Adaptive grasping dexterous hand thumb

Abstract

The application provides a self-adaptive grasping dexterous hand thumb, which comprises a side swing joint, a bending joint and a fingertip, the side swing joint comprises a fixed base, a side swing driver and a first reversing transmission assembly; the bending joint comprises a connecting base, a finger joint linkage assembly, a bending driver and a second reversing transmission assembly. The application realizes the three-joint structure of the bionic thumb, can realize multi-directional rotation and bending actions, improves the degree of freedom and action accuracy, realizes the double driving function of side swing and bending through the built-in driving structure, thereby expanding the movable range. The self-adaptive assembly can dynamically adjust the relative position and clamping force of each finger joint of the thumb in real time, so as to realize the self-adaptive enveloping of the object, and further significantly improve the grasping stability of the dexterous hand thumb for objects of different shapes and sizes, effectively expand the application scene, and the application has the advantages of high flexibility, strong grasping adaptability, high action accuracy, fast response speed, high degree of freedom, high space utilization and the like.

Description

Technical Field

[0001] This invention relates to the field of biomimetic mechanical technology, specifically to an adaptive grasping dexterity thumb. Background Technology

[0002] With the rapid development of modern industrial automation, medical assistance and service robots, robot technology is breaking through in the direction of "high precision, high dexterity and strong environmental adaptability". This breakthrough is highly dependent on the real-time control capability of computer technology, the environmental perception accuracy of sensor technology, the optimization of the mechanical properties of new materials and the algorithm iteration support of control theory.

[0003] In practical applications, human demand for robots has shifted from traditional heavy-duty handling and fixed-track operations to more precise operations that closely resemble human hand movements. Examples include the manipulation of minimally invasive surgical instruments in the medical field, the assembly of micro-components in the electronics industry, and the grasping of everyday items in service scenarios. These tasks all require robots to have dexterous manipulation capabilities similar to human hands, which has spurred a surge in the research and development of dexterous hands with multi-finger collaboration as the core.

[0004] From the perspective of the core components of a dexterous hand, its hand structure needs to simulate the movement logic of the human hand. It is usually composed of four fingers (index, middle, ring, and little fingers) and a thumb. The structural design and movement flexibility of the thumb are the key to the dexterous hand's operational ability: the human thumb can achieve precise grasping, complex operations, and tool use of objects of different shapes and sizes through multi-degree-of-freedom rotation and flexion. Therefore, the design of the thumb of a dexterous hand directly affects the overall operational performance.

[0005] Currently, existing thumb drive and transmission mechanisms for dexterous hands are mainly divided into rope-driven mechanisms, gear transmission mechanisms, and linkage mechanisms. Among them, gear transmission mechanisms have become the most widely used and extensively researched technical solution in the design of dexterous hand thumbs due to their advantages such as stable transmission efficiency, high structural reliability, low assembly difficulty, and large working space. They achieve power transmission through gear meshing and can flexibly adapt to different output torque requirements by adjusting the gear module and gear ratio, demonstrating good practicality in scenarios such as heavy-duty grasping and fixed-posture operation.

[0006] However, in practical applications, the aforementioned traditional gear-driven thumb structure still has significant technical limitations, making it difficult to meet the precision operation requirements in specific scenarios: Firstly, when performing simple and lightweight tasks, the gear transmission suffers from tooth backlash, transmission return error, and mechanical friction loss during power transmission, resulting in low precision of fingertip output force. This makes it impossible to precisely control the pressing pressure to avoid damaging fragile objects, and also makes it difficult to maintain a stable small clamping force to prevent lightweight objects from falling off. Secondly, the components of the gear transmission system have inertia, and the motion constraints of the meshing transmission are relatively strong, causing the thumb to move at a slower speed when quickly adjusting its posture. First, the speed is slow and the response is lagging, making it unable to adapt to the real-time operation requirements in dynamic environments. Second, due to the fixed motion trajectory of gear transmission, it is difficult to expand the degree of freedom of the thumb, making it difficult to achieve adaptive envelope grasping of irregularly shaped objects. At the same time, in narrow and limited spaces, the gear structure with a fixed transmission path is prone to interference with surrounding components, making it impossible to complete multi-posture fine operation tasks. Third, current dexterous hand thumbs mostly adopt underactuated solutions to simplify the structure and achieve thumb motion control through two drive units, but they still face the problem of difficulty in achieving adaptive envelope grasping of objects of different shapes under normal working conditions, resulting in limited dexterity.

