Reconfigurable under-actuated three-fingered hand with self-locking function

Abstract

The application belongs to the technical field of robot grasping, and discloses a reconfigurable underactuated three-fingered hand with self-locking function, which comprises an underactuated finger module, a reconfiguration device module, a planetary gear driving module and an electronic system module. Each finger is coupled with an elastic element through single driving input, so that adaptive parallel or enveloping grasping of knuckles is realized. The reconfiguration device module can adjust the relative positions of two fingers, and switch the two grasping modes of centering and finger pointing, so as to adapt to different objects and tasks. The planetary gear driving module drives the opening and closing of the fingers through a turbine-vortex rod mechanism and provides reverse self-locking, so as to ensure the stability of grasping. The electronic system module integrates control and power supply. The application has the advantages of simple adaptive underactuated structure, flexibility of layout reconfiguration and reliability of mechanical self-locking, and significantly improves the grasping adaptability and load holding performance of the dexterous hand on complex objects.

Description

Technical Field

[0001] This invention belongs to the field of robot grasping technology, and in particular relates to a reconfigurable underactuated three-finger dexterous hand with self-locking function. Background Technology

[0002] With the rapid development of robotics technology in industries such as manufacturing, healthcare, and services, the flexibility and adaptability of robotic grasping operations have become increasingly important. Traditional rigid multi-fingered manipulators, while offering high precision and rigidity, suffer from complex structures, difficult control, high costs, and difficulty adapting to objects of varying shapes and sizes. Underactuated manipulators, due to their inherent passive adaptability, can achieve coordinated movement of multiple joints with a single actuation input, simplifying control and reducing costs, making them an effective solution to these problems. However, most underactuated manipulators struggle to maintain a stable grip on objects during grasping, especially when the robot is moving or encountering external disturbances, as objects are prone to slipping, limiting their reliability in practical applications. Furthermore, existing underactuated manipulators often require complex designs or frequent structural adjustments to adapt to objects of different sizes and shapes. Therefore, developing a three-fingered dexterous hand that combines underactuation characteristics, structural reconfiguration based on task requirements, and stable self-locking functionality to improve the flexibility, adaptability, and reliability of robotic grasping operations has become a significant challenge in the field of robotic grasping technology. Summary of the Invention

[0003] The purpose of this invention is to provide a reconfigurable underactuated three-finger dexterous hand with a self-locking function to solve the above-mentioned technical problems.

[0004] To solve the above-mentioned technical problems, the specific technical solution of the present invention for a reconfigurable underactuated three-finger dexterous hand with self-locking function is as follows:

[0005] A reconfigurable underactuated three-finger dexterous hand with self-locking function, comprising:

[0006] Three underactuated fingers, each with multiple knuckles, achieve knuckle coupling and adaptive movement through a drive input and two elastic elements;

[0007] The reconstruction device module is connected to the underactuated finger and is used to adjust the relative position between the two fingers to achieve finger layout reconstruction.

[0008] The planetary gear drive module is connected to the underactuated finger through a worm gear-worm transmission mechanism, and is used to drive the finger to open and close, and to achieve position self-locking;

[0009] The electronic system module is used to control the operation of the reconfiguration device module and the planetary gear drive module.

[0010] Furthermore, each of the underactuated fingers includes a distal phalanx, a middle phalanx, a proximal phalanx, a short connecting rod, a long connecting rod, a finger base, a front push rod, and a rear push rod; the distal phalanx, middle phalanx, proximal phalanx, and finger base are sequentially hinged together, and the proximal phalanx, short connecting rod, long connecting rod, and finger base are mutually hinged to form a parallelogram mechanism; the distal phalanx, front push rod, rear push rod, and planetary gear drive module are sequentially hinged together.

