CN112641543B

CN112641543B - Self-adaptive gripping flexible artificial hand

Info

Publication number: CN112641543B
Application number: CN202011506009.1A
Authority: CN
Inventors: 孟巧玲; 布勒凯帝·弗兰切斯科; 姜明鹏; 沈志家; 陈立宇; 费翠芝; 喻洪流; 石萍; 李素姣
Original assignee: University of Shanghai for Science and Technology
Current assignee: University of Shanghai for Science and Technology
Priority date: 2020-10-21
Filing date: 2020-12-18
Publication date: 2023-07-21
Anticipated expiration: 2040-12-18
Also published as: CN112120837A; CN112641543A

Abstract

The invention discloses a self-adaptive flexible artificial hand, which relates to the technical field of medical rehabilitation equipment and comprises the following components: the device comprises four finger modules, a thumb module, a palm module connected with each finger module, a driving module fixed in the palm module and a rope transmission module. The finger module consists of a flexible bionic joint and a phalanx, and the flexible bionic joint connected with the phalanx has different rigidity characteristics. The artificial hand can move through the driving module in the palm to be matched with the reaction force of the object to be grasped, so that different gesture postures of the finger module according to the shape of the object to be grasped are realized. The self-adaptive flexible artificial hand can be better adapted to grasp objects with different shapes, realize self-adaptive grasping and pinching actions, and meet the daily life requirements of patients. The 3D printing manufacturing is adopted, so that the design modification and the manufacturing are convenient, the cost is low, and the popularization is easy.

Description

Self-adaptive gripping flexible artificial hand

Technical Field

The invention relates to the technical field of medical rehabilitation equipment, in particular to a self-adaptive flexible prosthetic hand.

Background

The prosthetic hand and the prosthetic limb which are suitable for amputees in the market can complete some simple actions, but the prosthetic hand and the prosthetic limb are generally too large in volume, are usually quite expensive, are not suitable for the daily life of the patients, and have not been popularized on a large scale until now.

Furthermore, most of the prosthetic hand prostheses on the market are composed of rigid members and are very heavy to move. Considering the safety of sports and the portability of equipment, designing a flexible artificial hand suitable for the daily life of amputees and assisting the patients to complete basic gesture actions has wide prospect.

Accordingly, those skilled in the art have focused their effort on designing an adaptive gripping flexible prosthetic hand to achieve multiple gripping configurations while having better compliance and lighter weight, suitable for amputee's daily life.

Disclosure of Invention

In view of the above-mentioned drawbacks of the prior art, the present invention aims to solve the technical problems of how to realize multiple gripping gestures of a prosthetic hand by controlling the mutual movements of the thumb and other fingers, how to improve the safety of the prosthetic hand, how to reduce the weight of the prosthetic hand, and make the prosthetic hand easy to wear, and is more suitable for the daily life scene of amputees.

In order to achieve the above purpose, the invention provides an adaptive gripping flexible artificial hand, which comprises a finger module, a thumb module, a palm module, a driving module and a rope transmission module;

the number of the finger modules is four, the finger modules are respectively corresponding to the index finger, the middle finger, the ring finger and the little finger, and each finger module has similar structure and different size;

the thumb module is arranged to correspond to a thumb;

the finger module is positioned at the top of the palm module and hinged with the finger base at the top of the palm module; the thumb module is positioned at the side part of the palm module and hinged with a thumb base at the lower corner of the side of the palm module;

the driving module is positioned in the palm module and comprises a left sub-driving module and a right sub-driving module; the sub-driving module comprises a motor and a spool; the spool comprises an upper spool and a lower spool; the spool is fixed at the top of the motor; the motor is fixed in a motor seat in the palm module; the left sub-driving module and the right sub-driving module are arranged in a motor base inside the palm module upside down;

the cord drive mechanism module includes a cord for a finger drive mechanism and a cord for a thumb drive mechanism.

