Hand rehabilitation exoskeleton based on metamorphic principle series elastic drive and motion control method thereof

Abstract

The invention discloses a series elastic drive hand rehabilitation exoskeleton based on a metamorphic principle and a motion control method thereof. The hand rehabilitation exoskeleton comprises a hand back supporting plate, a thumb coupling module, an index finger coupling module and a three-finger metamorphic mechanism module, wherein the thumb coupling module, the index finger coupling module and the three-finger metamorphic mechanism module are arranged on the hand back supporting plate. The device can assist a patient to perform fine grasping training and strength grasping training, and the fine grasping training mainly comprises a thumb coupling mechanism and an index finger coupling mechanism of an exoskeleton to assist an index finger and a thumb of a human body to bend and stretch in a certain angle relation so as to accord with a hand biological grasping angle relation. The other three fingers are three-finger metamorphic mechanisms based on the metamorphic principle and are matched with the thumb coupling mechanism and the index finger coupling mechanism to perform power grasping, and the three-finger metamorphic mechanisms meet the finger movement sequence of power grasping training; the problems that an existing exoskeleton is single in motion mode, poor in man-machine coupling, unreasonable in structural design, incapable of achieving accurate grabbing and the like are solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of hand rehabilitation exoskeleton robots, and specifically relates to a hand rehabilitation exoskeleton driven by series elasticity based on the metamorphosis principle and a motion control method thereof. Background Art

[0002] As the aging population intensifies year by year, the number of patients who lose their hand motor ability increases, which brings great difficulties to society, family and personal life. Solving the hand motor problem of patients has become a major problem that society needs to solve. In order to restore the lost function, hand rehabilitation training is required. From the patient's point of view, rehabilitation training of hand grasping movement is very important, which directly affects whether the patient can complete daily life activities. Traditional rehabilitation therapy has problems such as small number of trainers, low efficiency and high cost. New engineering technologies are needed to overcome them. First, patients need long-term rehabilitation exercises, which may last for months or even years. Second, rehabilitation training is monotonous and cannot inspire patients' desire and motivation to participate in rehabilitation training independently. These two factors make it difficult for patients to persist in rehabilitation training. Third, the rehabilitation process requires therapists to directly guide or even help patients in training, so a large number of therapists are needed. However, the current number of therapists does not meet the demand, and the lack of therapists makes rehabilitation treatment very expensive. In addition, treatment and evaluation depend on the experience of therapists, resulting in poor objectivity of rehabilitation evaluation. The rehabilitation exoskeleton hand can accurately train patients for a long time and repeatedly, achieving the training purpose while solving the shortcomings of traditional rehabilitation treatment.

[0003] The current wearable hand exoskeleton can be divided into two types, namely soft hand exoskeleton robots and rigid hand exoskeleton robots. Soft hand exoskeleton robots are light and flexible, fit the physiological structure of the human hand, and are easy to put on and take off. Although these exoskeletons have the advantages of light weight and softness, their disadvantages are also obvious. The torque transmitted to the joints may be insufficient due to insufficient rigidity of the transmission part and inaccurate positioning. Soft exoskeletons have challenges in force generation and control accuracy. The other is a rigid hand exoskeleton robot. Although these exoskeletons can provide controllable auxiliary force / torque, they usually require multiple motors to work, which will increase the size and weight of the exoskeleton, and the motion compatibility of the exoskeleton joints and the human finger joints needs to be considered. The misalignment of the joint axis will produce parasitic torque, affecting the rehabilitation effect. In addition, there is a lack of research on grasping training for exoskeletons. Existing wearable hand exoskeleton robots only grasp some common objects, lack research on grasping objects of different sizes, and the grasping action is relatively simple. Summary of the invention

[0004] In order to solve a series of problems such as the single movement mode of the above exoskeleton, poor human-machine coupling, unreasonable structural design, and inability to achieve precise grasping, the present invention designs a hand rehabilitation exoskeleton based on the metamorphosis principle and serial elastic drive, which can assist patients in fine grasping training and power grasping training. The fine grasping training mainly uses the thumb coupling mechanism and the index finger coupling mechanism of the exoskeleton to assist the index finger and thumb of the human body to perform flexion and extension movements at a certain angle relationship to meet the biological grasping angle relationship of the hand. For the remaining three fingers, a three-finger metamorphosis mechanism based on the metamorphosis principle can be used to cooperate with the thumb coupling mechanism and the index finger coupling mechanism for power grasping. The three-finger metamorphosis mechanism based on the metamorphosis principle separates the bending movement and straightening movement of the metacarpophalangeal joints and proximal interphalangeal joints of the middle finger, ring finger and little finger, and realizes the bending of the metacarpophalangeal joints of the three fingers first, followed by the bending of the proximal interphalangeal joints of the three fingers, the straightening of the proximal interphalangeal joints of the three fingers, and finally the straightening of the metacarpophalangeal joints of the three fingers, so as to meet the finger movement sequence of power grasping training. The hand rehabilitation exoskeleton drives the bending and extension of the metacarpophalangeal joints and proximal interphalangeal joints of the middle finger, ring finger and little finger through a series elastic driver, drives the flexion and extension of the metacarpophalangeal joint, proximal interphalangeal joint and distal interphalangeal joint of the index finger through a series elastic driver, and drives the flexion and extension of the metacarpophalangeal joint and interphalangeal joint of the thumb through a series elastic driver, thereby reducing the number of required motors, reducing the weight of the entire exoskeleton, and improving the comfort of the wearer.

[0005] In order to solve the above technical problems, a technical solution adopted by the present invention is:

[0006] A hand rehabilitation exoskeleton based on metamorphosis principle and series elastic drive, comprising a back-of-hand support plate and a thumb coupling module, an index finger coupling module and a three-finger metamorphosis mechanism module respectively arranged on the back-of-hand support plate;

[0007] The thumb coupling module comprises a thumb metacarpal phalangeal finger sleeve and a thumb interphalangeal finger sleeve which are sequentially located at the front side of the back of hand support plate, a first series elastic driver is fixedly arranged on the back of hand support plate, an output shaft end of the first series elastic driver is connected to an input long rod which is rotatably connected to the back of hand support plate, a middle part of the input long rod is rotatably connected to a thumb metacarpal phalangeal bone rod, a bottom end of the thumb metacarpal phalangeal bone rod is rotatably connected to a top end of the thumb metacarpal phalangeal finger sleeve, a tip end of the input long rod is rotatably connected to a thumb interphalangeal bone rod, a bottom end of the thumb interphalangeal bone rod is rotatably connected to a top end of the thumb interphalangeal bone sleeve;

[0008] The index finger coupling module comprises an index finger proximal phalanx finger sleeve, an index finger middle phalanx finger sleeve and an index finger distal phalanx finger sleeve which are sequentially located on the front side of the back of the hand support plate, a second series elastic driver is fixedly arranged on the back of the hand support plate, an output shaft end of the second series elastic driver is connected with an index finger metacarpal phalanx rod rotatably connected to the back of the hand support plate, the top end of the index finger metacarpal phalanx rod is rotatably connected with the index finger proximal phalanx rod, the top end of the index finger proximal phalanx finger sleeve is rotatably connected with an incomplete gear pair, the bottom end of the index finger proximal phalanx rod is fixedly connected with the input end of the incomplete gear pair, the output end of the incomplete gear pair is fixedly connected with an index finger long rod, the middle part of the index finger long rod is rotatably connected with the index finger middle phalanx rod, the bottom end of the index finger middle phalanx rod is rotatably connected with the top end of the index finger middle phalanx finger sleeve, the end of the index finger long rod is rotatably connected with the index finger distal phalanx rod, and the bottom end of the index finger distal phalanx rod is rotatably connected with the bottom end of the index finger distal phalanx finger sleeve;

