Bionic prosthetic hand

Abstract

The invention discloses a bionic prosthetic hand. The bionic prosthetic hand comprises a palm part, a thumb part, a four-finger part and a pneumatic control system, wherein the thumb part comprises a thumb metacarpal bone and a thumb, the thumb metacarpal bone is hinged to the palm part through a first hinge shaft and is driven by a first pneumatic device to rotate, and first cavity units which are connected in series are arranged in the thumb; the thumb is hinged to the thumb metacarpal bone through a second hinge shaft and is driven by a second pneumatic device to swing. Second cavity units connected in series are arranged in all fingers of the four-finger part, and all the fingers are hinged to the palm part through third hinge shafts and driven by a third pneumatic device to swing independently. The pneumatic control system is arranged in the prosthetic hand and used for controlling air intake and exhaust of the cavity units and the pneumatic device. The two-degree-of-freedom design of thumb metacarpal bone rotation and thumb swinging is adopted, the pneumatic device is combined for driving, flexible movement of the thumb is achieved, and the coordination and fine operation capacity of the prosthetic hand are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of bionic prosthetic hands, in particular to a bionic prosthetic hand. Background Art

[0002] As a cross-field of bionics and robotics, the bionic hand aims to imitate the structure and function of the human hand to achieve highly flexible and delicate manipulation capabilities. In recent years, with the advancement of technology, pneumatic soft prosthetic hands have gained widespread attention in this field due to their simple structure, light weight, and high output power. Compared with traditional electric or hydraulic drive systems, pneumatic drives achieve the movement of prosthetic hands by controlling changes in air pressure, which not only makes the overall weight lighter, but also simplifies the system structure.

[0003] However, the existing pneumatic prosthetic hands still have the following problems in structural design:

[0004] Insufficient freedom of thumb movement: The thumb design of existing pneumatic prosthetic hands often adopts a simple single-axis rotation structure, which makes it difficult to achieve complex movements similar to the human thumb. This design results in the thumb being able to perform only simple gripping movements, and is unable to complete complex grasping postures such as pinching and side gripping. Especially when delicate operations are required, it is difficult to adapt to different grasping requirements due to the lack of independent movement capabilities of the metacarpophalangeal joint and interphalangeal joint.

[0005] Single finger drive structure: The finger structure of traditional pneumatic prosthetic hands usually adopts a single air cavity design, and the entire finger bends as a whole. This structure causes the fingers to lack flexibility during movement and cannot achieve segmented bending movements. At the same time, the connection between the fingers and the palm is simple, which can only achieve simple flexion and extension movements, lacks independent swinging ability, and limits the freedom of grip of the prosthetic hand.

[0006] Therefore, it is urgent to develop a pneumatic prosthetic hand with a multi-degree-of-freedom thumb structure and a flexible finger drive mechanism. The focus needs to be on solving the coordination of the thumb's metacarpophalangeal joint movement and interphalangeal bending, as well as the segmented bending and independent swinging ability of the fingers, so as to improve the flexibility and adaptability of the prosthetic hand. Summary of the invention

[0007] The purpose of the present invention is to provide a bionic prosthetic hand in view of the above problems, aiming to solve the technical problems of insufficient freedom of thumb movement and poor finger driving flexibility in the prior art.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is: a bionic prosthetic hand, comprising:

[0009] The palm part forms the base of the bionic prosthetic hand;

[0010] The thumb part comprises a thumb metacarpal bone and a thumb, wherein the thumb metacarpal bone is hinged to the palm part through a first hinge shaft and is driven by a first pneumatic device to rotate around the first hinge shaft; a plurality of first cavity units connected in series along the length direction of the thumb are arranged inside the thumb, and adjacent first cavity units are connected through through holes, and the first cavity units are used to drive the thumb to bend when inflated; the thumb is hinged to the thumb metacarpal bone through a second hinge shaft and is driven by a second pneumatic device to swing around the second hinge shaft;

[0011] A four-finger portion, comprising four fingers, each finger being provided with a plurality of second cavity units connected in series along the length direction of the finger, adjacent second cavity units being connected through through holes, the second cavity units being used to drive the corresponding fingers to bend when inflated; the four fingers are respectively hinged to the palm portion through corresponding third hinge shafts, and each finger is respectively driven by a corresponding third pneumatic device to independently swing around the corresponding third hinge shaft;

[0012] The pneumatic control system is arranged in the bionic prosthetic hand and is used for controlling the air intake and exhaust of the first cavity unit, the second cavity unit, the first pneumatic device, the second pneumatic device and the third pneumatic device.