Further, the finger module comprises a fingertip block, a distal phalange block, a deformation compensation module, a middle phalange block, a proximal phalange block, a flexible hinge and a spring;

a first chute is arranged in the fingertip block, the fingertip block is connected with the distal phalanx block through a screw and a nut, and the screw and the nut are fixed in the first chute;

the lower end of the fingertip block is provided with a first thread boss, and the spring is embedded on the first thread boss and is contacted with the distal phalangeal block;

the deformation compensation module is internally provided with a second chute, the distal phalange block is hinged with the deformation compensation module through the flexible hinge and is fixed through a screw and a nut, and the screw and the nut are fixed in the second chute;

the lower end of the deformation compensation module is provided with a second threaded boss, and the spring is embedded on the second threaded boss and is contacted with the middle phalangeal block;

a third chute is also arranged in the deformation compensation module, the deformation compensation module and the middle phalangeal block are fixed by a screw and a nut, and the screw and the nut are fixed in the third chute;

the proximal phalanx block is internally provided with a fourth chute, the middle phalanx block is hinged with the proximal phalanx block through the flexible hinge, and is fixed through a screw and a nut, and the screw and the nut are fixed in the fourth chute.

A fifth sliding groove is further formed in the proximal phalanx block, the proximal phalanx block is hinged to the finger base at the top of the palm module through the flexible hinge, and meanwhile the proximal phalanx block is fixed through a screw and a nut, and the screw and the nut are fixed in the fifth sliding groove.

Further, first guide holes are formed in two sides of the lower portion of the fingertip block, second guide holes are formed in two sides of the lower portion of the distal phalange block, third guide holes are formed in two sides of the lower portion of the deformation compensation module, fourth guide holes are formed in two sides of the lower portion of the middle phalange block, and fifth guide holes are formed in two sides of the lower portion of the proximal phalange block; the two ends of the rope for the finger driving mechanism respectively pass through the first guide hole, the second guide hole, the third guide hole, the fourth guide hole and the fifth guide hole on the two sides of the corresponding finger module in sequence and then are fixed on the driving module.

Further, the finger module comprises a distal interphalangeal joint, a proximal interphalangeal joint, a metacarpophalangeal joint, a middle interphalangeal joint and a distal interphalangeal joint;

the distal interphalangeal joint is composed of the flexible hinge, the deformation compensation module and the spring, the proximal interphalangeal joint is composed of the flexible hinge, the metacarpophalangeal joint is composed of the flexible hinge, the middle phalangeal interphalangeal joint is composed of the flexible hinge, and the distal phalangeal interphalangeal joint is composed of the flexible hinge, the deformation compensation module and the spring;

stiffness of the middle phalangeal interphalangeal joint = stiffness of the distal phalangeal interphalangeal joint < stiffness of the metacarpophalangeal joint < stiffness of the proximal interphalangeal joint < stiffness of the distal interphalangeal joint.

Further, the thumb module comprises a thumb tip block, a thumb base block and a flexible hinge, wherein the thumb tip block is hinged with the thumb base block through the flexible hinge; the thumb base block is connected with a thumb base at the lower corner of the palm module side through a screw and a nut, and the screw and the nut are fixed in a sliding groove structure on the thumb base; the right side of the thumb base block is provided with a thumb base block groove; the thumb base block and the palm module are fixed in the palm upper chute and the palm lower chute, and the positions of the palm upper chute and the palm lower chute are parallel to the horizontal plane.

Further, the lower part of the thumb fingertip block is provided with a thumb first guide hole and a thumb second guide hole which are perpendicular to each other; the inside of the thumb base block is provided with a bent thumb third guide hole, and the outside of the thumb base is provided with a thumb fourth guide hole; the rope for the thumb transmission mechanism sequentially passes through the thumb fourth guide hole, the thumb third guide hole, the thumb second guide hole, the thumb first guide hole, the thumb third guide hole and the thumb fourth guide hole and then is fixed on the driving module.

Further, the palm module includes a palm top member, a palm bottom member, a palm frame, a back upper cover, a back lower cover, and a motor mount.

Further, four first palm guide holes are formed in front of the finger base at the top of the palm module; three second palm guide holes are formed in the upper end of the inner wall of the palm module; seven third guide holes are formed in the lower end of the inner wall of the palm module; twenty driving first guide holes are formed in the top of the upper spool in the driving module; the rope for the finger driving mechanism is fixed at the driving first guide hole after passing through the first guide hole, the second guide hole, the third guide hole, the fourth guide hole and the fifth guide hole on the finger module; the thumb drive mechanism is fixed to the drive first guide hole by the palm third guide hole after passing through the thumb fourth guide hole, the thumb third guide hole, the thumb second guide hole and the thumb first guide hole on the thumb module.

