Modular flexible bionic hand based on dual-mode wire drive

Abstract

The application discloses a modular flexible bionic hand based on a dual-mode wire driving, and belongs to the technical field of robots. The dexterous hand comprises a finger assembly, a palm base assembly, an independent driving module, a coupling driving module, an arm base assembly and a tendon; the inner cavity of the arm base assembly is provided with the coupling driving module for driving the opening and closing of the thumb, the index finger and the middle finger simultaneously, and the independent driving module for driving the independent bending of each finger and the lateral bending of the thumb. The bionic hand can be provided with 7 degrees of freedom, adopts a tendon driving mode; the finger assembly is composed of five modular flexible fingers; the knuckles adopt equidistant porous microstructures to improve the shape adaptability and impact resistance, realize the positive active bending and the lateral passive bending; the external driving makes the driving module away from the end effector, and is beneficial to improving the dynamic performance of the bionic hand. The application adopts modular assembly, has the advantages of reliable structure, convenient manufacturing, light weight, high efficiency and low cost.

Description

Technical Field

[0001] This invention belongs to the field of soft robots and relates to a bionic robot, specifically a modular flexible bionic hand based on dual-mode line drive. Background Technology

[0002] With the rapid development of science and technology, robotics has matured and is widely used in many fields. However, despite their excellent performance in many tasks, robots still face significant challenges in performing dexterous maneuvers. Dexterous maneuvers, such as grasping, assembling, and manufacturing, require a high degree of precision and adaptability, which is very difficult for robots. Therefore, developing robots with human-like dexterous maneuvering capabilities has become a current research hotspot.

[0003] However, traditional anthropomorphic dexterous robotic hands typically employ rigid joints and complex control systems, resulting in high assembly and maintenance costs, as well as difficulty in adapting to complex environments and tasks. Furthermore, these robotic hands often require sophisticated control algorithms and sensing strategies to overcome their lack of compliance, further increasing the system's complexity and cost.

[0004] In recent years, with the rise of soft robotics technology, the design and research of flexible anthropomorphic dexterous hands have gradually become a focus of attention. Compared with traditional rigid robot systems, flexible anthropomorphic dexterous hands have better compliance and adaptability, enabling them to better adapt to complex environments and tasks. At the same time, flexible anthropomorphic dexterous hands can replace rigid joints through flexible structural design, reducing the number of parts required in the dexterous hand mechanism, lowering manufacturing and maintenance costs, and improving system reliability and maintainability.

[0005] The design solutions for flexible dexterous hands commonly found on the market still have the following shortcomings:

[0006] 1) Conventional flexible hands use only a single degree of freedom for the fingers, resulting in insufficient overall dexterity;

[0007] 2) Gas-driven flexible hand-operated systems are bulky and difficult to manufacture;

[0008] 3) Dexterous hands that use linkage and rack and pinion drives lack structural flexibility, which affects the robustness and stability of dexterous hand operation;

[0009] 4) The various finger modules inside the dexterous hand have a structural and assembly coupling relationship, which has a significant negative impact on the assemblability, maintainability and cost control of the overall structure. Summary of the Invention

[0010] To address the shortcomings of existing technologies, the purpose of this invention is to provide a modular flexible bionic hand based on dual-mode line drive. This modular flexible humanoid dexterous hand can perform multi-degree-of-freedom maneuvering tasks with independent and coupled drive, and features strong shape adaptability, reliable structure, convenient manufacturing, low cost, and lightweight.

[0011] To achieve the above objectives, the technical solution provided by the present invention is as follows:

[0012] This invention provides a modular flexible bionic hand based on dual-mode line actuation, comprising:

[0013] The palm base component has multiple finger mounting points at the front end;

[0014] The finger assembly includes multiple wire-driven flexible fingers, each mounted on a multiple finger mounting point;

[0015] The arm base assembly is installed at the rear end of the hand base assembly and is hollow inside;

[0016] The coupling drive module, installed inside the hollow part of the arm base assembly, is used to couple the rope to drive at least two flexible fingers;

[0017] An independent drive module, installed inside the hollow core of the arm's base assembly, is used for independently cable-driven actuation of each flexible finger; and

[0018] The tendon ligaments connect the coupled drive module or the independent drive module to their respective flexible fingers.

[0019] Preferably, the multiple flexible fingers are named thumb, index finger, middle finger, ring finger and little finger respectively. The thumb has two degrees of freedom: frontal bending and lateral bending. The index finger, middle finger, ring finger and little finger each have one degree of freedom for frontal bending.

[0020] Preferably, the flexible finger includes a fixing member and a continuous microstructure disposed on the fixing member. The continuous microstructure is made of an elastic material and is formed by stacking multiple unit structures along the length direction. The multiple unit structures of the continuous microstructure can achieve flexible bending movements under the drive of tendon chords. Each flexible finger is set with a corresponding continuous microstructure length according to different functional needs.

[0021] Preferably, the unit structure includes an outer connection point, an inner connection point, and several connecting parts;

[0022] Among them, the eight external connection points are connected in sequence by the horizontal connectors to form a quadrilateral structure, which serves as the center of the unit structure. Each side of the quadrilateral structure has two external connection points; the external connection points of adjacent unit structures are connected by the concave first longitudinal connector.

[0023] The two opposite sides of the quadrilateral structure are defined as the front and back sides. The two internal connection points are located at the junction of adjacent unit structures. The upper and lower parts of one of the internal connection points are connected to the adjacent horizontal connection members on the front side through the second vertical connection members. The upper and lower parts of the other internal connection point are connected to the adjacent horizontal connection members on the back side through the second vertical connection members.

[0024] Each inner connection point is connected to the two first longitudinal connectors on the corresponding sides via a third connector on its left and right sides.