[0013] In a possible embodiment, a plurality of inter-grooves are provided on the pulp surfaces of the thumb and each finger of the four fingers, and the inter-grooves divide the pulp of each finger into a plurality of sections, each section is provided with a first cavity unit or a second cavity unit; two grooves corresponding to the positions of the interphalangeal joints and metacarpophalangeal joints of real fingers are provided on the back surface of the thumb, and three grooves corresponding to the positions of the distal interphalangeal joints, proximal interphalangeal joints and metacarpophalangeal joints of real fingers are provided on the back surface of each finger of the four fingers.

[0014] In a possible embodiment, a first hinge seat is fixedly provided at the position corresponding to each finger on the palm, and each finger of the four-finger part is hinged to the corresponding first hinge seat through a corresponding third hinge axis; the third pneumatic device includes a first pneumatic muscle and a second pneumatic muscle, one end of the first pneumatic muscle and the second pneumatic muscle are respectively connected to the two sides of the bottom of the first hinge seat, and the other end is connected to the palm, for driving the corresponding finger to swing around its third hinge axis by inflating and expelling air.

[0015] In a possible embodiment, a second hinge seat is provided at the base of the thumb, and the second hinge axis is provided on the second hinge seat; the second pneumatic device is a third pneumatic muscle, one end of the third pneumatic muscle is connected to the metacarpal bone of the thumb, and the other end is connected to the second hinge seat, and the thumb is driven to swing around the second hinge axis by inflating and expelling air.

[0016] In a possible embodiment, the first pneumatic device includes a fourth pneumatic muscle and a fifth pneumatic muscle, and the fourth pneumatic muscle and the fifth pneumatic muscle are arranged in the palm, one end of the fourth pneumatic muscle and the fifth pneumatic muscle are fixed to the inner wall of the palm, and the other end is connected to the thumb metacarpal bone through an elastic member, and the first pneumatic device drives the thumb metacarpal bone to rotate around the first hinge axis by inflating and exhausting air.

[0017] In a possible embodiment, a return torsion spring is provided at the connection position between the thumb metacarpal bone and the palm.

[0018] In a possible embodiment, the elastic member is a spring or an elastic rope.

[0019] In a possible embodiment, the thumb and the four fingers of the four-finger portion are all integrally formed of a flexible material.

[0020] In a possible embodiment, the pneumatic control system includes:

[0021] An air pump and an air storage tank, wherein the air pump delivers compressed air to the air storage tank;

[0022] An air inlet valve connected to the air outlet end of the air storage tank;

[0023] A multi-way valve, the air inlet end of which is connected to the air inlet valve;

[0024] A plurality of proportional valves are connected to the multi-way valve, and each of the proportional valves is connected to a corresponding actuator; wherein the actuator comprises the first cavity unit, the second cavity unit, the first pneumatic device, the second pneumatic device and the third pneumatic device;

[0025] A plurality of exhaust throttle valves, each of the exhaust throttle valves is connected to a corresponding proportional valve;

[0026] A recovery gas tank connected to the gas outlet end of each exhaust throttle valve and connected to the multi-way valve;

[0027] A control module, electrically connected to the air pump, the air inlet valve, the multi-way valve and each proportional valve, for controlling the operation of the entire pneumatic system;

[0028] A plurality of pressure sensors are arranged at the fingertips and the pulps of each finger, and are used to detect the pressure of the fingertips and the pulps and transmit the detection signals to the control module. The control module controls the inflation and exhaust of the corresponding actuators according to the pressure signals to adjust the gripping force of the prosthetic hand.

