swing-flexion-extension module and the gripping drive module cooperate with each other to drive the knuckle assembly to complete the specified action;

[0056] The lateral swing-flexion module includes: a first drive link 5 connected to both sides of the proximal phalanx 4 at the end away from the middle phalanx 3; the gripping drive module includes: two second drive links 6 movably connected to the ends of the proximal phalanx 4 and the middle phalanx 3 that are close to each other, and two third drive links 7 movably connected to the distal phalanx 2.

[0057] In this embodiment of the invention, the finger connecting base 1 provides an installation space for the knuckle assembly and the drive assembly. On the mounting surface of the finger connecting base 1, the knuckle assembly and the drive assembly can cooperate with each other to work together to complete actions such as bending and grasping objects and stretching the fingers. The knuckle assembly is a skeleton that simulates the shape and basic movement trajectory of a finger. It consists of three sequentially connected distal knuckles 2, mid-knuckles 3, and proximal knuckles 4, presenting a knuckle distribution similar to that of a human finger: the distal knuckle 2 is located at the very end of the entire finger assembly, similar to the fingertip knuckle in humans, and its movement determines the fine movements of the "fingertip"; the mid-knuckle 3 connects the distal knuckle 2 and the proximal knuckle 4, similar to the middle knuckle in humans, and this mid-knuckle 3 is used to form coordinated movements with the distal knuckle 2 and the proximal knuckle 4, creating favorable possibilities for optimizing the grasping space; the proximal knuckle 4 is positioned close to the finger connecting base 1, similar to the knuckles close to the palm in humans; the distal knuckle 2, mid-knuckle 3, and proximal knuckle 4 can complete specified movements under different requirements through the cooperation of the lateral swing-flexion-extension module and the grasping drive module. The drive assembly is the power source for realizing the movement of the knuckles. It converts external power into mechanical movement of the knuckles through a multi-stage linkage structure. The drive assembly is divided into a lateral swing-flexion-extension module and a grasping drive module, which can control the fingers to complete core actions such as lateral swing, flexion-extension and grasping respectively.

[0058] Specifically, the lateral swing-flexion-extension module includes first drive links 5 connected to both sides of the proximal phalanx 4 at the end furthest from the middle phalanx 3; the grasping drive module includes a second drive link 6 and a third drive link 7 connected to the proximal phalanx 4 and the middle phalanx 3; based on this design, when an external force drives the first drive link 5 (such as controlling the swing of the first drive links 5 on both sides), the two first drive links 5 drive the ball joint link 9 to rotate around the axis of the rotating seat 8, thereby causing the proximal phalanx 4 to swing left and right around the connection point of the ball joint link 9; since the middle phalanx 3, the distal phalanx 2 and the proximal phalanx 4 are connected in sequence, the lateral swing of the proximal phalanx 4 will drive the entire phalanx assembly to complete the lateral swing action synchronously, realizing the adduction and abduction movement of the fingers (see details). Figure 9 and Figure 10 When the second drive link 6 and the third drive link 7 are pushed or pulled, the middle phalanx 3 will first rotate relative to the proximal phalanx 4 (e.g., the middle phalanx 3 bends towards the proximal phalanx 4 when pushed, and straightens when pulled), thus realizing the grasping of the middle phalanx of the finger; the third drive link 7 is essentially used to drive the movement of the distal phalanx 2, but the middle phalanx 3 and the distal phalanx 2 have a common rotational connection axis, so the movement of the distal phalanx 2 is powered by the second drive link 6 and the third drive link 7, thus realizing the bending or straightening of the fingertip (e.g., the bending of the fingertip when pinching something).

