CN113771067A

CN113771067A - Bionic mechanical arm without shaking

Info

Publication number: CN113771067A
Application number: CN202110891610.5A
Authority: CN
Inventors: 王宏涛; 金永斌; 朱颖
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2019-05-29
Filing date: 2019-05-29
Publication date: 2021-12-10
Anticipated expiration: 2039-05-29
Also published as: CN110116420B; CN110116420A; CN113771067B; CN113524248A

Abstract

A bionic manipulator without shaking comprises at least one driving motor, wherein each driving motor is provided with a traction part, a force output line and a plurality of wire shafts are arranged between each driving motor and each traction part, each force output line comprises at least two segments which can be wound mutually, one end of each force output line is fixed with the traction part, and the other end of each force output line is fixed with the output end of each driving motor; the path that the force output line passes through is provided with a beam splitting piece, and the line segments wound by the force output line are separated at the beam splitting piece. The beam splitting piece isolates the influence of the torque of the line segment winding on the middle knuckle and the far knuckle, can separate the line segments wound together, cannot retard the transmission of force, avoids the shaking of fingers, and ensures the service life of a force output line.

Description

Bionic mechanical arm without shaking

Technical Field

The invention relates to a bionic machine, in particular to a bionic manipulator without shaking.

Background

The main fields of bionic mechanical research are biomechanics, control bodies and robots. Biomechanics study the mechanical phenomena and laws of life, including living body mechanics, living body hydromechanics, and body mechanics. The control body and the robot are engineering technical systems built based on knowledge learned from living beings.

According to statistics, the hand is one of the most easily damaged human organs, and once damaged, the treatment difficulty is very high due to criss-cross of internal nerves, blood vessels and small muscles, and the function recovery after treatment is not ideal. In addition, not only the motor function of the hand itself is affected by the damage of the hand itself, but also the brain, spine, arm, etc. are damaged, and the motor function of the hand is lost without affecting the body of the hand.

The bionic hand is a key functional part of the existing bionic robot which is increasingly developed, the existing bionic hand mainly comprises the following two types, the first type is relatively flexible in function, but obviously mechanized in appearance, the bionic hand mainly comprises a rigid connecting rod and a hinge, and the linkage between finger joints is realized through a connecting rod transmission or a wire pulling mode. The bionic hand has the advantages that all movable joints of a human hand can be detached, so that more degrees of freedom are realized. The output force of the bionic hand using the connecting rod transmission mode is larger, but the rigidity of the connecting rod mechanism is large, the flexibility is low, the weight is large, and the difference between the appearance and the appearance of a natural hand is larger. The pull-cord type bionic hand has high flexibility, but the output finger force is small, and the pull cord is easy to break, so that functional failure is easy to occur. The second type is a silica gel hand with the appearance color and texture close to the height of a human hand, and the hand is made by reverse molding of a real human hand and then pouring silica gel. However, such hands have only a decorative function and no substantial movement function.

Disclosure of Invention

The invention aims to provide a bionic machine which is similar to a human body limb in shape or can be combined with the human body limb losing exercise function, simultaneously considers flexibility and freedom degree of movement and can output large finger force.

A bionic machine is provided with at least one driving motor, each driving motor is provided with a traction part, a force output line and a plurality of wire shafts are arranged between each driving motor and each traction part, each force output line comprises at least two segments which can be wound mutually, one end of each force output line is fixed with the traction part, and the other end of each force output line is fixed with the output end of each driving motor.

The torque that driving motor output transmits to the power output line, and the mutual winding of power output line or loosen each other, the length of power output line changes to make the displacement of traction part, whole structure of being hauled is crooked or unbends. When the force output line is pressed against the guide shaft, the force output line turns from the pressed guide shaft, and the pulled mechanism is also driven to bend.

In a first aspect, the present invention aims to provide a lead shaft position and spring stiffness optimization method for achieving harmonious biological force transmission of mechanism motion, achieving natural motion conforming to biomechanics, and avoiding actions violating natural biological motion.

The lead shaft position optimization method can be used for hands and/or arms losing motion functions, mechanical arms reconstructed by connecting rods and springs, mechanical arms and the like. These structures are collectively referred to herein as a towed mechanism. The towed mechanism is virtualized as a link model with links and elastic hinges. For the manipulator and the mechanical arm, the connecting rod of the manipulator and the mechanical arm is used as a connecting rod, and the joint of the manipulator and the mechanical arm is an elastic hinge. For the hands and arms of people who lose the movement function, the hand bones are used as connecting rods, and joints are used as elastic hinges.

Preferably, a natural limb movement database is obtained, a movement model is established for the natural limb, in the movement model of the natural limb, a bone is used as a connecting rod, a joint is used as an elastic hinge, a tendon is used as a force output line, parameters of each joint comprise tendon length l and joint stiffness, and the relation l between the natural limb tendon movement amount delta l and the joint angle theta is obtained by utilizing positive and negative kinematics (theta is f) (theta is_i) (ii) a Using a PCA algorithm to obtain the dimension direction of the first principal component of the natural limb, the relation between the tendon movement amount delta l and the joint angle theta in the dimension direction, and the proportional relation between a plurality of joint angles when a plurality of joints exist;

establishing a motion model of a towed structure, and constraining the freedom of motion of the motion model in the dimension direction of a first principal component, wherein the motion model comprises connecting rods, elastic hinges between adjacent connecting rods and force output lines, the parameters of each elastic hinge comprise the positions of two insertion points and the rigidity of a spring, and the length of the force output line between the two insertion points represents the length of a tendon;

taking the spring stiffness and the tendon length as input, taking the angle of each joint as output, taking the minimum difference between the relationship between the tendon movement amount delta l and the joint angle theta in the movement model and the relationship between the tendon movement amount delta l and the joint angle theta in the natural limb as a target, continuously adjusting the position of an insertion point and the spring stiffness, and carrying out iterative calculation until the target is achieved; and outputting the position of the insertion point and the spring stiffness, and finishing the optimization of the position of the lead shaft and the spring stiffness.

The core of the method is that each joint is virtualized into two insertion points and a rigidity value of the joint; the insertion point is specifically indicative of the tendon length.

Further, the positive and negative kinematics model obtains the relationship between the tendon exercise amount Δ l and the joint angle θ, and the positive kinematics model is as follows:

wherein J represents a rotation transformation matrix,

Representing the amount of movement of the tendon in that dimension;

the inverse kinematics model was:

J⁺representing a weighted rotation transformation matrix, wherein the weighted weight is W spring stiffness; when in use

The relationship between the exercise amount of the tendon and the joint angle is obtained.

Further, when there are a plurality of joints, the method for acquiring the proportional relation between the angles of the plurality of joints is as follows: a curve graph is established according to the relation between the tendon exercise amount delta l and the joint angle theta, the tendon length l is used as a horizontal coordinate, the angle value is used as a vertical coordinate, and each joint angle has a curve of which the joint angle changes according to the tendon length under the coordinate system;

selecting a joint as a reference joint, establishing a two-dimensional coordinate system with the angle of the reference joint as a horizontal coordinate and the angle value as a vertical coordinate, and obtaining a curve of each joint relative to the reference coordinate, wherein the slope of the curve represents the proportional relation between the angle of the joint and the angle of the reference joint. The more the proportional relation between the angle of the joint and the angle of the reference joint approaches the angle proportional relation obtained by PCA analysis, the more the motion model approaches the motion of the natural limb. If the proportional relation between the angle of the joint and the angle of the reference joint is farther from the angular proportional relation obtained by the PCA analysis, the relative position of the insertion point is adjusted with the result obtained by approximating the PAC principal component analysis as the target.

Preferably, the traction mechanism is a finger, and the finger motion model is established for the finger, the finger including a proximal knuckle-metacarpal joint MCP, a proximal knuckle-middle knuckle joint PIP and a middle knuckle-distal knuckle joint DIP, each joint having a respective two insertion points.