[0029] In some embodiments, the control method of the pneumatic control system includes:

[0030] The air pump starts and fills the air tank with compressed air until the preset working pressure is reached;

[0031] Determine the initial air pressure value required for each actuator according to the set target gripping force, and control the multi-way valve and proportional valve to charge the compressed air in the air tank into the corresponding actuator;

[0032] The pressure sensor detects the fingertip pressure of each finger in real time and transmits the pressure signal to the control module;

[0033] The control module dynamically adjusts the opening of each proportional valve according to the pressure signal and controls the air pressure entering the actuator to maintain the target gripping force;

[0034] When it is detected that the gas pressure exceeds the preset upper limit threshold, the corresponding exhaust throttle valve is opened to discharge the excess gas into the recovery gas tank;

[0035] When the fingertip pressure is detected to be lower than the preset lower threshold, the exhaust throttle valve is closed and the gas in the gas storage tank is replenished through the multi-way valve;

[0036] After receiving the grip end signal, the gas in each actuator is recovered to the recovery gas tank through the exhaust throttle valve.

[0037] Beneficial effects of the present invention:

[0038] 1. The dual-degree-of-freedom design of thumb metacarpal rotation and thumb swing, combined with the drive of the pneumatic device, realizes the flexible movement of the thumb, makes the coordinated movement between the thumb and other fingers more tight and efficient, and significantly improves the coordination and fine operation ability of the prosthetic hand.

[0039] 2. By designing multiple cavity units in series on the fingers and combining them with the groove design on the back of the fingers, the fingers can achieve natural bending movements similar to those of human hands under the drive of air pressure, which improves flexibility and grasping accuracy, and at the same time enhances the adaptability of the fingers to objects of complex shapes.

[0040] 3. Design an independent articulated seat and pneumatic muscle drive structure to enable each finger to swing independently, expanding the freedom of movement of the prosthetic hand and improving the diversity of grasping postures.

[0041] 4. Through the reasonable design of pneumatic systems such as air pumps, air tanks, multi-way valves, proportional valves, etc., precise control of the movement of the prosthetic hand is achieved.

[0042] 5. A pressure sensor and control module are set up to monitor and adjust fingertip pressure in real time, achieve precise control of grip force, and improve operation stability.

[0043] 6. The recycling gas tank design significantly reduces the consumption of external gas sources, optimizes system energy efficiency, and extends endurance through the recovery and reuse of compressed air. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a schematic diagram of the back of a prosthetic hand provided by an embodiment of the present invention.

[0045] Figure 2 A schematic diagram of the palm surface of a prosthetic hand provided by an embodiment of the present invention.

[0046] Figure 3 A cross-sectional view of one of the four fingers of a prosthetic hand provided in one embodiment of the present invention.

[0047] Figure 4 A cross-sectional view of the thumb portion of a prosthetic hand provided by an embodiment of the present invention.

[0048] Figure 5 A side view of a thumb provided according to an embodiment of the present invention.

[0049] Figure 6 A schematic diagram of the connection between the thumb and the palm provided by an embodiment of the present invention.

[0050] Figure 7 A structural block diagram of a pneumatic system provided in one embodiment of the present invention.

[0051] Figure 8 The present invention provides a flow chart of a pneumatic system control method.

[0052] The text labels in the figure are as follows: 100, four fingers; 101, second cavity unit; 102, intermediate groove; 103, through hole; 104, notch; 105, first hinge seat; 200, palm; 300, thumb; 310, thumb; 311, first cavity unit; 312, second hinge seat; 320, thumb metacarpal bone; 321, hinged lug; 400, pneumatic system; 401, air pump; 402, air storage tank; 403, intake valve; 404, control module; 405, multi-way valve; 406, proportional valve; 407, exhaust throttle valve; 408, recovery gas tank; 409, air pipe; 410, sensor; 411, first pneumatic muscle; 412, second pneumatic muscle; 413, fourth pneumatic muscle; 414, fifth pneumatic muscle; 415, third pneumatic muscle; 416, sixth pneumatic muscle; 417, seventh pneumatic muscle. DETAILED DESCRIPTION

[0053] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings. The description in this part is only exemplary and explanatory and should not have any limiting effect on the protection scope of the present invention.