[0059] Generally, the coupled movement of the fingers in a bionic dexterous robotic hand is achieved through a corresponding mechanism design. This mechanism design allows the fingertip to move along a fixed trajectory, giving the bionic dexterous robotic hand fingers the characteristics of high grasping ability, strong gripping function, stability and reliability, and low operational difficulty. However, bionic dexterous robotic hand fingers with only a coupled mode have relatively fixed movement relationships between the phalanges, making it difficult to adapt to objects of different shapes and sizes. In contrast, the bionic dexterous robotic hand finger with a coupled adaptive mode proposed in this embodiment of the invention can automatically decouple its middle phalanx 3 from its distal phalanx 2 after contacting an object. This allows the distal phalanx 2 to continue moving until the bionic dexterous robotic hand finger completely envelops the object (see details in [link to relevant documentation]). Figure 7 and Figure 8 (as shown in the dynamic illustration), this grasping mode can effectively grasp objects of different shapes and sizes, and the fingers of the bionic dexterous hand with the coupling adaptive mode have stronger operational adaptability and higher dexterity than the fingers of the bionic dexterous hand with only the coupling mode.

[0060] In a preferred embodiment, the lateral swing-flexion module includes at least two sets of lateral swing-flexion units that are connected by transmission, a rotating seat 8 and a ball joint 9 that are connected to both lateral swing-flexion units;

[0061] The rotating seat 8 is located on the top of the finger connecting base 1, and the rotating seat 8 includes two rotating ends 81, which are rotatably connected to different lateral swing-flexion-extension units respectively; one end of the proximal phalanx 4 is rotatably located in the middle of the ball joint 9; the two lateral swing-flexion-extension units can synchronously drive the proximal phalanx 4 to move through the rotating seat 8 and the ball joint 9.

[0062] Specifically, both sets of transmission-connected lateral swing-flexion / extension units include a first drive link 5, and the two first drive links 5 are synchronously driven through a rotating seat 8 and a ball joint link 9; see [link to relevant documentation]. Figure 3 Two first drive links 5 are symmetrically arranged on both sides of the proximal phalanx 4 and connected to the proximal phalanx 4 through ball joint links 9. The other ends of the two first drive links 5 are also connected to different rotating ends 81 of the same rotating seat 8. In this way, the two first drive links 5 can achieve synchronous control, ensuring that the movement of the proximal phalanx 4 is stable and accurate.

[0063] Furthermore, each lateral swing-flexion-extension unit includes a front slider 10, which is disposed on the finger connecting base 1, and the front sliders 10 included in the two lateral swing-flexion-extension units are parallel and correspondingly disposed along the first direction; the front sliders 10 can slide along the first direction, and the specific design can be found in [reference needed]. Figure 1 , Figure 2 and Figure 6 ;

[0064] Specifically, the front slider 10 is a sliding component used to drive the lateral swing-flexion unit to move. Since the two lateral swing-flexion units need to move synchronously, the front sliders 10 contained in the two lateral swing-flexion units are parallel and correspondingly arranged. The movement of the front slider 10 can drive the various connecting rods connected to it to move, thereby controlling the swing of the proximal phalanx 4.

[0065] The first double-headed articulated bearing rod 11 is rotatably mounted on the top of the front slider 10, and the ends of the first double-headed articulated bearing rods 11 included in the two side-swing-flexion-extension units that are away from the front slider 10 are respectively rotatably connected to both ends of the ball joint connecting rod 9; one end of each of the two first drive connecting rods 5 is rotatably connected to the rod body of the ball joint connecting rod 9, and the other end of each is rotatably connected to a rotating end 81 of the rotating seat 8; the rotating connection points of the two first drive connecting rods 5 on the ball joint connecting rod 9 are located on both sides of the proximal phalanx 4, as detailed in the following document. Figure 6 .

[0066] Specifically, the first double-headed articulated bearing rod 11 serves as a connecting part between the front slider 10 and the ball joint connecting rod 9. Both ends of the rod are bearing ends. The bearing end is connected to the top of the front slider 10 via a corresponding ball shaft, and the other bearing end is connected to the ball end of the ball joint connecting rod 9. In this way, the two lateral swing-flexion-extension units can form a transmission control with the proximal phalanx 4 by connecting to the ball joint connecting rod 9. The connection between the two ends of the first drive connecting rod 5 is rotatably connected to the ball joint connecting rod 9 and the rotating seat 8. One end is sleeved on the rod body of the ball joint connecting rod 9 and located on both sides of the proximal phalanx 4, while the other end is rotatably connected to the rotating end 81 of the rotating seat 8. The rotating end 81 extends in the direction close to the proximal phalanx 4, and a pivot pin is provided through the middle of the rotating end 81 (see details). Figure 1 The first drive link 5 is connected to the first drive link 5 through the corresponding shaft pin. The first drive link 5 can better control the swing posture when the proximal phalanx 4 swings.