[0007] In summary, while existing gear-driven dexterous hand thumb structures have advantages in reliability and working range, their shortcomings in output force accuracy, operating speed, and environmental adaptability make them unsuitable for lightweight and precise operations, adaptive grasping, and confined space operation scenarios. This has become a key technical bottleneck restricting the application of dexterous hands in a wider range of fields. There is an urgent need to propose a thumb structure design scheme that can optimize fingertip force control accuracy, improve motion response speed, and adapt to multiple operation scenarios. Summary of the Invention

[0008] Therefore, the technical problem to be solved by the present invention is to overcome the problems of insufficient fingertip force control precision, low motion response speed, insufficient dexterity and limited applicable scenarios in the prior art, and to provide an adaptive grasping dexterous hand thumb.

[0009] To address the aforementioned technical problems, this invention provides an adaptive grasping dexterous thumb, comprising: a lateral swing joint, the lateral swing joint including a fixed base, a lateral swing actuator, and a first reversing transmission assembly; the fixed base being connectable to an external bionic palm; the lateral swing actuator being disposed in the fixed base; and the first reversing transmission assembly being connected to the working end of the lateral swing actuator; a bending joint, the bending joint including a connecting base, a knuckle linkage assembly, a bending actuator, and a second reversing transmission assembly; the connecting base being rotatably connected to the power output end of the first reversing transmission assembly to drive the bending joint to rotate around a rotation centerline; one end of the knuckle linkage assembly being rotatably connected to the connecting base; the bending actuator being disposed on the knuckle linkage assembly; and the second reversing transmission assembly being connected to the working end of the lateral swing actuator, with its power output end rotatably connected to the knuckle linkage assembly to drive the linkage assembly to bend and move; and a fingertip, the fingertip being rotatably connected to the other end of the knuckle linkage assembly.

[0010] In one embodiment of the present invention, the first reversing transmission assembly includes a first worm and a first worm wheel. The first worm is connected to the working end of the side swing driver, the first worm wheel is connected through the first worm and meshes with the worm shaft of the first worm, and the connecting base is connected to the first worm wheel.

[0011] In one embodiment of the present invention, the bending joint includes two knuckle linkage assemblies symmetrically arranged along the width direction of the thumb of the adaptive grasping dexterity hand. The two linkage assemblies are connected by a pivot shaft for synchronous movement. Each knuckle linkage assembly includes an outer link and an inner link that are rotatably connected relative to each other. One end of the outer link and one end of the inner link are respectively rotatably connected to the connecting base. The other end of the outer link and the other end of the inner link are respectively rotatably connected to the fingertip. The middle portion of the outer link and the middle portion of the inner link are rotatably connected, so that the knuckle linkage assembly forms a bendable and rotatable four-bar structure. The inner link is connected to the power output end of the second reversing transmission assembly. The bending actuator is connected to the rotatable connection between the outer link and the inner link to drive the knuckle linkage assembly to bend / extend.

[0012] In one embodiment of the present invention, the outer connecting rod includes a first rod body and a second rod body, wherein one end of the first rod body is rotatably connected to the connecting base, and the other end is rotatably connected to one end of the second rod body, and the other end of the second rod body is rotatably connected to the fingertip; the inner connecting rod includes a third rod body and a fourth rod body, one end of the third rod body is rotatably connected to the connecting base and the power output end of the second reversing transmission assembly, and the other end is rotatably connected to one end of the fourth rod body, the bending actuator is disposed on the third rod body, and the other end of the fourth rod body is rotatably connected to the fingertip.

[0013] In one embodiment of the present invention, the second reversing transmission assembly includes a mounting bracket, a second worm, and a second worm wheel. The bending actuator is connected to the mounting bracket, the second worm is connected to the working end of the bending actuator, the second worm wheel is connected through the second worm and meshes with the worm shaft of the second worm, and the third rod is connected to the second worm wheel.

[0014] In one embodiment of the present invention, the second reversing transmission assembly further includes a drive gear and a transmission gear, both of which are disposed on the mounting bracket. The drive gear is connected to the working end of the bending actuator, and the transmission gear meshes with the drive gear and is connected to the second worm. The diameter of the drive gear is smaller than the diameter of the transmission gear.