[0025] Preferably, the palm base assembly includes

[0026] Forehand shell;

[0027] The rear palm shell is fixedly connected to the front palm shell, and a palm space for the tendon tract is reserved between the two.

[0028] A finger base, disposed between the front ends of the forearm shell and the rear shell of the hand, has several positioning grooves for mounting the index finger, middle finger, ring finger, and little finger; and

[0029] The thumb base is located between the sides of the forehand and rearhand shells and is used to mount the thumb.

[0030] Preferably, the finger base and thumb base are each provided with a plurality of tendon cord routing holes, and the position and number of tendon cord routing holes are set according to the degree of freedom of movement of each flexible finger.

[0031] Preferably, the coupling drive module includes

[0032] Multiple guide wheels are connected to multiple flexible fingers to be coupled and driven via corresponding tendon ropes, and multiple guide wheels are installed inside the hollow arm base component via a drive shaft;

[0033] Coupled servo motors are used to provide coupled power; and

[0034] The transmission gear set is used to connect the coupling servo motor and the power transmission of the drive shaft.

[0035] Preferably, the independent drive module includes six servos and several guide plates; each servo has an output end equipped with a servo wheel for winding the tendon rope, and the guide plate is provided with tendon rope guide holes for the tendon rope to pass through.

[0036] Preferably, the arm base assembly includes a forearm shell, an upper arm shell, and a wrist. The forearm shell is connected to the forearm shell via the wrist, and the upper arm shell is detachably connected to the forearm shell. The wrist is provided with several tendon guide holes. The coupling drive module and the independent drive module are respectively installed inside the forearm shell and the upper arm shell.

[0037] Preferably, the forehand shell has a connecting end at its tail end that connects to the wrist.

[0038] Preferably, the lateral connector includes a first lateral connector that is recessed and used to connect two external connection points on the same side, and a second lateral connector that is recessed and used to connect two external connection points at a corner.

[0039] Preferably, the upper and lower parts of the inner connection point are connected to the arc-shaped back of the first transverse connection through the second longitudinal connection member; the arc-shaped backs of two adjacent first longitudinal connection members located at the corners are connected by the concave fourth connection member.

[0040] Preferably, the concave first longitudinal connector is used as the knot point of the tendon rope, and the shape of the flexible finger bending is adjusted by fixing the tendon rope with knot points of different height unit structures.

[0041] Preferably, the number of tie points is selected to adjust the degree of freedom of movement of the flexible finger, forming a multi-degree-of-freedom flexible finger, and at least one side of the quadrilateral structure is provided with a tie point.

[0042] Preferably, the fixing member is provided with a cable outlet hole for the tendon rope to pass through.

[0043] Preferably, the gaps between the outer connection point, the inner connection point, and the plurality of connecting members constitute a rope channel.

[0044] Preferably, the continuous microstructure is made of thermoplastic elastomer material by 3D printing.

[0045] Preferably, the topmost unit structure is provided with fingertips.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] 1) The flexible finger of this invention adopts an equidistant, enhanced flexible porous microstructure, which improves the shape adaptability and impact resistance of the dexterous hand, and can achieve positive active bending and lateral passive bending. By adjusting the position of the tendon rope fixed in different micropores of the finger, the stiffness and bending direction of the finger can be changed, realizing multi-degree-of-freedom transformation and enhancing the overall hand operation capability.

[0048] 2) The integration of independent drive and coupled drive enables multiple gripping methods. At the same time, the coupled drive module only needs one drive motor to control the coordinated bending of multiple fingers, effectively improving hand flexibility.

[0049] 3) The underactuated tendon chords simplify the transmission structure, while the tendon chords have a certain degree of elasticity, providing a degree of flexibility and grip adaptability for finger movements. In addition, the drive is placed outside the arm, keeping the drive module away from the end effector, reducing the load and inertia on the end effector, which is beneficial to improving the dynamic performance of the dexterous hand.

[0050] 4) The five fingers adopt the same modular structure, which is convenient for assembly and disassembly, and enhances the assemblability and maintainability of the dexterous hand; at the same time, the modular design is simple and reliable, easy to manufacture and the overall cost is controllable. Attached Figure Description

[0051] Figure 1 This is a schematic diagram of the overall structure of the modular flexible bionic hand based on dual-mode line-driven invention.

[0052] Figure 2 This is an exploded structural diagram of the finger component and palm base component of the present invention.

[0053] Figure 3 This is a schematic diagram of the coupling drive module structure of the present invention.

[0054] Figure 4 This is an exploded view of the independent drive module of the present invention.

[0055] Figure 5 This is an exploded structural diagram of the arm base component of the present invention.

[0056] Figure 6 This is a schematic diagram of the tendon cord routing in the palm and arm portions of the present invention.

[0057] Figure 7 The diagram shows the overall shape of the microstructure-based flexible finger designed according to this invention, with the unit structure divided by dashed lines.

[0058] Figure 8 Front view (front view) of the microstructure-based flexible finger designed for this invention.

[0059] Figure 9 This is a side view of the microstructure-based flexible finger designed according to the present invention.

[0060] Figure 10 for Figure 8 BB section view.

[0061] Figure 11 for Figure 8 Sectional view of AA.

[0062] Figure 12 for Figure 1 A partial schematic diagram of a flexible finger with a three-segment unit structure.

[0063] Figure 13for Figure 12 A schematic diagram showing a portion of the flexible finger with a three-section unit structure having one-quarter cut off.

[0064] Figure 14 for Figure 12 A schematic diagram showing a portion of the flexible finger with a three-unit structure being cut off in half.

[0065] Figure 15 for Figure 14 Front view diagram.