[0011] Furthermore, the elastic element consists of a torsion spring one disposed between the distal phalanx and the middle phalanx, and a torsion spring two disposed between the proximal phalanx and the finger base. When the distal phalanx rotates inward relative to the middle phalanx, it is resisted by the torsion spring one; when the fingers are opened, the torsion spring two is compressed. The distal phalanx is provided with a stepped baffle for limiting the maximum angle between the distal phalanx and the middle phalanx; the short connecting rod is provided with a platform for limiting the maximum angle between the middle phalanx and the proximal phalanx.

[0012] Furthermore, when there is no external resistance, the distal phalanx remains at a 180-degree angle to the middle phalanx under the combined action of the torsion spring and the stepped baffle. During the closing of the fingers, the elastic force of the torsion spring causes the proximal phalanx to tend to move inward, thereby causing the platform of the short link to be close to the middle phalanx. The distal and middle phalanxes move synchronously with the short link, moving in parallel inward, which is a parallel grasping action. When the closed fingers encounter an irregular object, the proximal or middle phalanx encounters resistance to inward movement. At this time, the distal phalanx, still under the action of the forward push rod, resists the torsion spring between the distal and middle phalanxes and flips inward, which is an enveloping grasping action.

[0013] Furthermore, the reconstruction device module includes a reconstruction fixing plate and a reconstruction device. One underdriven finger is fixedly mounted on the reconstruction fixing plate, and two underdriven fingers are rotatably mounted on the reconstruction fixing plate through the reconstruction device. The relative positions of the two underdriven fingers are adjusted by the reconstruction device. The angles of the three underdriven fingers are 120 degrees to each other, configured as a centered grasping mode. Two underdriven fingers are parallel to each other, with two on one side and one on the other side, configured as a finger-to-finger grasping mode.

[0014] Furthermore, the reconfiguration device includes a reconfiguration linkage, a reconfiguration gear set, and a reconfiguration motor mounted above the reconfiguration fixed plate;

[0015] The bases of the two fingers are fixed on two symmetrically arranged reconfiguration links; the reconfiguration motor drives the two reconfiguration links to rotate synchronously through the reconfiguration gear set, thereby driving the two fingers to rotate synchronously and realizing finger layout reconfiguration.

[0016] Furthermore, the reconfigurable gear set includes a reconfigurable gear, a reconfigurable motor gear, and an intermediate gear. The reconfigurable motor is connected to the reconfigurable motor gear. Two sets of reconfigurable connecting rods and reconfigurable gears are symmetrically arranged. The two reconfigurable gears mesh with each other. The reconfigurable connecting rod has an inwardly protruding tooth sector. The tooth sector of the reconfigurable connecting rod meshes with the two reconfigurable gears respectively. The reconfigurable motor gear meshes with the intermediate gear. The intermediate gear meshes with one of the reconfigurable gears.

[0017] Furthermore, the planetary gear drive module includes a drive motor, a drive main gear, a double-layer gear, a drive pinion, a worm, a worm wheel, and a worm wheel shaft;

[0018] The drive motor is connected to the drive main gear, the drive main gear meshes with the lower layer of the double-layer gear, and the upper layer of the double-layer gear meshes with the drive pinion.

[0019] The drive pinion is fixed coaxially with the worm, the worm meshes with the worm wheel, and the worm wheel is connected to the rear push rod through the worm wheel shaft; the worm and worm wheel constitute a one-way transmission drive mechanism to achieve position self-locking.

[0020] Furthermore, the planetary gear drive module also includes a drive spindle, the upper end of which is fixedly connected to the finger base, and the lower end is coaxially connected to the drive pinion and worm gear; the drive spindle passes through the slide groove on the reconstruction fixed plate and is eccentrically rotatably connected to the reconstruction connecting rod, so that the drive mechanism moves accordingly during finger reconstruction.

[0021] Furthermore, the electronic system module includes a microcontroller, a CAN communication module, and a step-down module; the step-down module is used to power the entire system; the microcontroller communicates with the host computer through the CAN communication module and controls the reconfigurable motor and the drive motor to work respectively.