The finger or the bionic manipulator is simplified into a finger connecting rod model, bones (such as phalanges, hand bones, phalanges models and the like) are used as connecting rods in the connecting rod model, and joints between adjacent bones are elastic hinges. The fingers and the handles can be self-heating fingers and arms which lose the motion function in the human body, and can also be artificial limbs and artificial hands reconstructed by using mechanical structures.

When the device is applied to a finger structure of a manipulator, the rigidity W is preferably the rigidity of a torsion spring, and the rigidity serves as a variable quantity and serves as a variable input value together with the insertion point position.

Patients who lose the function of finger movement, such as stroke patients, have the finger movement no longer controlled by the brain, the muscle stiffness at the finger joints, and the muscle stiffness degree at different joints of the same finger of the same patient are different, so when optimizing the wire axis insertion point of the glove, the joint stiffness W in the biomechanical model is different.

When applied to the finger structure of a human hand with lost motion function, the stiffness W is the actual stiffness of the finger joints as a preferred scheme; stiffness W is input as a fixed value and only the insertion point position is input as a variable input value. Before the optimization calculation, the stiffness of each finger of the patient is measured. The rigidity of the joints of the human hand can be obtained by giving known force, measuring the angle of the joints, calculating the rigidity W of the joints, and adopting the prior art to calculate the rigidity by the known force and the angle.

Further, when applied to rehabilitation of a human hand with lost exercise function, fingers usually lose the ability to actively stretch in addition to the ability to actively grip, and therefore, a mechanism for stretching the fingers is further provided in the rehabilitation tool, and when the elastic member is used as the mechanism for stretching the fingers, the joint stiffness is the joint equivalent stiffness combined with the action of the elastic member when the force output line pulls the fingers to grip. That is, when the elastic member is in the operating state, the finger joint rigidity test is performed.

Preferably, the towed mechanism is an arm, and the arm movement model comprises an elbow joint; the elbow joint includes two insertion points and a joint stiffness.

The arm motion model comprises a shoulder joint, the shoulder joint is a universal joint, the motion direction of the shoulder joint is determined firstly, and if the motion direction of the shoulder joint is consistent with that of the elbow joint, the input values of the arm motion model comprise a pair of shoulder joint insertion points, shoulder joint rigidity, a pair of elbow joint insertion points and elbow joint rigidity.

In a second aspect of the present invention, a structure of a bionic manipulator that can realize natural grasping by a simulated hand and has a large grasping force is provided.

A bionic manipulator is provided with a palm, a thumb, an index finger, a middle finger, a ring finger and a little finger, wherein the index finger, the middle finger, the ring finger and the little finger are respectively provided with a near knuckle, a middle knuckle and a far knuckle, and the near knuckle is hinged with the palm; each joint having a respective pair of wire guides and a spring located between the insertion points; each finger is provided with a respective driving motor and a respective force output line, each force output line comprises at least two segments which can be wound mutually, each force output line is fixed with the lead shaft on the distal knuckle through the lead shaft and the distal end on the finger in sequence, and the other end of each segment is fixed with the output end of the motor.

When the motor outputs torque, the wire segments are mutually wound to form a stranded wire, the length of the wire segments is shortened, so that pulling force is formed on finger tips, relative motion occurs between finger joints, finger bending is achieved, and grabbing motion of a hand is achieved. In the finger structure, except for the phalanges, the hinge and the spring, the finger structure does not need to be provided with

The insertion point and the stiffness of the spring are determined by the optimization method described above, driving the motor as a driver in the direction of the first principal component obtained by PCA analysis. The PCA analysis method is used for carrying out dimension analysis on the movement of the natural limb, and then, when the bionic mechanical design is carried out, a driver is arranged according to the main component direction obtained by the PCA analysis method. The more actuators, the more comprehensive the natural limb movement is restored.

Each finger is provided with a wire slot for accommodating a force output wire, a wire guide shaft is arranged along the wire slot, and two ends of the wire guide shaft are respectively fixed with the wire slots; the force output line passes through the space between the wire guide shaft and the wire groove.

According to the physiological structure of a human hand, the kinematics of fingers is simplified into a link mechanism driven by a force output line, finger bones are regarded as rigid connecting rods, ligaments and tendons connecting the finger bones are regarded as rigid elastic hinges, and the positions of a series of lead shaft insertion points and the positions of fixing points of the force output line determine how the force output line drives the fingers to move. Therefore, modeling of the force output line and the wire axis is required to clarify the relationship between the length of the force output line and the state of finger motion.

The position of the wire shaft is determined after optimized calculation of the insertion point and the rigidity, and the position is stable, so that after the manipulator is manufactured, the bending degree of fingers can be controlled by calculating the length of the force output line, and the accurate control of finger bending and hand grasping actions is realized.

The wire shaft comprises a mandrel and a wear-resistant sleeve, and the wear-resistant sleeve is sleeved outside the mandrel. The mandrel is fixed with the knuckle, and the wear-resistant sleeve is tightly matched with the mandrel. The wear-resisting sleeve reduces the frictional force that the power output line received to play the lubrication action to the power output line, minimize the wearing and tearing of power output line, fracture, the life of extension power output line.

The joint comprises a pair of insertion points and a torsion spring sleeved in the pin shaft. The torsion spring comprises a spiral spring part and support legs, two ends of each support leg extend outwards, and each support leg is fixed to the corresponding knuckle respectively. The rigidity of the torsion spring is used as the rigidity of the joint, and the torsion spring is convenient to install.

And/or a first reed is arranged at the joint between the proximal knuckle and the palm, a second reed is arranged at the joint between the proximal knuckle and the middle knuckle, and a third reed is arranged at the joint between the middle knuckle and the distal knuckle; and a sensor is arranged on each reed. The method and the structure for collecting the joint angle by the reed and the sensor adopt the prior art.

The output shaft of the motor is provided with a wire passing hole, and the force output wire is a rope ring passing through the wire passing hole. One end of the rope ring combined with the output shaft of the motor is used as a near end, the farthest end of the rope ring is fixed with the far knuckle, when the motor outputs torque, the rope ring forms a twisted pair, and the length of the force output line is changed.

The force output line penetrates through the rope passing hole, two ends of the rope are combined to enable the force output line to form a closed loop, and the two ends of the rope are fixed on the far knuckle.

The wire passing hole is a ring fixed on the output shaft of the motor or a through hole arranged on the output shaft of the motor.

The force output line is fixed on the far knuckle through the pressing piece; or, a far end wire shaft is arranged on the far finger joint, and the rope is looped around the far end wire shaft. The force output line bears the tensile force in the form of the twisted pair, the tensile deformation directly borne by the rope ring is small, the rope ring is not easy to break, and the output force is large.

The far knuckle, the middle knuckle and the near knuckle are respectively composed of respective frameworks and flexible pads, the adjacent frameworks are connected through elastic hinges, the wire grooves are formed in the frameworks, the flexible pads cover the frameworks, and the wire grooves are covered by the flexible pads. The skeleton is equivalent to a finger bone, and the flexible pad is equivalent to a muscle on a finger. The flexible pad covers the wire casing, prevents that the foreign matter from getting into the wire casing and causing the influence to the power output line.

The force output line is provided with lubricating oil, lubricating grease, colloid, a protective film and a protective layer. The force output line is coated with a little oil, so that the toughness of the force output line can be enhanced, and the service life is prolonged.

The rope loop formed after the force output line passes through the wire passing hole is arranged at the position close to the output shaft of the motor, and the line segments of the rope loop are bundled together. For example, after the force output line passes through the wire passing hole, the line sections on the two sides of the wire passing hole are knotted. Therefore, when the motor outputs torque, the starting points of winding of the line segments are the same every time, the influence of the natural separation tendency of the line segments on the two sides of the line passing hole on torque transmission is avoided, the effective utilization rate of the torque of the motor is improved, and the control of the length of the force output line by controlling the motor is further improved.

In the experimental process, the situation that the finger shakes when the twisted wire is used as a force output wire is found.