[0066] Figure 16 This is a schematic diagram of the wire outlet hole on a single-degree-of-freedom flexible finger.

[0067] 100-Finger component, 101-Thumb, 102-Index finger, 103-Middle finger, 104-Ring finger, 105-Little finger, 110-Flexible finger, 111-Fixer, 1111-Cable outlet, 112-Continuous microstructure, 1121-Unit structure, 11211-Outer connection point, 11212-Inner connection point, 11213-First longitudinal connector, 11214-Second longitudinal connector, 11215-First connecting part, 11216-Second connecting part, 11217-Third connector, 11218-First transverse connector, 11219-Second transverse connector, 11220-Fourth connector, 11221-Tie point, 11222-Inner rib, 113-Finger pad, 114-Rope channel;

[0068] 200-Palm base assembly; 201-Thumb base; 202-Front palm shell; 203-Rear palm shell; 204-Finger base; 205-Tension spring; 206-Connecting end; 207-Positioning groove;

[0069] 300-Coupled drive module; 301-Coupled servo shroud; 302-Reduction drive gear; 303-Drive shaft; 304-Reduction driven gear; 305-Third guide wheel; 306-Second guide wheel; 307-First guide wheel; 308-Bearing; 309-Coupled servo; 310-Coupled servo support; 311-Bearing housing; 312-Support boss;

[0070] 400 - Independent drive module; 401 - First servo motor; 402 - Second servo motor; 403 - Third servo motor; 404 - Fourth servo motor; 405 - Fifth servo motor; 406 - Sixth servo motor; 407 - Independent servo motor support; 408 - Servo disc reel; 409 - Independent servo motor servo disc; 410 - First guide plate; 411 - Second guide plate; 412 - Support boss;

[0071] 500 - Arm base assembly; 501 - Wrist; 502 - Upper forearm shell; 503 - Lower forearm shell; 504 - Upper upper arm shell; 505 - Lower upper arm shell; 506 - Tendon chord guide hole;

[0072] 600-Tendon Rosae. Detailed Implementation

[0073] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0074] In the description of this invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0075] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0076] like Figure 1 As shown, this embodiment of the invention provides a modular flexible bionic hand based on dual-mode line drive, including a palm base component 200, with multiple finger mounting points at the front end;

[0077] The finger assembly 100 includes multiple wire-driven flexible fingers 110, which are respectively mounted on multiple finger mounting points;

[0078] The arm base assembly 500 is installed at the rear end of the palm base assembly 200 and is hollow inside;

[0079] The coupling drive module 300 is installed inside the hollow part of the arm base assembly 500 and is used to couple the rope drive to drive at least two flexible fingers 110.

[0080] An independent drive module 400, installed inside the hollow of the arm base assembly 500, is used for independently cable-driven actuation of each flexible finger 110; and

[0081] The tendon 600 is connected to the coupling drive module 300 or the independent drive module 400 and their respective flexible fingers 110.

[0082] This invention employs rope-driven flexible fingers 110, allowing the selection of the corresponding degrees of freedom for each flexible finger 110 based on the number of fixing points on the tendon rope 600. The coupling drive module 300 can drive the coordinated coupling movements of some of the flexible fingers 110, simulating the dexterous and complex movements of a human hand. Furthermore, this invention uses independent drive modules 400 to independently drive each flexible finger 110, allowing for the selection of any desired degree of freedom. This enables the design of bionic hands with different characteristics to meet various needs, adapting to diverse applications at minimal cost. The invention cleverly integrates the coupling drive module 300 and the independent drive module 400 within the arm base assembly 500, providing ample installation space and enabling complex movements of the bionic hand while protecting the drive modules from damage during use.

[0083] It should be noted that the number of flexible fingers 110 in this invention is not necessarily exactly the same as that of a human hand, because in some special situations, having one more or one less flexible finger 110 can bring better efficiency. The degree of freedom of movement of each flexible finger 110 can also be set according to the requirements. This invention is illustrated using a fully bionic human hand as an example, so five flexible fingers 110 are set, named thumb 101, index finger 102, middle finger 103, ring finger 104 and little finger 105 respectively. Among them, thumb 101 has two degrees of freedom: front bending and lateral bending, while index finger 102, middle finger 103, ring finger 104 and little finger 105 each have one degree of freedom for front bending.

[0084] It should be noted that the palm base component 200 of the present invention can be configured into any desired shape, for example, such as Figure 1 and Figure 2 As shown, the palm base assembly 200 of the present invention includes

[0085] Forehand shell 202;

[0086] The rear palm shell 203 is fixedly connected to the front palm shell 202, and a palm space for the tendon tractor 600 is reserved between the two.

[0087] A finger base 204 is disposed between the front ends of the forehand shell 202 and the rearhand shell 203. The finger base 204 has several positioning grooves 207 for mounting the index finger 102, middle finger 103, ring finger 104, and little finger 105, respectively.

[0088] A thumb base 201 is disposed between the sides of the front palm shell 202 and the rear palm shell 203 for mounting the thumb 101.

[0089] The overall shape of the hand base component 200 of the present invention can be designed to completely imitate the shape of a human hand, or it can be specially designed according to special needs. The specific shape does not affect the technical problem solved by the present invention. The hand base component 200 is designed as a detachable front hand shell 202 and a rear hand shell 203, which are detachably connected by structures including but not limited to buckles and screws, which improves the maintainability of the bionic hand and reduces the manufacturing cost.

[0090] The present invention designs the front palm shell 202 as an integral human hand shape, and the rear palm shell 203 as a detachable cover, which reduces the manufacturing cost. There is a certain gap between the rear palm shell 203 and the front palm shell 202 for installing components such as tendon ligament 600, which plays a protective role for tendon ligament 600.