[0022] The reconfigurable underactuated three-finger dexterous hand with self-locking function of the present invention has the following advantages:

[0023] 1. Simplified structure and reduced cost: Through underactuated design, each finger only needs one drive input (planetary gear drive module) and two elastic elements to achieve multi-joint coupling and adaptive movement, which significantly reduces the number of actuators and system complexity, and reduces manufacturing costs and control difficulty.

[0024] 2. Reconfigurable layout for enhanced gripping flexibility: The reconfigurable module allows for dynamic adjustment of the relative positions of two fingers, enabling switching between two typical gripping layouts: "center-grasping mode" and "finger-grasping mode." This allows it to adapt to different sizes, shapes, and gripping task requirements (such as gripping spheres, cylinders, cubes, etc.), greatly expanding the application scenarios of a single robotic arm.

[0025] 3. Reliable mechanical self-locking function: The drive unit adopts a worm gear transmission mechanism, which utilizes its inherent reverse self-locking characteristic to allow the finger to maintain a locked position after grasping an object, maintaining gripping force without continuous power supply. This enhances the stability and reliability of the grip, making it particularly suitable for applications where vibration or external interference may occur, and enabling a larger load capacity.

[0026] 4. Decoupled Drive and Reconfiguration Design: The planetary gear drive module uses an eccentric connection between the drive spindle and the reconfiguration linkage, allowing the drive mechanism to adjust dynamically during finger layout reconfiguration, ensuring continuous drive transmission. Simultaneously, reconfiguration and drive are controlled by independent motors, ensuring no functional interference, high system integration, and clear control logic.

[0027] 5. Integration and Compactness: The electronic system modules (including control, communication, and power supply) are integrated inside the dexterous hand, resulting in a compact overall structure. This allows for easy installation as independent modules at the end of various robot arms, reducing external wiring and improving the system's portability and reliability.

[0028] In summary, this invention organically combines the adaptive advantages of underactuation, the flexibility of reconfigurable layout, and the self-locking stability of worm gear transmission, providing a three-finger dexterous hand solution that is highly adaptable, has strong grasping stability, is functionally flexible, and has a relatively simple structure, effectively improving the overall performance of robots in grasping operations in complex and unstructured environments. Attached Figure Description

[0029] Figure 1 : A schematic diagram of the three-finger dexterous hand structure of the present invention;

[0030] Figure 2 : Schematic diagram of the internal structure of the three-finger dexterous hand of the present invention;

[0031] Figure 3 Detailed structural diagram of the underactuated finger module;

[0032] Figure 4 A schematic diagram of the structural state of the fingers when they are closed;

[0033] Figure 5 : A schematic diagram of the structural state of fingers when they are spread open;

[0034] Figure 6 : Schematic diagram of the torsion spring connection for an underactuated finger;

[0035] Figure 7 : A schematic diagram of the reconfiguration device module;

[0036] Figure 8 : Connection diagram of the reconfigured gear set;

[0037] Figure 9 : Schematic diagram of the reconfiguration device;

[0038] Figure 10 Schematic diagram of the planetary gear drive module;

[0039] Figure 11 : A schematic diagram of the planetary gear drive module;

[0040] Figure 12 Schematic diagram of the electronic system modules;

[0041] Figure 13 : Component diagram of an electronic system module;

[0042] Figure 14 Schematic diagram of power supply and control for electronic system modules;

[0043] Figure 15 : Schematic diagram of the top and bottom shell structures of the housing assembly;

[0044] Figure 16 : Schematic diagram of the left and right outer shell structures of the outer shell assembly;

[0045] Figure 17 : Schematic diagram of the center-grabbing modal motion;

[0046] Figure 18 : Schematic diagram of finger grasping mode motion;

[0047] Figure 19 : A diagram illustrating the grasping of a square object with fingers;

[0048] Figure 20 : A schematic diagram of grasping a cylindrical object using the finger envelope;

[0049] Figure 21 : Schematic diagram of grasping a spherical object using the pericardium;