[0009] The three-finger metamorphosis mechanism module includes a metacarpophalangeal phalanx finger sleeve and a proximal interphalangeal phalanx finger sleeve which are sequentially located on the front side of a back-of-hand support plate; a third series elastic driver is fixedly arranged on the back-of-hand support plate; an output shaft end of the third series elastic driver is connected to the three-finger metamorphosis mechanism; a primary power output end of the three-finger metamorphosis mechanism is connected to a rotatably arranged gear connecting rod; a top end of the gear connecting rod is rotatably connected to a metacarpophalangeal phalanx rod; a bottom end of the metacarpophalangeal phalanx rod is rotatably connected to a top end of a proximal interphalangeal phalanx finger sleeve; a secondary power output end of the three-finger metamorphosis mechanism is connected to a rod groove rod; a top end of the rod groove rod is rotatably connected to a proximal interphalangeal phalanx rod; a bottom end of the proximal interphalangeal phalanx rod is rotatably connected to a top end of a proximal interphalangeal phalanx finger sleeve.

[0010] Furthermore, the first serial elastic driver, the second serial elastic driver and the third serial elastic driver all include a motor, an active bevel gear fixedly mounted on an output shaft of the motor, a driven bevel gear meshing with the active bevel gear, a fixed shaft coaxially sleeved in the driven bevel gear and a rotating sleeve movably sleeved on the outside of the fixed shaft, a plurality of active push plates are fixedly arranged on the inner wall of the driven bevel gear, a driven push plate paired with the active push plate is fixedly arranged on the outer wall of the rotating sleeve, and a spring is connected between each pair of active push plates and driven push plates.

[0011] Furthermore, the three-finger metamorphosis mechanism includes a metamorphosis mechanism mounting frame fixedly set on the back of the hand support plate, a handle shaft rotatably set on the metamorphosis mechanism mounting frame, a three-finger turning handle rotatably connected to the bottom end of the handle shaft, a push rod rotatably sleeved on the outside of the bottom end rotating shaft of the three-finger turning handle, and a three-finger push rod shaft rotatably connected to the other end of the push rod, a forward rack is fixedly connected to the upper inner end of the three-finger push rod shaft, and a gear rotatably set on the metamorphosis mechanism mounting frame is meshedly connected to the lower inner end of the forward rack, one side shaft end of the gear is the primary power output end of the three-finger turning handle, and the bottom end rotating shaft of the three-finger turning handle is the secondary power output end of the three-finger metamorphosis mechanism.

[0012] Furthermore, a track changing groove is provided at the bottom of the side wall of the cell-changing mechanism mounting frame, and the track changing groove includes a horizontal groove and an arc-shaped groove which is arranged at the top of the horizontal groove and bends toward the front side. The bottom end of the rod groove rod member is provided with a waist-shaped groove located on the inner side of the horizontal groove. An arc-shaped fixed groove located on the front side of the bottom end of the rod groove rod member is fixedly provided on the inner side wall of the cell-changing mechanism mounting frame. The three-finger push rod shaft and the bottom end rotating shaft of the three-finger turning handle are both slidably provided in the horizontal groove. When the three-finger push rod shaft slides horizontally to the front end of the horizontal groove, the front bottom end of the rod groove rod member is abutted against the arc-shaped fixed groove, the bottom end rotating shaft of the three-finger turning handle can slide along the arc-shaped groove, and the rod groove rod member can rotate relative to the arc-shaped fixed groove.

[0013] Furthermore, straps are provided below the thumb metacarpal phalangeal finger sleeve, thumb interphalangeal finger sleeve, index finger proximal phalangeal finger sleeve, index finger middle phalangeal finger sleeve, index finger distal phalangeal finger sleeve, metacarpal phalangeal finger sleeve and proximal interphalangeal finger sleeve.

[0014] Furthermore, the hand rehabilitation exoskeleton also includes a control system, which includes a single-chip microcomputer, an angle sensor, a pressure sensor and a human-computer interaction screen. The single-chip microcomputer is connected to the motor drivers of each series elastic driver through a CAN bus communication, the motor driver is connected to the encoder of each motor, the single-chip microcomputer is connected to the human-computer interaction screen through an I2C bus communication, and the single-chip microcomputer is connected to the angle sensor and the pressure sensor through a serial port.

[0015] Furthermore, at least one pressure sensor is arranged on the inner side surface of each of the straps, and angle sensors are arranged at the transition between the input long rod and the back of the hand support plate, the transition between the index finger metacarpal phalanx rod and the back of the hand support plate, the transition between the index finger long rod and the index finger proximal phalanx finger sleeve, the transition between the index finger long rod and the index finger distal phalanx rod, the transition between the gear connecting rod and the metacarpal phalanx rod, and the transition between the rod slot rod and the proximal interphalanx rod.

[0016] Furthermore, the control system also includes a WIFI module connected to the single-chip microcomputer via serial port communication, and the WIFI module is wirelessly connected to the cloud server.

[0017] A motion control method for a hand rehabilitation exoskeleton driven by series elasticity based on the metamorphosis principle is also provided, comprising the following steps:

[0018] S1. The wearer wears the hand rehabilitation exoskeleton on the healthy hand and the affected hand respectively, so that all joints of the hand are in an initial state of straightening;

[0019] S2, turning on the power of the hand rehabilitation exoskeleton and resetting and initializing the control system;

[0020] S3, starting the hand rehabilitation exoskeleton and initializing the motor of the series elastic actuator;

[0021] S4, the healthy hand bends, and the hand rehabilitation exoskeleton on the corresponding side collects the angle information of the healthy hand, and performs position feedback adjustment on each motor on the affected hand to drive the affected hand to reach the target position with the same angle;

[0022] S5, after the affected hand moves to the target position, the hand rehabilitation exoskeleton on the healthy hand grasps the object, and the pressure sensor on it begins to change and obtains the target pressure value, and the affected hand will perform grasping training;

[0023] S6. The pressure sensor on the hand rehabilitation exoskeleton of the healthy hand collects the contact pressure between the healthy hand and the object, and feeds it back to the control system, and the control system controls the hand rehabilitation exoskeleton of the affected hand to adjust synchronously;

[0024] The three-finger metamorphosis mechanism of the hand rehabilitation exoskeleton of the affected hand will drive the proximal interphalangeal joints and metacarpophalangeal joints of the little finger, ring finger and middle finger to bend in sequence, and the thumb coupling mechanism and the index finger coupling mechanism will drive the index finger and thumb to bend for power grasping, or the thumb coupling mechanism and the index finger coupling mechanism will drive the index finger and thumb to bend for fine grasping, so that the contact pressure between the affected hand side and the object reaches the target pressure value;

[0025] S7, after the contact pressure collected by the pressure sensor on the hand rehabilitation exoskeleton of the healthy hand disappears, it is fed back to the control system, and the control system controls the three-finger metacarpophalangeal mechanism of the hand rehabilitation exoskeleton of the affected hand to drive the proximal interphalangeal joints and metacarpophalangeal joints of the little finger, ring finger and middle finger to extend in sequence, and the thumb coupling mechanism and the index finger coupling mechanism will drive the index finger and thumb to extend;

[0026] S8, repeating the above steps S3 to S7, repeatedly performing strength grasping and fine grasping training on the hands to achieve the effect of rehabilitation training;

[0027] S9. After the wearer completes rehabilitation training, turn off the power supply in time and take off the hand rehabilitation exoskeleton

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] 1. The hand rehabilitation exoskeleton designed by the present invention can achieve good cooperation with the human hand joints, has good alignment ability, can avoid the generation of parasitic torque, ensure the comfort of the exoskeleton during wearing, and meet the requirements of patients' daily rehabilitation training. The hand rehabilitation exoskeleton is driven by a series elastic driver, which can better and accurately apply the driving force of the motor to the exoskeleton, improve the flexibility of the exoskeleton, and help patients recover better.

