A servo-driven, multi-degree-of-freedom self-sensing bionic dexterous hand

Abstract

This invention discloses a servo-driven, multi-degree-of-freedom, self-sensing bionic dexterous hand, comprising five fingers and a palm. The fingers of this dexterous hand can flexibly bend and swing, with a large spatial range. An innovative "figure-eight rope" structure replaces the traditional linkage mechanism that restricts finger degrees of freedom, thus simplifying the underactuated structure of the fingers. Integrated bus servos within the palm and arm work in conjunction with the transmission rope, and a built-in return spring enables finger extension. The servos possess precise angle control and position and load feedback functions, endowing the dexterous hand with excellent proprioceptive capabilities. This invention features a compact structure, flexible control, strong tactile perception, and strong environmental adaptability, making it suitable for service robots, human-computer interaction, remote control, rehabilitation aids, and other scenarios, with broad application prospects.

Description

Technical Field

[0001] This invention relates to a servo motor-driven, multi-degree-of-freedom self-sensing bionic dexterous hand, belonging to the field of robotics technology. Background Technology

[0002] With the widespread application of robotics in fields such as medical rehabilitation, human-computer interaction, and precision operations, the requirements for end effectors in terms of operational precision, flexibility, and perception capabilities are constantly increasing. While traditional rigid grippers are simple in structure and easy to control, they are ill-suited for flexible grasping and multi-tasking in complex environments. Humanoid dexterous hands, due to their multiple degrees of freedom and high degree of anthropomorphism, have become one of the important directions in robotics research.

[0003] Existing dexterous hands generally suffer from complex drive structures, low system integration, high costs, and poor sensing capabilities, making them difficult to promote in lightweight platforms, scientific research and teaching, or large-scale robotic systems. While traditional rigid structures offer a certain level of control precision, they are bulky and lack flexibility, hindering flexible grasping and adaptation to complex environments. Furthermore, most dexterous hands only possess position control functions, lacking effective perception of contact information. Common external tactile sensors suffer from integration difficulties, poor stability, and susceptibility to detachment, making it difficult to meet the requirements of long-term, stable, and highly reliable applications.

[0004] Therefore, there is an urgent need for a dexterous hand device that is compact, easy to control, and has rich sensing capabilities, so as to meet the needs of high-degree-of-freedom motion control and multimodal sensing. Summary of the Invention

[0005] Objective: To overcome the shortcomings of existing technologies, this invention provides a servo-driven, multi-degree-of-freedom self-sensing bionic dexterous hand. This dexterous hand employs a bus-based servo drive and chordal transmission system. Static and dynamic force sensors are integrated at each finger joint, and real-time feedback of position, load, and other information is achieved through the bus servo drive, thus providing tactile and proprioceptive functions. Furthermore, a flexible material is cast to form the skin on the outside of the fingers, creating a structure that combines a rigid skeleton with flexible coverage, enhancing its bionic nature and adaptability. This dexterous hand possesses multiple degrees of freedom and strong sensing capabilities, enabling it to flexibly handle various complex working conditions.

[0006] Technical solution: To solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0007] A servo-driven, multi-degree-of-freedom self-sensing bionic dexterous hand includes: a first finger, a second finger, a third finger, a fourth finger, a fifth finger, a palm, a wrist, and an arm.

[0008] The hand includes: metacarpal base, first metacarpal, second metacarpal, third metacarpal and fourth metacarpal.

[0009] The first finger is connected to the metacarpal base via a finger universal joint, the second finger is connected to the first metacarpal via a finger universal joint, the third finger is connected to the second metacarpal via a finger universal joint, the fourth finger is connected to the third metacarpal via a finger universal joint, and the fifth finger is connected to the fourth metacarpal via a finger universal joint.

[0010] The free ends of the metacarpal base, the first metacarpal, the second metacarpal, the third metacarpal, and the fourth metacarpal are connected to the front end of the wrist via a pivot.

[0011] The wrist end is connected to the front end of the arm.

[0012] Optionally, the first, second, third, fourth, and fifth fingers each include the fingertip, the finger pad, and the base of the finger.

[0013] Optionally, the first metacarpal, second metacarpal, third metacarpal, and fourth metacarpal each include: a finger seat, a frame, a rope reel, a first servo motor, and a second servo motor; a finger seat is provided at one end of the frame, a rope reel is provided at the other end of the frame, a first servo motor and a second servo motor are respectively provided on one side of the frame, a first turntable is provided at the output end of the first servo motor, and a second turntable is provided at the output end of the second servo motor.