[0050] Explanation of markings in the diagram: 1. Underactuated finger module; 101. Distal phalanx; 1011. Stepped baffle; 102. Middle phalanx; 103. Proximal phalanx; 104. Short link; 1041. Platform; 105. Long link; 106. Finger base; 107. Front push rod; 108. Rear push rod; 109. Torsion spring one; 110. Torsion spring two; 2. Reconstruction device module; 201. Reconstruction fixing plate; 2011. Slide; 202. Reconstruction link; 203. Reconstruction gear; 204. Reconstruction motor gear; 205. Intermediate gear; 206. Reconfigurable motor; 3. Planetary gear drive module; 301. Worm gear carrier; 302. Worm gear; 303. Double-layer gear; 304. Drive fixed plate; 305. Drive pinion; 306. Drive main gear; 307. Worm gear shaft; 308. Worm; 309. Drive spindle; 310. Drive motor; 4. Electronic system module; 401. Microcontroller; 402. CAN communication module; 403. Step-down module; 5. Housing assembly; 501. Top housing; 502. Left housing; 503. Right housing; 504. Bottom housing. Detailed Implementation

[0051] To better understand the purpose, structure, and function of this invention, the following detailed description of a reconfigurable underactuated three-finger dexterous hand with self-locking function is provided in conjunction with the accompanying drawings.

[0052] like Figure 1 Figure 2 As shown, this invention provides a reconfigurable underactuated three-finger dexterous hand with a self-locking function. Its specific structure includes an underactuated finger module 1, a reconfiguration device module 2, a planetary gear drive module 3, an electronic system module 4, and a housing assembly 5. The modules work together through mechanical and electrical connections to achieve the finger's driving, reconfiguration, and self-locking functions.

[0053] like Figures 3-6 As shown, the underactuated finger module 1 includes three underactuated fingers. Each underactuated finger includes a distal phalanx 101, a middle phalanx 102, a proximal phalanx 103, a short link 104, a long link 105, a finger base 106, a front push rod 107, and a rear push rod 108. The distal phalanx 101 is hinged to the middle phalanx 102, with a torsion spring 109 in between; the middle phalanx 102, short connecting rod 104, and proximal phalanx 103 are hinged; the proximal phalanx 103 is hinged to the finger base 106, with a torsion spring 110 in between; the proximal phalanx 103, short connecting rod 104, long connecting rod 105, and finger base 106 are hinged together to form a parallelogram structure; the distal phalanx 101 is hinged to the front push rod 107, the front push rod 107 is hinged to the rear push rod 108, and the rear push rod 108 is hinged to the planetary gear drive module 3, which drives the movement.

[0054] The distal phalanx 101 and the front push rod 107 are connected by a stepped baffle 1011, which limits the maximum angle between the distal phalanx 101 and the middle phalanx 102 to 180 degrees. During the opening of the hand, the front push rod 107 pulls the distal phalanx 101 backward. When the angle between the distal phalanx 101 and the middle phalanx 102 is at its maximum, continuing to pull the distal phalanx 101 can move the middle phalanx 102 along with it. The head of the short link 104 has a protruding platform 1041, which, like the stepped baffle 1011, limits the maximum angle between the middle phalanx 102 and the proximal phalanx 103. Since the proximal phalanx 103, short link 104, long link 105, and finger base 106 form a parallelogram mechanism, the short link 104 undergoes translational motion.

[0055] like Figure 5 As shown, when the fingers are opened, the front push rod 107 pulls the distal phalanx 101 backward. Restricted by the stepped baffle 1011 and platform 1041, the middle phalanx 102 and short connecting rod 104 also move simultaneously in a translational motion. A torsion spring 110 is installed between the proximal phalanx 103 and the finger base 106; when the fingers are opened, the torsion spring 110 is compressed.