[0030] 2. The design of the coupling mechanism in the thumb coupling mechanism and the index finger coupling mechanism can realize the bending and extension of the metacarpophalangeal joint, interphalangeal joint of the thumb and the metacarpophalangeal joint, proximal interphalangeal joint and distal interphalangeal joint of the index finger according to a certain angle relationship, so as to realize fine grasping; the use of a series elastic driver to drive the three-finger metamorphosis mechanism can realize the mutual transformation between the moving pair and the rotating pair, separate the flexion and extension movement of the metacarpophalangeal joint and the proximal interphalangeal joint, and realize the flexion and extension movement of the three fingers with six degrees of freedom for power grasping; it can realize different modes of rehabilitation training of fine grasping and power grasping, which can not only achieve better rehabilitation training effects, but also better cooperate with the patient's hand movements;

[0031] 3. The three-finger metamorphosis mechanism module of the hand rehabilitation exoskeleton drives the bending and straightening of three fingers through a series elastic actuator, which reduces the number of motors required, reduces the weight of the entire exoskeleton, and improves the comfort of the wearer. At the same time, it has a compact structure and light weight, and can provide effective rehabilitation training for patients;

[0032] 4. The bilateral control method proposed in the present invention, that is, controlling the affected hand with the healthy hand, performing position control in the grasping preparation stage, and performing pressure control in the grasping process, can achieve stable grasping, coordinate the bilateral synchronous operation of the affected hand and the healthy hand, and achieve bilateral balance training, which helps to improve the effect of rehabilitation training and help patients adapt to daily life faster. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a schematic diagram of the overall structure of the hand rehabilitation exoskeleton of the present invention;

[0034] Figure 2 is a structural schematic diagram of the thumb coupling module;

[0035] Figure 3 is a structural schematic diagram of the index finger coupling module;

[0036] Figure 4 Schematic diagram of the structure of the three-finger metamorphosis mechanism module;

[0037] Figure 5 is a structural schematic diagram of the three-finger metamorphosis mechanism;

[0038] Figure 6 It is a structural block diagram of the control system of the hand rehabilitation exoskeleton of the present invention;

[0039] Figure 7 is a flow chart of the motion control method of the hand rehabilitation exoskeleton of the present invention;

[0040] Figure 8 Schematic diagram of the information feedback process of the motion control of the hand rehabilitation exoskeleton of the present invention. DETAILED DESCRIPTION

[0041] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0042] It should be noted that when a component is referred to as being "mounted on" another component, it may be directly on the other component or there may be a central component. When a component is considered to be "set on" another component, it may be directly set on the other component or there may be a central component at the same time. When a component is considered to be "fixed to" another component, it may be directly fixed on the other component or there may be a central component at the same time.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "or / and" used herein includes any and all combinations of one or more of the related listed items.

[0044] The hand rehabilitation exoskeleton of the present invention is designed for rehabilitation training of patients' daily grasping process, which requires precise control of the thumb and index finger, and also requires five fingers to achieve power grasping. In the power grasping process, the metacarpophalangeal joints of the little finger, ring finger, and middle finger are first driven to bend, then the proximal interphalangeal joints are driven to bend, then the proximal interphalangeal joints are driven to extend, and finally the metacarpophalangeal joints are driven to extend. This sequential drive meets the grasping sequence and helps to better perform power grasping training.

[0045] For ease of understanding, it should be noted that the little finger, ring finger, middle finger and index finger are all composed of three phalanges, which are the proximal phalanges, middle phalanges and distal phalanges from the base to the tip. Finger joints are mainly divided into three categories. The first category is the metacarpophalangeal joint, which is the joint between the metacarpal bone and the proximal phalange. It is located at the base of the finger and only allows the finger to flex and extend, as well as a certain degree of adduction and abduction. The second category is the proximal interphalangeal joint, which is the joint between the proximal phalange and the middle phalange. It is mainly responsible for the flexion and extension of the finger. The third category is the distal interphalangeal joint, which is the joint between the middle phalange and the distal phalange. It is mainly responsible for the bending and flexion and extension of the finger. The thumb is composed of two phalanges. From the base to the middle, they are the metacarpophalangeal bones and interphalanges. The joint between the metacarpal bone and the metacarpophalangeal bone is the metacarpophalangeal joint, and the joint between the metacarpophalangeal bone and the interphalangeal bone is the interphalangeal joint.

[0046] See attached Figure 1A hand rehabilitation exoskeleton based on the metamorphosis principle and serial elastic drive includes a back-of-hand support plate 4 and a thumb coupling module 1, an index finger coupling module 2 and a three-finger metamorphosis mechanism module 3 respectively arranged on the back-of-hand support plate 4. The shape of the back-of-hand support plate 4 matches the surface contour of the back of a person's hand to achieve its wearing on a person's hand, and also improves the wearing comfort. The thumb coupling module 1 and the index finger coupling module 2 use a serial elastic driver to drive the gear mechanism, quadrilateral connecting rod mechanism, etc. in the thumb coupling mechanism and the index finger coupling mechanism, so that the metacarpophalangeal joint, interphalangeal joint of the thumb and the metacarpophalangeal joint, proximal interphalangeal joint, and distal interphalangeal joint of the index finger can be bent and extended according to a certain angle relationship to achieve fine grasping. The three-finger metamorphosis mechanism module 3 uses a serial elastic driver to drive the three-finger metamorphosis mechanism to achieve mutual conversion between the moving pair and the rotating pair, separate the flexion and extension movement of the metacarpophalangeal joint and the proximal interphalangeal joint, and achieve the flexion and extension movement of the little finger, ring finger, and middle finger with six degrees of freedom for power grasping.

[0047] To facilitate the display and explanation of the local structure, the back-of-hand support plate 4 is divided into three local blocks according to three functional modules for description below, and are named respectively: the first back-of-hand support plate 1-17, the second back-of-hand support plate 2-23 and the third back-of-hand support plate 3-17; the names of the same structural parts in the three modules (such as the series elastic drive) are also named first, second and third, respectively, for the convenience of description and distinction.

[0048] The specific structure and working principle of each functional module of the finger rehabilitation exoskeleton are described in detail below.

[0049] like Figure 2 As shown, the thumb coupling module 1 includes a thumb metacarpophalangeal finger sleeve 1-13 and a thumb interphalangeal finger sleeve 1-9 which are sequentially located on the front side of the first back-of-hand support plate 1-17, and the bottom ends of the thumb metacarpophalangeal finger sleeve 1-13 and the thumb interphalangeal finger sleeve 1-9 are both arched arc structures to respectively buckle on the metacarpophalangeal and interphalangeal bones of the thumb, and the bottoms of the thumb metacarpophalangeal finger sleeve 1-13 and the thumb interphalangeal bone finger sleeve 1-9 are respectively provided with thumb metacarpophalangeal straps 1-12 and thumb interphalangeal bone straps 1-11, so that the thumb metacarpophalangeal finger sleeve 1-13 can be fixed on the metacarpophalangeal bone of the thumb, and the thumb interphalangeal bone finger sleeve 1-9 can be fixed on the interphalangeal bone of the thumb, so as to realize the binding and fixation of the thumb coupling module 1 as a whole on the thumb.