[0067] It should be noted that the rotating seat 8 here includes a bearing set on the top of the finger connecting base 1 and a rotating rod rotatably set in the bearing. The rotating rod has a forked structure, with the two forks being two rotating ends 81. This design is more conducive to the finger completing lateral swinging movements, as described below.

[0068] The first driving member 12 is rotatably connected to the front slider 10 and is used to drive the front slider 10 to reciprocate along the first direction.

[0069] Specifically, the first driving component 12 includes a first motor 121, a first bushing 122, and a first lead screw 123, etc. The front slider 10 is threadedly connected to the first lead screw 123 through a nut 33. When the two first motors 121 drive their respective first lead screws 123 to rotate in the same direction, the two front sliders 10 can synchronously complete the movement along the first direction with the help of the first lead screws 123, that is, the reciprocating movement in the vertical direction. The first bushing 122 is externally connected to the driving end of the first motor 121. The driving end of the first motor 121 is externally connected to the first lead screw 123 through an internal thread. The first bushing 122 can further ensure the stable rotation of the first motor 121, and at the same time, it is used to prevent the first lead screw 123 from being subjected to rigid impact from the object when the finger assembly performs the task of manipulating the object, thus protecting the finger assembly. This allows the finger assembly to be applicable to more application scenarios, thereby expanding the application range of dexterous hands.

[0070] It should be noted that the first lead screw 123 here is the designed length. Because the length of the first lead screw 123 affects the travel of the front slider 10, and the movement of the front slider 10 is related to the action of the side swing-flexion unit, the adjustment of the designed length of the first lead screw 123 can effectively create the advantage of flexibly designing the required contact point range between the finger and the object. For example, when we need the contact point range between the finger and the object to be far apart, the length of the first lead screw 123 can be increased during the design. Of course, all kinds of components involved in the embodiments of the present invention can be adjusted according to actual needs, which will not be elaborated on here.

[0071] Based on the above description of the lateral swing-flexion-extension module, it can be seen that when the proximal phalanx 4 needs to perform flexion-extension movement around the third axis L3 formed by the ball joint 9, the two first drive members 12 simultaneously drive the two front sliders 10. Figure 2 When the finger slides downwards at the position shown, the proximal phalanx 4 will flex and extend around the third axis L3 under the action of the front slider 10. That is, the proximal phalanx 4 rotates around the ball joint 9, thereby realizing the flexion movement of the finger (see details). Figure 11 and Figure 12 When the robotic hand's fingers need to perform lateral swinging motions on both sides of the fourth axis L4, the two first drive components 12 drive the two first lead screws 123 to rotate in opposite directions, and the nut 33 drives the two front sliders 10 to move in opposite directions simultaneously. At this time, a deflection force is generated at both ends of the ball joint 9, thereby causing the proximal phalanx 4 and the first drive link 5 to deflect in the same direction (with the help of the rotation design of the rotating seat 8, when the first drive link 5 deflects, the rotation connection between the rotating rod and the bearing can provide a certain degree of rotational freedom for the first drive link 5), thus realizing the lateral swinging motion of the fingers (see details). Figure 9 and Figure 10In this design, components such as the rotating seat 8, ball joint 9, and first drive link 5 can all support the lateral movement of the finger, making the finger structure more stable and reliable. In addition, the distal phalanx 2 also includes a sensor, which is built into the fingertip of the distal phalanx 2. This sensor is a pressure sensor. With this design, the pressure sensor set in the distal phalanx 2 can collect the contact force between the finger and the object in real time, which makes it easy for the finger to adjust the gripping force according to the characteristics of the object (such as brittleness and softness) to avoid damaging the object or unstable gripping.