[0056] like Figure 4 As shown, when the fingers are closed, the front push rod 107 pushes the distal phalanx 101 inward, and the stepped baffle 1011 and platform 1041 no longer function, allowing the fingers to grasp. However, because a torsion spring 109 is provided between the distal phalanx 101 and the middle phalanx 102, the distal phalanx 101 will be resisted by the torsion spring 109 when rotating inward relative to the middle phalanx 102. Therefore, when there is no external resistance, the distal phalanx 101 remains at a 180-degree angle to the middle phalanx 102 under the combined action of the torsion spring 109 and the stepped baffle 1011. A torsion spring 110 is provided between the proximal phalanx 103 and the finger base 106. During the process of closing the fingers, the elastic force of the torsion spring 110 causes the proximal phalanx 103 to tend to move inward, thereby causing the platform 1041 of the short connecting rod 104 to be pressed tightly against the middle phalanx 102. Therefore, the distal phalanx 101 and the middle phalanx 102 move synchronously with the short connecting rod 104, moving inward in parallel.

[0057] When the closed fingers encounter an irregular object, the proximal phalanx 103 or the middle phalanx 102 encounters resistance to inward movement. At this time, the distal phalanx 101, under the action of the front push rod 107, resists the torsion spring 109 between the distal phalanx 101 and the middle phalanx 102 and flips inward, which manifests as an enveloping grasp.

[0058] Underactuated fingers, due to having three knuckles, two hinge points, and only one actuation input, have fewer degrees of freedom than the number of actuators. For example... Figures 19-20As shown, when grasping regular, flat objects, it exhibits a parallel grasp. When grasping irregular objects, the middle knuckle 102 and proximal knuckle 103 rotate inward to form an adaptive arc, exhibiting an envelope grasp.

[0059] like Figures 7-9 As shown, the reconstruction device module 2 includes a reconstruction fixed plate 201 and a reconstruction device. One underdriven finger is fixedly mounted on the reconstruction fixed plate 201, and two other underdriven fingers are rotatably mounted on the reconstruction fixed plate 201 via the reconstruction device. The reconstruction device includes a reconstruction link 202, a reconstruction gear 203, a reconstruction motor gear 204, an intermediate gear 205, and a reconstruction motor 206. The reconstruction motor 206 is mounted below the reconstruction fixed plate 201, while the reconstruction link 202, reconstruction gear 203, reconstruction motor gear 204, and intermediate gear 205 are mounted above the reconstruction fixed plate 201. The reconstruction motor 206 is connected to the reconstruction motor gear 204. Two sets of reconstruction links 202 and reconstruction gears 203 are symmetrically arranged, with the two reconstruction gears 203 meshing with each other. The reconstruction link 202 has inwardly protruding tooth sectors, which mesh with the two reconstruction gears 203 respectively. The reconstruction motor gear 204 meshes with the intermediate gear 205, and the intermediate gear 205 meshes with one of the reconstruction gears 203. The finger bases 106 of the two sets of underactuated finger modules 1 are respectively fixedly mounted on two reconfiguration linkages 202; the rotation of the reconfiguration motor 206 controls the simultaneous rotation of the two sets of reconfiguration linkages 202, thereby controlling the two fingers to rotate inward or outward simultaneously, realizing the function of reconfiguring the finger position. Figure 17-21 As shown, the shape of the finger can be reconstructed based on the shape of the object being grasped.

[0060] Reconfiguration transmission route: Reconfiguration motor gear 204 - intermediate gear 205 - reconfiguration gear 203 - reconfiguration link 202 - finger base 106. When the reconfiguration motor 206 drives the reconfiguration motor gear 204 to rotate counterclockwise, it drives the reconfiguration link 202 to rotate inward through the reconfiguration gear set. At this time, the angle of each of the three underactuated fingers is 120 degrees, configured as a centered grasping mode. When the reconfiguration motor 206 drives the reconfiguration motor gear 204 to rotate clockwise, it drives the reconfiguration link 202 to rotate outward through the reconfiguration gear set. At this time, the three underactuated fingers are parallel to each other, two on one side and one on the other side, configured as a finger-to-finger grasping mode.