[0050] A first serial elastic driver is fixedly arranged on the first back-of-hand support plate 1-17, and the output shaft end of the first serial elastic driver is connected to an input long rod 1-5 rotatably connected to the first back-of-hand support plate 1-17. Specifically, the first serial elastic driver includes a first motor 1-1 fixedly mounted on the first back-of-hand support plate 1-17, a first active bevel gear fixedly mounted on the output shaft of the first motor 1-1, a first driven bevel gear meshing with the first active bevel gear, a first fixed shaft 1-16 coaxially sleeved in the first driven bevel gear, and a first rotating sleeve movably sleeved on the outer side of the first fixed shaft 1-16. In this embodiment, a first bevel gear pair 1-2 composed of a first active bevel gear and a first driven bevel gear is adopted to realize the change of transmission direction, so that the position layout of the components is more reasonable and compact. The first driven bevel gear is a hollow structure, and a plurality of active push plates (four in this embodiment) are fixedly arranged on its inner wall, and a driven push plate matched with the active push plate is fixedly arranged on the outer wall of the first rotating sleeve, and a first spring 1-15 is connected between each pair of active and driven push plates. A first rotating shaft support is fixedly arranged on the top surface of the first back of hand support plate 1-17, and a first fixed shaft 1-16 is fixedly arranged horizontally on the top side of the first rotating shaft support. The bottom end of the input long rod 1-5 is fixedly sleeved on the outside of the first rotating sleeve, so that the first motor 1-1 can drive the first bevel gear pair 1-2 to rotate forward / reverse, thereby applying a forward / reverse rotation torque to the first rotating sleeve by compressing / pulling the first spring 1-15, and realizing the downward (counterclockwise) / upward (clockwise) swing of the input long rod 1-5. A first angle sensor 1-3 is provided at the rotational connection between the input long axis 1-5 and the back of the hand support plate 1-17 (specifically, the rotational pair between the first rotating sleeve and the first fixed axis 1-16) for detecting the angle change of the metacarpophalangeal joint of the thumb in real time.

[0051] The middle part of the input long rod 1-5 is rotationally connected to the thumb metacarpophalangeal bone rod 1-6 through the metacarpophalangeal bone input shaft 1-4, the bottom end of the thumb metacarpophalangeal bone rod 1-6 and the top end of the thumb metacarpophalangeal bone sleeve 1-13 are rotationally connected through the metacarpophalangeal bone output shaft 1-14, the end of the input long rod 1-5 is rotationally connected to the thumb interphalangeal bone rod 1-8 through the interphalangeal bone input shaft 1-7, the bottom end of the thumb interphalangeal bone rod 1-8 and the top end of the thumb interphalangeal bone sleeve 1-9 are rotationally connected through the interphalangeal bone output shaft 1-10. The length of the thumb interphalangeal bone rod 1-8 is slightly larger than the length of the thumb metacarpophalangeal bone rod 1-6. Thus, the lower section of the input long rod 1-5, the first shaft support, the metacarpophalangeal joint of the thumb and the thumb metacarpophalangeal bone rod 1-6 form a parallelogram linkage mechanism, and the upper section of the input long rod 1-5, the thumb metacarpophalangeal bone rod 1-6, the interphalangeal joint of the thumb and the thumb interphalangeal bone rod 1-8 form a non-parallelogram linkage mechanism. In the process of the input long rod 1-5 swinging downward, the thumb metacarpophalangeal bone rod 1-6 presses down the thumb metacarpophalangeal bone sleeve 1-13 to achieve the bending of the thumb metacarpophalangeal joint, and the thumb interphalangeal bone rod 1-8 presses down the thumb interphalangeal bone sleeve 1-9 to achieve the bending of the thumb interphalangeal joint, thereby achieving the overall bending process of each joint of the thumb according to a certain angle relationship. On the contrary, when the input rod 1-5 swings upward, the interphalangeal joint and the metacarpophalangeal joint of the thumb can be stretched respectively, thereby achieving the overall stretching process of the thumb.

[0052] like Figure 3 As shown, the index finger coupling module 2 includes an index finger proximal phalanx finger sleeve 2-18, an index finger middle phalanx finger sleeve 2-14 and an index finger distal phalanx finger sleeve 2-12 which are sequentially located on the front side of the second back of hand support plate 2-23, and the bottom ends of the index finger proximal phalanx finger sleeve 2-18, the index finger middle phalanx finger sleeve 2-14 and the index finger distal phalanx finger sleeve 2-12 are also arched arc structures to respectively buckle on the proximal phalanx, middle phalanx and distal phalanx of the index finger, and the index finger proximal phalanx finger sleeve 2-18, the index finger middle phalanx finger sleeve 2-14 and the index finger distal phalanx finger sleeve 2-12 are also arched arc structures. The bottom of the sleeve 2-14 and the index finger distal phalanx sleeve 2-12 are respectively provided with the index finger proximal phalanx strap 2-17, the index finger middle phalanx strap 2-15 and the index finger distal phalanx strap 2-13, so that the index finger proximal phalanx sleeve 2-18 can be fixed on the proximal phalanx of the index finger, the index finger middle phalanx sleeve 2-14 can be fixed on the middle phalanx of the index finger, and the index finger distal phalanx sleeve 2-12 can be fixed on the distal phalanx of the index finger, so as to realize the binding and fixation of the index finger coupling module 2 as a whole on the index finger.

[0053] A second serial elastic driver is fixedly arranged on the second back-of-hand support plate 2-23, and the output shaft end of the second serial elastic driver is connected to the index finger metacarpophalangeal bone rod 2-3 rotatably connected to the back-of-hand support plate. Specifically, the second serial elastic driver includes a second motor 2-1 fixedly mounted on the second back-of-hand support plate 2-23, a second active bevel gear fixedly mounted on the output shaft of the first motor 2-1, a second driven bevel gear meshing with the second active bevel gear, a second fixed shaft 2-21 coaxially sleeved in the second driven bevel gear, and a second rotating sleeve movably sleeved on the outer side of the second fixed shaft 2-21. In this embodiment, the second bevel gear pair 2-2 composed of the second active bevel gear and the second driven bevel gear is adopted to realize the change of the transmission direction, so that the position layout of the components is more reasonable and compact. The second driven bevel gear is a hollow structure, and a plurality of active push plates (four in this embodiment) are fixedly arranged on its inner wall, and a driven push plate matched with the active push plate is fixedly arranged on the outer wall of the second rotating sleeve, and a second spring 2-22 is connected between each pair of active and driven push plates. A second rotating shaft support is fixedly arranged on the top surface of the second back of hand support plate 2-23, and the second fixed shaft 2-21 is horizontally fixedly arranged on the top side of the first rotating shaft support. The bottom end of the index finger metacarpal bone rod 2-3 is fixedly sleeved on the outside of the second rotating sleeve, so that the second motor 2-1 can drive the second bevel gear pair 2-2 to rotate forward / reverse, thereby applying a forward / reverse rotation torque to the second rotating sleeve by compressing / pulling the second spring 2-22, so as to realize the downward (counterclockwise) / upward (clockwise) swing of the index finger metacarpal bone rod 2-3.