[0072] In a preferred embodiment, the gripping drive module includes a first gripping drive unit and a second gripping drive unit that are connected by transmission, and a fixed-length rod 23 that cooperates with the two gripping drive units. The first gripping drive unit, the second gripping drive unit and the fixed-length rod 23 are all connected to a first ball shaft 13.

[0073] The fixed-length rod 23 has one end rotatably connected to the first ball shaft 13 and the other end rotatably connected to the ball head connecting rod 9; a first buffer 29 is provided at the end of the fixed-length rod 23 connected to the ball head connecting rod 9.

[0074] Specifically, the cooperation of the first gripping drive unit, the second gripping drive unit, and the fixed-length rod 23 mainly controls the gripping action of the middle phalanx 3 and the distal phalanx 2. With the coordinated cooperation of the fixed-length rod 23, the first gripping drive unit, and the second gripping drive unit, not only can the flexion and extension of the fingers be controlled, but also the coupling and decoupling movements of the middle phalanx 3 and the distal phalanx 2 can be further controlled.

[0075] Furthermore, the first gripping drive unit includes: a rear slider 14, which is disposed on the finger connecting base 1; the extension direction of the rear slider 14 is parallel to the extension direction of the front slider 10, and it is located between the two front sliders 10 and in a different plane from the front sliders 10; a second ball shaft 20 is rotatably disposed on the top of the rear slider 14.

[0076] With the finger extended, the rear slider 14 and the front slider 10 are in different initial positions, and the resulting finger movements also differ. The rear slider 14 is positioned at the rear end of the front slider 10, located at the extension line between the two front sliders 10, i.e., in a different plane from the front sliders 10. The three sliders are arranged in a triangle, making the overall structure of the finger assembly more compact. The specific relative positions of the two front sliders 10 and the rear slider 14 are as follows: Figure 1 or Figure 8 This will not be elaborated further here; meanwhile, the first ball shaft 13 serves as a swing fulcrum, and it is connected to the rear slider 14 via the second double-headed joint bearing rod 15 described below, which makes it easier to control the swing of the subsequent third drive link 7.

[0077] The second double-headed spherical bearing rod 15 has one end rotatably connected to the first ball shaft 13 and the other end rotatably connected to the second ball shaft 20.

[0078] The fourth drive link 16 has one end rotatably mounted on the first ball shaft 13, and its other end is connected to two second drive links 6 via the first pin shaft 17.

[0079] Two second drive links 6 are rotatably connected to the two ends of the first pin 17, respectively; the other ends of the two second drive links 6 are also rotatably connected to the second pin 18; the middle finger joint 3 and the proximal finger joint 4 are rotatably connected to the rod body of the second pin 18 at their respective close ends, and the rotatable connection points of the two second drive links 6 and the second pin 18 are located on both sides of the middle finger joint 3 and the proximal finger joint 4, and a second buffer 30 is also provided at the connection point of one of the second drive links 6 and the middle finger joint 3.

[0080] It should be noted that the second buffer 30 can be composed of a torsion spring and a torsion spring sleeve. The torsion spring sleeve is fixed to the middle finger joint 3 by a keyway, and it is provided with an arc-shaped track 301 that satisfies the finger joint movement. At the same time, there is a wedge 61 on the inner side of the second drive linkage 6 where the second buffer 30 is provided. The movement trajectory of the wedge 61 coincides with the center line of the arc-shaped track 301 and can move along the arc-shaped track 301. When the distal finger joint 2 does not contact the object, but the proximal finger joint 4 and the middle finger joint 3 stop moving due to contact with the object, the second gripping drive unit continues to move. The wedge 61 on the second drive linkage 6 moves along the arc-shaped track 301, compressing one end of the torsion spring, and the middle finger joint 3 and the distal finger joint 2 are decoupled.