A third aspect of the present invention is directed to a structure for preventing finger shake for a bionic manipulator using a force output line in the form of a twisted wire.

Preferably, the path of the force output wires is provided with a splitter, at which the segments around which the force output wires are wound are separated. The torque output by the motor enables the line segments of the force output lines to be wound together, further enables the length of the force output lines to be changed, enables the distance between the far knuckle and the palm to be changed, and therefore the fingers are bent. The winding of the line segments can lead to the shaking of fingers during movement, which is not beneficial to grasping.

The beam splitting piece is arranged at the proximal knuckle; or the beam splitting piece is arranged on the palm, each finger is provided with the respective beam splitting piece, and the beam splitting pieces are rigid pieces. After tests, the beam splitting piece is arranged, the beam splitting piece enables the motor torque to act on the section from the beam splitting piece to the motor, the beam splitting piece interrupts the motor torque to enable the active winding trend of the line section, the influence of the torque wound by the line section on the middle knuckle and the far knuckle is isolated, and finger shaking is avoided. The rigid part referred to herein means a rigid part which is stable in shape and is not easily deformed; and not an absolute stiffness or hardness.

Each finger is provided with a wire groove for containing a force output wire, the beam splitting piece is positioned in the wire groove close to the knuckle, and a gap is formed between the beam splitting piece and the wall of the wire groove. The gap allows the force output line to pass through, the line segment of the force output line is separated by the beam splitting piece, then the stranded wire is continuously formed at the far end of the beam splitting piece in a natural winding mode, the stress distribution of the naturally wound stranded wire is natural, and fingers cannot shake due to the torque output by the motor.

The splitter is a streamlined body partition centered with the axial centerline of the trunking. The bundling element can separate the wound wire sections without blocking the force transmission.

The far end and the near end of the beam splitting component are respectively smooth curved surfaces. The proximal and distal ends of the splitter are both domes. The smooth curved surface can not only smoothly guide the force output line, but also avoid mutual cutting between the beam splitting piece and the force output line, and guarantee the service life of the force output line.

The wire groove of the proximal knuckle is internally provided with two wire guide shafts, and the beam splitting piece is positioned between the two wire guide shafts. The distal knuckles are of sufficient length that the beam splitter is positioned between the two guide shafts rather than in the palm space. In addition, the transmission distance of the force output line to the torque is also required, and if the bundling piece is placed in the palm, the force output line affected by the torque of the motor is short, so that the problem that the force output line is easily twisted and broken is caused. The bundling piece is placed in the proximal knuckle, the force output line is suitable for the length of the torque of the motor, the torque of the motor can be effectively transmitted, and the problem of twisting and breaking of the force output line is solved.

The beam splitter is equidistant from both guide axes, or the beam splitter is near the proximal guide axis. In this way, the beam splitter has minimal effect on torque transmission and no finger wobble.

The proximal knuckle is integral with a beam splitter that is higher than the guide axis. The height of the splitter needs to be high enough so that the wire guide shaft confines the force output wires to a region below the splitter to avoid the force output wires from disengaging the splitter.

In a fourth aspect of the present invention, it is an object to provide a highly integrated bionic manipulator capable of integrating all drive motors in a palm.

As a preferred scheme, the palm comprises a back skeleton and a palm skeleton, the back skeleton and the palm skeleton form an accommodating cavity, a finger driving motor group is arranged in the accommodating cavity, the finger driving motor group comprises an index finger motor, a middle finger motor, a ring finger motor and a little finger motor, and output shafts of the index finger motor, the middle finger motor, the ring finger motor and the little finger motor are respectively aligned to the corresponding fingers; the force output line is fixed with an output shaft of the finger driving motor; one guide wire shaft of the proximal knuckle-metacarpal joint is positioned in the proximal knuckle, and the other guide wire shaft is positioned in the palm.

As can be seen from the anatomical structure of the human metacarpal bones, 5 metacarpal bones are arranged in the palm of the human hand, each metacarpal bone is connected with the corresponding finger bone to form a line hinged through a joint, and the metacarpal bones are connected with the proximal phalanx through the joints. The forefinger motor, the middle finger motor, the ring finger motor and the little finger motor are arranged relative to respective fingers according to the direction of a metacarpal bone, namely in the palm model, the finger driving motor is a miniature low-speed gear motor.

The fixing part of the motor output shaft and the force output line is used as a wire guide shaft of the proximal knuckle-metacarpal joint positioned in the palm. Therefore, after the position of the wire axis in the palm is determined through optimization calculation, the position of the finger driving motor is also determined. The scheme has the advantages that the threading of the force output wire is simple, but the requirement on the positioning precision of the finger driving motor is high.

Alternatively, the guide wire shaft of the proximal knuckle-metacarpal joint located in the palm is located between the finger drive motor and the proximal knuckle-metacarpal joint. That is, the position of the finger driving motor is irrelevant to the wire guide shaft of the proximal knuckle-metacarpal joint, and only the force output wire passes through the wire guide shaft, so that the requirement on the positioning precision of the finger driving motor is reduced.

The containing cavity is provided with an index finger motor mounting position, a middle finger motor mounting position, a ring finger motor mounting position and a little finger motor mounting position, each motor mounting position is fixedly corresponding to a finger driving motor, and each motor mounting position is provided with a through hole which allows a motor output shaft to pass through and can rotate freely. Each motor installation position comprises a pair of side plates and a far-end baffle, the through holes are formed in the far-end baffles, and the near ends of the motor installation positions are open.

The forefinger motor, the middle finger motor, the ring finger motor and the little finger motor are respectively provided with a limiting assembly, and when the motors are installed at the motor installation positions, the limiting assemblies limit the motors to rotate relative to the motor installation positions. For example, the motor and the motor mounting position are fixed by means of fasteners, bonding and the like, and the fasteners and the bonding structure can also be used as a limiting component. The forefinger motor, the middle finger motor, the ring finger motor and the little finger motor are provided with speed reducing mechanisms, and the base frame of the speed reducing mechanisms is provided with a stop surface matched with the motor mounting positions. For example, reduction gears is gear reducer, and gear reducer's bed frame is cuboid or square, and gear reducer and finger driving motor combination together, put into motor installation position, and the side of gear reducer's bed frame is laminated with the curb plate of motor installation position respectively, and the relative motor installation position rotation of restriction finger driving motor. The near end of the motor installation position is set to be open, so that the motor can be conveniently placed into the motor installation position.

The palm needs to be hinged with the index finger, the middle finger, the ring finger and the little finger, so the palm needs to be provided with connecting parts with the index finger, the middle finger, the ring finger and the little finger. The invention provides the following structural scheme for connecting palms and fingers:

the first structural scheme for connecting the palm and the fingers is as follows: the back skeleton is provided with a connecting part hinged with the fingers, and the palm skeleton is provided with finger grooves corresponding to the connecting part; and a skeleton wire shaft of the force output line is arranged on the palm skeleton, and the skeleton wire shaft is positioned between the finger driving motor and the corresponding finger. The finger grooves on the palm skeleton provide space for finger movement, limit positions of finger movement are limited by the finger grooves on the palm skeleton, and excessive movement of fingers which does not accord with biological rules is prevented.

The connecting parts are arranged at the far end of the back skeleton, and a far end plate is arranged between the adjacent connecting parts and is flush with the edge of the far end of the back skeleton; the finger grooves are formed in the far end of the palm skeleton, the separating parts are arranged between the adjacent finger grooves, and when the back skeleton and the palm skeleton are combined, the separating parts and the far end plate separate the finger grooves.