[0054] The top end of the index finger metacarpal bone rod 2-3 is rotatably connected to the index finger proximal phalanx rod 2-5 through the index finger input shaft 2-4, the top end of the index finger proximal phalanx finger sleeve 2-18 is integrally provided with a rotating frame plate, and an incomplete gear pair 2-7 is rotatably connected in the rotating frame plate, the bottom end of the index finger proximal phalanx rod 2-5 is fixedly connected to the input end of the incomplete gear pair, the output end of the incomplete gear pair 2-7 is fixedly connected to the index finger long rod, the middle part of the index finger long rod is rotatably connected to the index finger middle phalanx rod 2-9 through the middle phalanx input shaft, the bottom end of the index finger middle phalanx rod 2-9 and the top end of the index finger middle phalanx finger sleeve 2-14 are rotatably connected through the middle phalanx output shaft 2-16, the end of the index finger long rod is rotatably connected to the index finger distal phalanx rod 2-10 through the distal phalanx input shaft 2-8, and the bottom end of the index finger distal phalanx rod 2-10 and the bottom end of the index finger distal phalanx finger sleeve 2-12 are rotatably connected through the distal phalanx output shaft 2-11.

[0055] The index finger metacarpophalangeal bone rod 2-3, the second rotating shaft support, the metacarpophalangeal joint of the index finger and the index finger proximal phalanx bone rod 2-5 form a non-parallelogram connecting rod structure, the lower half of the index finger long rod, the rotating frame plate, the proximal interphalangeal joint of the index finger and the index finger middle phalanx bone rod 2-9 form a non-parallelogram connecting rod mechanism, and the upper half of the index finger long rod, the index finger middle phalanx bone rod 2-9, the distal interphalangeal joint of the index finger and the index finger distal phalanx bone rod 2-10 also form a non-parallelogram mechanism. In the process of the index finger metacarpophalangeal bone rod 2-3 swinging downward, the index finger proximal phalanx bone rod 2-5 presses down the index finger proximal phalanx finger sleeve 2-18 to achieve the bending of the index finger metacarpophalangeal joint. At the same time, the proximal phalanx rod 2-5 of the index finger rotates clockwise around the active incomplete gear shaft 2-6 at the bottom end, and through the meshing transmission of the incomplete gear pair 2-7, the long rod of the index finger rotates counterclockwise and swings toward the front side and below, and then the middle phalanx rod 2-9 of the index finger presses down the middle phalanx finger sleeve 2-14 of the index finger to achieve the bending of the proximal interphalangeal joint of the index finger; at the same time, the length of the distal phalanx rod 2-10 of the index finger is greater than the length of the middle phalanx rod 2-9 of the index finger, so the top end of the long rod of the index finger presses down the distal phalanx finger sleeve 2-12 of the index finger through the distal phalanx rod 2-10 of the index finger to achieve the bending of the distal interphalangeal joint of the index finger. In this way, the various joints of the index finger are bent as a whole according to a certain angle relationship. On the contrary, during the upward swinging process of the metacarpophalangeal rod 2-3 of the index finger, the extension process of the distal interphalangeal joint, the proximal interphalangeal joint and the metacarpophalangeal joint of the index finger can be achieved respectively.

[0056] The rotational connection between the index finger metacarpophalangeal bone rod 2-3 and the second back of the hand support plate 2-23 (specifically, the rotation pair between the second rotating sleeve and the second fixed axis 2-21), the rotational connection between the index finger long rod and the index finger proximal phalanx finger sleeve (specifically, the rotating frame plate), and the rotational connection between the index finger long rod and the index finger distal phalanx bone rod 2-10 are all provided with a second angle sensor 2-20, which are respectively used to detect the angle changes of the metacarpophalangeal joint, proximal interphalangeal joint and distal interphalangeal joint of the index finger in real time.

[0057] like Figure 4 and Figure 5 As shown, the three-finger transformation mechanism module 3 includes a metacarpal phalangeal finger sleeve 3-10 and a proximal interphalangeal finger sleeve 3-9 which are sequentially located on the front side of the third back of hand support plate 3-17. The metacarpal phalangeal finger sleeve 3-10 and the proximal interphalangeal finger sleeve 3-9 are both long arched structures, which are respectively buckled on the proximal phalanges and middle phalanges of three fingers (middle finger, ring finger and little finger), and the bottoms of the metacarpal phalangeal finger sleeve 3-10 and the proximal interphalangeal finger sleeve 3-9 are also respectively provided with straps, so that the metacarpal phalangeal finger sleeve 3-10 can be fixed on the proximal phalanges of the three fingers at the same time, and the proximal interphalangeal finger sleeve 3-9 can be fixed on the middle phalanges of the three fingers at the same time, thereby realizing the binding and fixation of the three-finger transformation mechanism module 3 as a whole on the three fingers.

[0058] The third back of hand support plate 3-17 is fixedly provided with a third series elastic driver, and the output shaft end of the third series elastic driver is connected with a three-finger cell mechanism. Specifically, the third series elastic driver includes a third motor 3-1 fixedly installed on the third back of hand support plate 3-17, a third active bevel gear fixedly installed on the output shaft of the first motor 3-1, a third driven bevel gear meshing with the third active bevel gear, and a third fixed shaft 3-19 coaxially sleeved in the third driven bevel gear. In this embodiment, the third bevel gear pair 3-2 composed of the third active bevel gear and the third driven bevel gear is adopted to realize the change of transmission direction, so that the position layout of the components is more reasonable and compact. The third driven bevel gear is a hollow structure, and a plurality of (4 in this embodiment) active push plates are fixedly provided on its inner wall, and a driven push plate paired with the active push plate is fixedly provided on the outer wall of the third rotating sleeve, and a third spring 3-21 is connected between each pair of active push plates and driven push plates. A metamorphosis mechanism mounting frame 3-11 is fixedly arranged on the top surface of the third back-of-hand support plate 2-23, and a third fixed shaft 3-19 is horizontally rotatably arranged on the top of the metamorphosis mechanism mounting frame 3-11 through a bearing. In this way, the third motor 3-1 can drive the third bevel gear pair 3-2 to rotate forward / reverse, thereby applying a forward / reverse rotation torque to the third fixed shaft 3-19 by compressing / pulling the third spring 3-21, thereby realizing the clockwise / counterclockwise swing of the rotating handle 3-18 fixedly connected to its outer end.

[0059] The three-finger transmutation mechanism includes a transmutation mechanism mounting frame 3-11 fixedly mounted on the third back-of-hand support plate 3-17, a handle shaft 3-18 rotatably mounted on the transmutation mechanism mounting frame 3-11, a three-finger turning handle 3-15 rotatably connected to the bottom end of the turning handle shaft 3-18, a push rod 3-13 rotatably sleeved on the outside of the bottom end rotating shaft of the three-finger turning handle 3-15, and a three-finger pushing rod shaft 3-14 rotatably connected to the other end of the push rod 3-13. A track changing groove 3-12 is provided at the bottom of the side wall of the transmutation mechanism mounting frame 3-11, and the track changing groove 3-12 includes a horizontal groove and an arc groove penetrating through the top of the horizontal groove and bending toward the front side. The three-finger push rod shaft 3-14 and the bottom end shaft of the three-finger turning handle 3-15 are both slidably set in the horizontal groove. When the turning handle 3-18 rotates clockwise, its bottom end pushes the push rod 3-13 to move horizontally forward through the three-finger turning handle 3-15 (at this time, the three-finger push rod shaft 3-14 and the bottom end shaft of the three-finger turning handle 3-15 can only slide horizontally in the horizontal groove); when the three-finger push rod shaft 3-14 slides horizontally to the front end of the horizontal groove, it stops moving and remains in place. At this time, the bottom end shaft of the three-finger turning handle 3-15 is just located at the bottom end of the arc groove, and the turning handle 3-18 continues to rotate clockwise, and the bottom end shaft of the three-finger turning handle 3-15 drives the push rod 3-13 to rotate counterclockwise around the axis of the three-finger push rod shaft 3-14, so that the bottom end shaft of the three-finger turning handle 3-15 enters the arc groove upward and slides toward the upper front side along the arc groove. In this way, the three-finger metamorphosis mechanism can realize the mutual conversion between the moving pair and the rotating pair, and achieve two-level power output.