[0014] Optionally, the metacarpal seat includes: a first finger mounting seat, a first connecting part and a second connecting part, wherein the first finger is connected to the first finger mounting seat via a finger universal joint, one end of the first connecting part is connected to one side of the first finger mounting seat, the other end of the first connecting part is connected to the second metacarpal bone, and the second connecting part is connected to the other side of the first finger mounting seat.

[0015] Optionally, a rotating shaft is fixed to the end of the fingertip, and bearings are provided at both ends of the rotating shaft. The bearings on the end of the fingertip are rotatably connected to the front end of the finger pad. A rotating shaft is fixed to the front end of the finger root, and bearings are provided at both ends of the rotating shaft. The rear end of the finger pad is rotatably connected to the bearings on the front end of the finger root.

[0016] Optionally, the fingertip is provided with a first through hole, the finger pad is provided with an X-shaped groove, the finger root is provided with a Y-shaped groove, and a second through hole. One end of the first reinforcing rope is fixed to the first through hole by a nut, and the other end passes around the top surface and rear end of the fingertip, enters through the first opening of the X-shaped groove in the finger pad, exits through the fourth opening of the X-shaped groove, then passes around the through hole of the front end of the finger root and enters the second through hole, and is fixed by a nut. One end of the second reinforcing rope is fixed to the first through hole by a nut, and the other end passes around the bottom surface and rear end of the fingertip, enters through the second opening of the X-shaped groove in the finger pad, exits through the third opening of the X-shaped groove, then enters the second through hole through the fifth through hole of the Y-shaped groove in the finger root, and is fixed by a nut. This is used to connect the three moving parts—finder, finger pad, and finger root—which are in contact with each other via bearings.

[0017] Optionally, the fingertips of the first, second, third, fourth, and fifth fingers are further provided with a first groove perpendicular to the first through hole. One end of the third reinforcing rope passes around the nut inside the first through hole. Both ends of the third reinforcing rope pass through the pivot at the end of the fingertip from the first groove, enter from the front end of the fingertip, pass through the groove inside the fingertip, exit from the rear end of the fingertip, pass through the pivot at the front end of the finger root, enter the sixth through hole of the Y-shaped groove at the finger root, enter the front end of the finger universal joint from the seventh through hole of the Y-shaped groove, and exit from the rear end of the finger universal joint. The arm is equipped with a first bending servo, a second bending servo, a third bending servo, a fourth bending servo, and a fifth bending servo. The other end of the third ligament in the first finger passes through the palm and connects to a turntable on the first bending servo. The other end of the third ligament in the second finger passes through the palm and connects to a turntable on the second bending servo. The other end of the third ligament in the third finger passes through the palm and connects to a turntable on the third bending servo. The other end of the third ligament in the fourth finger passes through the palm and connects to a turntable on the fourth bending servo. The other end of the third ligament in the fifth finger passes through the palm and connects to a turntable on the fifth bending servo. These third ligaments are used to achieve inward bending of the fingers.

[0018] Optionally, a first fixing shaft is provided inside the fingertip of the second, third, fourth, and fifth fingers. One end of a fourth tendon passes around the first fixing shaft, and both ends of the fourth tendon emerge from the rear end of the fingertip, pass through the fifth through hole of the Y-shaped groove at the base of the finger, pass through the seventh through hole of the Y-shaped groove to the front end of the finger universal joint, and emerge from the rear end of the finger universal joint, connecting to one end of an elastic element inside the palm. The other end of the elastic element can be fixed to the palm by the tendon. The first fingertip has a first fixing shaft inside its fingertip, and one end of the fourth tendon passes around the first fixing shaft. Both ends of the fourth tendon emerge from the rear end of the fingertip and connect to one end of an elastic element located on the front of the base of the finger. The other end of the elastic element is fixed to a fixing pin on the metacarpal base by the tendon. This is used to achieve finger repositioning after bending via the elastic element.

[0019] Optionally, the inner sides of the bases of the second, third, fourth, and fifth fingers are respectively provided with a first slot and a second slot. One end of the fifth reinforcing rope is connected to a fixed shaft in the first slot, and the other end of the fifth reinforcing rope is connected to the second turntable of the second servo. The sixth reinforcing rope is connected to the fixed shaft in the second slot, and the other end of the sixth reinforcing rope is connected to the first turntable of the first servo. The inner sides of the bases of the first fingers are respectively provided with a first slot and a second slot. One end of the fifth reinforcing rope is connected to a fixed shaft in the first slot, and the other end of the fifth reinforcing rope is connected to the turntable of the first oscillating servo. The sixth reinforcing rope is connected to the fixed shaft in the second slot, and the other end of the sixth reinforcing rope is connected to the turntable of the second oscillating servo. This is used to realize the left and right oscillation of the fingers.