[0015] In one embodiment of the present invention, the knuckle link assembly further includes an adaptive elastic element disposed between the outer link and the inner link of the same knuckle link assembly.

[0016] In one embodiment of the present invention, the fingertip includes a rotating connection portion and an elastic bionic portion, the rotating connection portion being rotatably connected to the knuckle linkage assembly and fixedly connected to the elastic bionic portion.

[0017] In one embodiment of the invention, the adaptive grasping dexterous hand thumb further includes an elastic shell that covers the outer surface of the lateral joint and / or the flexion joint.

[0018] In one embodiment of the present invention, the adaptive grasping dexterous hand thumb further includes a control mechanism, wherein the lateral swing driver and the bending driver are respectively connected to the control mechanism.

[0019] The technical solution of the present invention has the following advantages compared with the prior art: The adaptive grasping dexterous thumb described in this invention innovatively achieves a bionic thumb three-joint structure through the design of the lateral swing joint, the bending joint, and the fingertip. This enables multi-directional rotation and bending movements that closely approximate the height of the human hand, greatly improving its degree of freedom and motion precision, and significantly enhancing its adaptability to irregular objects. Furthermore, this application overcomes the constraints of single-motor drive by using a built-in drive structure to achieve dual-drive functions of lateral swing and bending within the limited thumb design space, thereby expanding its range of motion without increasing its overall size. Compared to conventional dexterous thumb structures, this application offers significant advantages such as flexibility, high motion precision, fast response speed, high degree of freedom, high space utilization, and strong controllability, providing new design ideas and directions for dexterous hand structures. Attached Figure Description

[0020] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0021] Figure 1 This is a three-dimensional structural diagram of the adaptive grasping dexterity hand thumb in a preferred embodiment of the present invention; Figure 2 yes Figure 1 The diagram shows a three-dimensional structural schematic of the lateral pivot joint of the thumb in an adaptive grasping dexterity hand. Figure 3 yes Figure 1 The diagram shows a three-dimensional structure of the flexion joint and fingertip joint in the thumb of an adaptive grasping dexterous hand. Figure 4 yes Figure 3 The diagram shows a three-dimensional structural schematic of the bending actuator and the second reversing transmission assembly in the bending joint.

[0022] Explanation of reference numerals in the accompanying drawings: 100, Side-swing joint; 110, Fixed base; 120, Side-swing actuator; 130, First reversing transmission assembly; 131, First worm; 1311, Worm shaft; 132, First worm wheel; 200, Bending joint; 210, Connecting base; 220, Finger joint linkage assembly; 221, Outer link; 2211, First rod; 2212, Second rod; 222, Inner link; 2221, Third rod; 2222, Fourth rod; 223, Adaptive elastic element; 230, Bending actuator; 240, Second reversing transmission assembly; 241, Mounting bracket; 242, Drive gear; 243, Transmission gear; 244, Second worm; 245, Second worm wheel; 300, Finger tip; 310, Rotating connection; 320, Elastic bionic part; 1001, Rotation center line. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0024] Example: See Figure 1 As shown, this embodiment provides an adaptive grasping dexterous thumb, comprising: a lateral swing joint 100, the lateral swing joint 100 including a fixed base 110, a lateral swing actuator 120, and a first reversing transmission assembly 130, the fixed base 110 being connectable to an external bionic palm, the lateral swing actuator 120 being disposed in the fixed base 110, and the first reversing transmission assembly 130 being connected to the working end of the lateral swing actuator 120; and a bending joint 200, the bending joint 200 including a connecting base 210, a knuckle linkage assembly 220, a bending actuator 230, and a second reversing transmission assembly 240. The connecting base 210 is rotatably connected to the power output end of the first reversing transmission assembly 130 to drive the bending joint 200 to rotate around the rotation center line 1001. One end of the finger joint link assembly 220 is rotatably connected to the connecting base 210. The bending actuator 230 is disposed on the finger joint link assembly 220. The second reversing transmission assembly 240 is connected to the working end of the side swing actuator 120, and its power output end is rotatably connected to the finger joint link assembly 220 to drive the link assembly to bend and move. The fingertip 300 is rotatably connected to the other end of the finger joint link assembly 220.