[0081] See Figure 9 The specific structure of the front slider 10 and the rear slider 14: The top of the front slider 10 and the rear slider 14 are provided with an opening, and the corresponding second ball shaft 20 is provided in the opening for mounting the second double-headed joint bearing rod 15; the second double-headed joint bearing rod 15 here serves as the connection part between the rear slider 14 and the first ball shaft 13; both ends of the middle finger joint 3 are in the shape of a "U", so that the proximal finger joint 4 and the distal finger joint 2 can be inserted into the groove and connected to it. Therefore, the second buffer 30 is provided at the connection between the second drive link 6 and the middle finger joint 3. It can be understood that the second buffer 30 is provided on the second pin 18 and is located between the second drive link 6 and the middle finger joint 3, which can control and constrain the rotation of the middle finger joint 3 and the proximal finger joint 4.

[0082] The fourth drive link 16 has a certain length and a certain bending angle in its shape, and is used to connect the second double-headed spherical bearing rod 15, the second drive link 6, the distal phalanx 2, and the middle phalanx 3; specifically, the top of the fourth drive link 16 is provided with a first pin 17, and the extension direction of the first pin 17 is the direction of the second axis L2, as detailed in [reference needed]. Figure 1 or Figure 4 As shown in the diagram, one end of the second drive link 6 is connected to the first pin 17, and the other end is connected to the rod body of the second pin 18. The second pin 18 is connected to the middle finger joint 3 and the proximal finger joint 4. In this way, the transmission connection of the second double-headed joint bearing rod 15, the second drive link 6, the distal finger joint 2, the middle finger joint 3, the fourth drive link 16, and the third drive link 7 is formed.

[0083] The second driving member 25 is rotatably connected to the rear slider 14. The second driving member 25 is used to drive the rear slider 14 to reciprocate along the first direction.

[0084] Specifically, the structure and function of the second driving component 25 are basically similar to those of the first driving component 12. It also includes a second motor 251, a second bushing 252, and a second lead screw 253. The rear slider 14 is threadedly connected to the second lead screw 253 through a nut 33. When the motor 251 drives the second lead screw 253 to rotate, the rear slider 14 can synchronously complete the movement along the first direction with the help of the second lead screw 253, which is the reciprocating movement in the vertical direction.

[0085] In a preferred embodiment, the distal phalanx 2 is provided with two lugs 31 at the end near the middle phalanx 3; one of the lugs 31 is rotatably connected to the middle phalanx 3 via a third pin 19;

[0086] The second gripping drive unit includes: a fourth pin 21 rotatably connected to another lug 31, the fourth pin 21 being connected to one end of the third drive link 7, and the other end of the third drive link 7 being rotatably connected to the first ball shaft 13; wherein, the connection points of the two third drive links 7 and the first ball shaft 13 are located on both sides outside the connection points of the fourth drive link 16, the second double-headed joint bearing rod 15, and the fixed length rod 23 and the first ball shaft 13.

[0087] Specifically, the distal phalanx 2 has two lugs 31 at its bottom for connecting to the middle phalanx 3 and the third drive link 7 respectively; one lug 31 is rotatably connected to the end of the middle phalanx 3 away from the proximal phalanx 4 via a third pin 19, ensuring flexible connection of the finger joints; the other lug 31 is rotatably equipped with a fourth pin 21, which is rotatably connected to the two third drive links 7, while the other end of the third drive link 7 is directly rotatably connected to the first ball shaft 13; the positional relationship between the fixed length rod 23, the second double-headed joint bearing rod 15, the fourth drive link 16, and the third drive link 7 after they are connected to the first ball shaft 13 can be found in [reference needed]. Figure 13 The end of the fixed length rod 23 connected to the first ball shaft 13 and the end of the fourth drive link 16 connected to the first ball shaft 13 both have mounting slots; at the same time, the connection position of the second double-headed joint bearing rod 15 and the first ball shaft 13 is located in the mounting slot of the fourth drive link 16, while the fourth drive link 16 is located in the mounting slot of the fixed length rod 23, and the two third drive links 7 are located on the outer sides of the fixed length rod 23.