Further, a palm-wrist interface is arranged at the bottom of the palm module so as to be connected with wrist equipment; the thumb drive mechanism rope is fixed to the left side of the driving unit, the finger drive mechanism rope on the finger module corresponding to the index finger is fixed to the left side of the driving unit, and the finger drive mechanism rope on the finger module corresponding to the middle finger, the ring finger and the little finger is fixed to the right side of the driving unit.

Further, the adaptive gripping flexible prosthetic hand is manufactured using 3D printing techniques.

Compared with the prior art, the technical scheme provided by the invention has the following beneficial technical effects:

1. the finger module adopts a 5-rotation pair model design and consists of five sections of knuckles; wherein the fingertip mass and the distal phalange mass simulate the distal phalange of a finger, the deformation compensation module and the middle phalange mass simulate the middle phalange of a finger, and the proximal phalange mass simulate the proximal phalange of a finger.

2. The finger module adopts flexible hinge connection, spring connection and screw-nut connection, wherein the screw nut can slide in the chute at the connecting structure. The flexible connection and the rigid connection are combined, so that the finger has flexibility, the flexibility of the finger of the artificial hand is improved, the motion trail of the artificial hand is more in line with the motion trail of a healthy hand, and objects with different surface conditions can be better attached. The rigidity of the flexible hinge is different from that of the spring, under the action of the rope tension force, the joint bends according to the design sequence, the action of a human hand when grasping an object is simulated, and for objects with different sizes, the artificial hand carries out different bending strategies to complete the self-adaptive grasping action.

3. The thumb module is connected by a flexible hinge, and is connected by a screw and a nut. The screw nuts can slide in the sliding grooves at the connecting structure, so that the thumb can realize buckling, stretching and abduction and adduction coupling motions, the palm-facing motion can be completed, the number of the grasping gestures which can be realized by the artificial hand is increased, and the applicable scene of the artificial hand is enriched. Simultaneously, the finger module is matched with the finger module, so that the pinching action can be realized.

4. And a plurality of guide holes are formed in the finger module, the thumb module, the palm module and the driving module, so that wiring is facilitated. Simultaneously, two motors are adopted for driving, one motor drives three finger modules of a middle finger, a ring finger and a little finger, and the other motor drives two modules of a thumb and an index finger; the two motors are independently driven and matched with each other, so that the artificial hand can be in more gripping postures.

5. The driving module is integrated with the inside of the palm module, so that the structure is compact and small; the whole is processed by a 3D printing technology, so that the cost is low, and personalized customization is convenient.

6. The bottom of the palm module is provided with a wrist-palm interface, so that the wrist-palm module is convenient to be matched with a subsequent wrist mechanism.

The conception, specific structure, and technical effects of the present invention will be further described with reference to the accompanying drawings to fully understand the objects, features, and effects of the present invention.

Drawings

FIG. 1 is a partial schematic view of a preferred embodiment of the present invention;

FIG. 2 is a schematic diagram of a finger module according to a preferred embodiment of the present invention;

FIG. 3 is a diagram of a fingertip block structure in accordance with a preferred embodiment of the present invention;

FIG. 4 is a schematic view of a distal phalangeal module and distal fingertip joint module in accordance with a preferred embodiment of the present invention;

FIG. 5 is a schematic view of a middle phalangeal module and a proximal fingertip joint module in accordance with a preferred embodiment of the present invention;

FIG. 6 is a schematic view of a proximal phalangeal module and metacarpophalangeal joint module in accordance with a preferred embodiment of the present invention;

FIG. 7 is a schematic view of a thumb module according to a preferred embodiment of the invention;

FIG. 8 is a schematic diagram of a driving module according to a preferred embodiment of the present invention;

FIG. 9 is a schematic diagram of a palm module according to a preferred embodiment of the invention;

wherein, 1-finger module; a 2-thumb module; 3-palm module; 4-a driving module; 5-rope; 6-fingertip mass; 7-distal phalangeal pieces; 8-a deformation compensation module; 9-middle phalangeal mass; 10-proximal phalangeal mass; 11-a flexible hinge; 12-screws; 13-a nut; 14-a spring; 15-a first threaded boss; 16-a first guide hole; 17-a first chute; 18-a second guide hole; 19-a third guide hole; 20-fourth guide holes; 21-a fifth guide hole; 22-a fifth chute; 23-fourth slide groove; 24-a second threaded boss; 25-a third chute; 26-thumb fingertip pieces; 27-a thumb first guide hole; 28-a thumb third guide hole; 29-thumb base block groove; 30-a thumb fourth guide hole; 31-thumb base block; 32-winding up the spool; 33-driving the first guide hole; 34-lower spool; 35-an electric motor; 36-finger base; 37-palm first guide hole; 38-a palm second guide hole; 39-palmar top component; 40-a right groove of the motor base; 41-palm frame; 42-palm frame side aperture; 43-palmar base member; 44-upper palm chute; 45-palm lower chute; 46-a palm third guide hole; 47-carpal-palm interface; 48-lower dorsum manus cover plate; 49-upper back cover plate; 50-a left groove of the motor base; 51-motor cabinet.