[0020] Optionally, the finger bases of the first, second, third, and fourth metacarpal bones are sequentially secured by wrapping them with a seventh tendon.

[0021] Beneficial Effects: This invention provides a servo-driven, multi-degree-of-freedom self-sensing bionic dexterous hand, mimicking the structure of a human hand, including five fingers and a palm. The fingers of this dexterous hand can flexibly bend and swing, with a large spatial range. An innovative "figure-eight rope" structure replaces the traditional linkage mechanism that restricts finger freedom, thus simplifying the underactuated structure of the fingers. Integrated bus servos within the palm and arm work in conjunction with the transmission rope, and a built-in return spring enables finger extension. The servos possess precise angle control and position and load feedback functions, giving the dexterous hand excellent proprioceptive capabilities. Static and dynamic force tactile sensors are integrated at the fingertips and pads of each finger, and the knuckles are covered with flexible material, forming a rigid-flexible structure that combines strong manipulative force with compliant adaptability to objects of different shapes and materials. This dexterous hand is compact, flexible in control, and possesses strong tactile perception and environmental adaptability, making it suitable for service robots, human-computer interaction, remote control, rehabilitation aids, and other scenarios, with broad application prospects. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of a servo-driven, multi-degree-of-freedom self-sensing bionic dexterous hand according to the present invention.

[0023] Figure 2 This is a frontal view of the fingers and palm of the present invention.

[0024] Figure 3 This is a schematic diagram of the back of the fingers and palm of the present invention.

[0025] Figure 4 This is a schematic diagram of the structure of the first finger and metacarpal seat of the present invention.

[0026] Figure 5 This is a schematic diagram of the structure of the fingertip, finger pad, and finger root of the present invention, which are connected by tendons.

[0027] Figure 6 This is a schematic diagram of the structure of the finger of the present invention, which bends through the tendon.

[0028] Figure 7 This is a schematic diagram of the distribution of servo motors within the arm of the present invention.

[0029] Figure 8 This is a schematic diagram of the structure in which the second, third, fourth, and fifth fingers of the present invention are repositioned via reinforcing ropes.

[0030] Figure 9 This is a schematic diagram of the structure of the first finger of the present invention, which plays a repositioning role through the reinforcing rope.

[0031] Figure 10 This is a schematic diagram of the structure in which the second, third, fourth, and fifth fingers of the present invention swing through the tendon rope.

[0032] Figure 11 This is a schematic diagram of the structure of the metacarpals of the present invention, which are linked together by tendons.

[0033] Figure 12 This is a schematic diagram of the finger universal joint of the present invention.

[0034] Figure 13 This is a schematic diagram of the structure of the finger sensor of the present invention. Detailed Implementation

[0035] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0036] The present invention will be further described below with reference to specific embodiments.

[0037] Example 1:

[0038] This embodiment describes a servo-driven, multi-degree-of-freedom self-sensing bionic dexterous hand, such as... Figure 1 As shown, it includes: first finger 1, second finger 2, third finger 3, fourth finger 4, fifth finger 5, palm 6, wrist 40, and arm 50.

[0039] like Figure 2-3 As shown, the palm 6 includes: metacarpal base 10, first metacarpal bone 11, second metacarpal bone 12, third metacarpal bone 13 and fourth metacarpal bone 14.

[0040] The first finger 1 is connected to the metacarpal seat 10 via a finger universal joint 22, the second finger 2 is connected to the first metacarpal 11 via a finger universal joint 22, the third finger 3 is connected to the second metacarpal 12 via a finger universal joint 22, the fourth finger 4 is connected to the third metacarpal 13 via a finger universal joint 22, and the fifth finger 5 is connected to the fourth metacarpal 14 via a finger universal joint 22.

[0041] The free ends of the metacarpal base 10, the first metacarpal 11, the second metacarpal 12, the third metacarpal 13, and the fourth metacarpal 14 are connected to the front end of the wrist 40 via a pivot.

[0042] The wrist 40 is connected at its end to the forearm 50.

[0043] Furthermore, the first finger 1, the second finger 2, the third finger 3, the fourth finger 4, and the fifth finger 5 each include a fingertip 7, a finger pad 8, and a finger root 9.