[0061] like Figure 10 Figure 11As shown, the planetary gear drive module 3 includes: a worm gear carrier 301, a worm gear 302, a double-layer gear 303, a drive fixed disk 304, a drive pinion 305, a drive main gear 306, a worm gear shaft 307, a worm 308, a drive main shaft 309, and a drive motor 310. The double-layer gear 303 and the drive main gear 306 are mounted on the drive fixed disk 304. The drive main gear 306 is directly connected to the drive motor 310 and meshes with the lower layers of the three double-layer gears 303. The upper layers of the double-layer gears 303 mesh with the drive pinion 305. The drive pinion 305 is fixedly connected to the worm 308, and the worm 308 is coaxially fixedly connected to the drive main shaft 309. The drive main shaft 309 passes through the reconfiguration fixed disk 201, is movably connected in the slide groove 2011 of the reconfiguration fixed disk 201, and is rotatably connected to the eccentric shaft hole of the reconfiguration connecting rod 202. Therefore, when the reconfigurable connecting rod 202 rotates, it drives the worm gear 308 and the drive pinion 305 to rotate coaxially and at the same angle. The drive spindle 309 is a D-shaped shaft, and its upper end passes through the reconfigurable connecting rod 202 and is fixedly connected to the finger base 106. When the reconfigurable connecting rod 202 rotates, it drives the drive spindle 309, worm gear 308, and drive pinion 305 to rotate around the circumference of the double-layer gear 303. The upper shaft of the worm gear carrier 301 passes through the reconfigurable fixed plate 201 and is fixedly connected to the rotation axis of the reconfigurable connecting rod 202, while the lower shaft is concentrically connected to the double-layer gear 303. The worm gear 302 is rotatably mounted on the worm gear carrier 301 via the worm gear shaft 307, and the rear push rod 108 is fixedly connected to the worm gear shaft 307. The underactuated finger drive transmission route is as follows: drive main gear 306 - double-layer gear 303 - drive pinion 305 - worm 308 - worm wheel 302 - worm wheel shaft 307 - rear push rod 108 - front push rod 107 - distal phalanx 101. With this structural setup, drive and reconfiguration can be controlled separately. Since the worm gear drive is unidirectional, motion can only be transmitted from the worm 308 to the worm wheel 302, and not from the worm wheel 302 to the worm 308. Therefore, after the front push rod 107, rear push rod 108, and worm wheel shaft 307 are connected, they cannot transmit the finger's motion back to the planetary gear drive module 3. This achieves finger position self-locking, allowing the robotic arm to handle larger loads.

[0062] like Figures 12-14 As shown, electronic system module 4 includes a microcontroller 401, a CAN communication module 402, and a step-down module 403. The step-down module 403 converts the externally input 24V DC voltage to 5V, powering the microcontroller 401, the reconfigurable motor 206, the drive motor 310, and related circuits. The microcontroller 401 controls the reconfigurable motor 206 via a serial port and communicates with the host computer via the CAN communication module 402 to receive commands and receive status feedback. The torque signal from the drive motor 310 is fed back to the microcontroller 401, forming a closed-loop control. All electronic system modules 4 are installed inside the robot hand, making the robot hand structure compact.

[0063] like Figure 15 Figure 16 As shown, three underactuated fingers are connected to the reconstruction device 2 via finger base 106, and the rear push rod 108 is connected to the planetary gear drive module 3. The housing assembly 5 includes a top housing 501, a left housing 502, a right housing 503, and a bottom housing 504, which are connected to the main body by screws.

[0064] Description of the exercise process:

[0065] like Figure 17 Figure 18 As shown, when the fingers are spread, driven by the planetary gear drive module 3, the rear push rod 108 and the front push rod 107 rotate downwards, pulling the distal phalanx 101 outwards. Because the distal phalanx 101 has a stepped baffle 1011 on its back, when the distal phalanx 101 flips outwards until the stepped baffle 1011 contacts the middle phalanx 102, it can drive the middle phalanx 102 to move outwards as well. When the middle phalanx 102 moves to contact the platform 1041 of the short connecting rod 104, it drives the short connecting rod 104 to move outwards as well. The short connecting rod 104 is a parallel four-bar linkage; during movement, the angle of the short connecting rod 104 does not change. Therefore, when flipping outwards, only the proximal phalanx 103 rotates, while the middle phalanx 102 and the distal phalanx 101 translate. A torsion spring 110 is provided between the proximal phalanx 103 and the finger base 106. When the angle between the two is less than 180 degrees, the torsion spring 110 is compressed. Therefore, when the fingers are opened, the angle between the proximal phalanx and the finger base 106 gradually decreases, eventually reaching 90 degrees. During this process, the elastic potential energy of the torsion spring 110 is stored.