Detailed Description

The following description of the preferred embodiments of the present invention refers to the accompanying drawings, which make the technical contents thereof more clear and easier to understand. The present invention may be embodied in many different forms of embodiments and the scope of the present invention is not limited to only the embodiments described herein.

In the drawings, like structural elements are referred to by like reference numerals and components having similar structure or function are referred to by like reference numerals. The dimensions and thickness of each component shown in the drawings are arbitrarily shown, and the present invention is not limited to the dimensions and thickness of each component. The thickness of the components is exaggerated in some places in the drawings for clarity of illustration.

As shown in fig. 1, is a schematic view of a part of the structure in an embodiment of the present invention. In this embodiment, the adaptive gripping flexible artificial hand includes a finger module 1, a thumb module 2, a palm module 3, a driving module 4, and a rope 5.

Fig. 2-6 are schematic views of a finger module structure in an embodiment of the invention. Wherein the four finger modules 1 correspond to the index finger, the middle finger, the ring finger and the little finger respectively. Because the components and connections of the finger structures are identical, they differ only in size. It should be noted that the arrangement of the finger module is not limited to the configuration shown in fig. 1, and may be selected according to the specific situation of the patient.

As shown in fig. 2-6, the finger module includes a fingertip mass 6, a distal phalange mass 7, a deformation compensation module 8, a middle phalange mass 9, a proximal phalange mass 10, a flexible hinge 11, a screw 12, a nut 13, a spring 14. The fingertip pieces 6 are connected with the distal phalangeal pieces 7 by screws 12 and nuts 13; the screw 12 and the nut 13 are fixed in the first runner 17. The lower end of the finger tip block 6 is provided with a first thread boss 15, and a spring 14 is embedded on the first thread boss 15 and is contacted with the distal phalangeal block 7. The distal phalange block 7 is hinged with the deformation compensation module 8 by a flexible hinge 11 and is fixed by a screw 12 and a nut 13, the screw 12 and the nut 13 being fixed in a second runner (not shown). The lower end of the deformation compensation module 8 is provided with a second threaded boss 24 structure, and the spring 14 is embedded on the second threaded boss 24 and is contacted with the middle phalangeal block 9. The deformation compensation module 8 and the middle phalanx block 9 are fixed by a screw 12 and a nut 13; the screw 12 and the nut 13 are fixed in the third slide groove 25. The middle phalanx block 9 and the proximal phalanx block 10 are hinged by a flexible hinge 11, and are fixed by a screw 12 and a nut 13, and the screw 12 and the nut 13 are fixed in a fourth chute 23. The proximal phalanx block 10 is hinged with the palm module top finger base 36 by a flexible hinge 11, and is fixed by a screw 12 and a nut 13, the screw 12 and the nut 13 being fixed in the fifth runner 22. The finger module 1 can complete the joint bending action under the action of the flexible hinge 11, the spring 14 and the screw 12 and the nut 13 which are positioned in the chute. The three phalangeal modules and the three flexible bionic joint modules form the flexible finger module 1, so that the artificial hand has better flexibility and motion compliance and can be better attached to the surface of a gripped object.

Fig. 7 is a schematic view of a thumb module structure in an embodiment of the invention.

As shown in fig. 7, the thumb module is made up of a thumb tip block 26, a thumb base block 31, and a flexible hinge 11. Thumb tip piece 26 and thumb base piece 31 are hinged by flexible hinge 11 and fixed by screw 12 and nut 13. The thumb block 31 is provided on the right side with a thumb block recess 29. The thumb base block 31 is hinged with the palm module 3 through a flexible hinge 11 and is fixed through a screw 12 and a nut 13; the screw 12 and the nut 13 are fixed in the palm upper runner 44 and the palm lower runner 45.

Fig. 8 is a schematic diagram of a driving module structure in an embodiment of the present invention.