[0091] The present invention provides a connecting end 206 at the tail end of the forehand shell 202 to facilitate connection with the arm base assembly 500. Specifically, the connecting end 206 can be an annular shell with an elliptical cross section to match the shape of the human wrist 501. The annular shell can be provided with some positioning groove structures and bolt holes to facilitate quick positioning and connection.

[0092] like Figure 2 As shown, the finger base 204 has four positioning grooves 207, which are used to install the index finger 102, middle finger 103, ring finger 104 and little finger 105 respectively. The positioning grooves 207 are provided with a certain gap and angle, so that the index finger 102, middle finger 103, ring finger 104 and little finger 105 have a certain gap and angle to simulate the posture of a real human hand when it is outstretched, and at the same time avoid interference between the flexible fingers 110 when they bend.

[0093] The thumb base 201 is also provided with a positioning groove 207. By controlling the position and angle of the positioning groove 207, the position and angle of the thumb 101 can be controlled. Specifically, it can be set to mimic the thumb 101 of a human hand. For example, through the cooperation of the thumb base 201 and the positioning groove 207, the thumb 101 is perpendicular to the palm surface of the forehand shell 202 in a bent state and forms a 45-degree angle with the side of the forehand shell 202, thus simulating an optimal initial state of the thumb 101 of a human hand.

[0094] The finger base 204 and thumb base 201 are connected to the forearm shell 202 using fasteners such as screws, and each has a plurality of tendon cable routing holes. These holes are smoothly designed to minimize friction and extend the lifespan of the tendon cable 600. In areas where the tendon cable 600's path is not straight, rolling elements, guide wheels, or other components can be used to steer it or further reduce its resistance. The position and number of tendon cable routing holes are determined based on the degrees of freedom of each flexible finger 110. For example, in this invention, the finger base... At least one tendon cord routing hole is provided in the corresponding positioning groove 207 on the index finger 102, middle finger 103, ring finger 104 and little finger 105 on the base 204. At least two tendon cord routing holes are provided in the positioning groove of the thumb base 201. The two tendon cord routing holes can ensure that the tendon cords 600 on the two degrees of freedom of movement of the thumb 101 do not interfere with each other. In a preferred embodiment, due to the driving requirements of the coupling drive module 300, an additional tendon cord routing hole should be provided in the positioning groove 207 corresponding to the thumb 101, index finger 102 and middle finger 103 to accommodate the additional tendon cords 600 used for coupling drive.

[0095] like Figure 1 and Figure 5 As shown, the arm base assembly 500 of the present invention includes a forearm shell, an upper arm shell, and a wrist 501. Figure 1 The mid-arm base component 500 conceals half of the forearm shell and upper arm shell. Figure 5 This is an exploded view of the entire arm base assembly 500. The forearm shell is connected to the forearm shell 202 via the wrist 501, and the upper arm shell is detachably connected to the forearm shell. The wrist 501 is provided with several tendon guide holes 506. The coupling drive module 300 and the independent drive module 400 are respectively installed inside the forearm shell and the upper arm shell. The present invention provides installation space for the coupling drive module 300 and the independent drive module 400 by setting the shell-shaped arm base assembly 500, thus protecting the drive structure. At the same time, the separate upper and lower arm configurations facilitate manufacturing, installation, and subsequent maintenance, achieving a modular design.

[0096] like Figure 5 As shown, the upper and lower arm shells of the present invention are connected by means including but not limited to buckles, screws, etc., and positioning grooves and bosses can be set as needed to achieve rapid positioning; the front end of the lower arm shell is detachably connected to the wrist 501, and the rear end is detachably connected to the upper arm shell. The rear end of the upper arm shell is connected to other carriers, such as a robotic arm or a humanoid robot. The shape of the upper and lower arm shells is designed to resemble a human arm.

[0097] To further improve disassembly and maintainability, such as Figure 5As shown, the forearm shell is divided into an upper forearm shell 502 and a lower forearm shell 503. The upper forearm shell 502 and the lower forearm shell 503 are detachably and fixedly connected. Similarly, the upper arm shell is also composed of an upper upper arm shell 504 and a lower upper arm shell 505 that are detachably connected. The specific connection method will not be described in detail in this invention.

[0098] like Figure 1 , 3 As shown in Figures 6 and 7, the coupling drive module 300 is installed inside the forearm housing, and the coupling drive module 300 includes...

[0099] Multiple guide wheels are connected to multiple flexible fingers 110 to be coupled and driven via corresponding tendon ropes 600, and multiple guide wheels are installed inside the hollow of the arm base assembly 500 via a drive shaft 303.

[0100] Coupled servo motor 309 is used to provide coupling power; and

[0101] The transmission gear set is used to connect the coupling servo motor 309 and the drive shaft 303 for power transmission.

[0102] For example, such as Figure 3 and Figure 5 As shown, the drive shaft 303 is mounted inside the lower forearm housing 503 at both ends via bearings 308. The coupling servo 309 is fixed inside the lower forearm housing 503 via a coupling servo support 310. Specifically, the lower forearm housing 503 is provided with a support boss 312 and a pair of bearing seats 311. The bearing seats 311 are used to mount the drive shaft 303 in conjunction with the bearings 308, and the support boss 312 is used to fix the coupling servo support 310. Generally, the drive shaft 303 should be arranged laterally inside the forearm housing, and the three guide wheels are respectively fixed to the drive shaft 303 by screws or splines. On shaft 303, a certain distance is maintained to prevent the tendon ropes 600 from interfering with each other. The three guide wheels are the first guide wheel 307, the second guide wheel 306, and the third guide wheel 305, which respectively connect the tendon ropes 600 to the thumb 101, index finger 102, and middle finger 103. The bending control of the thumb 101, index finger 102, and middle finger 103 is achieved by the guide wheels winding the tendon ropes 600. The diameter ratio of the three guide wheels is set according to the ratio of the maximum tendon displacement of the three fingers during contraction, so as to achieve different bending speeds for each flexible finger 110 during coupled drive.