[0060] The inner end of the three-finger push rod shaft 3-14 is fixedly provided with a connecting block 3-24, the upper part of the connecting block 3-24 is fixedly connected with a forward rack 3-25, the lower part of the forward rack 3-25 is meshed and connected with a gear rotatably provided on the metamorphosis mechanism mounting frame 3-11, the inner side of the metamorphosis mechanism mounting frame 3-11 is rotatably connected with a horizontally provided three-finger gear shaft 3-23, and the gear is fixedly installed on the three-finger gear shaft 3-23. The three-finger gear shaft 3-23 is the primary power output end of the three-finger metamorphosis mechanism, and the bottom end rotating shaft of the three-finger rotating handle 3-15 is the secondary power output end of the three-finger metamorphosis mechanism. The three-finger gear shaft 3-23 is fixedly connected with a gear connecting rod 3-22, the top end of the gear connecting rod 3-22 is rotatably connected with a metamorphosis phalanx rod 3-5 through a metamorphosis input shaft 3-3, and the bottom end of the metamorphosis phalanx rod 3-5 is rotatably connected with the top end of the proximal interphalangeal phalanx finger sleeve 3-10 through a metamorphosis output shaft 3-6. The outer side of the bottom rotating shaft of the finger push rod shaft 3-14 and the three-finger rotating handle 3-15 is movably sleeved with a rod groove rod member 3-27, and the bottom end of the rod groove rod member 3-27 is provided with a waist-shaped groove located inside the horizontal groove, and the bottom rotating shaft of the finger push rod shaft 3-14 and the three-finger rotating handle 3-15 is located in the waist-shaped groove. An arc-shaped fixed groove 3-26 located at the front side of the bottom end of the rod groove rod member 3-27 is fixedly provided on the inner side wall of the cell-changing mechanism mounting frame 3-11. The top end of the rod groove rod member 3-27 is rotatably connected with the proximal interdigital phalanx rod 3-8 through the proximal interdigital finger input shaft 3-20, and the bottom end of the proximal interdigital phalanx rod 3-8 is rotatably connected with the top end of the proximal interdigital phalanx finger sleeve 3-9 through the proximal interdigital finger output shaft 3-7.

[0061] When the push rod 3-13 moves forward horizontally, the forward rack 3-25 moves forward synchronously, thereby driving the gear to rotate clockwise ( Figure 4The push rod 3-13 rotates at the angle shown in the figure, and then drives the gear connecting rod 3-22 to swing downward through the three-finger gear shaft 3-23, and then presses the proximal interphalangeal phalanx finger sleeve 3-10 downward through the metacarpophalangeal phalanx rod 3-5, so as to realize the bending of the metacarpophalangeal joints of the three fingers; when the push rod 3-13 slides horizontally to the front end of the horizontal groove, it is also located at the front end of the waist-shaped groove of the rod groove rod member 3-27, and the front bottom end of the rod groove rod member 3-27 abuts against the arc-shaped fixed groove 3-26, the proximal interphalangeal phalanx finger sleeve 3-10 stops moving, and the bending movement of the metacarpophalangeal joint is completed. Then, the bottom rotating shaft of the three-finger rotating handle 3-15 can slide along the arc groove, and the rod groove rod member 3-27 can use the push rod shaft 3-14 as the rotating shaft to rotate relative to the arc fixed groove 3-26, so that the rod groove rod member 3-27 swings downward, and then the proximal interphalangeal phalangeal finger sleeve 3-9 is pressed down by the proximal interphalangeal phalangeal rod 3-8 to achieve the bending of the proximal interphalangeal joints of the three fingers. When the bottom rotating shaft of the three-finger rotating handle 3-15 reaches the top limit position of the arc groove, the bending movement of the proximal interphalangeal joint is completed. Then, the three-finger metamorphosis mechanism is driven to move in the opposite direction by the third series elastic driver, and the extension of the proximal interphalangeal joint and the extension of the metacarpophalangeal joint can be correspondingly achieved in sequence. Through the mutual conversion of the translation pair and the rotation pair, the metacarpophalangeal joint movement and the proximal interphalangeal joint movement in the whole process are separated.

[0062] The transition between the gear connecting rod 3-22 and the metacarpophalangeal phalanx rod 3-5 and the transition between the rod groove rod 3-27 and the proximal interphalangeal phalanx rod 3-8 are both provided with a third angle sensor 3-4, which is used to detect the angle changes of the metacarpophalangeal joint and the proximal interphalangeal joint of the three fingers in real time. According to the real-time reflection of the angles of the two joints, the angles are controlled by the designed force control method to realize the flexion and extension movement of the three fingers with six degrees of freedom for power grasping.

[0063] The hand rehabilitation exoskeleton can help each joint of the finger to perform rehabilitation training, wherein the parallelogram structure, gear mechanism, and non-parallelogram linkage mechanism of the thumb and index finger are driven by a series elastic driver, so that the metacarpophalangeal joint, interphalangeal joint of the thumb and the metacarpophalangeal joint, proximal interphalangeal joint, and distal interphalangeal joint of the index finger can be bent and extended according to a certain angle relationship to achieve fine grasping. Since the movement conditions of the other three fingers are similar, they are driven by an elastic driver. The three-finger metamorphosis mechanism can realize the mutual transformation between the moving pair and the rotating pair, separate the flexion and extension movement of the metacarpophalangeal joint and the proximal interphalangeal joint, and realize the flexion and extension movement of the three fingers with six degrees of freedom for power grasping. The two channels designed separate the grasping and bending movements of the fingers, enrich their movement modes, and improve the human-machine coupling. Therefore, the hand rehabilitation exoskeleton can better assist the hand training movement without generating additional torque. The hand rehabilitation exoskeleton drives the bending and straightening movements of the three fingers by a series elastic driver, which reduces the number of motors required, reduces the mass of the overall exoskeleton, and improves the comfort of the wearer.

[0064] The motion control of the hand rehabilitation exoskeleton requires the configuration of a control system. Figure 6 As shown, the control system includes a single-chip microcomputer, an angle sensor, a pressure sensor and a human-computer interaction screen. The single-chip microcomputer is connected to the motor driver of each series elastic drive through the CAN bus communication, the motor driver is connected to the encoder of each motor, the single-chip microcomputer is connected to the human-computer interaction screen through the I2C bus communication, and the single-chip microcomputer is connected to the angle sensor and the pressure sensor through the serial port. In this embodiment, the single-chip microcomputer adopts the ESP-12F development board, which has functional modules such as serial port communication, I2C communication, CAN communication, and WIFI module, and is powered by a lithium battery. A pressure sensor is provided on the inner side of each strap to detect the pressure of each phalanx on the object. The motor of each series elastic drive adopts a DC motor, and is equipped with an encoder, a driver and a reducer. The encoder can measure the rotation angle and rotation angular velocity of the motor. The battery is configured to directly power each DC motor, and a power emergency stop switch is provided on the power supply line of the battery to ensure the safety of the wearer during training. The battery supplies a 5V working voltage to the single-chip microcomputer through a voltage stabilizing module, and a power switch is provided on the power supply line. As a server, the WIFI module can be wirelessly connected to the cloud server, so that it can connect to mobile clients (such as mobile phones, tablets) or fixed computer clients to achieve data transmission and reflect the various parameters collected by the microcontroller in real time. The entire system is encapsulated in a box and fixed on the wearer's forearm for easy start and stop operation.