As shown in fig. 8, the drive module is composed of an upper bobbin 32, a lower bobbin 34, and a motor 35; the upper and lower bobbins 32 and 34 are combined up and down and fixed to a motor shaft (not shown). The motor 35 rotates the upper spool 32 and the lower spool 34.

Fig. 9 is a schematic diagram of a palm module structure in an embodiment of the invention.

As shown in fig. 9, palm module 3 is composed of palm top member 39, palm bottom member 43, palm frame 41, back upper cover 49, back lower cover 48, and motor mount 51. The upper end of palm top member 39 is provided with a structural finger base 36 for attachment to a finger module. The right side of palmar base member 43 is provided with structural palmar upper runner 44 and palmar lower runner 45 for connection with the thumb module. The lower end of the lower dorsum manus cover plate 48 is provided with a structural carpal-palm interface 47 for connecting with a subsequent wrist mechanism. Palm frame 41 and motor base 51 are fixed by screw 12 and nut 13; the screw 12 and the nut 13 are positioned in the side holes of the palm frame.

As shown in fig. 1, the motor base 51 has the following structure: a motor base left groove 50 and a motor base right groove 40; the driving module 4 and the motor base are fixed in the left groove 50 and the right groove 40 of the motor base. The left driving module and the right driving module are upside down, wherein in the driving module 4 on the left side, the upper spool 32 and the lower spool 34 are positioned below the motor 35; in the right drive module 4, the upper spool 32 and the lower spool 34 are located above the motor 35.

As shown in fig. 2-9, the technical scheme of the invention is that the finger module 1; a thumb module 2; a palm module 3; the driving modules 4 are provided with guide holes, wherein the lower ends of the fingertip blocks 6 are provided with first guide holes 16, the lower ends of the distal phalangeal blocks 7 are provided with second guide holes 18, the lower ends of the deformation compensation modules 8 are provided with third guide holes 19, the lower ends of the middle phalangeal blocks 9 are provided with fourth guide holes 20, and the lower ends of the proximal phalangeal blocks 10 are provided with fifth guide holes 21. A palm first guide hole 37 is provided in the inner wall of the palm top member 39, a palm second guide hole 38 is provided in front of the finger base 36 at the tip of the palm top member 39, and a palm third guide hole 46 is provided in the inner wall of the palm bottom member 43. A driving first guide hole 33 is opened at the top of the upper bobbin 32. Two vertical guide holes, namely a thumb first guide hole 27 and a thumb second guide hole (not shown), are formed in the lower part of the thumb tip block 26, a bent thumb third guide hole 28 is formed in the thumb base block 31, and a thumb fourth guide hole 30 is formed in the outer side of the thumb base block. The number of the guide holes is more than or equal to two except the guide holes in the thumb module, so that various choices are provided for the routing of the ropes.

As shown in fig. 1-7, the rope 5 connects the drive module 4, the palm module 3, and the finger module 1. A specific finger cord routing path is described below, as follows: one end of the rope 5 is fixed on the driving first guide hole 33 and then connected with the palm module through the palm first guide hole 37 and the palm second guide hole 38; then sequentially passing through the fifth guide hole 21, the fourth guide hole 20, the third guide hole 19, the second guide hole 18 and the first guide hole 16 on one side of the finger module, and then penetrating out from the first guide hole 16, the second guide hole 18, the third guide hole 19, the fourth guide hole 20 and the fifth guide hole 21 on the other side; then passes through the palm second guide hole 38, the palm first guide hole 37; finally, the driving module 4 is returned to be fixed on the driving first guide hole 33 again. The rope 5 is driven by a right-hand drive module 4 fixed to a right recess 40 of the motor mount. The rope arrangement mode is not unique, and other suitable paths can be selected according to the requirements.

As shown in fig. 1, 7, 8 and 9, a specific thumb cord routing path is described below, as follows: one end of the rope 5 is fixed on the driving first guide hole 33, then passes through the palm third guide hole 46, and then sequentially passes through the thumb fourth guide hole 30, the thumb third guide hole 28, the thumb second guide hole (not shown), the thumb first guide hole 27, the thumb third guide hole 28 and the thumb fourth guide hole 30, so that the connection of the thumb module is completed; then passes through the palm third guide hole 46 again and finally returns to the driving module 4 to be fixed again on the driving first guide hole 33. The rope 5 is driven by a left-hand drive module 4 fixed to a left recess 50 of the motor mount. The rope arrangement mode is not unique, and other suitable paths can be selected according to the requirements.