[0044] Furthermore, the first metacarpal bone 11, the second metacarpal bone 12, the third metacarpal bone 13, and the fourth metacarpal bone 14 each include: a finger seat 15, a frame 16, a rope reel 17, a first servo motor 18, and a second servo motor 19; the frame 16 has a finger seat 15 at one end and a rope reel 17 at the other end; the frame 16 has a first servo motor 18 and a second servo motor 19 on one side respectively; the output end of the first servo motor 18 has a first turntable 20, and the output end of the second servo motor 19 has a second turntable 21.

[0045] Furthermore, such as Figure 4 As shown, the metacarpal base 10 includes: a first finger mounting base 1001, a first connecting part 1002 and a second connecting part 1003. The first finger 1 is connected to the first finger mounting base 1001 through a finger universal joint 22. One end of the first connecting part 1002 is connected to one side of the first finger mounting base 1001, and the other end of the first connecting part 1002 is connected to the second metacarpal bone 12. The second connecting part 1003 is connected to the other side of the first finger mounting base 1001.

[0046] Furthermore, the through holes on the cord reels 17 of the first metacarpal bone 11, the second metacarpal bone 12, the third metacarpal bone 13, and the fourth metacarpal bone 14 are connected to the through holes on the second connecting portion 1003 of the metacarpal bone seat 10 via a rotating shaft to the front end of the wrist 40. This is used to realize the rotation of the entire palm and wrist.

[0047] Furthermore, the fingertip 7, finger pad 8, and finger root 9 are rotatably connected in sequence. Specifically, a rotating shaft is fixed to the end of the fingertip 7, and bearings are provided at both ends of the rotating shaft. The bearings at the end of the fingertip 7 are rotatably connected to the front end of the finger pad 8. A rotating shaft is fixed to the front end of the finger root 9, and bearings are provided at both ends of the rotating shaft. The rear end of the finger pad 8 is rotatably connected to the bearings at the front end of the finger root 9.

[0048] Furthermore, such as Figure 5As shown, the fingertip 7 is provided with a first through hole 701, the finger pad 8 is provided with an X-shaped groove 801, the finger root 9 is provided with a Y-shaped groove 901, and a second through hole 902. One end of the first reinforcing rope 23 is fixed to the first through hole 701 by a nut, and the other end passes around the top surface and rear end of the fingertip 7, enters through the first hole 802 of the X-shaped groove 801 of the finger pad 8, exits through the fourth hole 805 of the X-shaped groove 801, passes around the through hole of the front end of the finger root 9, enters the second through hole 902, and is fixed by a nut. One end of the second reinforcing rope 24 is fixed to the first through hole 701 by a nut, and the other end passes around the bottom surface and rear end of the fingertip 7, enters through the second hole 803 of the X-shaped groove 801 of the finger pad 8, exits through the third hole 804 of the X-shaped groove 801, enters the second through hole 902 through the fifth through hole 903 of the Y-shaped groove 901 of the finger root 9, and is fixed by a nut. It is used to connect the three moving parts, fingertip 7, finger pad 8 and finger root 9, which are connected by bearings, end to end.

[0049] Furthermore, such as Figure 6 , Figure 7 As shown, the fingertips 7 of the first finger 1, second finger 2, third finger 3, fourth finger 4 and fifth finger 5 are also provided with a first groove 702 perpendicular to the first through hole 701. One end of the third reinforcing rope 25 passes around the nut in the first through hole 701. Both ends of the third reinforcing rope 25 pass through the pivot at the end of the fingertip 7 from the first groove 702, enter from the front end of the finger pad 8, pass through the groove in the finger pad 8, exit from the rear end of the finger pad 8, pass through the pivot at the front end of the finger root 9, enter the sixth through hole 904 of the Y-shaped groove 901 of the finger root 9, enter the front end of the finger universal joint 22 from the seventh through hole 905 of the Y-shaped groove 901, and exit from the rear end of the finger universal joint 22. The arm 50 is equipped with a first bending servo 5001, a second bending servo 5002, a third bending servo 5003, a fourth bending servo 5004, and a fifth bending servo 5005. The other end of the third tendon 25 in the first finger 1 passes through the palm and connects to the turntable on the first bending servo 5001. The other end of the third tendon 25 in the second finger 2 passes through the palm and connects to the turntable on the second bending servo 5002. The other end of the third tendon 25 in the third finger 3 passes through the palm and connects to the turntable on the third bending servo 5003. The other end of the third tendon 25 in the fourth finger 4 passes through the palm and connects to the turntable on the fourth bending servo 5004. The other end of the third tendon 25 in the fifth finger 5 passes through the palm and connects to the turntable on the fifth bending servo 5005. These third tendons are used to achieve inward bending of the fingers.