[0103] The purpose of the transmission gear set of the present invention is to reduce speed and increase torque. For example, the transmission gear set includes a meshing reduction drive gear 302 and a reduction driven gear 304. The reduction driven gear 304 is coaxially fixed on the transmission shaft 303. The reduction drive gear 302 is fixed to the servo disc 301 of the coupling servo 309 by bolts. The servo disc 301 of the coupling servo 309 is connected to the spline on the output shaft of the coupling servo 309. The output torque of the coupling servo 309 is increased by the reduction engagement of the reduction drive gear 302 and the reduction driven gear 304.

[0104] like Figure 1 , 4 As shown in Figures 5 and 6, the independent drive module 400 of the present invention is installed inside the boom housing. The independent drive module 400 includes 6 servo motors and 2 guide plates. Each servo motor has a servo wheel 408 for winding the tendon rope 600 at its output end. The guide plate is provided with tendon rope guide holes 506 for the tendon rope 600 to pass through. For example, the lower arm housing 505 is provided with a support boss 412 for mounting an independent servo mount 407 and a guide plate. Six servos are fixed to the independent servo mount 407 by screws. The six servos are the first servo 401, the second servo 402, the third servo 403, the fourth servo 404, the fifth servo 405 and the sixth servo 406. The first servo 401 and the second servo 402 control the bending and lateral movement of the thumb 101, respectively. The third servo 403, the fourth servo 404, the fifth servo 405 and the sixth servo 406 control the bending of the index finger 102, the middle finger 103, the ring finger 104 and the little finger 105, respectively.

[0105] Each servo's output shaft is splined to an independent servo disc 409. Each independent servo disc 409 is fixedly connected to a corresponding servo disc reel 408 with screws, and each servo disc reel 408 is fixedly wound with a corresponding tendon rope 600. For example, to prevent interference, the present invention arranges the six servos in two groups, one in front and one behind, and simultaneously provides two guide plates distributed in front and behind: a first guide plate 410 at the front and a second guide plate 411 at the rear. Each guide plate has several tendon rope guide holes 506, ensuring that the tendon ropes 600 do not interfere with each other.

[0106] The bottom of the finger base 204 and the bottom of the thumb base 201 of this invention are respectively provided with tendon cord routing holes. The routing holes are located at the bottom of each finger to ensure that the transmission direction of the driving tendon is consistent with the bending direction of the finger and to reduce friction loss. The rear end of the forehand shell 202 and the wrist 501 are provided with multiple tendon cord guide holes 506. One end of each tendon cord 600 is symmetrically wrapped around the micro-hole of the finger joint at the end of the finger, and the other end passes around the routing hole of each finger, the finger base 204 or the thumb base 201, passes through the entire palm cavity, and then passes through the tendon cord guide holes 506 on the rear end of the forehand shell 202 and the wrist 501 in sequence to connect with the corresponding driving module.

[0107] In some embodiments, such as Figure 6 As shown, this invention segments the tendon cord 600, dividing the same degree of freedom driving tendon cord 600 into an execution segment connected to the flexible finger 110 and a power segment connected to the coupling drive module 300 and the independent drive module 400. A tension spring 205 connects the execution segment and the power segment within the palm cavity to form a fully functional tendon cord 600, enabling modular assembly of the tendon cord 600. The tension spring 205 also provides a certain initial preload and facilitates the replacement of finger components, enhancing the assemblability and maintainability of the dexterous hand. By adjusting the position of the tendon cord 6006 fixed in different micro-holes on the finger, the finger stiffness and bending direction can be changed.

[0108] It should be noted that, Figure 6 The orientation of the tendon cord 600 is for illustrative purposes only and does not represent the actual distribution in the above embodiments of the present invention. The coupled drive module 300 requires 3 tendon cords 600, and the independent drive module 400 requires 6 tendon cords 600, for a total of 9 independent tendon cords 600. Figure 6 Only 5 tendons are shown inside the palm base component 200; the remaining tendons 600 are hidden inside the palm base component 200.

[0109] like Figure 7 As shown, the present invention provides an example of the structure of a flexible finger. The flexible finger is based on a microstructure design and includes a fixing member 111 and a continuous microstructure 112 disposed on the fixing member 111. The continuous microstructure is made of an elastic material and is formed by stacking multiple unit structures 1121 along the length direction. The multiple unit structures 1121 of the continuous microstructure can achieve flexible bending movements under the drive of the tendon 600.

[0110] This invention fixes one end of the tendon cord 600 to the selected unit structure 1121, and pulls the tendon cord 600 under the pulling force of the external driving mechanism, thereby causing the continuous microstructure 112 to bend, simulating the movement of human fingers. By selecting different numbers of tendon cords 600, different degrees of freedom can be controlled, realizing multi-degree-of-freedom finger design.

[0111] like Figures 8 to 15 As shown, exemplarily, the unit structure 1121 includes an outer connection point 11211, an inner connection point 11212, and a plurality of connectors;

[0112] like Figure 10 , 11 As shown, eight external connection points 11211 are connected in sequence by transverse connectors to form a quadrilateral structure, which serves as the center of the unit structure 1121. Each side of the quadrilateral structure has two external connection points 11211. The external connection points 11211 of adjacent unit structures 1121 are connected by a concave first longitudinal connector 11213.