[0025] The adaptive grasping dexterous thumb shown in this embodiment innovatively realizes a bionic thumb three-joint structure through the design of the lateral swing joint 100, the bending joint 200, and the fingertip 300. It can achieve multi-directional rotation and bending movements that are similar to the height of the human hand, which greatly improves its degree of freedom and movement accuracy, and significantly enhances its adaptability to irregular objects. At the same time, this application breaks through the constraints of single motor drive. By using the design of built-in drive structure, it realizes the dual drive function of lateral swing and bending within the limited thumb design space, thereby expanding its range of motion without increasing its design volume.

[0026] The lateral swing joint 100 serves as the connection between the dexterous thumb and the external bionic hand. Its core function is to enable the thumb to swing laterally, providing initial posture adjustment for grasping irregular objects. The fixed base 110 serves both connection and load-bearing functions. It ensures the thumb remains stable during grasping by providing a stable connection to the external bionic hand, preventing loosening or displacement. It also provides a mounting platform for the lateral swing actuator 120 and the first reversing transmission assembly 130. The lateral swing actuator 120, preferably a rotary motor, acts as a power source. Its output rotational power, after being redirected by the first reversing transmission assembly 130, drives the subsequent bending joint 200 and fingertips 300 to rotate synchronously around a preset rotation center line 1001. This ultimately achieves the lateral swing of the thumb on the horizontal plane. This action simulates the basic opening and closing posture of the human thumb, allowing for pre-adjustment of the thumb's lateral position based on the position and size of the object being grasped, preventing interference with other fingers or objects.

[0027] Further, see Figure 2 As shown, the first reversing transmission assembly 130 is used to convert the rotational driving force of the lateral swing actuator 120 into a lateral swing driving force. It includes a first worm 131 and a first worm wheel 132. The first worm 131 is connected to the working end of the lateral swing actuator 120, and the first worm wheel 132 passes through and is connected to the first worm 131, meshing with the worm shaft 1311 of the first worm 131. The connecting base 210 is connected to the first worm wheel 132. Specifically, in this embodiment, the first reversing transmission assembly 130 serves as the core for power direction conversion and transmission. Through the precise meshing of the first worm 131 and the first worm wheel 132, it not only achieves efficient power transmission from the lateral swing actuator 120 to the connecting base 210, but also possesses a self-locking function based on the structural characteristics of the worm wheel and worm. Its structural fit, functional implementation, and self-locking advantage are logically and closely linked. The first worm gear 131 is directly connected to the working end of the side-swing actuator 120. When the side-swing actuator 120 starts and outputs rotational power, it directly drives the first worm gear 131 to rotate synchronously around its own axis. At this time, the first worm gear 131 acts as the driving element, and its helical teeth are embedded in the tooth grooves of the first worm wheel 132 to form a meshing transmission. This meshing structure drives the first worm wheel 132 to rotate around its own axis through the rotation of the helical teeth, converting the rotational power of the first worm gear 131 into a rotational power perpendicular to it provided by the first worm wheel 132, thereby completing a 90° power conversion.

[0028] Furthermore, the meshing transmission between the first worm 131 and the first worm wheel 132 has a self-locking function. When the side-swing driver 120 stops outputting power, if the lead angle of the first worm 131 is less than the friction angle between the worm and the worm wheel tooth surfaces, the worm wheel cannot drive the worm to rotate in the reverse direction. Thus, even if the connecting base 210, the bending joint 200, and the fingertip 300 generate a reverse force due to external load, the first worm wheel 132 will not drive the first worm 131 to rotate. This ensures that the connecting base 210 and subsequent structures always remain in the preset position when the side-swing driver 120 stops, and there will be no problem of attitude deviation or automatic retraction. This avoids damage to the side-swing driver 120 due to reverse force and improves the safety and service life of the components.