[0088] Based on the above description of the lateral swing-flexion-extension module, when the second motor 251 drives the rear slider 14 to move upward along the axis of the second lead screw 253, the second double-headed joint bearing rod 15, the fourth drive link 16, and the second drive link 6 drive the middle finger joint 3 to rotate around the second axis L2 formed by the second pin 18. When the middle finger joint 3 reaches the first state (the finger rotates to the coupling limit angle), the second pin 18 and the third drive link 7 continue to drive the distal finger joint 1 to rotate around the first axis L1 formed by the third pin 19 until the distal finger joint 1 reaches the second state (the finger completely envelops the object or reaches the rotation limit angle), thus completing the flexion-extension movement of the finger. It should be noted here that each ball shaft and link or other connecting structure connection end is generally provided with an elastic retaining ring 22. The elastic retaining ring 22 can be embedded in the groove of one end of the corresponding ball shaft and pin shaft, and clamped by snap ring clamps, thereby fixing the corresponding ball shaft and pin shaft.

[0089] Therefore, it can be seen that under the structural design of this invention, by adjusting the corresponding slide rail length setting through the driving stroke of the first driving member 12 and the second driving member 25 set during the design, the fingers can grasp objects that are farther away, or the grasping space of the fingers is larger. In this way, the reachable position of the fingertips is further expanded, enabling grasping actions that are difficult to achieve with conventional linkage structure bionic dexterity hands. At the same time, see also Figure 2 and Figure 3 The comparison shown is between the front slider 10 and the rear slider 14 under different motion states. Figure 2The front slider 10 and the rear slider 14 are simultaneously moved to the upper parts of the corresponding first lead screw 123 and second lead screw 253 by the drive of the two first motors 121 and the second motor 251. Figure 3 The front slider 10 and the rear slider 14 are simultaneously moved to the lower part of the corresponding first lead screw 123 and second lead screw 253 under the drive of three motors. With this structural design, by flexibly adjusting the length of the first lead screw 123 and the second lead screw 253, the three motors can simultaneously control the front slider 10 and the rear slider 14 to move a set distance (the set distance is determined based on the length of the first lead screw 123 and the second lead screw 253) in the same direction to raise the fingers, so that they can grasp objects that are farther away. That is, the reachable position of the fingertips is further expanded, realizing the grasping action that is difficult to achieve in conventional linkage structure bionic dexterous hands.

[0090] Next, see Figure 13 The fixed-length rod 23, which cooperates with the first gripping drive unit and the second gripping drive unit, is provided with a second buffer 29 (i.e., a torsion spring, which passes through the body of the ball-head link 9) at the connection with the ball-head link 9. The end of the fixed-length rod 23 near the ball-head link 9 is arc-shaped, which can be called the arc end 231. The part of the arc end 231 connected to the ball-head link 9 can be compressed by squeezing one end of the torsion spring. In the actual finger movement process, before the proximal phalanx 4 contacts the object, the torsion spring connected to the ball-head link 9 can be regarded as having no deformation. When the proximal phalanx 4 stops moving due to contact with the object, while the middle phalanx 3 has not yet contacted the object, the rear front slider 10 moves upward, and the end of the fixed-length rod 23 connected to the ball-head link 9 squeezes the torsion spring, causing the torsion spring to deform. The middle phalanx 3 and the distal phalanx 2 continue to move.

[0091] In a preferred embodiment, the finger connection base 1 includes: a main frame 26, which is used to install a first driving member 12 and a second driving member 25; a guide frame 27 is also provided on the top of the main frame 26, the guide frame 27 includes guide segments corresponding to the front slider 10 and the rear slider 14, each guide segment and the corresponding front slider 10 and rear slider 14 are slidably connected to the slide rail 34 through a slider 28, and the extension direction of the slide rail 34 is a first direction.