[0113] Two opposite sides of the quadrilateral structure are defined as the front and back sides. Two internal connection points 11212 are located at the junction of adjacent unit structures 1121. The upper and lower sides of one of the internal connection points 11212 are connected to the adjacent horizontal connector (the first horizontal connector 11218 on the front side) through the second vertical connector 11214. The upper and lower sides of the other internal connection point 11212 are connected to the adjacent horizontal connector (the first horizontal connector 11218 on the back side) through the second vertical connector 11214.

[0114] Each inner connection point 11212 is connected to the two first longitudinal connectors 11213 on the corresponding sides via a third connector 11217 on its left and right sides respectively.

[0115] This invention designs eight external connection points 11211, arranged in pairs to form a quadrilateral structure. Multiple unit structures 1121 are connected to form four sides, each of which is a bendable side. One side is the same as the pad of the fingertip 113, which is the front side. The side opposite the front side is the back side, and the other two sides are the left and right sides. By selecting the number of tendon cords 600, this invention can enable the flexible finger to bend forward, backward, or laterally, achieving multi-degree-of-freedom control. Alternatively, unit structures 1121 of different heights can be set to fix the tendon cords 600, allowing the flexible finger to be controlled in segments.

[0116] Since the external connection point 11211 of this invention is at the junction, its size is larger than that of the connector, forming a structure with relatively high strength, which constitutes the outer frame of the flexible finger. It is connected by the concave first longitudinal connector 11213 to provide bending margin, so that the flexible finger can bend to any side under the action of external force. Moreover, each connector is a flat part, and the bending modulus in one direction is much smaller than that in another direction. Taking the two first longitudinal connectors 11213 on the front as an example, when the front tendon 600 moves, the finger only bends to the front, which has a certain restraining effect on lateral bending; so that the flexible finger can bend in the desired control direction.

[0117] The second longitudinal connector 11214 of this invention is an irregularly shaped part, including a first connecting portion 11215 and a second connecting portion 11216. The first connecting portion 11215 is arranged along the length direction (longitudinal) of the flexible finger, and the second connecting portion 11216 is arranged laterally. Two second connecting portions 11216 connected to the same laterally connected member are combined, such that the total cross-sectional area of ​​the two second connecting portions 11216 is approximately equal to that of the first connecting portion 11215. This allows all inner connection points 11212 at different heights at the same location to connect and form an inner rib 11222. The two inner connection points 11212 constitute two inner ribs 11222 inside the flexible finger. Figure 13 As shown, the flexible finger is able to maintain its shape by means of two inner ribs 11222, so that it does not collapse when the flexible finger is bent; since the inner ribs 11222 provide strength to the flexible finger, the thickness of the first connecting part 11215 needs to be slightly greater than the thickness of the first longitudinal connecting member 11213.

[0118] The present invention connects each inner connection point 11212 to two first longitudinal connection pieces 11213 on the front or back through a third connection piece 11217, so that the first longitudinal connection pieces 11213 at the two corners are associated and connected, which has a synergistic association, increases the restraint on lateral bending, and makes the lateral bending curvature less than the front and back bending, thus more realistically simulating human finger movements.

[0119] To further illustrate the present invention, as follows: Figure 10 , 11 As shown in Figure 12, the lateral connector includes a first lateral connector 11218 that is recessed and used to connect two external connection points 11211 on the same side, and a second lateral connector 11219 that is recessed and used to connect two external connection points 11211 at the corner. The second lateral connector 11219 maintains the cross-sectional shape of the flexible finger and the overall skeleton shape. The recessed first lateral connector 11218 provides a margin for the change in distance between the two external connection points 11211 on the same side during bending. Therefore, the arc length of the first lateral connector 11218 is less than that of the first longitudinal connector 11213, approximately only half that of the first longitudinal connector 11213.

[0120] To further illustrate the present invention, as follows: Figure 13 , 14As shown, the upper and lower parts of the inner connection point 11212 are connected to the arc-shaped back of the first transverse connection point 11218 via the second longitudinal connection member 11214, respectively; the arc-shaped backs of two adjacent first longitudinal connection members 11213 located at the corners are connected by the concave fourth connection member 220. By setting the connection point on the back of the first longitudinal connection member 11213, the interference of the inner connection point 11212 itself on the bending movement is avoided, so that the flexible finger can bend smoothly.

[0121] To further illustrate the present invention, as follows: Figure 7 As shown, the concave first longitudinal connector 11213 serves as the tie point 11221 of the tendon cord 600. By selecting tie points 11221 of different height unit structures 1121, the shape of the flexible finger bending can be adjusted. Figure 8 As shown, taking frontal bending as an example, a unit structure 1121 is selected to install tie point 11221. The tendon rope 600 can be wrapped from the outside to the inside around the two first longitudinal connectors 11213 on the upper front of the unit structure 1121. The tendon rope 600 passes down through the gap between the two first longitudinal connectors 11213 and through the entire microstructure. Finally, the two free ends of the tendon rope 600 are led out from the bottom of the bottom unit structure 1121, pass through the fixing member 111 and are connected to the driving mechanism (such as a winding reel or drum). When the driving mechanism tightens the tendon rope 600, starting from the unit structure 1121 with tie point 11221, the unit structure 1121 sequentially compresses the first longitudinal connectors 11213 on the front until all adjacent first longitudinal connectors 11213 on the front come into contact with each other, reaching the maximum bending angle.

[0122] In a preferred embodiment, the outer connection point 11211 and the inner connection point 11212 are both square connection points with relatively high strength. Since the outer connection point 11211 and the inner connection point 11212 are multi-directional connection points, their size is actually larger than that of each connector during printing, and their strength is actually greater than that of each connector, thus forming the skeleton nodes of the flexible finger.

[0123] To reduce weight while maintaining strength, the square connection point is hollow in the middle.