[0029] See Figure 3 and Figure 4 As shown, the bending joint 200 is a key structure for the dexterous thumb to achieve the core grasping action. Its core function is to convert power into the bending motion of the knuckles through the coordination of multiple components, simulating the bending and grasping process of the human thumb, and providing clamping force for grasping objects. The connecting base 210 serves as the connecting component between the bending joint 200 and the lateral swing joint 100. On one hand, it rotatably connects to the power output end of the first reversing transmission assembly 130, ensuring that the lateral swinging motion of the lateral swing joint 100 is synchronously transmitted to the bending joint 200. On the other hand, it provides a rotational support point for the knuckle linkage assembly 220, allowing the knuckle linkage assembly 220 to achieve initial bending around the connecting base 210. One end of the knuckle linkage assembly 220 is rotatably connected to the connecting base 210, and the other end is rotatably connected to the fingertip 300. The entire assembly can achieve this through the coordination of multiple linkage segments. Similar to bending, the bending motion simulates the bending trajectory of the human thumb from the metacarpophalangeal joint to the interphalangeal joint. The bending actuator 230, as a dedicated power source for the bending motion, avoids the functional limitations of a single-motor drive. Its output power, after being adjusted in direction by the second reversing transmission component 240, precisely acts on the finger joint linkage assembly 220, driving the linkage assembly to bend and move along a biomimetic trajectory. Ultimately, this causes the fingertip 300 to approach the palm, forming a gripping action on the object. Furthermore, the built-in drive design achieves independent power control within a limited space, ensuring that the accuracy and force of the bending motion can be adjusted according to the gripping requirements. Specifically, the bending actuator 230 in this embodiment is also configured as a rotary motor.

[0030] Furthermore, the bending joint 200 includes two knuckle linkage assemblies 220 symmetrically arranged along the thumb width direction of the adaptive grasping dexterity hand. The two linkage assemblies are connected by a pivot for synchronous movement. Each knuckle linkage assembly 220 includes an outer link 221 and an inner link 222 that are rotatably connected relative to each other. One end of the outer link 221 and one end of the inner link 222 are respectively rotatably connected to the connecting base 210, and the other end of the outer link 221 is connected to the connecting base 210. The other end of the inner link 222 is rotatably connected to the fingertip 300. The middle part of the outer link 221 is rotatably connected to the middle part of the inner link 222, so that the knuckle link assembly 220 forms a flexible and rotatable four-bar structure. The inner link 222 is connected to the power output end of the second reversing transmission assembly 240. The bending actuator 230 is connected to the rotatable connection between the outer link 221 and the inner link 222 to drive the knuckle link assembly 220 to bend / extend.

[0031] In this embodiment, the two symmetrically arranged knuckle linkage assemblies 220 along the width of the thumb are the core framework for realizing biomimetic bending and straightening movements. The two are connected by a pivot to form a synchronous motion relationship, ensuring that the force on both sides is balanced and the movement is smooth when the thumb bends, avoiding posture deviation caused by force on one side. Each knuckle linkage assembly 220 consists of an outer link 221 and an inner link 222 that can rotate relative to each other, and forms a flexible four-bar linkage structure through rotational connections at multiple positions. This allows the power input to be converted into bending motion along a preset trajectory, perfectly simulating the natural bending trajectory of the human thumb knuckle and avoiding jamming or movement distortion.

[0032] Specifically, the inner connecting rod 222 is connected to the power output end of the second reversing transmission assembly 240 as a power receiving end, while the bending actuator 230 is connected to the rotational connection between the outer connecting rod 221 and the inner connecting rod 222. When the bending actuator 230 starts outputting power, it drives the outer connecting rod 221 and the inner connecting rod 222 to rotate relative to each other around their respective rotational connection points. During the bending action, the bending actuator 230 pushes the middle rotation points of the outer connecting rod 221 and the inner connecting rod 222 closer to each other, causing the outer connecting rod 221 and the inner connecting rod 222 to move closer together. 2. The four-bar linkage assemblies 221 and 222 rotate synchronously around their respective connection points on the base 210 and fingertip 300, bending the entire four-bar linkage towards the thumb and ultimately bringing the fingertip 300 closer to the palm, forming a grasping posture. During the straightening motion, the bending actuator 230 outputs power in the opposite direction, pulling the middle rotation points of the outer link 221 and inner link 222 away from each other, causing the outer link 221 and inner link 222 to return to their original positions, restoring the four-bar linkage to a straight state, and thus moving the fingertip 300 away from the palm and back to its initial straight position. Furthermore, the symmetrical arrangement of the two finger joint linkage assemblies 220 along the thumb width not only ensures more even force distribution during bending and straightening, reducing the shortened lifespan caused by unilateral wear, but also ensures that the fingertip 300 remains horizontal through synchronous movement, preventing tilting of the fingertip 300 when grasping objects, ensuring the stability and accuracy of the grasp, and providing a foundation for subsequent complex grasping actions in coordination with other fingers.