[0092] The finger connecting base 1 lays the foundation for the compact structure of the overall robotic hand fingers. Its design not only provides guidance for the two front sliders 10 and the rear slider 14, but also ensures that each link is not interfered with or obstructed during movement. Specifically, the main frame 26 of the finger connecting base 1 is located at the lower end and is C-shaped. The first drive component 12 and the second drive component 25 are respectively located at the bottom of the main frame 26, and are connected to each slider by a lead screw running through the entire main frame 26. A guide frame 27 is also provided at the top of the main frame 26. The height of the guide frame 27 is related to the length of the lead screw and design requirements. The guide frame 27 has three guide sections, and each guide section is provided with a corresponding slide rail 34. Each slide rail 34 provides movement guidance for the front slider 10 and the rear slider 14. Corresponding limiting components 32 are also provided on both sides of the slide rail 34 to prevent the movement of the front slider 10 and the rear slider 14 from exceeding the set stroke range.

[0093] Combination Figures 1-13 Based on the above description, this invention proposes a coupled adaptive underactuated bionic dexterous manipulator finger, the specific working principle of which is as follows:

[0094] Taking the initial state, where the fingers are relaxed and extended, as an example, if it is necessary to control the fingers to complete the grasping action, firstly, the two first driving components 12 need to be activated to control the two front sliders 10 to move from top to bottom along the corresponding first lead screw 123, following its slide rail 34, and drive the proximal phalanx 4 to flex and extend around the third axis L3. Under such action, the entire finger can swing towards the object to be grasped. When the swing reaches the target distance, the distal phalanx 2 and the middle phalanx 3 need to perform further actions to grasp the object. At this time, the second driving component 25 is activated, and the second driving component 25 controls the rear slider 14 to move from bottom to top along the corresponding second lead screw 253, following its slide rail 34. At this time, the fourth driving link 16 drives the second driving link 6 to swing upward, while the two third driving links 7 swing forward, so that the middle phalanx 3 and the distal phalanx 2 simulate the action of the fingertip grasping the object, thereby completing the simulation of the entire finger grasping the object.

[0095] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention is not limited to the specific combination of the above-described technical features, but also includes other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in this invention.

Claims

1. A coupled adaptive underactuated bionic dexterous manipulator finger, characterized in that, include: Finger connecting base (1), the finger connecting base (1) forms a mounting surface, the mounting surface is used to support the interlocking knuckle assembly and drive assembly; The knuckle assembly includes: a distal knuckle (2), a mid knuckle (3), and a proximal knuckle (4) that cooperate with each other and are connected in sequence; wherein the proximal knuckle (4) is located on the side close to the finger connecting base (1); The drive assembly is connected to the knuckle assembly; the drive assembly includes a lateral swing-flexion-extension module and a gripping drive module, and both the lateral swing-flexion-extension module and the gripping drive module are structures composed of multiple links. The lateral swing-flexion-extension module and the gripping drive module cooperate with each other to drive the knuckle assembly to complete a specified action. The lateral swing-flexion module includes: a first drive link (5) connected to both sides of the proximal phalanx (4) away from the middle phalanx (3); the gripping drive module includes: two second drive links (6) movably connected to the proximal phalanx (4) and the middle phalanx (3) at their respective ends close to each other, and two third drive links (7) movably connected to the distal phalanx (2). The lateral swing-flexion module includes at least two sets of lateral swing-flexion units connected by transmission, a rotating seat (8) connected to both lateral swing-flexion units, and a ball joint connecting rod (9). The rotating seat (8) is disposed on the top of the finger connecting base (1), and the rotating seat (8) includes two rotating ends (81), which are respectively rotatably connected to different side swing-flexion-extension units; one end of the proximal phalanx (4) is rotatably disposed in the middle of the ball joint (9); the two side swing-flexion-extension units can synchronously drive the proximal phalanx (4) to move through the rotating seat (8) and the ball joint (9); The lateral swing-flexion-extension unit includes: A front slider (10) is disposed on the finger connecting base (1), and the front sliders (10) included in the two side swing-flexion units are parallel and correspondingly disposed along the first direction; the front slider (10) can slide along the first direction; The first double-headed joint bearing rod (11) is rotatably disposed on the top of the front slider (10), and the ends of the first double-headed joint bearing rods (11) contained in the two side swing-flexion units that are away from the front slider (10) are respectively rotatably connected to the two ends of the ball joint connecting rod (9). One end of each of the two first drive links (5) is rotatably connected to the body of the ball joint (9), and the other end is rotatably connected to one of the rotating ends (81) of the rotating seat (8); the two first drive links (5) are located on both sides of the proximal phalanx (4) at the rotation connection point of the ball joint (9). The first driving member (12) is rotatably connected to the front slider (10), and the first driving member (12) is used to drive the front slider (10) to reciprocate along the first direction; The gripping drive module includes a first gripping drive unit and a second gripping drive unit connected by transmission, and a fixed-length rod (23) that cooperates with the two gripping drive units. The first gripping drive unit, the second gripping drive unit and the fixed-length rod (23) are connected to a first ball shaft (13). One end of the fixed-length rod (23) is rotatably connected to the first ball shaft (13), and the other end is rotatably connected to the ball head connecting rod (9); a first buffer (29) is provided at the end of the fixed-length rod (23) connected to the ball head connecting rod (9).