[0054] refer to Figure 1 and Figure 2This embodiment aims to provide a bionic prosthetic hand, including a thumb portion 300 , four finger portions 100 , a palm portion 200 and a pneumatic system 400 .

[0055] refer to Figure 1 and Figure 6 The palm portion 200 constitutes the base of the prosthetic hand and adopts a hollow structure design, with a channel for arranging an air path inside.

[0056] refer to Figure 1 , Figure 3 and Figure 6 , wherein the four-finger portion 100 includes four fingers, namely the index finger, the middle finger, the ring finger and the little finger, and the four fingers are made of a flexible material such as silicone. Each finger is provided with a plurality of second cavity units 101 connected in series along the length direction of the finger, and adjacent second cavity units 101 are connected through through holes 103. A plurality of inter-grooves 102 are provided on the finger pulp surface of each finger, and these inter-grooves divide the finger pulp into a plurality of sections, each of which is provided with a second cavity unit 101. Optionally, the transverse cross-section of the second cavity unit 101 is fan-shaped, and drives the corresponding finger to bend when it is inflated.

[0057] refer to Figure 3 In some embodiments, the back of each finger is provided with three grooves 104 corresponding to the positions of the distal interphalangeal joint, the proximal interphalangeal joint and the metacarpophalangeal joint of the real finger.

[0058] Specifically, in some possible embodiments, the shape of each finger of the four-finger part is the same, including 10 equally spaced second cavity units 101, each air cavity cross-section may be fan-shaped, and the second cavity units 101 are connected through through holes 103. The bottom of each finger is thickened, and a groove 104 is provided at the corresponding joint of the bottom of the finger of the four-finger part. In this embodiment, the number of grooves 104 is 3, and the three grooves 104 are all in the gap of the second cavity unit 101. In this embodiment, the 10 cavity units are divided into three finger joints. Since the cavity units are connected by through holes 103, only one air pump is needed to drive the movement of the entire finger. Specifically, when gas is filled into the second cavity unit 101, each cavity unit will gradually expand, while the thickened layer at the bottom of the second cavity unit 101 will be less deformed, and the entire finger will bend in the direction of the thickened layer. The bending amplitude will be greater at the groove due to the thinner wall. This design makes the fingers more flexible and precise when grasping and manipulating objects.

[0059] refer to Figure 6The first hinge seat 105 is fixedly arranged at the position corresponding to each finger on the palm part 200, and each finger of the four-finger part 100 is hinged on the corresponding first hinge seat 105 through the corresponding third hinge axis. The third pneumatic device includes a first pneumatic muscle 411 and a second pneumatic muscle 412, and one end of the first pneumatic muscle 411 and the second pneumatic muscle 412 are respectively connected to the bottom two sides of the first hinge seat 105 (left and right sides, Figure 6 The first pneumatic muscle 411 and the second pneumatic muscle 412 are both GRACE-A (Geometric Rotationally Actuated Contra

[0060] ctible Elastomer-Artificial, a pneumatic muscle based on a contractible elastic artificial muscle driven by geometric rotation.

[0061] In specific implementation, when the fingers of the four-finger part 100 need to swing left and right, the pneumatic muscle on one side is inflated, and the pneumatic muscle on the other side remains relaxed or releases gas in a controlled manner. The cooperation of this expansion and contraction drives the first hinge seat 105 connected to the base of the four fingers to swing, generating a tilting action in the left and right directions. By controlling the amount of gas charged and released, the tilt angle of the finger can be adjusted to achieve precise swinging.

[0062] refer to Figure 1-Figure 6 In some possible embodiments, the thumb portion 300 includes a thumb metacarpal bone 320 and a thumb 310. A hinged lug 321 is provided at the connection between the thumb metacarpal bone 320 and the palm portion 200, and a connecting seat is provided at a corresponding position of the palm portion 200. The hinged lug 321 is hinged to the connecting seat on the palm portion 200 through a first hinge axis. In some possible embodiments, a torsion spring is connected at the connection position between the hinged lug 321 and the connecting seat, and the torsion spring is used to keep the thumb metacarpal bone 320 and the palm portion 200 in an extended state.