[0066] When the fingers are closed, driven by the planetary gear drive module 3, the rear push rod 108 and the front push rod 107 rotate upward, pushing the distal phalanx 101 forward. However, since the distal phalanx 101 and the middle phalanx 102 are equipped with a torsion spring 109, when the angle between them is less than 180 degrees, the torsion spring 109 will be compressed, exerting an outward pushing force. Therefore, under the pushing force of the torsion spring 109, the middle phalanx 102 and the distal phalanx 101 move inward simultaneously. When the fingers are opened, the torsion spring 110 of the proximal phalanx 103 and the finger base 106 stores elastic potential energy, causing the proximal phalanx 103 to have a tendency to rotate inward. Therefore, when the fingers are closed, the short link 104 of the parallel four-bar linkage can push the middle phalanx 102 to move inward in parallel.

[0067] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. A reconfigurable underactuated three-finger dexterous hand with self-locking function, characterized in that, include: Three underactuated fingers, each with multiple knuckles, achieve knuckle coupling and adaptive movement through a drive input and two elastic elements; The reconstruction device module (2) is connected to the underactuated finger and is used to adjust the relative position between the two fingers to realize finger layout reconstruction; The planetary gear drive module (3) is connected to the underdriven finger through a worm gear-worm transmission mechanism to drive the finger to open and close and achieve position self-locking; Electronic system module (4) is used to control the operation of reconfiguration device module (2) and planetary gear drive module (3); Each of the underactuated fingers includes a distal phalanx (101), a middle phalanx (102), a proximal phalanx (103), a short link (104), a long link (105), a finger base (106), a front push rod (107), and a rear push rod (108); the distal phalanx (101), middle phalanx (102), proximal phalanx (103), and finger base (106) are sequentially hinged together, and the proximal phalanx (103), short link (104), long link (105), and finger base (106) are hinged together to form a parallelogram mechanism; the distal phalanx (101), front push rod (107), rear push rod (108), and planetary gear drive module (3) are sequentially hinged together; The elastic element is a torsion spring one (109) disposed between the distal phalanx (101) and the middle phalanx (102) and a torsion spring two (110) disposed between the proximal phalanx (103) and the finger base (106). When the distal phalanx (101) rotates inward relative to the middle phalanx (102), it is resisted by the resistance of the torsion spring one (109); when the fingers are opened, the torsion spring two (110) is compressed. The distal phalanx (101) is provided with a spring for... A stepped baffle (1011) limits the maximum angle between the distal phalanx (101) and the middle phalanx (102); the short link (104) is provided with a platform (1041) for limiting the maximum angle between the middle phalanx (102) and the proximal phalanx (103); during the process of closing the fingers, the elastic force of the second torsion spring (110) causes the proximal phalanx (103) to tend to move inward, thereby causing the platform (1041) of the short link (104) to be in close contact with the middle phalanx (102).

2. The reconfigurable underactuated three-finger dexterous hand with self-locking function according to claim 1, characterized in that, When there is no external resistance, the distal phalanx (101) remains at a 180-degree angle to the middle phalanx (102) under the combined action of the torsion spring (109) and the stepped baffle (1011). During the process of closing the fingers, the distal phalanx (101), the middle phalanx (102), and the short connecting rod (104) move synchronously and move in parallel inward, which is a parallel grasp. When the closed fingers encounter an irregular object, the proximal phalanx (103) or the middle phalanx (102) encounters an obstacle to inward movement. At this time, the distal phalanx (101) is still resisted by the torsion spring (109) between the distal phalanx (101) and the middle phalanx (102) under the action of the front push rod (107), and flips inward, which is an enveloping grasp.