2. The coupled adaptive underactuated bionic dexterous manipulator finger according to claim 1, characterized in that, The first grasping driving unit includes: A rear slider (14) is disposed on the finger connecting base (1); the extension direction of the rear slider (14) is parallel to the extension direction of the front slider (10), and it is located between the two front sliders (10) and in a different plane from the front sliders (10); a second ball shaft (20) is rotatably disposed on the top of the rear slider (14). The second double-headed spherical bearing rod (15) has one end rotatably connected to the first ball shaft (13) and the other end rotatably connected to the second ball shaft (20); The fourth drive link (16) has one end rotatably mounted on the first ball shaft (13), and its other end is connected to two second drive links (6) via the first pin (17). Among them, the two second drive links (6) are rotatably connected to the two ends of the first pin (17); the other end of the two second drive links (6) is also rotatably connected to the second pin (18); the middle finger joint (3) and the proximal finger joint (4) are rotatably connected to the rod body of the second pin (18) at their respective close ends, and the rotatable connection points of the two second drive links (6) and the second pin (18) are located on both sides of the middle finger joint (3) and the proximal finger joint (4); The second driving member (25) is rotatably connected to the rear slider (14) and is used to drive the rear slider (14) to reciprocate along the first direction.

3. The coupled adaptive underactuated bionic dexterous manipulator finger according to claim 2, characterized in that, The distal phalanx (2) is provided with at least two lugs (31) at the end near the middle phalanx (3); one of the lugs (31) is rotatably connected to the end of the middle phalanx (3) away from the proximal phalanx (4) by a third pin (19); The second gripping drive unit includes: a fourth pin (21) rotatably connected to another lug (31), the fourth pin (21) being connected to one end of a third drive link (7), and the other end of the third drive link (7) being rotatably connected to a first ball shaft (13); wherein the connection points of the two third drive links (7) and the first ball shaft (13) are located on both sides outside the connection points of the fourth drive link (16), the second double-headed joint bearing rod (15), and the fixed length rod (23) and the first ball shaft (13).

4. The coupled adaptive underactuated bionic dexterous manipulator finger according to claim 3, characterized in that, The finger connection base (1) includes: a main frame (26), which is used to install the first drive member (12) and the second drive member (25); the top of the main frame (26) is also provided with a guide frame (27), which includes guide segments corresponding to the front slider (10) and the rear slider (14). Each guide segment is slidably connected to the corresponding front slider (10) and the rear slider (14) through a slider (28) and a slide rail (34). The extension direction of the slide rail (34) is the first direction.

5. The coupled adaptive underactuated bionic dexterous manipulator finger according to claim 1, characterized in that, A second buffer (30) is also provided at the connection between the second drive link (6) and the middle finger joint (3).

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