[0063] In some embodiments, the first pneumatic device includes a fourth pneumatic muscle 413 and a fifth pneumatic muscle 414, and the two pneumatic muscles are arranged in the palm 200 at intervals along the up-down direction. One end of the fourth pneumatic muscle 413 and the fifth pneumatic muscle 414 is fixed to the internal support of the palm 200, and the other end is connected to the thumb metacarpal 320 through the elastic member 418. Optionally, a pulley is fixedly arranged on the thumb metacarpal 320, and the elastic member 418 is wound around the pulley, and the two ends of the elastic member 418 are respectively connected to the inner ends of the fourth pneumatic muscle 413 and the fifth pneumatic muscle 414.

[0064] Optionally, the elastic member 418 is a spring or an elastic rope.

[0065] Optionally, the fourth pneumatic muscle 413 and the fifth pneumatic muscle 414 are both GRACE-A type pneumatic muscles.

[0066] When the thumb metacarpal 320 needs to be moved toward the palm, the fourth pneumatic muscle 413 and the fifth pneumatic muscle 414 shorten their contraction length when inflated, and their contraction force is transmitted to the thumb metacarpal through the elastic member 418, so that the hinged ear 321 of the thumb metacarpal rotates at the hinge, driving the thumb metacarpal to move toward the palm, and cooperates with the four fingers of the four-finger part to form a grasping action, so as to achieve stable clamping of the target object. When the fourth pneumatic muscle 413 and the fifth pneumatic muscle 414 are exhausted, they extend, and the torsion spring drives the thumb metacarpal 320 to move in the extension direction, so that it gradually returns to the neutral position, and the thumb metacarpal 320 is reset.

[0067] refer to Figure 4 The thumb 310 is provided with a plurality of first cavity units 311 connected in series along the length direction of the thumb, and adjacent first cavity units 311 are connected through through holes. A plurality of inter-grooves are provided on the finger pulp surface of the thumb 310, and these inter-grooves divide the finger pulp into a plurality of sections, each of which is provided with a first cavity unit 311. The back surface of the thumb 310 is provided with two grooves corresponding to the positions of the interphalangeal joint and the metacarpophalangeal joint. In some embodiments, the thumb 310 contains 7 first cavity units 311 therein, and the cross-section of each cavity unit is the same as that of the four fingers. The first cavity unit 311 drives the thumb 310 to bend when inflated.

[0068] refer to Figure 2 and Figure 4 In some embodiments, the bending of the thumb 310 is achieved by ventilating each first cavity unit 311 in the thumb 310, and the material of the thumb is an elastic material. When the first cavity unit 311 is inflated, it expands and generates tension, pushing the thumb to bend. After the task is completed, the air pressure begins to release, and the gas in the first cavity unit 311 is gradually discharged. Since the thumb is made of an elastic material, such as a silicone material, it can automatically reset after deformation.

[0069] refer to Figure 6 The thumb 310 is hinged to the thumb metacarpal bone 320 via a second hinge axis, the second hinge axis is arranged on a second hinge seat 312, and the second hinge seat 312 is arranged at the root of the thumb 310. The second pneumatic device is a third pneumatic muscle 415, one end of the third pneumatic muscle 415 is connected to the thumb metacarpal bone 320, and the other end is connected to the second hinge seat 312.

[0070] Optionally, the third pneumatic muscle 415 is designed based on PneuNet (Pneumatic Networks). When the third pneumatic muscle 415 is inflated, the thumb swings to one side around its hinge axis, and when the third pneumatic muscle 415 is exhausted, the thumb swings to the other side around its hinge axis.