[0065] The core of the hand rehabilitation exoskeleton to achieve fine grasping is that the index finger coupling mechanism and the thumb coupling mechanism drive the index finger and thumb to bend and stretch at a certain angle relationship at the same time. The bending angle relationship is consistent with the angle relationship of a normal human hand during the grasping process. The process of achieving fine grasping includes the grasping preparation stage and the grasping stage. The grasping preparation stage is the process of bending the fingers to contact the object but not implementing the grasping, and the grasping stage is the process of the fingers contacting the object to completing the grasping. The core of the hand rehabilitation exoskeleton to achieve power grasping is that the three-finger metacarpophalangeal mechanism first bends the metacarpophalangeal joints of the middle finger, ring finger and little finger, and then bends the proximal interphalangeal joints of the middle finger, ring finger and little finger, and cooperates with the index finger coupling mechanism and the thumb coupling mechanism to complete the power grasping. The grasping preparation stage is angle control, which is mainly controlled by collecting the bending angle control of the healthy side fingers, and the affected side fingers are bent to the target angle. The grasping stage is force control, and the synchronous matching of the motor output force of the affected side hand is controlled by collecting the pressure during the grasping process of the healthy side hand.

[0066] like Figure 7 and Figure 8 As shown, a motion control method for a hand rehabilitation exoskeleton driven by series elasticity based on the metamorphosis principle comprises the following steps:

[0067] S1. The wearer wears the hand rehabilitation exoskeleton on the healthy hand and the affected hand respectively, so that all joints of the hand are in an initial state of straightening.

[0068] S2, turn on the power of the hand rehabilitation exoskeleton, and reset and initialize the control system. At this time, the microcontroller is in the reset and initialization state, and no instructions have been sent to any motor, so all motors are in standby state.

[0069] S3. After the wearer presses the "start" button of the microcontroller, the hand rehabilitation exoskeleton starts working and the motors of each series elastic drive are initialized.

[0070] S4. In the grasping preparation stage, the healthy hand is bent, and the hand rehabilitation exoskeleton on the corresponding side collects the angle information of the healthy hand, and performs position feedback adjustment on each motor on the affected hand side, driving the affected hand to reach the target position at the same angle, preparing for grasping training.

[0071] S5. After the affected hand moves to the target position, the hand rehabilitation exoskeleton on the healthy hand grasps the object, and the pressure sensor on it begins to change and obtains the target pressure value, and the affected hand will perform grasping training.

[0072] S6. The pressure sensor on the hand rehabilitation exoskeleton of the healthy hand collects the contact pressure between the healthy hand and the object, and feeds it back to the control system. The control system controls the hand rehabilitation exoskeleton of the affected hand to adjust synchronously.

[0073] The three-finger metacarpal mechanism of the hand rehabilitation exoskeleton of the affected hand will drive the proximal interphalangeal joints and metacarpophalangeal joints of the little finger, ring finger and middle finger to bend in sequence, and the thumb coupling mechanism and index finger coupling mechanism will drive the index finger and thumb to bend for force grasping, or the thumb coupling mechanism and index finger coupling mechanism will drive the index finger and thumb to bend for fine grasping, so that the contact pressure between the affected hand side and the object reaches the target pressure value.

[0074] S7. After the contact pressure collected by the pressure sensor on the hand rehabilitation exoskeleton of the healthy hand disappears, that is, the object is grasped and put down, feedback is given to the control system. The control system controls the three-finger metacarpophalangeal mechanism of the hand rehabilitation exoskeleton of the affected hand to drive the proximal interphalangeal joints and metacarpophalangeal joints of the little finger, ring finger and middle finger to extend in sequence, and the thumb coupling mechanism and index finger coupling mechanism will drive the index finger and thumb to extend.

[0075] S8, repeating the above steps S3 to S7, repeatedly performing strength grasping and fine grasping training on the hands to achieve the effect of rehabilitation training;

[0076] S9. After the wearer completes rehabilitation training, he / she should turn off the power supply in time and take off the hand rehabilitation exoskeleton.

[0077] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0078] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A hand rehabilitation exoskeleton based on metamorphosis principle and series elastic drive, characterized by: It includes a back-of-hand support plate and a thumb coupling module, an index finger coupling module and a three-finger cell-changing mechanism module respectively arranged on the back-of-hand support plate; The thumb coupling module comprises a thumb metacarpal phalangeal finger sleeve and a thumb interphalangeal finger sleeve which are sequentially located at the front side of the back of hand support plate, a first series elastic driver is fixedly arranged on the back of hand support plate, an output shaft end of the first series elastic driver is connected to an input long rod which is rotatably connected to the back of hand support plate, a middle part of the input long rod is rotatably connected to a thumb metacarpal phalangeal bone rod, a bottom end of the thumb metacarpal phalangeal bone rod is rotatably connected to a top end of the thumb metacarpal phalangeal finger sleeve, a tip end of the input long rod is rotatably connected to a thumb interphalangeal bone rod, a bottom end of the thumb interphalangeal bone rod is rotatably connected to a top end of the thumb interphalangeal bone sleeve; The index finger coupling module comprises an index finger proximal phalanx finger sleeve, an index finger middle phalanx finger sleeve and an index finger distal phalanx finger sleeve which are sequentially located on the front side of the back of the hand support plate, a second series elastic driver is fixedly arranged on the back of the hand support plate, an output shaft end of the second series elastic driver is connected with an index finger metacarpal phalanx rod rotatably connected to the back of the hand support plate, the top end of the index finger metacarpal phalanx rod is rotatably connected with the index finger proximal phalanx rod, the top end of the index finger proximal phalanx finger sleeve is rotatably connected with an incomplete gear pair, the bottom end of the index finger proximal phalanx rod is fixedly connected with the input end of the incomplete gear pair, the output end of the incomplete gear pair is fixedly connected with an index finger long rod, the middle part of the index finger long rod is rotatably connected with the index finger middle phalanx rod, the bottom end of the index finger middle phalanx rod is rotatably connected with the top end of the index finger middle phalanx finger sleeve, the end of the index finger long rod is rotatably connected with the index finger distal phalanx rod, and the bottom end of the index finger distal phalanx rod is rotatably connected with the bottom end of the index finger distal phalanx finger sleeve; The three-finger metamorphosis mechanism module includes a metacarpophalangeal phalanx finger sleeve and a proximal interphalangeal phalanx finger sleeve which are sequentially located on the front side of a back-of-hand support plate; a third series elastic driver is fixedly arranged on the back-of-hand support plate; an output shaft end of the third series elastic driver is connected to the three-finger metamorphosis mechanism; a primary power output end of the three-finger metamorphosis mechanism is connected to a rotatably arranged gear connecting rod; a top end of the gear connecting rod is rotatably connected to a metacarpophalangeal phalanx rod; a bottom end of the metacarpophalangeal phalanx rod is rotatably connected to a top end of a proximal interphalangeal phalanx finger sleeve; a secondary power output end of the three-finger metamorphosis mechanism is connected to a rod groove rod; a top end of the rod groove rod is rotatably connected to a proximal interphalangeal phalanx rod; a bottom end of the proximal interphalangeal phalanx rod is rotatably connected to a top end of a proximal interphalangeal phalanx finger sleeve.