As shown in fig. 1, the driving module is integrated in the palm module, so that the whole volume of the artificial hand is reduced, and the artificial hand is lighter. Meanwhile, the artificial hand body is processed by a 3D printing technology, so that the cost is low, and personalized customization is facilitated.

The working flow of the pinching action of the self-adaptive flexible artificial hand under the no-load condition is as follows: first, only the right motor 35 of the two motors is operated when the pinching operation is performed. The motor 35 is operated and the thumb rope 5 fixedly connected to the right driving module 4 is contracted. The thumb base block 31 slides along the palm upper sliding groove 44 and the palm lower sliding groove 45 under the contraction of the rope 5, so that the adduction rotation movement of the metacarpophalangeal joints of the thumb module 2 is realized; as the cord 5 continues to contract, bending movement of the proximal interphalangeal joint between the thumb pad 26 and thumb pad 31 occurs. Simultaneously, the finger rope 5 fixedly connected to the right driving module 4 is contracted, and the finger rope is an index finger thumb rope. The index finger thumb rope 5 contracts to drive each joint of the index finger to bend, and the bending sequence is as follows: first the interphalangeal joint between the strain compensating module 8 and the interphalangeal phalange block 9 is bent first, then the interphalangeal joint between the fingertip block 6 and the distal phalange block 7 is bent, then the metacarpophalangeal joint between the proximal phalange block 10 and the finger base 36 is bent, then the interphalangeal joint between the first closing block 9 and the proximal phalange block 10 is bent, and finally the interphalangeal joint between the distal phalange block 7 and the strain compensating module 8 is bent. The bending and rotating movements of the thumb and the bending movements of the index finger are coupled, so that the pinching gesture is realized. At this time, the middle finger, ring finger and little finger remain in the extended state.

The working flow of the self-adaptive gripping action of the self-adaptive gripping flexible artificial hand under the no-load condition is as follows: firstly, the motor 35 on the left side of the finger module 1 which performs bending motion is driven to rotate, and the rope 5 is contracted; the interphalangeal joint between the strain compensating module 8 and the interphalangeal phalange block 9 is first flexed, then the interphalangeal joint between the fingertip block 6 and the distal phalange block 7 is flexed, then the metacarpophalangeal joint between the proximal phalange block 10 and the finger base 36 is flexed, then the proximal interphalangeal joint between the first articular block 9 and the proximal phalange block 10 is flexed, and finally the interphalangeal joint between the distal phalange block 7 and the strain compensating module 8 is flexed. The motor 35 on the left side simultaneously drives the bending of the middle finger, ring finger and thumb. While the motor 35 on the right side driving the thumb module 1 to perform bending motion rotates and the cord 5 is contracted. The movement process of the index finger module 1 connected to the right motor 35 is similar to that of the middle finger module 1 driven by the left motor 35 to perform bending movement. For the thumb rope 5 connected to the motor 35 on the right side, the thumb base block 31 slides along the palm upper chute 44 and the palm lower chute 45 under the contraction of the rope 5, so that the adduction movement of the metacarpophalangeal joints of the thumb module 2 is realized; as the cord 5 continues to contract, bending movement of the proximal interphalangeal joint between the thumb pad 26 and thumb pad 31 occurs. The motor 35 on the right side simultaneously drives the bending of the index finger and the bending and rotation of the thumb.

The following explains why the invention can adapt to grasp objects of different shapes, and realize the actions of self-adapting grasping and pinching.

Firstly, compared with the traditional artificial hand, the artificial hand finger module adopts a 5R (R-revolute pair) model design on a finger structure to form three flexible bionic joints, namely flexible bionic metacarpophalangeal joints, flexible bionic proximal interphalangeal joints and flexible bionic distal interphalangeal joints, wherein the distal interphalangeal joints are formed by flexible hinges, deformation compensation modules and spring energy storage elements, the artificial hand finger module is a composite bionic joint, the proximal interphalangeal joints are formed by flexible hinges, the metacarpophalangeal joints are common bionic joints, and the metacarpophalangeal joints are formed by flexible hinges, so that the artificial hand finger module is a common bionic joint. The design optimizes the position of the holding point, so that the artificial hand can be more fit with the actual situation when the pinching action is realized, and the grasping effect is improved. Each finger module can realize buckling extension of the finger joints under the action of the flexible hinges, the sliding grooves, the springs and the ropes. The flexible hinge and the spring serve as bending units, and are bent and deformed under the action of the tension force of the rope, so that the finger buckling function is realized, and when the rope is released, the elastic force is provided by utilizing the energy storage of the flexible hinge and the spring in the bending process, so that the stretching function of the finger is realized. The spring and the flexible hinge have bionic effect. The rigidity of the spring is smaller than that of the flexible hinge, and the spring is bent at first under the action of the tension of the rope; upon release of the cord, the flexible hinge is first stretched. The springs and the flexible hinges are alternately arranged among the distal phalanx block, the middle phalanx block and the proximal phalanx block, and complete the flexion and extension actions of the fingers together with the ropes.