[0071] For further reference, Figure 5 and Figure 6 In some possible embodiments, a fourth pneumatic device is also provided at the joint connection between the thumb metacarpal bone 320 and the palm 200. The fourth pneumatic device is used to assist the left and right swing of the thumb. The fourth pneumatic device includes two GRACE-A pneumatic muscles (the sixth pneumatic muscle 416 and the seventh pneumatic muscle 417). The sixth pneumatic muscle 416 and the seventh pneumatic muscle 417 are respectively connected to the second hinge seat 312 through connecting rods. When the sixth pneumatic muscle 416 is inflated, the connecting rod system transmits the expansion force to the second hinge seat 312, driving the connecting rod to stretch forward, the fixed angle at the connecting rod connection remains unchanged, the hinge is connected and fixed to the pivot, and the driving angle at the base of the finger is deflected together, driving the thumb 310 to move closer to the four fingers. At the same time, the seventh pneumatic muscle 417 remains relaxed to ensure smooth and interference-free tilting. If the thumb 310 needs to tilt to the other side, the seventh pneumatic muscle 417 is inflated and the gas in the sixth pneumatic muscle 416 is released at the same time. This reverse drive causes the second articulated seat 312 to tilt to the other side, completing the left-right swinging motion. This expansion and contraction coordination drives the second articulated seat 312 connected to the root of the thumb to swing, generating a left-right tilting motion, and a more precise control of the thumb can be achieved through the action of the fourth pneumatic device.

[0072] refer to Figure 7 In some possible embodiments, the pneumatic control system 400 of the bionic prosthetic hand includes:

[0073] An air pump 401, for generating compressed air;

[0074] The air storage tank 402 is connected to the air outlet of the air pump 401 and is used to store compressed air;

[0075] The air inlet valve 403 is arranged at the air outlet end of the air storage tank 402 and is connected to the multi-way valve 405 through the main pipeline;

[0076] The control module 404 is electrically connected to the air pump 401, the air inlet valve 403, the multi-way valve 405 and each proportional valve 406, and is used to control the operation of the entire pneumatic system;

[0077] A multi-way valve 405, whose air inlet end is connected to the air inlet valve 403, is used to distribute the compressed air in the air storage tank 402 to the multiple proportional valves 406 connected thereto;

[0078] A plurality of proportional valves 406 are connected to the multi-way valve 405 through an air pipe 409, and each proportional valve 406 is connected to a corresponding actuator to accurately control the air pressure entering each actuator. The actuators include:

[0079] A plurality of first cavity units 311 disposed in the thumb;

[0080] A plurality of second cavity units 101 arranged in the four fingers;

[0081] A first pneumatic device (a fourth pneumatic muscle 413 and a fifth pneumatic muscle 414) for driving the thumb metacarpal bone to rotate;

[0082] A second pneumatic device (third pneumatic muscle 415) for driving the thumb to swing;

[0083] A third pneumatic device (a first pneumatic muscle 411 and a second pneumatic muscle 412 ) for driving the four fingers to swing;

[0084] A plurality of exhaust throttle valves 407, each exhaust throttle valve 407 is connected to a corresponding proportional valve 406, and is used to control the exhaust speed of the actuator;

[0085] The recovery gas tank 408 is connected to the gas outlet end of each exhaust throttle valve 407 and to the multi-way valve 405, and is used to collect the exhausted gas and realize the recycling of the gas;

[0086] A plurality of pressure sensors 410 are arranged at the fingertips and finger webs of each finger for real-time detection of fingertip pressure and transmission of pressure signals to the control module 404. The control module 404 controls the inflation and exhaust of the corresponding actuator according to the pressure signals to adjust the gripping force of the prosthetic hand.

[0087] refer to Figure 8 , when this embodiment provides a control method of a pneumatic control system, the method comprises the following steps:

[0088] S100: System initialization step: Start the air pump 401 to inflate the air tank 402. The control module 404 starts the air pump to deliver compressed air to the air tank 402. The air enters each actuator through the air pipe 409, and the air flow and pressure are adjusted by the control module 404. The pressure sensor 410 monitors the air pressure in the air pipe 409 in real time to ensure that the air flow is evenly supplied and maintained within a suitable range.

[0089] S200: Initial driving step: Determine the initial air pressure value according to the target gripping force, and deliver the compressed air in the air tank 402 to the corresponding actuators by controlling the multi-way valve 405 and the plurality of proportional valves 406, so that the air pressure in each actuator reaches the initial air pressure value to drive the four fingers and the thumb to move.

[0090] S210: The four-finger actions mainly include:

[0091] S211: Four-finger bending, the specific steps include:

[0092] The control module 404 gradually increases the air pressure of the air cavities of the four fingers to 0.18 MPa;

[0093] The pressure sensor 410 feeds back air pressure data to ensure that the pressure rises evenly according to the control curve;

[0094] The second cavity units 101 expand one by one, and the natural bending is achieved by combining the slot design;

[0095] Once the target pressure is reached, a natural grip is formed.