[0050] Furthermore, such as Figure 8As shown, a first fixed shaft is provided inside the fingertip 8 of the second finger 2, the third finger 3, the fourth finger 4, and the fifth finger 5. One end of the fourth reinforcing rope 26 passes around the first fixed shaft, and both ends of the fourth reinforcing rope 26 pass out from the rear end of the fingertip 8, enter through the fifth through hole 903 of the Y-shaped groove 901 of the finger root 9, enter the front end of the finger universal joint 22 through the seventh through hole 905 of the Y-shaped groove 901, and exit from the rear end of the finger universal joint 22, connecting with one end of the elastic element 27 inside the palm 6. The other end of the elastic element 27 can be fixed to the palm by the reinforcing rope. Figure 9 As shown, a first fixed shaft is provided inside the fingertip 8 of the first finger 1. One end of the fourth tendon 26 passes around the first fixed shaft, and both ends of the fourth tendon 26 pass through the rear end of the fingertip 8 and are connected to one end of the elastic element provided on the front of the finger root 9. The other end of the elastic element is fixed to the fixing pin 1004 of the metacarpal seat 10 by the tendon. This is used to realize the return of the finger after bending through the elastic element.

[0051] Furthermore, such as Figure 10 As shown, the inner sides of the base 9 of the second finger 2, third finger 3, fourth finger 4, and fifth finger 5 are respectively provided with a first slot 906 and a second slot 907. One end of the fifth reinforcing rope 28 is connected to the fixed shaft in the first slot 906, and the other end of the fifth reinforcing rope 28 is connected to the second turntable 21 of the second servo 19. The sixth reinforcing rope 29 is connected to the fixed shaft in the second slot, and the other end of the sixth reinforcing rope 29 is connected to the first turntable 20 of the first servo 18. The inner sides of the base 9 of the first finger are respectively provided with a first slot 906 and a second slot 907. One end of the fifth reinforcing rope 28 is connected to the fixed shaft in the first slot 906, and the other end of the fifth reinforcing rope 28 is connected to the turntable of the first swing servo 5006. The sixth reinforcing rope 29 is connected to the fixed shaft in the second slot, and the other end of the sixth reinforcing rope 29 is connected to the turntable of the second swing servo 5007. This is used to realize the left and right swing of the fingers.

[0052] Furthermore, such as Figure 11 As shown, the finger bases 15 of the first metacarpal bone 11, the second metacarpal bone 12, the third metacarpal bone 13 and the fourth metacarpal bone 14 are sequentially wrapped and fixed by the seventh tendon rope 30.

[0053] Furthermore, such as Figure 12 As shown, the finger universal joint 22 includes: an upper support portion 2201 and a lower support portion 2202. The upper support portion 2201 has a pivot at its center and on both horizontal sides, and the lower support portion 2202 has a pivot on both vertical sides. All pivots are equipped with bearings 2203. The upper support portion 2201 and the lower support portion 2202 are rotatably connected to each other via the bearings at the center of the upper support portion 2201. This allows for multi-degree-of-freedom rotation.

[0054] Furthermore, such as Figure 13 As shown, a static force sensor 31 and a dynamic force sensor 32 are respectively provided on the fingertip 7 and fingertip 8. These are used to realize the proprioception and tactile sensation of the dexterous hand through feedback voltage signals.

[0055] Furthermore, a flexible material is provided at the connection between the fingertip 7, finger pad 8, and finger root 9. This forms a rigid-flexible structure that combines strong maneuverability with adaptability to objects of different shapes and materials.

[0056] Example 2

[0057] This embodiment describes the working principle of a servo-driven, multi-degree-of-freedom self-sensing bionic dexterous hand. The first finger is referred to as the thumb, and the second, third, fourth, and fifth fingers are referred to as the four fingers. Each of the four fingers is positioned on its corresponding metacarpal bone. The fingertip, pad, and base of each finger are connected together, sharing a bending degree of freedom. The base of each finger is connected to a universal joint with bearings mounted on four sides, creating a two-degree-of-freedom revolute joint similar to a spherical joint, resulting in a total of 12 degrees of freedom.

[0058] The fingertip has an opening for heat-fused nuts to be installed, the fingertip has an X-shaped cross channel structure for wiring, the finger root has a Y-shaped cross channel structure for wiring, and the bottom universal joint also has a through hole for wiring.

[0059] Hand: The hand module consists of 4 metacarpal bones and integrates 8 servo motors, which are responsible for controlling the swinging degree of freedom of the four fingers.