All the motor mounting positions are arranged on the hand back framework, and the palm framework and the hand back framework are fixed through screws; countersunk screw holes are formed in the palm skeleton, screw hole columns are arranged in the back skeleton, and the screw hole columns correspond to the countersunk screw holes one to one. The structure is matched with a scheme that the position of a finger driving motor is irrelevant to a wire guide shaft of a proximal knuckle-metacarpal joint, both a back skeleton and a palm skeleton are provided with grooves inwards from edges to provide a moving space for fingers, the groove forming mode is simple, and the outer surfaces of the palm skeleton and the palm skeleton are flat and attractive. However, the disadvantage is that the palm needs to be provided with a wire guide shaft of the force output wire, and when the threading of the force output wire is realized, the threading needs to be passed through the wire guide shaft on the palm, so that the threading is slightly complicated.

The second structure scheme for connecting the palm and the fingers is as follows: the scheme is used in combination with a scheme that a fixing part of the motor output shaft and the force output line is used as a wire guide shaft of the proximal knuckle-metacarpal joint positioned in the palm. The palm skeleton is provided with connecting blocks hinged with fingers, the connecting blocks are bumps extending far from the far end of the palm skeleton, a distance is reserved between the connecting blocks, the far end of each connecting block is provided with a hinge, and each connecting block is provided with a limiting surface; the palm skeleton is provided with wire holes, and each connecting block corresponds to one wire hole.

The far end of connecting block is articulated with the finger, and after the finger moved to the spacing face of contact, nearly knuckle can't move to the direction that is close to the palm again, and spacing face prevents that the finger from taking place the excessive motion, makes the motion of manipulator accord with ergonomic. The force output line is led out from the output shaft of the motor, passes through the wire guide hole and then passes through the wire guide shaft on the finger. The position of the wire passing hole and the position of the wire guide hole on the output shaft of the motor can also be used as a wire guide shaft and arranged in the optimized distribution scheme to calculate the optimal position so as to obtain the finger control with high bionics degree and according with biomechanics and biological motion forms. The connecting blocks and the corresponding finger driving motors form a metacarpal model.

The palm skeleton forms the chamber that holds finger driving motor clan, and the back of the hand skeleton is the apron, and the back of palm skeleton is equipped with the chamber opening that holds that matches with the back of the hand skeleton, is the step between connecting block and the palm skeleton, and the wire guide sets up on the step. That is, the connecting block is lower than the palm surface; when the proximal knuckle contacts the limit surface, a gap is still reserved between the proximal knuckle and the palm skeleton, and a space is reserved for the cushion of the proximal knuckle.

The limiting surface is an inclined surface, and the far end of the limiting surface is closer to the back of the hand than the near end. When the fingers move to contact with the limiting surface, the fingers slightly incline to conform to the movement of natural human fingers.

The far end of the proximal knuckle and the far end of the middle knuckle are respectively provided with a knuckle limiting surface, and the knuckle limiting surfaces are inclined surfaces with a far height and a near height. The height is lower near the back of the hand and higher near the palm. The purpose of the knuckle limiting surface is to enable the knuckle to be in a slightly inclined state when the knuckle is at the bending limit, and the knuckle accords with human engineering and biomechanics.

The hinge parts of the near knuckle are positioned in the hinge parts of the connecting block, the two hinge parts are in clearance fit, a pin shaft penetrates through the two hinge parts, and a torsion spring is sleeved on the pin shaft; the edge of the hinged part of the connecting block is arc-shaped. The rounded edges avoid interference during hinge movement.

The motor mounting positions of the forefinger driving motor, the middle finger driving motor, the ring finger driving motor and the little finger driving motor are respectively aligned with respective connecting blocks, the position of each motor mounting position is used as the position of a motor output shaft, and when the lead shafts are optimally distributed, the motor mounting positions are listed in an optimal distribution scheme as the lead shafts of the proximal knuckle-metacarpal joint in the palm. The motor installation position is used as a lead shaft on the force output line, after the position distribution is optimized, the bending action of the fingers can be accurately controlled through the length of the force output line, and the bending form of the fingers is determined in the process of optimizing the distribution, so that the phenomenon that the fingers do not accord with the inharmonious movement of biomechanics is avoided.

Each motor installation position comprises a pair of side plates and a far-end baffle, the side plates are perpendicular to the palm skeleton and connected with the palm skeleton, the through holes are formed in the far-end baffle, and the near end of each motor installation position is open; the finger driving motor is tightly matched with the side plate.

The finger driving motor group uses motors with speed reducers, the speed reducers are provided with square supports, and the motor mounting positions are tightly matched with the supports of the speed reducers.

The advantages of this finger and palm construction are: only need with finger driving motor installation position, the power output line directly passes the wire guide on the palm skeleton, again pass between wire axle and the finger skeleton in proper order can, the arrangement of power output line is simple.

In a fifth aspect of the present invention, a highly integrated thumb structure capable of achieving finger flexion and metacarpal swing of the thumb is provided.

Preferably, the thumb is provided with a thumb finger and a scaphoid, the thumb finger comprises a thumb metacarpal bone, a proximal knuckle and a distal knuckle, the thumb metacarpal bone is hinged with the proximal knuckle through an elastic hinge, and the proximal knuckle is hinged with the distal knuckle through an elastic hinge; the thumb and the finger are provided with lead shafts, the thumb and the finger are provided with corresponding thumb driving motors, force output lines are led out from the thumb driving motors and then sequentially pass through the lead shafts, and the far ends of the force output lines are fixed on the far knuckle; the scaphoid is hinged with the palm and provided with a scaphoid driving motor.

The scaphoid driving motor enables the scaphoid to rotate around the hinge shaft, so that the motion that the thumb points to other four fingers to approach is realized, and the thumb is matched with other fingers to realize the grasping motion.

The near end of the force output line of the scaphoid penetrates through the output shaft of the scaphoid driving motor, and the far end of the force output line is arranged on the scaphoid; the palm skeleton is provided with an opening, and the thumb is arranged in the area of the opening. The scaphoid driving motor enables the force output lines to be mutually wound or loosened, so that the distance between the force output lines is changed, the purpose of adjusting the angle of the scaphoid and controlling the motion angle of the thumb relative to the palm is achieved. The structure has the advantages that the structure is simple, the scaphoid motor can be inherited in the palm, the requirement on the motor is relatively low, and the motor of the same type as the finger driving motor can be adopted.

Or the output shaft of the scaphoid motor is used as a hinge pin shaft of the scaphoid and the palm. The palm is provided with a fixed seat which is fixed with the scaphoid motor shell; one end of the scaphoid close to the fixed seat is provided with a through hole which is in clearance fit with the motor shell of the scaphoid; the other end of the scaphoid is fixed with an output shaft of the scaphoid motor. Therefore, the shell of the scaphoid motor is fixed by the fixing seat, the fixing seat is fixed with the palm, and the output shaft of the scaphoid motor outputs torque to realize the rotation of the scaphoid relative to the palm. The rotation angle of the motor for controlling the scaphoid of the hand can control the angle of the thumb relatively close to or far away from the palm, the control is simple and accurate, but the requirement on the volume of the motor is high, and the motor capable of being integrated on the palm must be selected.

The opening on the palm skeleton provides the activity space of the thumb. Among the bony structures of the thumb, the proximal and distal knuckles are included, as well as the metacarpal bones of the thumb, which lie within the palm of the hand. However, the metacarpal bones of the thumb are different from those of other four fingers, and the metacarpal bones of the thumb have a movement function in a natural palm, so that the metacarpal bones of the thumb are arranged outside the palm to realize the biological movement function of the metacarpal bones of the thumb in the scheme. The thumb drive motor drives the swing of the thumb toward or away from the palm of the hand, and the bending motion of the thumb, through the force output line.

The opening on the palm skeleton is covered with a soft cushion. The soft cushion is equivalent to palm muscle and plays the roles of skid resistance and buffering.

The thumb metacarpal bone is connected with the hand back framework through the hand scaphoid, the hand back framework is provided with a scaphoid connecting seat, the scaphoid comprises a first connecting part hinged with the scaphoid connecting seat and a second connecting part hinged with the thumb metacarpal bone, and the force output line of the scaphoid is tied on the second connecting part.