[0096] S212: Four-finger stretching, the specific steps include:

[0097] The control module 404 controls the proportional valve 406 to open the exhaust path;

[0098] The air pressure in the second cavity unit 101 is gradually released;

[0099] Achieve smooth rebound under the elasticity of the material;

[0100] The pressure sensor 410 is used to monitor and ensure that the stretching process is smooth.

[0101] S213: four-finger swing, the specific steps include:

[0102] Control the first pneumatic muscle 411 and the second pneumatic muscle 412 to alternately inflate and exhaust;

[0103] Achieve precise swing angle through air pressure control;

[0104] Make sure the left and right swinging motion is smooth and coordinated.

[0105] S220: The actions of the thumb 300 mainly include:

[0106] S221: Move closer to the palm. The specific steps include:

[0107] Controlling the inflation and contraction of the fourth pneumatic muscle 413 and the fifth pneumatic muscle 414;

[0108] Transmitting force to the thumb metacarpal bone 320 via the elastic member 418;

[0109] The first cavity unit 311 is inflated synchronously to achieve bending;

[0110] Cooperate with four fingers to form a grasping posture.

[0111] S222: Thumb Extension:

[0112] Control the fourth pneumatic muscle 413 and the fifth pneumatic muscle 414 to exhaust air and drive the thumb metacarpal to abduct by the torsion spring;

[0113] After the first cavity unit 311 is exhausted, it is reset under the action of the torsion spring.

[0114] S223: Coordinated Movement:

[0115] Adjust the air pressure of each pneumatic muscle according to the grip requirements;

[0116] Achieve coordinated cooperation between the thumb and four fingers.

[0117] S300: Pressure monitoring step: The pressure sensor 410 continuously detects fingertip pressure and feeds back a pressure signal to the control module 404 in real time.

[0118] S400: Pressure adjustment step: The control module 404 dynamically adjusts the air pressure of each actuator through the multi-way valve 405 and the proportional valve 406 according to the pressure feedback signal.

[0119] S500: Energy recovery step: When the air pressure exceeds a preset threshold (set to 80% to 95% of the target gripping force), the excess gas (at a ratio of 50% to 90% of the overpressure portion) is discharged into the recovery gas tank 408 through the exhaust throttle valve 407.

[0120] S600: Pressure replenishment step: When the fingertip pressure is lower than the preset threshold, the gas in the recovery gas tank 408 is preferentially used to replenish the corresponding actuator through the multi-way valve 405.

[0121] S700: Action ending step: After the gripping is completed, the remaining gas in each actuator is discharged into the recovery gas tank 408 in an orderly manner.

[0122] It should be noted that, in this article, the terms "comprises", "includes" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or apparatus that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or apparatus.

[0123] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. The above is only a preferred implementation of the present invention. It should be pointed out that due to the limitations of textual expression and the objective existence of infinite specific structures, ordinary technicians in this technical field can make several improvements, modifications or changes without departing from the principles of the present invention, and can also combine the above technical features in an appropriate manner; these improvements, modifications, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, should be regarded as the protection scope of the present invention.

Claims

1. A bionic prosthetic hand, characterized in that: include: The palm part forms the base of the bionic prosthetic hand; The thumb part comprises a thumb metacarpal bone and a thumb, wherein the thumb metacarpal bone is hinged to the palm part through a first hinge shaft and is driven by a first pneumatic device to rotate around the first hinge shaft; a plurality of first cavity units connected in series along the length direction of the thumb are arranged inside the thumb, and adjacent first cavity units are connected through through holes, and the first cavity units are used to drive the thumb to bend when inflated; the thumb is hinged to the thumb metacarpal bone through a second hinge shaft and is driven by a second pneumatic device to swing around the second hinge shaft; A four-finger portion, comprising four fingers, each finger being provided with a plurality of second cavity units connected in series along the length direction of the finger, adjacent second cavity units being connected through through holes, the second cavity units being used to drive the corresponding fingers to bend when inflated; the four fingers are respectively hinged to the palm portion through corresponding third hinge shafts, and each finger is respectively driven by a corresponding third pneumatic device to independently swing around the corresponding third hinge shaft; The pneumatic control system is arranged in the bionic prosthetic hand and is used for controlling the air intake and exhaust of the first cavity unit, the second cavity unit, the first pneumatic device, the second pneumatic device and the third pneumatic device.