[0124] For example, the number of tie points 11221 in the same unit structure 1121 can be selected to adjust the degree of freedom of movement of the flexible finger, forming a multi-degree-of-freedom flexible finger. Each side of the quadrilateral structure can be provided with a tie point 11221. For instance, if the present invention provides tie points 11221 on the first longitudinal connectors 11213 on the front and both sides, then when different tendons 600 are driven, the flexible finger can perform frontal bending and bending on both sides; Figure 7 and Figure 8As shown, if the tie point 11221 is provided only on the first longitudinal connector 11213 on the front, then when the tendon rope 600 is driven, the flexible finger can bend in the front.

[0125] For example, by selecting unit structures 1121 of different heights to set the tie point 11221, the number of bends of the flexible finger can be adjusted. For instance, if the topmost unit structure 1121 is selected as the tie point 11221, the entire flexible finger can bend in the selected direction. If the second-to-top unit structure 1121 is selected as the tie point 11221, the topmost unit structure 1121 will not bend when bending. The appropriate unit structure 1121 of the corresponding height can be selected as the tie point 11221 according to the application scenario.

[0126] It should be noted that the number of unit structures 1121 is generally unlimited. To meet basic bending requirements, it is generally greater than 3. The more unit structures 1121 there are, the greater the degree of bending and the more flexible it is. However, too many unit structures 1121 not only waste materials and make manufacturing difficult, but also result in insufficient strength. Therefore, the number is generally 3-20, as shown in the appendix of this invention. Figure 7 , 8 It consists of 6 unit structures 1121.

[0127] For example, the gaps between the outer connection point 11211, the inner connection point 11212, and the several connectors constitute the rope channel 114. Generally, in order to complete normal bending, a large gap is reserved between the outer connection point 11211, the inner connection point 11212, and the several connectors. Therefore, the rope channel 114 is relatively easy to set up, and the present invention does not impose any special limitations.

[0128] For example, such as Figure 16 As shown, the fixing member 111 is provided with a cable outlet hole 111 for the tendon rope 600 to pass through. The edge of the cable outlet hole 111 is smooth, which is beneficial to improving the service life of the tendon rope 600. It should be noted that the number and position of the cable outlet hole 111 should match the number and position of the tie point 11221. It can be adjusted according to common knowledge. This invention will not elaborate further.

[0129] For example, the continuous microstructure 112 is made of thermoplastic elastomer material by 3D printing, such as TPU95A material, which can simultaneously meet the requirements of strength, flexibility, and manufacturing process. Due to the softness of the material, this flexible finger can achieve precise grasping of fragile and delicate objects, and because the flexible material has a high coefficient of friction, the grasped object is not easy to slip.

[0130] The drive cord 600 is available with either fishing line or stainless steel wire.

[0131] Due to the complex structure of this invention, the requirement for homogeneous materials, and the need for a long bending life, 3D printing is the preferred method of fabrication.

[0132] For example, the topmost unit structure 1121 is provided with a fingertip 113, which is fixed to two inner connection points 11212 and several first longitudinal connectors 11213 of the topmost unit structure 1121.

[0133] The working principle of the multi-degree-of-freedom flexible finger of this invention is as follows:

[0134] like Figure 7 and Figure 8 As shown, the drive rope (tendon rope 600) is wound around the selected unit structure 1121 through the positive rope channel 114 inside the continuous microstructure, forming a movable connection with the flexible finger. One end of the drive rope is fixed to the microstructure, and the other end leads out two traction lines from the outlet hole 111. The traction lines are driven by a power source such as a motor. When the two traction lines are pulled by the motor at the same time, the total length of the drive rope inside the flexible finger decreases, and relative displacement occurs with the inner wall of the finger, causing it to continuously slide out of the outlet hole 111 and drive the finger to complete the bending action. Because there are first longitudinal connectors 11213 with low stiffness between the outer connection points 11211, when the flexible finger bends, the concave first longitudinal connectors 11213 evenly distributed on the inner side of the bending direction of the flexible finger contract gradually from bottom to top until all the first longitudinal connectors 11213 have completed contraction, and the flexible finger reaches the maximum degree of bending. Due to the support of the external connection point 11211, when the flexible finger is bent to a large degree, the external connection points 11211 corresponding to the adjacent unit structures 1121 come into contact with each other, which antagonizes the bending movement of the flexible finger, so that the flexible finger will not collapse or twist, and maintains a certain rigidity and stability.

[0135] The workflow of the present invention will be further described below with reference to specific embodiments:

[0136] In this embodiment, serial bus servos with stall torques of 4.5 kg and 6 kg are used as independent drive servos and coupled drive servos 309, and 8-strand PE wire is used as tendon rope 600.

[0137] In coupling mode, the coupling drive servo 309 drives the reduction drive gear 302 to rotate by a specified angle. The reduction drive gear 302 meshes with the reduction driven gear 304 at a transmission ratio of 1:1.5, increasing the output torque. The reduction driven gear 304 drives the first guide wheel 307, the second guide wheel 306, and the third guide wheel 305, which are fixed to the drive shaft 303, to rotate. The diameters of the first guide wheel 307, the second guide wheel 306, and the third guide wheel 305 are set to 1.2:1:0.8 according to the ratio of the maximum tendon displacement of the three fingers during contraction. Taking the bending of the thumb 101 as an example, one end of the tendon cord 600 is fixed to the first guide wheel 307, and the other end passes through the wiring holes of the wrist 501, the forearm shell 202, and the thumb base 201 in sequence, and is symmetrically wrapped around the micro-holes on the front of the phalanx of the thumb 101, controlling the forward bending of the thumb 101. The driving method of the index finger 102 and the middle finger 103 is similar. The coupling drive mechanism 300 can realize the coordinated movement of the thumb 101, index finger 102 and middle finger 103. It has a reliable structure, simple control, and enhances hand dexterity.