The first scaphoid protocol: the axial direction of the pin shaft in the first connecting part and the axial direction of the pin shaft in the second connecting part form an included angle. The first connecting part faces to the direction of the four fingers, and the second connecting part faces to the direction of the palm of the hand, so that the scaphoid driving motor controls the length of the force output line, and the motion that the thumb points to the four fingers to be closed is realized.

The scaphoid connecting seat comprises a base and a hinge part connected with the scaphoid, the hinge part is positioned on the base surface of the base, and the base surface is an inclined surface with a low outer part and a high inner part. Outer means near the edge of the palm. The bevel provides the thumb with a natural slope.

According to the second scheme, a first part of a scaphoid connecting seat is arranged on a hand back framework, a second part of the scaphoid connecting seat is arranged on the hand back framework, the first part and the second part of the scaphoid connecting seat are hinged with a first connecting part of the scaphoid through a pin shaft, and a torsion spring is arranged on the pin shaft; a scaphoid drive motor is arranged in the palm. The motion of the scaphoid approaching or leaving the palm is realized by controlling the scaphoid through the scaphoid driving motor, so as to realize grasping. In the natural state, the thumb and the four fingers are basically flush, similar to the natural open state of the human hand.

The thumb metacarpal bone is internally provided with a cavity of a thumb driving motor. The force output line of the thumb and the finger is led out from the thumb driving motor, sequentially passes through the wire guide shaft and is finally fixed on the far knuckle. The thumb drive motor is integrated in the thumb to realize the bending motion of the thumb and the fingers.

According to the scheme for arranging the scaphoid, all force is concentrated in the direction from the thumb to the palm through the matching of the scaphoid driving motor and the thumb driving motor, and the finger tip force output by the thumb and the gripping force on the whole hand are greatly improved.

The pin shaft of the scaphoid connecting seat hinged with the scaphoid faces to the direction of four fingers, and the pin shaft of the scaphoid hinged with the metacarpal of the thumb is parallel to the pin shaft of the metacarpal of the thumb hinged with the proximal knuckle. Like this the navicular bone realizes drawing close to the palm direction, if with thumb driving motor integration in the palm, then thumb driving motor can control the thumb and draw close and crooked to the four fingers, realizes the gripping, promotes the gripping power.

The invention has the advantages that:

1. the invention simplifies each joint into two insertion points and a rigidity value, realizes the natural movement of the bionic machinery in the given freedom degree direction by the optimized configuration of the insertion points, the rigidity value and the force output line, and has the advantages of simple structure, portability and small volume.

2. The twisted force output line is used for driving the finger to bend, the torque of the motor is converted into the length change of the force output line, the tension born by the force output line is small, the finger is not easy to break, and the output force is large.

3. The finger driving motor family is completely integrated in the palm and/or fingers, the size of the whole mechanical type is close to that of an adult hand, the integration is high, the signal line and the power line of the finger driving motor family are led out from the palm, and plug and play can be achieved.

4. The forward and reverse kinematics has high calculation speed, can meet the minimum principle of biological energy, meet the force balance condition and avoid singularity.

Drawings

Fig. 1 is a schematic diagram of a finger as an example, in which a force output line is led out from a driving motor, passes through all guide shafts, and is fixed with a lead shaft on a far knuckle.

Fig. 2 is a schematic view of a finger movement model in an initial state.

Fig. 3 is a schematic view of the finger motion model when bent.

FIG. 4 is a comparison of the results of several prior PCA algorithms on a robot.

FIG. 5 is a plot of the dispersion points between force output line length and joint angle before linear fitting, one dispersion point curve for each joint.

Fig. 6 is a graph showing the correspondence between the force output lines and the joint angles after linear fitting.

Fig. 7 is a comparison of the force output performance of the manipulator of the present invention with a natural human hand, a begion brand manipulator, of the same mass.

Fig. 8 is a schematic view of the first manipulator as seen from the palm.

Fig. 9 is a schematic view of the first manipulator with the index finger attached to the dorsum manus skeleton.

Figure 10 is a schematic view of the thumb of a first manipulator attached to the skeleton of the palm.

Fig. 11 is a schematic view of the palm of the first robot.

Fig. 12 is a schematic view of a hand skeleton of the first manipulator.

Fig. 13 is a schematic view of the second robot hand as seen from the palm direction.

Fig. 14 is a schematic view of the second robot hand as seen from the back of the hand.

Fig. 15 is a schematic view of the second robot with the hand back frame removed.

Fig. 16 is a schematic view of the connection of the skeleton of the palm of the hand and the index finger of the second manipulator.

Fig. 17 is a schematic view of the connection of the hand skeleton and thumb of the second manipulator.

Fig. 18 is a schematic view of the hand skeleton of the second manipulator viewed from the back of the hand with the thumb attached.

Fig. 19 is a perspective view of the hand skeleton of the second manipulator connected to the thumb.

Fig. 20 is a schematic view of the third robot hand viewed from the palm direction.

Fig. 21 is a schematic view of the third robot hand viewed from the back of the hand.

Fig. 22 is a perspective view of a third robot arm.

Fig. 23 is a schematic view of the hand skeleton of the third manipulator seen from the back of the hand.

Fig. 24 is a schematic view of the hand skeleton of the third robot hand as viewed from the hand direction.

Fig. 25 is a schematic view showing the connection of the index finger of the third manipulator to the skeleton of the palm.

Fig. 26 is a schematic view of the thumb of the third manipulator attached to the skeleton of the palm.

Fig. 27 is a perspective view of the thumb of the third manipulator attached to the skeleton of the palm.

Fig. 28 is a back frame of the third robot hand.

Fig. 29 shows a four-finger structure represented by an index finger.

Detailed Description

The structures referred to in this application, or the terminology used, are further described below in the specification and drawings in a general sense and are not intended to be limiting, unless otherwise specified.

Principal Component Analysis (PCA)

principal component analysis (pca) is a mathematical transformation method that transforms a given set of correlated variables into another set of uncorrelated variables by linear transformation, the new variables being arranged in descending order of variance. Maintaining sum of variables in mathematical transformationVariance (variance)Invariably, the first variable is made to have the greatest variance, called the first principal component, the second variable is made to have the second greatest variance and is uncorrelated with the first variable, called the second principal component, and so on.

Force output line

The force output line refers to a twisted wire connected with a driving motor, the twisted wire is provided with at least two sections, the two sections of twisted wires are mutually wound or loosened by torque output by the motor, and further the actual length of the force output line is changed, so that the traction action of the traction mechanism is realized. Each section of stranded wire is provided with a plurality of stranded wires, and the stranded wires can be smoothly installed on the bionic machinery and meet the flexibility requirement.

Bionic machinery

The machine which is designed and manufactured by imitating the form, structure and control principle of organisms has more centralized functions, higher efficiency and biological characteristics. Biomimetic mechanics herein refers to a mechanism for reconstructing the natural limb movements of a person, including but not limited to: the mechanical arm, the fingers, the mechanical arm, the rehabilitation glove which can be worn on the hand losing the motor function to drive the fingers to move, the arm rehabilitation article which can drive the arm losing the motor function to move, and the like.

A bionic machine is provided with at least one driving motor R as shown in figure 1, each driving motor R is provided with a traction part, a force output line B and a plurality of lead shafts A are arranged between the driving motor R and the traction parts, the force output line B comprises at least two line segments which can be wound mutually, one end of the force output line B is fixed with the traction part, and the other end of the force output line B is fixed with the output end of the driving motor R.

The torque that driving motor R output transmits to power output line B, and power output line B twines each other or loosens each other, and power output line B's length changes to make the displacement of traction part, whole structure that is hauled is crooked or unbends. When the force output line B is pressed against the wire guide shaft A, the force output line B turns from the pressed wire guide shaft A, and the pulled mechanism is also driven to bend.

Bionic mechanical kinematics optimization method based on joint insertion point

The optimization method aims to provide the optimization method of the position of the guide wire shaft A and the spring stiffness, which realizes the harmonious biological force transmission of the mechanism motion, realizes the natural motion according with the biomechanics and avoids the action violating the natural biological motion.