[0033] Further, in this embodiment, the outer connecting rod 221 includes a first rod body 2211 and a second rod body 2212, wherein one end of the first rod body 2211 is rotatably connected to the connecting base 210, and the other end is rotatably connected to one end of the second rod body 2212, and the other end of the second rod body 2212 is rotatably connected to the fingertip 300; the inner connecting rod 222 includes a third rod body 2221 and a fourth rod body 2222, one end of the third rod body 2221 is rotatably connected to the connecting base 210 and the power output end of the second reversing transmission assembly 240 respectively, and the other end is rotatably connected to one end of the fourth rod body 2222, the bending actuator 230 is disposed on the third rod body 2221, and the other end of the fourth rod body 2222 is rotatably connected to the fingertip 300. Based on the above structure, the outer connecting rod 221 is composed of a first rod body 2211 and a second rod body 2212, forming a two-section foldable structure. One end of the first rod body 2211 is rotatably connected to the connecting base 210 through a revolute joint. This connection point provides the outer connecting rod 221 with an initial fulcrum for rotation around the connecting base 210, ensuring that the movement of the outer connecting rod 221 is always based on the connecting base 210. The other end of the first rod body 2211 is also connected to one end of the second rod body 2212 through a revolute joint, forming a middle movable joint of the outer connecting rod 221, which can realize the relative rotation of the two rod sections according to bending requirements. The other end of the second rod body 2212 is rotatably connected to the fingertip 300, becoming the end connection for the outer connecting rod 221 to transmit the movement to the fingertip 300. This segmented design allows the outer link 221 to conform to the biomimetic trajectory of the thumb when bending. When the bending action is initiated, the first link 2211 rotates around the connecting base 210, while simultaneously driving the second link 2212 to rotate around the connection point of the two. Ultimately, the second link 2212 pulls the fingertip 300 closer to the palm. When straightening, it rotates in the opposite direction, pushing the fingertip 300 back to its initial position, thus avoiding the problem of stiff single-segment link movements that cannot adapt to the natural bending trajectory.

[0034] Similarly, the inner link 222 is composed of the third link 2221 and the fourth link 2222. Its structural design not only needs to cooperate with the outer link 221 to achieve synchronous action, but also needs to undertake the core functions of power reception and drive output. The rotational connection between one end of the third link 2221 and the connecting base 210 can ensure that the action reference of the inner link 222 is consistent with that of the outer link 221, avoiding misalignment of their actions. Its connection with the second reversing transmission assembly 240 makes it a power receiving end, which can convert the power transmitted by the second reversing transmission assembly 240 into its own rotational action. The other end of the third rod 2221 is connected to one end of the fourth rod 2222 via a revolute joint, forming the middle movable joint of the inner connecting rod 222. The bending actuator 230 is directly mounted on the third rod 2221, so that the power output of the actuator can directly act on the third rod 2221, driving the third rod 2221 to rotate around the connecting base 210, and simultaneously driving the fourth rod 2222 to move. The other end of the fourth rod 2222 is rotatably connected to the fingertip 300, serving as the end connection point for the inner connecting rod 222 to transmit the action to the fingertip 300. It also cooperates with the connection point of the second rod 2212 of the outer connecting rod 221 at the fingertip 300, ensuring that the fingertip 300 can maintain a stable posture under the joint pull of the two.

[0035] See Figure 4 As shown, in this embodiment, the second reversing transmission assembly 240 includes a mounting bracket 241, a second worm 244, and a second worm wheel 245. The bending actuator 230 is connected to the mounting bracket 241. The second worm 244 is connected to the working end of the bending actuator 230. The second worm wheel 245 passes through and is connected to the second worm 244, and meshes with the worm shaft 1311 of the second worm 244. The third rod body 2221 is connected to the second worm wheel 245. Its actual operation and principle are the same as those of the first worm 131 and the first worm wheel 132, and will not be described in detail here. Furthermore, the second reversing transmission assembly 240 in this embodiment also includes a drive gear 242 and a transmission gear 243. Both the drive gear 242 and the transmission gear 243 are disposed on the mounting bracket 241. The drive gear 242 is connected to the working end of the bending actuator 230. The transmission gear 243 meshes with the drive gear 242 and is connected to the second worm gear 244. The diameter of the drive gear 242 is smaller than the diameter of the transmission gear 243.