[0060] The first, second, third, and fourth metacarpal bones of the hand serve as the metacarpal bones of the index, middle, ring, and little fingers, respectively. Each metacarpal bone has two bases for servo motors. The bottom has through holes for pins to fix the shaft, and the top is fixed with cross-wound metacarpal bone fixing ropes.

[0061] The metacarpal bones of the index and middle fingers open to the right, with a groove in the middle of the index metacarpal bone for arranging the right wrist drive cable, and the middle metacarpal bone also extends a base for arranging the metacarpal seat. The metacarpal bones of the ring and little fingers open to the left, with a groove in the middle of the little metacarpal bone for arranging the left wrist drive cable.

[0062] Thumb: The thumb universal joint at the bottom of the fingertip has two degrees of freedom, the same as the four-finger universal joint, as well as a degree of freedom of rotation around itself, for a total of four degrees of freedom.

[0063] The universal joint at the base of the thumb is divided into an upper part and a lower part, and the two parts are connected by a bearing through a hole, giving it the freedom of rotation.

[0064] Wrist: The wrist connects the palm and the arm. The palm, wrist, and arm are connected together and share a single degree of freedom for bending.

[0065] Arm: The arm integrates a four-finger drive module, a thumb drive module, and a wrist drive module.

[0066] The four-finger drive module inside the arm is located at the top inside the arm and outputs its axis outward, while the thumb drive module is located below and outputs its axis inward.

[0067] The connection of the fingertip, finger pad, and finger root adopts an eight-character rope structure. This structure starts from the through hole at the fingertip, extends to both sides, enters the finger pad from the top and bottom respectively, crosses inside the X-shaped channel of the finger pad, and finally exits from the finger root and is fixed at the fingertip and finger root. Its core is to wrap the fingertip, finger pad, and finger root together, so that the movement of the two joints is simultaneous, thereby simplifying the bending movement.

[0068] The finger's rebound mechanism consists of a spring traction cord, a spring, and a spring fixing cord. The spring traction cord extends from a pin on the back of the fingertip, passes through a Y-shaped channel inside the finger root, and then passes through a through-hole in the finger root universal joint to connect to the spring. The spring is placed inside the metacarpal bone, and the spring fixing cord is connected to the end of the spring. This completes the arrangement of the rebound mechanism. When the finger bends, the spring is stretched. When the load is removed, the spring returns to its initial state, and the finger also returns to its original position.

[0069] One end of the fingertip traction rope is wrapped around the hot melt nut at the fingertip, and then passes through the fingertip, finger pad, finger root, universal joint, metacarpal bone, and wrist, before reaching the servo motor of the four-finger drive module inside the arm, where it is pulled and bent by the servo motor.

[0070] The finger swing mechanism consists of two servo motors connected to the metacarpal bones by a finger swing rope, and the rotation of the finger root is controlled by the rotation of the servo motors.

[0071] The servo motor is an STS3032 bus servo motor, which has functions such as load feedback, temperature feedback, position feedback, current and voltage feedback, and speed feedback, and can realize the sensing of load, temperature, position, etc.

[0072] The tactile perception uses static force sensors and dynamic force sensors, which are realized through feedback voltage signals. The combination of the two can realize the proprioception and tactile sensation of the dexterous hand.

[0073] A servo-driven, multi-degree-of-freedom, self-sensing bionic dexterous hand consists of an index finger, middle finger, ring finger, little finger, and thumb, all with identical structure and driving principles. Each finger moves using spring-loaded return and tendon traction. Servo motors are integrated into the palm portion of each finger, and the fingers are arranged sequentially according to the human hand's order, connecting to the wrist joint. Tactile sensors are located at the fingertips and pads of each finger, with the sensors encased in a flexible material to form a rigid-flexible hybrid structure.

[0074] The index, middle, ring, little, and thumb fingers are connected to the servo turntable via tendon cords. The servo can monitor the extension and retraction of the tendon cords in real time by controlling the rotation angle of the turntable, thereby determining the degree of bending and swaying of the fingers.

[0075] Bearings are used between the various parts to reduce friction.

[0076] The fingertips, pads, and roots of the index, middle, ring, little, and thumb are connected by a figure-eight rope to restrict the freedom of the fingertips and pads.

[0077] The index, middle, ring, little, and thumb fingers use the same spring return mechanism. One end of the spring traction rope is connected to the pin on the fingertip, and the other end is connected to the spring. One end of the spring fixing rope is fixed to the metacarpal bone, and the other end is connected to the other end of the spring. The spring is reset by the deformation and tension of the spring.