2. The bionic prosthetic hand according to claim 1, characterized in that: A plurality of inter-grooves are provided on the pulp surfaces of the thumb and each of the four fingers, and the inter-grooves divide the pulp of each finger into a plurality of sections, each section being provided with a first cavity unit or a second cavity unit; two grooves corresponding to the positions of the interphalangeal joint and the metacarpophalangeal joint are provided on the back surface of the thumb, and three grooves corresponding to the positions of the distal interphalangeal joint, the proximal interphalangeal joint and the metacarpophalangeal joint are provided on the back surface of each of the four fingers.

3. The bionic prosthetic hand according to claim 1, characterized in that: A first hinge seat is fixedly provided at the position corresponding to each finger on the palm, and each finger of the four-finger part is hinged to the corresponding first hinge seat through a corresponding third hinge axis; the third pneumatic device includes a first pneumatic muscle and a second pneumatic muscle, one end of the first pneumatic muscle and the second pneumatic muscle are respectively connected to the two sides of the bottom of the first hinge seat, and the other end is connected to the palm, and is used to drive the corresponding finger to swing around its third hinge axis by inflating and exhausting air.

4. The bionic prosthetic hand according to claim 1, characterized in that: A second hinge seat is provided at the base of the thumb, and the second hinge axis is provided on the second hinge seat; the second pneumatic device is a third pneumatic muscle, one end of the third pneumatic muscle is connected to the metacarpal bone of the thumb, and the other end is connected to the second hinge seat, and the thumb is driven to swing around the second hinge axis by inflating and expelling air.

5. The bionic prosthetic hand according to claim 1, characterized in that: The first pneumatic device includes a fourth pneumatic muscle and a fifth pneumatic muscle, and the fourth pneumatic muscle and the fifth pneumatic muscle are arranged in the palm part. One end of the fourth pneumatic muscle and the fifth pneumatic muscle are fixed to the inner wall of the palm part, and the other end is connected to the thumb metacarpal bone through an elastic member. The first pneumatic device drives the thumb metacarpal bone to rotate around the first hinge axis by inflating and exhausting air.

6. The bionic prosthetic hand according to claim 5, characterized in that: A return torsion spring is arranged at the connection position between the thumb metacarpal bone and the palm.

7. The bionic prosthetic hand according to claim 5, characterized in that: The elastic member is a spring or an elastic rope.

8. The bionic prosthetic hand according to any one of claims 1 to 7, characterized in that: The thumb and the four fingers of the four-finger portion are all integrally made of flexible material.

9. The bionic prosthetic hand according to any one of claims 1 to 7, characterized in that: The pneumatic control system comprises: An air pump and an air storage tank, wherein the air pump delivers compressed air to the air storage tank; An air inlet valve connected to the air outlet end of the air storage tank; A multi-way valve, the air inlet end of which is connected to the air inlet valve; A plurality of proportional valves are connected to the multi-way valve, and each of the proportional valves is connected to a corresponding actuator; wherein the actuator comprises the first cavity unit, the second cavity unit, the first pneumatic device, the second pneumatic device and the third pneumatic device; A plurality of exhaust throttle valves, each of the exhaust throttle valves is connected to a corresponding proportional valve; A recovery gas tank connected to the gas outlet end of each exhaust throttle valve and connected to the multi-way valve; A control module, electrically connected to the air pump, the air inlet valve, the multi-way valve and each proportional valve, for controlling the operation of the entire pneumatic system; A plurality of pressure sensors are arranged at the fingertips and the pulps of each finger, and are used to detect the pressure of the fingertips and the pulps and transmit the detection signals to the control module. The control module controls the inflation and exhaust of the corresponding actuators according to the pressure signals to adjust the gripping force of the prosthetic hand.

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