The method for optimizing the position of the guide wire axis A can be used for hands and/or arms which lose movement functions, mechanical arms and mechanical arms reconstructed by connecting rods and springs and the like. These structures are collectively referred to herein as a towed mechanism. The towed mechanism is virtualized as a link model with links and elastic hinges. For the manipulator and the mechanical arm, the connecting rod of the manipulator and the mechanical arm is used as a connecting rod, and the joint of the manipulator and the mechanical arm is an elastic hinge. For the hands and arms of people who lose the movement function, the hand bones are used as connecting rods, and joints are used as elastic hinges.

The specific scheme comprises the following steps: obtaining a natural limb movement database, as shown in fig. 2 and 3, building a movement model for the natural limb, wherein in the movement model for the natural limb, a bone is used as a connecting rod, a joint C is used as an elastic hinge, tendons are used as a force output line B, parameters of each joint comprise tendon length l and rigidity of the joint C, and a relation l ═ f (theta) (theta is obtained by positive and negative kinematics) between natural limb tendon movement amount delta l and joint angle theta_i)。

Using the PCA algorithm, the dimension direction of the first principal component of the natural limb, and the relationship of the tendon movement amount Δ l to the joint C angle θ in the dimension direction, and the proportional relationship between the plurality of joint C angles when there are a plurality of joints C, are obtained. As shown in fig. 4, the PCA algorithm is an existing algorithm, and the analysis results of different PCA algorithms on the three principal component directions of the bionic mechanical motion are basically consistent. As shown in fig. 5, a discrete plot of the relationship between the angle of each joint C and the force output line B is obtained. FIG. 6 is a linear regression fit of the discrete points of FIG. 5 to a straight line.

Establishing a motion model of a towed structure, and constraining the freedom of motion of the motion model in the dimension direction of a first principal component, wherein the motion model comprises connecting rods, elastic hinges between adjacent connecting rods and force output lines B, the parameters of each elastic hinge comprise the positions of two insertion points and the rigidity of a spring 12, and the length of the force output line B between the two insertion points represents the length of a tendon;

taking the spring stiffness and the tendon length as input, taking the angle of each joint C as output, continuously adjusting the position of an insertion point and the spring stiffness by taking the minimum difference between the relationship between the tendon movement amount delta l and the joint C angle theta in a movement model and the relationship between the tendon movement amount delta l and the joint C angle theta in a natural limb as a target, and carrying out iterative calculation until the target is achieved; and (4) outputting the position of the insertion point and the spring stiffness, and finishing optimization of the position of the wire guide shaft A and the spring stiffness. As shown in fig. 1, the lead axes a are positionally fixed and the force output line B passes through all the lead axes a in sequence.

The positive and inverse kinematics model obtains the relationship between the tendon exercise amount delta l and the joint angle theta, and the positive kinematics model is as follows:

wherein J represents a rotation transformation matrix,

Representing the amount of movement of the tendon in that dimension;

the inverse kinematics model was:

When a plurality of joints C exist, the method for acquiring the proportional relation among the angles of the plurality of joints C comprises the following steps: a curve graph is established according to the relation between the tendon exercise amount delta l and the joint C angle theta, the tendon length l is used as a horizontal coordinate, the angle value is used as a vertical coordinate, and each joint angle has a curve of the joint C angle changing according to the tendon length under the coordinate system;

selecting a joint as a reference joint C, establishing a two-dimensional coordinate system with the angle of the reference joint as a horizontal coordinate and the angle value as a vertical coordinate, and obtaining a curve of each joint C relative to the reference coordinate, wherein the slope of the curve represents the proportional relation between the angle of the joint C and the angle of the reference joint C. The closer the proportional relation between the angle of the joint C and the angle of the reference joint C is to the angle proportional relation obtained by PCA analysis, the closer the motion model is to the motion of the natural limb. If the proportional relationship between the angle of the joint and the angle of the reference joint C is farther from the angular proportional relationship obtained by the PCA analysis, the relative position of the insertion point is adjusted with the result obtained by approximating the PAC principal component analysis as the target.

In some embodiments, the motion model is created for a finger in the case of a finger comprising a proximal knuckle-metacarpal joint MCP, a proximal knuckle-middle knuckle PIP and a middle knuckle-distal knuckle DIP, each having a respective two insertion points.

Taking a finger as an example, the detailed optimization process comprises the following steps:

as shown in fig. 2 and 3, the finger is simplified into a phalanx-joint model, the phalanx is used as a connecting rod, the proximal phalanx-metacarpal joint is MCP, the proximal phalanx-middle phalanx joint is PIP, and the middle phalanx-distal phalanx joint is DIP; each joint model includes two insertion points [ x ]_i，y_i]Stiffness of joint w_i；

The positive kinematic model is

The essence is that Taylor expansion takes a primary term;

the inverse kinematics model is

Wherein

Represents Jd θ and

approximation, min (λ)²| d θ |) represents the singularity of the avoidance model; substituting the inverse kinematics model into the weights, rewrite as:

when in use

The relationship between the exercise amount of the tendon and the angle of the joint C is obtained.

The optimization process comprises the following steps: the spring 12 is in a natural state, the force output line B is in a natural extension state as an initial state, and the joint angle of the initial state is set as

As input values, the line B length and insertion point position (L) are output as force_i，[x_i，y_i]) As variable input quantity, in terms of actual angle of joint C

As output value, inputting into the positive and negative motion model, when dl > epsilon, making

Continuously updated to force output line B length and insertion point location (L)_i，[x_i，y_i]) And outputting the position of the current insertion point until the dl is less than or equal to the epsilon.

In some embodiments, the stiffness W is the stiffness of a torsion spring as a variable amount, along with the insertion point location as a variable input value, when applied to the finger structure of the manipulator. As can be seen from fig. 7, the unit weight and force output performance of the benonic brand manipulator, the natural human hand, and the manipulator of the present invention are substantially on the same performance curve, and the force output performance is substantially consistent.

In some embodiments, a patient with lost finger motion, such as a stroke patient, has finger motion no longer controlled by the brain, has muscle stiffness at the finger joints, and has different levels of muscle stiffness at different joints on the same finger of the same patient, and thus has different joint stiffness W in the biomechanical model when optimizing the wire axis A insertion point of the glove.

When applied to a finger structure of a human hand that loses motor ability, the stiffness W is the actual stiffness of the finger joint; stiffness W is input as a fixed value and only the insertion point position is input as a variable input value. Before the optimization calculation, the stiffness of each finger of the patient is measured. The rigidity of the joints of the human hand can be obtained by measuring the angle of the joint C given known force, calculating the joint rigidity W, and adopting the prior art to calculate the rigidity through the known force and the angle.

When the rehabilitation tool is applied to rehabilitation of a human hand without motor functions, fingers usually lose the active gripping capacity and the active stretching capacity, so that the rehabilitation tool is also provided with a mechanism for stretching the fingers, and when the elastic members are used as the mechanism for stretching the fingers, the joint rigidity is equivalent to the joint rigidity of the joint C combined with the action of the elastic members when the force output line B pulls the fingers to grip. That is, when the elastic member is in the operating state, the finger joint rigidity test is performed.

In some embodiments, the towed mechanism is an arm, and the arm motion model includes an elbow joint; the elbow joint includes two insertion points and a joint stiffness.

Mechanical arm

The embodiment aims to provide a bionic manipulator which is close to a human hand in shape and structure, can realize natural gripping of the human hand and is high in gripping force.