[0138] In independent mode, the first servo 401, the second servo 402, the third servo 403, the fourth servo 404, the fifth servo 405, and the sixth servo 406 control the bending and lateral movement of the thumb 101, as well as the bending of the index finger 102, the middle finger 103, the ring finger 104, and the little finger 105, respectively. Taking the bending of the index finger 102 as an example, one end of the tendon cord 600 is fixed to the servo disc reel 408, and the other end passes through the tendon cord guide hole of the second guide plate 411, the first guide plate 410, the wrist 501, the tendon cord guide hole of the forearm shell 202, and the tendon cord routing hole of the finger base 204 in sequence, and is symmetrically wound around the micro-hole of the front knuckle of the index finger 102. The output shaft of the third servo 403 drives the independent servo disc 409 and the servo disc reel 408 to rotate at a certain angle, thereby controlling the bending of the index finger 102. The method of driving the thumb 101 to swing side is similar to that of driving the thumb 101 to bend. One end of the tendon rope is symmetrically wrapped around the micro-hole of the phalanx on the side of the thumb 101, and the other end is connected to the second servo motor 402. The lateral swinging motion of the thumb 101 is controlled by rotating the second servo motor 402.

[0139] The above embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Although the invention has been described in detail with reference to the embodiments, those skilled in the art should understand that various combinations, modifications, or equivalent substitutions of the technical solutions of the invention do not depart from the spirit and scope of the invention and should be covered within the scope of the claims of the invention.

Claims

1. A modular flexible bionic hand based on dual-mode line actuation, characterized in that: include The palm base component has multiple finger mounting points at the front end; The finger assembly includes multiple wire-driven flexible fingers, each mounted on a multiple finger mounting point; The arm base assembly is installed at the rear end of the hand base assembly and is hollow inside; The coupling drive module, installed inside the hollow part of the arm base assembly, is used to couple the rope to drive at least two flexible fingers; An independent drive module, installed inside the hollow of the arm base assembly, is used to independently drive each flexible finger with a cable. as well as The tendon ligaments connect the coupled drive module or the independent drive module to their respective flexible fingers. The flexible finger includes a fixing element and a continuous microstructure disposed on the fixing element. The continuous microstructure is made of elastic material and is formed by stacking multiple unit structures along the length direction. The multiple unit structures of the continuous microstructure can achieve flexible bending movements under the drive of tendon chords. Each flexible finger has a corresponding continuous microstructure length set according to different functional needs. The unit structure includes an external connection point, an internal connection point, and several connecting components; Among them, the eight external connection points are connected in sequence by the horizontal connectors to form a quadrilateral structure, which serves as the center of the unit structure. Each side of the quadrilateral structure has two external connection points; the external connection points of adjacent unit structures are connected by the concave first longitudinal connector. The two opposite sides of the quadrilateral structure are defined as the front and back sides. The two internal connection points are located at the junction of adjacent unit structures. The upper and lower parts of one of the internal connection points are connected to the adjacent horizontal connection members on the front side through the second vertical connection members. The upper and lower parts of the other internal connection point are connected to the adjacent horizontal connection members on the back side through the second vertical connection members. Each inner connection point is connected to the two first longitudinal connectors on the corresponding sides via a third connector on its left and right sides.

2. The modular flexible bionic hand based on dual-mode line actuation according to claim 1, characterized in that: The multiple flexible fingers are named thumb, index finger, middle finger, ring finger, and little finger. The thumb has two degrees of freedom: frontal bending and lateral bending. The index finger, middle finger, ring finger, and little finger each have one degree of freedom for frontal bending.

3. The modular flexible bionic hand based on dual-mode line actuation according to claim 2, characterized in that: The palm base assembly includes Forehand shell; The rear palm shell is fixedly connected to the front palm shell, and a palm space for the tendon tract is reserved between the two. A finger base is disposed between the front end of the forehand shell and the rearhand shell. The finger base is provided with several positioning grooves for mounting the index finger, middle finger, ring finger and little finger respectively. as well as A thumb base, located between the sides of the forehand and rearhand shells, is used to mount the thumb.

4. The modular flexible bionic hand based on dual-mode line actuation according to claim 3, characterized in that: The finger base and thumb base are respectively provided with a number of tendon cord routing holes, and the position and number of tendon cord routing holes are set according to the degree of freedom of movement of each flexible finger.

5. The modular flexible bionic hand based on dual-mode line actuation according to claim 3, characterized in that: The coupling drive module includes Multiple guide wheels are connected to multiple flexible fingers to be coupled and driven via corresponding tendon ropes, and multiple guide wheels are installed inside the hollow arm base component via a drive shaft; Coupled servo motor, used to provide coupled power; as well as The transmission gear set is used to connect the coupling servo motor and the power transmission of the drive shaft.

6. The modular flexible bionic hand based on dual-mode line actuation according to claim 3, characterized in that: The independent drive module includes 6 servos and several guide plates; each servo has an output end with a servo wheel for winding the tendon rope, and the guide plate has tendon rope guide holes for the tendon rope to pass through.

7. The modular flexible bionic hand based on dual-mode line actuation according to claim 3, characterized in that: The arm base assembly includes a forearm shell, an upper arm shell, and a wrist. The forearm shell is connected to the forearm shell via the wrist. The upper arm shell is detachably connected to the forearm shell. The wrist is provided with several tendon guide holes. The coupling drive module and the independent drive module are respectively installed inside the forearm shell and the upper arm shell.

8. The modular flexible bionic hand based on dual-mode line actuation according to claim 7, characterized in that: The forehand shell has a connecting end at its tail end that connects to the wrist.

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