Secondly, the prosthetic hand has an adaptive gripping function: when the artificial hand is in contact with the object to be grasped, under the action of the tensile force provided by the rope, the middle phalangeal joint and the far phalangeal joint are connected by the springs with smaller rigidity, so that the artificial hand is bent firstly until the springs between the middle phalangeal joint and the far phalangeal joint contact the threaded boss, and the bending is stopped; the metacarpophalangeal joint becomes the joint with the least rigidity at this point, and if the article to be grasped is small, the article can be grasped with the thumb at this position. If the object is bigger, the rope continues to stretch, at the moment, the proximal phalanges contact the object, the flexible hinges between the metacarpophalangeal joints reach the bending limit, the metacarpophalangeal joints stop bending, the proximal interphalangeal joints become joints with the minimum rigidity, and the proximal interphalangeal joints bend along with the stretching of the rope. However, if the size of the object to be grasped is too large, all the fingers are required to grasp, at which time the middle phalanges contact the object, the flexible hinges between the proximal interphalangeal joints reach the bending limit, the proximal interphalangeal joints stop bending, the distal interphalangeal joints become the joints with the least rigidity, and bend with the stretching of the rope until the distal phalanges contact the object. The bending action of the joints of the prosthetic hand is completely dependent on the size of the article to be grasped, and springs and flexible hinges of different stiffness can provide an adaptive gripping action during bending.

And thirdly, the thumb module realizes buckling extension and abduction adduction of the finger joints under the action of the flexible hinge, the sliding groove and the rope. The thumb base block and the palm module are fixed in the palm upper chute and the palm lower chute, the positions of the palm upper chute and the palm lower chute are parallel to the horizontal plane, and when the rope pulls the thumb to bend, the flexible hinge connecting the thumb base block and the palm module bends and deforms under the action of the rope tension force, so that the buckling action of the thumb is realized; meanwhile, as the upper palm chute and the lower palm chute are horizontally arranged, the thumb moves horizontally along the chute under the action of the tension force of the rope, so as to realize the adduction action and complete the motion coupling of the bending action and the adduction action; when the rope is released, the elastic force is provided by the energy storage of the flexible hinge in the bending process, and meanwhile, the movement coupling of the expansion and the abduction of the thumb is realized by the movement track of the thumb retreating in the chute.

The foregoing describes in detail preferred embodiments of the present invention. It should be understood that numerous modifications and variations can be made in accordance with the concepts of the invention by one of ordinary skill in the art without undue burden. Therefore, all technical solutions which can be obtained by logic analysis, reasoning or limited experiments based on the prior art by the person skilled in the art according to the inventive concept shall be within the scope of protection defined by the claims.

Claims

1. The self-adaptive gripping flexible artificial hand is characterized by comprising a finger module, a thumb module, a palm module, a driving module and a rope transmission module;

the thumb module is arranged to correspond to a thumb;

the driving module is positioned in the palm module and comprises a left sub-driving module and a right sub-driving module; the sub-driving module comprises a motor and a spool; the spool comprises an upper spool and a lower spool; the upper spool and the lower spool are fixed at the top of the motor; the motor is fixed in a motor seat in the palm module; the left sub-driving module and the right sub-driving module are arranged in a motor base inside the palm module upside down;

the rope transmission module comprises a rope for a finger driving mechanism and a rope for a thumb transmission mechanism;

the finger module comprises a fingertip block, a distal phalanx block, a deformation compensation module, a middle phalanx block, a proximal phalanx block, a flexible hinge and a spring;

the lower end of the fingertip block is provided with a first thread boss, and one end of the spring is embedded on the first thread boss and is contacted with the distal phalangeal block;