As shown in fig. 8, a bionic manipulator has a palm, a thumb 1, an index finger 2, a middle finger 3, a ring finger 4, and a little finger 5. The index finger 2, the middle finger 3, the ring finger 4 and the little finger 5 are consistent in structure and respectively provided with a proximal knuckle J, a middle knuckle Z and a distal knuckle Y, and as shown in fig. 29, the proximal knuckle J is hinged with the palm; each joint has a respective pair of wire axes a and a spring located between the insertion points; each finger is provided with a respective driving motor R and a respective force output line B, each force output line B comprises at least two line segments which can be wound mutually, each force output line B is fixed with the wire axis A on the distal knuckle Y through the wire axis A and the distal end on the finger in sequence, and the other end of each line segment is fixed with the output end of the motor.

As shown in fig. 29, each finger is provided with a wire slot 11 for accommodating a force output line B, a wire axis a is arranged along the wire slot 11, and two ends of the wire axis a are respectively fixed with the wire slots 11; the force output line B passes through the space between the wire axis a and the wire chase 11.

According to the physiological structure of a human hand, the kinematics of fingers is simplified into a link mechanism driven by a force output line B, finger bones are regarded as rigid connecting rods, ligaments and tendons connecting the finger bones are regarded as rigid elastic hinges, and the positions of insertion points of a series of lead shafts A and the positions of fixing points of the force output line B determine how the finger is driven by the force output line B to move. Therefore, the force output line B and the lead axis a need to be modeled to clarify the relationship between the length of the force output line B and the state of finger motion.

The position of the wire shaft A is determined after optimized calculation of the insertion point and the rigidity, and the position is stable, so that after the manipulator is manufactured, the bending degree of fingers can be controlled by calculating the length of the force output line B, and the accurate control of finger bending and hand grasping actions is realized.

As shown in fig. 8, the wire guide shaft a includes a mandrel and a wear-resistant sleeve, and the wear-resistant sleeve is sleeved outside the mandrel. The mandrel is fixed with the knuckle, and the wear-resistant sleeve is tightly matched with the mandrel. The wear-resistant sleeve reduces the friction force applied to the force output line B, plays a role in lubricating the force output line B, reduces the abrasion and the breakage of the force output line B as much as possible, and prolongs the service life of the force output line B.

As shown in fig. 9, the joint includes a pair of insertion points and a torsion spring 12 nested within the pin. The torsion spring 12 includes a coil spring portion and legs extending outwardly at both ends, each leg being secured to a corresponding knuckle. The rigidity of the torsion spring is used as the rigidity of the joint, and the torsion spring is convenient to install.

As shown in fig. 10, a first spring leaf is arranged at the joint between the proximal knuckle J and the palm, a second spring leaf is arranged at the joint between the proximal knuckle J and the middle knuckle Z, and a third spring leaf is arranged at the joint between the middle knuckle Z and the distal knuckle Y; and a sensor is arranged on each reed. The method and the structure for collecting the joint angle by the reed and the sensor adopt the prior art.

The output shaft of the motor is provided with a wire passing hole, and the force output wire B is a rope loop passing through the wire passing hole. One end of the rope ring combined with the output shaft of the motor is used as a near end, the farthest end of the rope ring is fixed with the far knuckle Y, when the motor outputs torque, the rope ring forms a twisted pair, and the length of the force output line B is changed.

The force output line B is a rope which penetrates through the wire passing hole, two ends of the rope are combined to enable the force output line B to form a closed loop, and the two ends of the rope are fixed on the far knuckle Y.

The force output line B is fixed on the far knuckle Y through a pressing piece; or the far knuckle Y is provided with a far wire axis A, and the rope is looped around the far wire axis A. The force output line B bears the tensile force in the form of a twisted pair, the tensile deformation directly borne by the rope ring is small, the rope ring is not easy to break, and the output force is large.

The far knuckle Y, the middle knuckle Z and the near knuckle J are respectively composed of respective frameworks and flexible pads 13, the adjacent frameworks are connected through elastic hinges, the wire grooves 11 are formed in the frameworks, the flexible pads 13 cover the frameworks, and the flexible pads cover part of the wire grooves 11. The skeleton corresponds to a phalanx, and the flexible pad 13 corresponds to a muscle on the finger. The flexible pad 13 shields the trunking 11 from foreign matter entering the trunking 11 and affecting the force output line B.

The force output line B is provided with lubricating oil, grease, colloid, a protective film and a protective layer. A little oil is coated on the force output line B, so that the toughness of the force output line B can be enhanced, and the service life is prolonged.

The force output line B penetrates through the line passing hole to form a rope loop at a position close to the output shaft of the motor, and line segments of the rope loop are bundled together. For example, after the force output line B passes through the wire through hole, the line sections on the two sides of the wire through hole are knotted. Therefore, when the motor outputs torque, the starting points of line segment winding are the same every time, the influence of the natural separation tendency of the line segments on the two sides of the line passing hole on torque transmission is avoided, the effective utilization rate of the torque of the motor is improved, and the control of the length of the force output line B by controlling the motor is further improved.

Bionic mechanical arm without shaking

In the experimental process, the situation that the finger shakes when the twisted wire is used as the force output wire B is found. The present embodiment aims to provide a structure for preventing finger shake for a bionic manipulator using a force output line B in the form of a twisted wire.

As shown in fig. 27, the path of the force output line B is provided with the beam splitter 6, and the line segment around which the force output line B is wound is separated at the beam splitter 6. The torque output by the motor enables the line segments of the force output line B to be wound together, further enables the length of the force output line B to be changed, enables the distance between the far knuckle Y and the palm to be changed, and therefore the fingers are bent. The winding of the line segments can lead to the shaking of fingers during movement, which is not beneficial to grasping.

As shown in fig. 25, the beam splitter 6 is provided at the proximal knuckle J; or the splitter 6 is arranged in the palm 7 and each finger has a respective splitter 6, the splitters 6 being rigid members. After tests, the beam splitting piece 6 is arranged, the beam splitting piece 6 acts the torque of the motor on the section from the beam splitting piece 6 to the motor, the beam splitting piece 6 interrupts the torque of the motor to enable the active winding trend of the line section, the influence of the torque wound by the line section on the middle knuckle Z and the far knuckle Y is isolated, and finger shaking is avoided. The rigid part referred to herein means a rigid part which is stable in shape and is not easily deformed; and not an absolute stiffness or hardness.

Each finger is provided with a wire slot 11 for accommodating a force output wire B, the beam splitting piece 6 is positioned in the wire slot 11 near the knuckle J, and a gap is reserved between the beam splitting piece 6 and the wall of the wire slot 11. The gap allows the force output line B to pass through, after the line segment of the force output line B is separated by the beam splitting piece 6, a stranded wire is continuously formed at the far end of the beam splitting piece 6 in a natural winding mode, the stress distribution of the naturally wound stranded wire is natural, and fingers cannot shake due to the torque output by the motor.

The splitter 6 is a streamlined body partition centered with the axial centerline of the trunking 11. The splitter 6 can separate the twisted wire sections without retarding the force transmission.

The far end and the near end of the beam splitter 6 are respectively smooth curved surfaces. Both the proximal and distal ends of the splitter 6 are rounded. The smooth curved surface can not only smoothly guide the force output line B, but also avoid mutual cutting between the beam splitting piece 6 and the force output line B, and the service life of the force output line B is guaranteed.

The wire casing 11 of the proximal knuckle J has two wire axes A therein, and the beam splitter 6 is located between the two wire axes A. The distal knuckles Y are of sufficient length that the beam splitter 6 is positioned between the two guide axes A rather than in the volar space. Further, the force output line B is also required for the torque transmission distance, and if the bundling tool 6 is placed in the palm, the force output line B affected by the motor torque is short, and the force output line B is easily broken. The beam splitting piece 6 is placed in the proximal knuckle J, the force output line B is suitable for the length of the torque of the motor, the torque of the motor can be effectively transmitted, and the problem that the force output line B is twisted and broken is solved.

The beam splitter 6 is equidistant from both wire axes a, or the beam splitter 6 is near the proximal wire axis a. In this way, the beam splitter 6 has minimal effect on torque transmission and no finger wobble.