2. The hand rehabilitation exoskeleton based on metamorphosis principle and series elastic drive according to claim 1, characterized in that: The first series elastic driver, the second series elastic driver and the third series elastic driver all include a motor, an active bevel gear fixedly mounted on an output shaft of the motor, a driven bevel gear meshing with the active bevel gear, a fixed shaft coaxially sleeved in the driven bevel gear and a rotating sleeve movably sleeved on the outside of the fixed shaft, a plurality of active push plates are fixedly arranged on the inner wall of the driven bevel gear, a driven push plate paired with the active push plate is fixedly arranged on the outer wall of the rotating sleeve, and a spring is connected between each pair of active push plates and driven push plates.

3. The hand rehabilitation exoskeleton based on metamorphosis principle and series elastic drive according to claim 1, characterized in that: The three-finger metamorphosis mechanism includes a metamorphosis mechanism mounting frame fixedly set on the back of the hand support plate, a handle shaft rotatably set on the metamorphosis mechanism mounting frame, a three-finger turning handle rotatably connected to the bottom end of the handle shaft, a push rod rotatably sleeved on the outside of the bottom end rotating shaft of the three-finger turning handle, and a three-finger pushing rod shaft rotatably connected to the other end of the push rod. A forward rack is fixedly connected to the upper inner end of the three-finger pushing rod shaft, and a gear rotatably set on the metamorphosis mechanism mounting frame is meshedly connected to the lower inner end of the forward rack. One side shaft end of the gear is the primary power output end of the three-finger metamorphosis mechanism, and the bottom end rotating shaft of the three-finger turning handle is the secondary power output end of the three-finger metamorphosis mechanism.

4. The hand rehabilitation exoskeleton based on metamorphosis principle and series elastic drive according to claim 3, characterized in that: A track changing groove is provided at the bottom of the side wall of the cell-changing mechanism mounting frame, and the track changing groove includes a horizontal groove and an arc-shaped groove that is arranged at the top of the horizontal groove and bends forward. A waist-shaped groove is provided at the bottom end of the rod groove rod member on the inner side of the horizontal groove. An arc-shaped fixed groove is fixedly provided on the inner side wall of the cell-changing mechanism mounting frame and is located on the front side of the bottom end of the rod groove rod member. The three-finger push rod shaft and the bottom end rotating shaft of the three-finger turning handle are both slidably provided in the horizontal groove. When the three-finger push rod shaft slides horizontally to the front end of the horizontal groove, the front bottom end of the rod groove rod member is abutted against the arc-shaped fixed groove, the bottom end rotating shaft of the three-finger turning handle can slide along the arc-shaped groove, and the rod groove rod member can rotate relative to the arc-shaped fixed groove.

5. A hand rehabilitation exoskeleton based on metamorphosis principle and series elastic drive according to any one of claims 1 to 4, characterized in that: The thumb metacarpal phalangeal finger sleeve, thumb interphalangeal finger sleeve, index finger proximal phalangeal finger sleeve, index finger middle phalangeal finger sleeve, index finger distal phalangeal finger sleeve, metacarpal phalangeal finger sleeve and proximal interphalangeal finger sleeve are all provided with binding straps below.

6. The hand rehabilitation exoskeleton based on metamorphosis principle and series elastic drive according to claim 5, characterized in that: The hand rehabilitation exoskeleton also includes a control system, which includes a single-chip microcomputer, an angle sensor, a pressure sensor and a human-computer interaction screen. The single-chip microcomputer is connected to the motor drivers of each series elastic driver through a CAN bus communication, the motor driver is connected to the encoder of each motor, the single-chip microcomputer is connected to the human-computer interaction screen through an I2C bus communication, and the single-chip microcomputer is connected to the angle sensor and the pressure sensor through a serial port.

7. The hand rehabilitation exoskeleton based on metamorphosis principle and series elastic drive according to claim 6, characterized in that: At least one pressure sensor is arranged on the inner side surface of each of the straps, and angle sensors are arranged at the transition between the input long rod and the back of the hand support plate, the transition between the index finger metacarpal phalanx rod and the back of the hand support plate, the transition between the index finger long rod and the index finger proximal phalanx finger sleeve, the transition between the index finger long rod and the index finger distal phalanx rod, the transition between the gear connecting rod and the metacarpal phalanx rod, and the transition between the rod slot rod and the proximal interphalanx rod.

8. A hand rehabilitation exoskeleton based on metamorphosis principle and series elastic drive according to claim 6 or 7, characterized in that: The control system also includes a WIFI module connected to the single-chip microcomputer via serial port communication, and the WIFI module is wirelessly connected to the cloud server.

9. A motion control method for a hand rehabilitation exoskeleton based on the metamorphosis principle and series elastic drive, characterized in that: The following steps are involved: S1. The wearer wears the hand rehabilitation exoskeleton on the healthy hand and the affected hand respectively, so that all joints of the hand are in an initial state of straightening; S2, turning on the power of the hand rehabilitation exoskeleton and resetting and initializing the control system; S3, starting the hand rehabilitation exoskeleton and initializing the motor of the series elastic actuator; S4, the healthy hand bends, and the hand rehabilitation exoskeleton on the corresponding side collects the angle information of the healthy hand, and performs position feedback adjustment on each motor on the affected hand to drive the affected hand to reach the target position with the same angle; S5, after the affected hand moves to the target position, the hand rehabilitation exoskeleton on the healthy hand grasps the object, and the pressure sensor on it begins to change and obtains the target pressure value, and the affected hand will perform grasping training; S6. The pressure sensor on the hand rehabilitation exoskeleton of the healthy hand collects the contact pressure between the healthy hand and the object, and feeds it back to the control system, and the control system controls the hand rehabilitation exoskeleton of the affected hand to adjust synchronously; The three-finger metamorphosis mechanism of the hand rehabilitation exoskeleton of the affected hand will drive the proximal interphalangeal joints and metacarpophalangeal joints of the little finger, ring finger and middle finger to bend in sequence, and the thumb coupling mechanism and the index finger coupling mechanism will drive the index finger and thumb to bend for power grasping, or the thumb coupling mechanism and the index finger coupling mechanism will drive the index finger and thumb to bend for fine grasping, so that the contact pressure between the affected hand side and the object reaches the target pressure value; S7, after the contact pressure collected by the pressure sensor on the hand rehabilitation exoskeleton of the healthy hand disappears, it is fed back to the control system, and the control system controls the three-finger metacarpophalangeal mechanism of the hand rehabilitation exoskeleton of the affected hand to drive the proximal interphalangeal joints and metacarpophalangeal joints of the little finger, ring finger and middle finger to extend in sequence, and the thumb coupling mechanism and the index finger coupling mechanism will drive the index finger and thumb to extend; S8, repeating the above steps S3 to S7, repeatedly performing strength grasping and fine grasping training on the hands to achieve the effect of rehabilitation training; S9. After the wearer completes rehabilitation training, he / she should turn off the power supply in time and take off the hand rehabilitation exoskeleton.

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