[0078] Static / dynamic tactile sensors are arranged on the front of the fingertips and pads of the index finger, middle finger, ring finger, little finger, and thumb. The static force sensors are composed of strain gauges, and the dynamic force sensors are made of PVDF.

[0079] The flexible material uses a one-component room temperature curing rubber.

[0080] The dexterous hand of this invention comprises the index finger, middle finger, ring finger, little finger, and thumb arranged in sequence according to the bionic structure of the human body. The metacarpal bones of each finger are merged together to form the palm. A bus servo motor is integrated inside the palm, simulating the physiological structure of the human hand and the principle of bionic movement. All fingers are connected to the wrist, and bending and swinging of the fingers are achieved through tendon cable transmission.

[0081] Static and dynamic force sensors are arranged in the middle part between the fingertip and the fingertip, and a flexible skin is poured around the outside to collect tactile sensory signals collected by the finger during grasping movements.

[0082] Taking the index finger as an example, the structure of a finger consists of the fingertip, finger pad, finger base, four universal joints, metacarpals, servo motor, and servo motor dial. Bearings connect the various rotating parts to reduce friction between joints. Each part has a pin hole, allowing the traction cable to be connected at one end to the pin and at the other end to the servo motor dial. The servo motor is built into the metacarpals, with slight differences in the metacarpal portion of each finger. The overall finger structure is simple and compact.

[0083] The figure-eight rope starts at the fingertip, crosses at the fingertip, and connects to the base of the finger, thus connecting the fingertip, fingertip, and base of the finger, and also restricting the freedom of the first two knuckles. The rebound mechanism consists of a spring traction rope, a spring, and a spring fixing rope. When the finger bends, the spring traction rope fixed to the fingertip is stretched and then transmitted to the spring, and the spring (19) is also stretched, thus giving a restoring force, thereby forming a restoring effect.

[0084] The servo-driven, multi-DOF self-sensing bionic dexterous hand proposed in this invention not only boasts a simple and compact structure, achieving flexible finger control through a bus-based servo-driven linear motion, but also possesses both dynamic and static force sensing capabilities. The fingers are encased in a flexible material, effectively protecting the internal tactile sensing unit and allowing for more stable grasping of complex, fragile, or easily deformable objects through the compression and deformation of the flexible surface upon contact. Simultaneously, relying on the position and load feedback functions of the bus servo, the dexterous hand possesses proprioceptive capabilities. Through its multi-DOF bionic structure, it can not only accurately grasp various types of objects but also acquire dynamic and static tactile information in real time during the grasping process, constructing a closed-loop control system to achieve dexterous and precise manipulation of target objects.

[0085] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A servo-driven, multi-degree-of-freedom self-sensing bionic dexterous hand, characterized in that: include: First finger, second finger, third finger, fourth finger, fifth finger, palm, wrist, and arm; The palm includes: metacarpal base, first metacarpal bone, second metacarpal bone, third metacarpal bone and fourth metacarpal bone; The first finger is connected to the metacarpal base via a finger universal joint; the second finger is connected to the first metacarpal via a finger universal joint; the third finger is connected to the second metacarpal via a finger universal joint; the fourth finger is connected to the third metacarpal via a finger universal joint; and the fifth finger is connected to the fourth metacarpal via a finger universal joint. The free ends of the metacarpal base, first metacarpal, second metacarpal, third metacarpal and fourth metacarpal are connected to the front end of the wrist via a pivot. The wrist end connects to the front end of the arm; The first, second, third, fourth, and fifth fingers each include: the fingertip, the finger pad, and the base of the finger; The first metacarpal bone, the second metacarpal bone, the third metacarpal bone, and the fourth metacarpal bone each include: a finger base, a frame, a rope reel, a first servo motor, and a second servo motor; a finger base is provided at one end of the frame, a rope reel is provided at the other end of the frame, a first servo motor and a second servo motor are respectively provided on one side of the frame, a first turntable is provided at the output end of the first servo motor, and a second turntable is provided at the output end of the second servo motor. The fingertip is provided with a first through hole, the finger pad is provided with an X-shaped groove, the root of the finger is provided with a Y-shaped groove, and a second through hole. One end of the first reinforcing rope is fixed to the first through hole by a nut, and the other end passes around the upper surface and rear end of the fingertip, enters from the first opening of the X-shaped groove in the finger pad, exits from the fourth opening of the X-shaped groove, passes around the through hole on the lower surface of the front end of the root of the finger, enters the second through hole, and is fixed by a nut. One end of the second reinforcing rope is fixed to the first through hole by a nut, and the other end passes around the lower surface and rear end of the fingertip, enters from the second opening of the X-shaped groove in the finger pad, exits from the third opening of the X-shaped groove, enters the second through hole from the fifth through hole of the Y-shaped groove in the root of the finger, and is fixed by a nut. The fingertips of the first, second, third, fourth, and fifth fingers are also provided with a first groove perpendicular to the first through hole. One end of the third reinforcing rope passes around the nut inside the first through hole. Both ends of the third reinforcing rope pass through the pivot at the end of the fingertip from the first groove, enter from the front end of the fingertip, pass through the groove inside the fingertip, exit from the rear end of the fingertip, pass through the pivot at the front end of the finger root, enter the sixth through hole of the Y-shaped groove at the finger root, enter the front end of the finger universal joint from the seventh through hole of the Y-shaped groove, and exit from the rear end of the finger universal joint. The arm is provided with a first bending servo, a second bending servo, and a third bending servo. The first, second, and third servos are configured with the following configurations: a servo with a curved head, a fourth servo with a curved head, and a fifth servo with a curved head. The third ligament in the first finger passes through the palm and connects to the turntable on the first servo; the third ligament in the second finger passes through the palm and connects to the turntable on the second servo; the third ligament in the third finger passes through the palm and connects to the turntable on the third servo; the third ligament in the fourth finger passes through the palm and connects to the turntable on the fourth servo; and the third ligament in the fifth finger passes through the palm and connects to the turntable on the fifth servo.