a second chute is arranged in the deformation compensation module, the distal phalange block is hinged with the deformation compensation module through a first flexible hinge, and the distal phalange block is fixed through a screw and a nut, and the screw and the nut are fixed in the second chute;

the lower end of the deformation compensation module is provided with a second threaded boss, and the other end of the spring is embedded on the second threaded boss and is in contact with the middle phalangeal block;

a third chute is further arranged in the deformation compensation module, the deformation compensation module and the middle phalangeal block are fixed by a screw and a nut, and the screw and the nut are fixed in the third chute;

a fourth sliding groove is formed in the proximal phalanx block, the middle phalanx block is hinged with the proximal phalanx block through a second flexible hinge, and the middle phalanx block is fixed through a screw and a nut, and the screw and the nut are fixed in the fourth sliding groove;

a fifth sliding groove is further formed in the proximal phalanx block, the proximal phalanx block is hinged with a finger base at the top of the palm module through a third flexible hinge, and meanwhile, the proximal phalanx block is fixed through a screw and a nut, and the screw and the nut are fixed in the fifth sliding groove.

2. The adaptive gripping flexible artificial hand according to claim 1, wherein the two sides of the lower part of the fingertip block are provided with first guide holes, the two sides of the lower part of the distal phalange block are provided with second guide holes, the two sides of the lower part of the deformation compensation module are provided with third guide holes, the two sides of the lower part of the middle phalange block are provided with fourth guide holes, and the two sides of the lower part of the proximal phalange block are provided with fifth guide holes; the two ends of the rope for the finger driving mechanism respectively pass through the corresponding first guide hole, second guide hole, third guide hole, fourth guide hole and fifth guide hole on two sides of the finger module in sequence and then are fixed on the driving module.

3. The adaptive gripping flexible artificial hand of claim 2, wherein the thumb module comprises a thumb tip block, a thumb base block, and a fourth flexible hinge, the thumb tip block and the thumb base block being hinged by the fourth flexible hinge; the thumb base block is connected with a thumb base at the lower corner of the palm module side through bolts and nuts in a chute structure on the thumb base; the right side of the thumb base block is provided with a thumb base block groove; the thumb base block and the palm module are fixed in the palm upper chute and the palm lower chute, and the positions of the palm upper chute and the palm lower chute are parallel to the horizontal plane.

4. The adaptive gripping flexible artificial hand according to claim 3, wherein the thumb tip block is provided at a lower portion thereof with a thumb first guide hole and a thumb second guide hole perpendicular to each other; the inside of the thumb base block is provided with a bent thumb third guide hole, and the outside of the thumb base is provided with a thumb fourth guide hole; the rope for the thumb transmission mechanism sequentially passes through the thumb fourth guide hole, the thumb third guide hole, the thumb second guide hole, the thumb first guide hole, the thumb third guide hole and the thumb fourth guide hole and is then fixed on the driving module.

5. The adaptive gripping flexible artificial hand according to claim 1, wherein the palm module comprises a palm top member, a palm bottom member, a palm frame, a back upper cover, a back lower cover, and a motor mount.

6. The adaptive gripping flexible artificial hand according to claim 4, wherein four palm first guide holes are provided in front of the finger base at the top of the palm module; three second palm guide holes are formed in the upper end of the inner wall of the palm module; seven third guide holes are formed in the lower end of the inner wall of the palm module; twenty driving first guide holes are formed in the top of the upper spool in the left sub-driving module and the right sub-driving module; the rope for the finger driving mechanism is fixed at the driving first guide hole after passing through the first guide hole, the second guide hole, the third guide hole, the fourth guide hole and the fifth guide hole on the finger module; the thumb drive mechanism is fixed to the drive first guide hole by the palm third guide hole after passing through the thumb fourth guide hole, the thumb third guide hole, the thumb second guide hole and the thumb first guide hole on the thumb module.

7. The adaptive gripping flexible artificial hand according to claim 1, wherein the palm module has a palm-wrist interface at the bottom for connection with wrist devices; the thumb drive mechanism rope is fixed on the left side of the sub-driving module, the finger drive mechanism rope on the finger module corresponding to the index finger is fixed on the left side of the sub-driving module, and the finger drive mechanism rope on the finger module corresponding to the middle finger, the ring finger and the little finger is fixed on the right side of the sub-driving module.

8. The adaptive gripping flexible prosthetic hand of claim 1, wherein the adaptive gripping flexible prosthetic hand is fabricated using 3D printing techniques.