[0036] Based on the above structure, the drive gear 242 is directly connected to the working end of the bending actuator 230 for power transmission, directly transmitting the rotational power output by the bending actuator 230 to the transmission gear 243. The transmission gear 243 meshes with the drive gear 242 and is fixedly connected to the second worm gear 244. Furthermore, the drive gear 242 and the transmission gear 243 adopt a small gear driving a large gear structure design, which enables them to have a pre-reduction and torque amplification function. Specifically, since the gear transmission ratio is inversely proportional to the diameter, when the drive gear 242 drives the transmission gear 243 to rotate, the rotational speed of the transmission gear 243 will be lower than that of the drive gear 242, while the torque will be amplified proportionally according to the transmission ratio. This design works in conjunction with the subsequent reduction and torque amplification of the second worm 244 and the second worm wheel 245. The high-speed, low-torque power output from the bending actuator 230 is first reduced and amplified through the drive gear 242 and transmission gear 243, reducing the speed and increasing the base torque, before being transmitted to the second worm 244. The worm wheel then performs a second stage of direction conversion and reduction and torque amplification, ultimately outputting low-speed, high-torque power with a suitable direction to the third link 2221. This multi-stage transmission structure, on the one hand, allows for flexible matching of the power requirements of the bending joint 200 under different working conditions by adjusting the gear ratio, avoiding the problem of a single transmission not being able to meet multiple needs. On the other hand, the front gear set can filter out some power fluctuations, making the power transmitted to the worm wheel more stable, reducing wear on the worm wheel caused by instantaneous impact loads, and extending the service life of the components. Even when using the bending joint 200 to grasp heavier objects, it can still maintain precise and smooth movements, providing stronger power support for the reliable grasping of the dexterous thumb.

[0037] In this embodiment, the knuckle linkage assembly 220 further includes an adaptive elastic element 223, which is disposed between the outer link 221 and the inner link 222 of the same knuckle linkage assembly 220. The adaptive elastic element 223 can absorb the power fluctuation of the bending actuator 230 when the knuckle linkage assembly 220 is bent by means of a tension spring, avoiding jamming, and release potential energy to assist in straightening and buffering impact when straightened; at the same time, it can also adapt to the slight displacement of the outer link 221 and the inner link 222 caused by irregular objects by deformation, ensuring that the fingertip 300 is in contact with the object, and can also limit the gripping force to protect fragile objects, thereby improving the gripping performance and adaptability of the dexterous hand thumb.

[0038] In this embodiment, the fingertip 300, in conjunction with the bending joint 200, completes the final grasping or releasing action. The fingertip 300, by rotating and connecting to the other end of the knuckle linkage assembly 220, can adaptively adjust the contact angle according to the curvature and shape of the object's surface during the grasping process. When contacting irregular objects, the fingertip 300 can slightly rotate around the connection point to maximize the contact area and prevent the object from slipping due to an insufficient contact point. Specifically, the fingertip 300 includes a rotating connection part 310 and an elastic bionic part 320. The rotating connection part 310 is rotatably connected to the knuckle linkage assembly 220 and fixedly connected to the elastic bionic part 320. This upgrades the knuckle linkage assembly 220 from a rigid transmission structure to a rigid-flexible combined structure, improving the grasping performance and adaptability of the dexterous thumb.

[0039] The adaptive grasping dexterous thumb provided in this embodiment also includes a control mechanism, with the side-swing driver 120 and the bending driver 230 respectively connected to the control mechanism. In actual production and processing, operators can adjust the above structure in real time through the control mechanism, thereby improving the flexibility of using this adaptive grasping dexterous thumb. Parameters can also be preset through the control system, thereby improving the automation level of this adaptive grasping dexterous thumb.

[0040] Furthermore, the adaptive grasping dexterous thumb also includes an elastic shell that covers the outer surface of the lateral joint 100 and / or the bending joint 200. On one hand, this shell isolates the thumb from external dust, moisture, and minor impacts, preventing damage to the internal precision structures such as the first reversing transmission assembly 130 of the lateral joint 100 and the finger joint linkage assembly 220 of the bending joint 200. On the other hand, it optimizes the gripping feel of the thumb, and in human-computer interaction scenarios, it can also reduce the risk of scratching the contact object, further enhancing the practicality and safety of the dexterous thumb.

[0041] In summary, compared with conventional bionic finger structures at present, this application has significant advantages such as flexible use, high motion precision, fast response speed, high degree of freedom, high space utilization and strong controllability, providing new design ideas and directions for dexterous hand structures.