2. The servo-driven multi-degree-of-freedom self-sensing bionic dexterous hand according to claim 1, characterized in that: The metacarpal seat includes: a first finger mounting seat, a first connecting part, and a second connecting part. The first finger is connected to the first finger mounting seat via a finger universal joint. One end of the first connecting part is connected to one side of the first finger mounting seat, and the other end of the first connecting part is connected to the second metacarpal bone. The second connecting part is connected to the other side of the first finger mounting seat.

3. The servo-driven multi-degree-of-freedom self-sensing bionic dexterous hand according to claim 1, characterized in that: The fingertip is fixed with a pivot, and bearings are provided at both ends of the pivot. The bearings at the fingertip are rotatably connected to the front end of the fingertip. The front end of the finger root is fixed with a pivot, and bearings are provided at both ends of the pivot. The rear end of the fingertip is rotatably connected to the bearings at the front end of the finger root.

4. A servo-driven, multi-degree-of-freedom self-sensing bionic dexterous hand according to claim 2, characterized in that: The second, third, fourth, and fifth fingers each have a first fixed shaft inside their fingertips. One end of a fourth tendon passes around the first fixed shaft, and both ends of the fourth tendon emerge from the rear end of the fingertip, pass through the fifth through hole of the Y-shaped groove at the base of the finger, pass through the seventh through hole of the Y-shaped groove to the front end of the finger universal joint, emerge from the rear end of the finger universal joint, and connect to one end of an elastic element inside the palm. The other end of the elastic element is fixed to the palm by the tendon. The first finger also has a first fixed shaft inside its fingertip. One end of a fourth tendon passes around the first fixed shaft, and both ends of the fourth tendon emerge from the rear end of the fingertip, connecting to one end of an elastic element located on the front of the base of the finger. The other end of the elastic element is fixed to a fixing pin on the metacarpal base by the tendon.

5. A servo-driven, multi-degree-of-freedom self-sensing bionic dexterous hand according to claim 1, characterized in that: The inner sides of the bases of the second, third, fourth, and fifth fingers are respectively provided with a first slot and a second slot. One end of the fifth reinforcing rope is connected to a fixed shaft in the first slot, and the other end of the fifth reinforcing rope is connected to the second turntable of the second servo. The sixth reinforcing rope is connected to a fixed shaft in the second slot, and the other end of the sixth reinforcing rope is connected to the first turntable of the first servo. The inner sides of the bases of the first fingers are respectively provided with a first slot and a second slot. One end of the fifth reinforcing rope is connected to a fixed shaft in the first slot, and the other end of the fifth reinforcing rope is connected to the turntable of the first oscillating servo. The sixth reinforcing rope is connected to a fixed shaft in the second slot, and the other end of the sixth reinforcing rope is connected to the turntable of the second oscillating servo.

6. A servo-driven, multi-degree-of-freedom self-sensing bionic dexterous hand according to claim 1, characterized in that: The finger bases of the first, second, third, and fourth metacarpal bones are sequentially secured by the seventh tendon rope.

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