3. The reconfigurable underactuated three-finger dexterous hand with self-locking function according to claim 2, characterized in that, The reconstruction device module (2) includes a reconstruction fixing plate (201) and a reconstruction device. One underdriven finger is fixedly installed on the reconstruction fixing plate (201), and two underdriven fingers are rotatably installed on the reconstruction fixing plate (201) through the reconstruction device. The relative positions of the two underdriven fingers are adjusted by the reconstruction device. The angles of the three underdriven fingers are 120 degrees to each other, which is configured as a centered grasping mode. Two underdriven fingers are parallel to each other, with two on one side and one on the other side, which is configured as a finger-to-finger grasping mode.

4. The reconfigurable underactuated three-finger dexterous hand with self-locking function according to claim 3, characterized in that, The reconfiguration device includes a reconfiguration link (202) mounted above the reconfiguration fixed plate (201), a reconfiguration gear set, and a reconfiguration motor (206) mounted below the reconfiguration fixed plate (201). The finger bases (106) of the two fingers are fixed on two symmetrically arranged reconstructed connecting rods (202); the reconstructed motor (206) drives the two reconstructed connecting rods (202) to rotate synchronously through the reconstructed gear set, so as to drive the two fingers to rotate synchronously and realize the finger layout reconstruction.

5. The reconfigurable underactuated three-finger dexterous hand with self-locking function according to claim 4, characterized in that, The reconfigurable gear set includes a reconfigurable gear (203), a reconfigurable motor gear (204), and an intermediate gear (205). The reconfigurable motor (206) is connected to the reconfigurable motor gear (204). Two sets of reconfigurable connecting rods (202) and reconfigurable gears (203) are symmetrically arranged. The two reconfigurable gears (203) mesh with each other. The reconfigurable connecting rod (202) has an inwardly protruding tooth sector. The tooth sector of the reconfigurable connecting rod (202) meshes with the two reconfigurable gears (203) respectively. The reconfigurable motor gear (204) meshes with the intermediate gear (205). The intermediate gear (205) meshes with one of the reconfigurable gears (203).

6. The reconfigurable underactuated three-finger dexterous hand with self-locking function according to claim 4, characterized in that, The planetary gear drive module (3) includes a drive motor (310), a drive main gear (306), a double-layer gear (303), a drive pinion (305), a worm (308), a worm wheel (302), and a worm wheel shaft (307). The drive motor (310) is connected to the drive main gear (306), the drive main gear (306) meshes with the lower layer of the double-layer gear (303), and the upper layer of the double-layer gear (303) meshes with the drive pinion (305). The drive pinion (305) is fixed coaxially with the worm (308), the worm (308) meshes with the worm wheel (302), and the worm wheel (302) is connected to the rear push rod (108) through the worm wheel shaft (307); the worm (308) and the worm wheel (302) constitute a unidirectional transmission drive mechanism to achieve position self-locking.

7. The reconfigurable underactuated three-finger dexterous hand with self-locking function according to claim 6, characterized in that, The planetary gear drive module (3) also includes a drive spindle (309). The upper end of the drive spindle (309) is fixedly connected to the finger base (106), and the lower end is coaxially connected to the drive pinion (305) and the worm gear (308). The drive spindle (309) passes through the slide groove (2011) on the reconstruction fixed plate (201) and is eccentrically connected to the reconstruction connecting rod (202) so that the drive mechanism moves with the finger during reconstruction.

8. The reconfigurable underactuated three-finger dexterous hand with self-locking function according to claim 6, characterized in that, The electronic system module (4) includes a microcontroller (401), a CAN communication module (402), and a step-down module (403); the step-down module (403) is used to power the entire system; the microcontroller (401) communicates with the host computer through the CAN communication module (402) and controls the reconfigurable motor (206) and the drive motor (310) to work respectively.

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