[0042] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. An adaptive grasping dexterous hand thumb, characterized in that: include: A lateral swing joint, comprising a fixed base, a lateral swing driver, and a first reversing transmission assembly, wherein the fixed base can be connected to an external bionic hand, the lateral swing driver is disposed in the fixed base, and the first reversing transmission assembly is connected to the working end of the lateral swing driver; A bending joint, comprising a connecting base, a knuckle linkage assembly, a bending actuator, and a second reversing transmission assembly, wherein the connecting base is rotatably connected to the power output end of the first reversing transmission assembly to drive the bending joint to rotate around a rotation center line, one end of the knuckle linkage assembly is rotatably connected to the connecting base, the bending actuator is disposed on the knuckle linkage assembly, and the second reversing transmission assembly is connected to the working end of the side swing actuator, and its power output end is rotatably connected to the knuckle linkage assembly to drive the linkage assembly to bend and move; The fingertip is rotatably connected to the other end of the knuckle linkage assembly.

2. The adaptive grasping dexterous hand thumb according to claim 1, characterized in that: The first reversing transmission assembly includes a first worm and a first worm wheel. The first worm is connected to the working end of the side swing driver. The first worm wheel is connected to the first worm and meshes with the worm shaft of the first worm. The connecting base is connected to the first worm wheel.

3. The adaptive grasping dexterous hand thumb according to claim 1, characterized in that: The bending joint includes two knuckle linkage assemblies symmetrically arranged along the width direction of the thumb of the adaptive grasping dexterity hand. The two linkage assemblies are connected by a pivot for synchronous movement. Each knuckle linkage assembly includes an outer link and an inner link that are rotatably connected relative to each other. One end of the outer link and one end of the inner link are rotatably connected to the connecting base, and the other end of the outer link and the other end of the inner link are rotatably connected to the fingertip. The middle part of the outer link and the middle part of the inner link are rotatably connected to form a bendable and rotatable four-bar linkage structure. The inner link is connected to the power output end of the second reversing transmission assembly. The bending actuator is connected to the rotatable connection between the outer link and the inner link to drive the knuckle linkage assembly to bend / extend.

4. The adaptive grasping dexterous hand thumb according to claim 3, characterized in that: The outer connecting rod includes a first rod body and a second rod body, wherein one end of the first rod body is rotatably connected to the connecting base, and the other end is rotatably connected to one end of the second rod body, and the other end of the second rod body is rotatably connected to the fingertip; the inner connecting rod includes a third rod body and a fourth rod body, one end of the third rod body is rotatably connected to the connecting base and the power output end of the second reversing transmission assembly, and the other end is rotatably connected to one end of the fourth rod body, the bending actuator is disposed on the third rod body, and the other end of the fourth rod body is rotatably connected to the fingertip.

5. The adaptive grasping dexterous hand thumb according to claim 4, characterized in that: The second reversing transmission assembly includes a mounting bracket, a second worm, and a second worm wheel. The bending actuator is connected to the mounting bracket, the second worm is connected to the working end of the bending actuator, the second worm wheel is connected to the second worm and meshes with the worm shaft of the second worm, and the third rod is connected to the second worm wheel.

6. The adaptive grasping dexterous hand thumb according to claim 5, characterized in that: The second reversing transmission assembly further includes a drive gear and a transmission gear, both of which are mounted on the mounting bracket. The drive gear is connected to the working end of the bending actuator, and the transmission gear meshes with the drive gear and is connected to the second worm. The diameter of the drive gear is smaller than the diameter of the transmission gear.

7. The adaptive grasping dexterous hand thumb according to claim 3, characterized in that: The knuckle link assembly also includes an adaptive elastic element, which is disposed between the outer link and the inner link of the same knuckle link assembly.

8. The adaptive grasping dexterous hand thumb according to claim 1, characterized in that: The fingertip includes a rotating connection part and an elastic bionic part. The rotating connection part is rotatably connected to the knuckle linkage assembly and is fixedly connected to the elastic bionic part.

9. The adaptive grasping dexterous hand thumb according to claim 1, characterized in that: The adaptive grasping dexterous hand thumb also includes a resilient shell that covers the outer surface of the lateral joint and / or the flexion joint.

10. The adaptive grasping dexterous hand thumb according to claim 1, characterized in that: The adaptive grasping dexterous hand thumb also includes a control mechanism, and the lateral swing driver and the bending driver are respectively connected to the control mechanism.

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