The proximal knuckle J is integral with the beam splitter 6, the beam splitter 6 being higher than the guide axis a. The height of the beam splitter 6 needs to be high enough so that the wire guide axis a limits the force output line B to a region below the beam splitter 6, avoiding the force output line B from escaping the beam splitter 6.

High-integration bionic manipulator

The purpose of this scheme is to provide a highly integrated bionic manipulator that can be with the whole integrations of driving motor in the palm.

As shown in fig. 20 and 23, the palm 7 includes a back skeleton 71A and a palm skeleton 72A, the back skeleton and the palm skeleton form an accommodating cavity, a finger driving motor group is arranged in the accommodating cavity, the finger driving motor group includes a forefinger motor, a middle finger motor, a ring finger motor and a little finger motor, and output shafts of the forefinger motor, the middle finger motor, the ring finger motor and the little finger motor are respectively aligned with respective corresponding fingers; the force output line B is fixed with an output shaft of the finger driving motor; one guide line axis A of the proximal knuckle-metacarpal joint is positioned in the proximal knuckle J, and the other guide line axis A is positioned in the palm.

As can be seen from the anatomical structure of the human metacarpal bones, 5 metacarpal bones are arranged in the palm of the human hand, each metacarpal bone is connected with the corresponding finger bone to form a line hinged through a joint, and the metacarpal bones are connected with the proximal knuckles J through the joints. The forefinger motor, the middle finger motor, the ring finger motor and the little finger motor are arranged relative to respective fingers according to the direction of a metacarpal bone, namely in the palm model, the finger driving motor is a miniature low-speed gear motor.

As shown in fig. 18 and 19, the accommodating cavity is provided with a forefinger motor mounting position 1-1, a middle finger motor mounting position 2-1, a ring finger motor mounting position 3-1 and a little finger motor mounting position 4-1, each motor mounting position is fixedly corresponding to a finger driving motor, and each motor mounting position is provided with a through hole K allowing a motor output shaft to pass through and freely rotating. Each motor installation position comprises a pair of side plates 14 and a far-end baffle 15, the through hole K is formed in the far-end baffle 15, and the near end of each motor installation position is open. The forefinger motor, the middle finger motor, the ring finger motor and the little finger motor are respectively provided with a limiting assembly, and when the motors are installed at the motor installation positions, the limiting assemblies limit the motors to rotate relative to the motor installation positions.

For example, the motor and the motor mounting position are fixed by means of fasteners, bonding and the like, and the fasteners and the bonding structure can also be used as a limiting component. The forefinger motor, the middle finger motor, the ring finger motor and the little finger motor are provided with speed reducing mechanisms, and the base frame of the speed reducing mechanisms is provided with a stop surface matched with the motor mounting positions. For example, reduction gears is gear reducer, and gear reducer's bed frame is cuboid or square, and gear reducer and finger driving motor combination together, put into motor installation position, and the side of gear reducer's bed frame is laminated with the curb plate of motor installation position respectively, and the relative motor installation position rotation of restriction finger driving motor. The near end of the motor installation position is set to be open, so that the motor can be conveniently placed into the motor installation position.

The palm 7 needs to be hinged with the index finger 2, the middle finger 3, the ring finger 4 and the little finger 5, so the palm 7 needs to be provided with connecting parts with the index finger 2, the middle finger 3, the ring finger 4 and the little finger 5.

High-integration bionic manipulator of first scheme

In some embodiments, the proximal knuckle-metacarpal joint is located between the finger drive motor and the proximal knuckle-metacarpal joint. That is, the position of the finger driving motor is independent of the wire axis A of the proximal knuckle-metacarpal joint, and only the force output line B is required to pass through the wire axis A, so that the requirement on the positioning precision of the finger driving motor is reduced.

The back skeleton is provided with a connecting part hinged with the fingers, and the palm skeleton 72A is provided with a finger groove 74 corresponding to the connecting part; and a skeleton lead shaft A of the force output line B is arranged on the palm skeleton, and the skeleton lead shaft A is positioned between the finger driving motor and the corresponding finger. The finger slots on the palm skeleton 72A provide space for finger movement, and the finger slots 74 on the palm skeleton 72A also limit the extreme positions of finger movement, preventing finger movement that is not in compliance with biological laws.

As shown in fig. 11, the connecting portions 75 are provided at the distal ends of the dorsum manus chassis 71A, and distal plates are provided between adjacent connecting portions 75, the distal plates being flush with the distal edges of the dorsum manus chassis; the finger grooves 74 are provided at the distal end of the palm skeleton, and the partition portions 76 are provided between the adjacent finger grooves, so that when the back skeleton and the palm skeleton are combined, the partition portions 75 and the distal plate partition the finger grooves.

As shown in fig. 12, all the motor mounting positions are arranged on the back skeleton, and the palm skeleton and the back skeleton are fixed by screws; countersunk screw holes 77 are formed in the palm skeleton, screw hole columns 78 are formed in the back skeleton, and the screw hole columns 78 correspond to the countersunk screw holes 77 one to one. The structure is matched with a scheme that the position of a finger driving motor is independent of a wire guide shaft A of a proximal knuckle-metacarpal joint, both a back skeleton and a palm skeleton are grooved inwards from the edges to provide a moving space for fingers, the grooving mode is simple, and the outer surfaces of the palm skeleton and the palm skeleton are flat and attractive. However, the threading of the force output line B requires threading through the thread guide shaft a on the palm, which is a disadvantage of a slightly complicated threading.

High-integration bionic manipulator of second scheme

In some embodiments, the fixed portion of the motor output shaft to the force output line B is a wire guide axis A located in the palm of the hand as the proximal phalangeal-metacarpal joint. Thus, after the position of the guide line axis A in the palm is determined through optimization calculation, the position of the finger driving motor is also determined. According to the scheme, the force output line B is easy to thread, but the requirement on the positioning precision of the finger driving motor is high.

The scheme is used in combination with a scheme that a fixing part of the motor output shaft and the force output line B is used as a wire guide shaft A of a proximal knuckle-metacarpal joint positioned in a palm. The palm skeleton 72A is provided with connecting blocks hinged with fingers, the connecting blocks are bumps extending far from the far end of the palm skeleton, the distance is reserved between the connecting blocks, the far end of the connecting blocks is provided with a hinge, and the connecting blocks are provided with limiting surfaces; the palm skeleton is provided with wire holes, and each connecting block corresponds to one wire hole.

The distal end of connecting block is articulated with the finger, and after the finger moved to the spacing face of contact, nearly knuckle J can't move to the direction that is close to the palm again, and spacing face prevents that the finger from taking place the excessive motion, makes the motion of manipulator accord with ergonomic. The force output line B is led out from the output shaft of the motor, passes through the wire guide hole and then passes through the wire guide shaft A on the finger. The position of the wire passing hole and the position of the wire guide hole on the output shaft of the motor can also be used as a wire guide shaft A to be listed in the optimized distribution scheme for calculating the optimal position so as to obtain the finger control with high bionics degree and according with biomechanics and biological motion forms. The connecting blocks and the corresponding finger driving motors form a metacarpal model.

As shown in fig. 13, the palm skeleton forms the chamber that holds finger driving motor clan, and the back of the hand skeleton is the apron, and the back of the palm skeleton is equipped with the chamber opening that holds that matches with the back of the hand skeleton, is the step between connecting block and the palm skeleton, and the wire guide sets up on the step. That is, the connecting block is lower than the palm surface; when the proximal knuckle J contacts the limit surface, a gap is still reserved between the proximal knuckle J and the palm skeleton, and a space is reserved for the cushion of the proximal knuckle J.

As shown in fig. 14, the distal end of the proximal knuckle J and the distal end of the middle knuckle Z are respectively provided with a knuckle limiting surface, and the knuckle limiting surface is an inclined surface with a far lower part and a near higher part. The height is lower near the back of the hand and higher near the palm. The purpose of the knuckle limiting surface is to enable the knuckle to be in a slightly inclined state when the knuckle is at the bending limit, and the knuckle accords with human engineering and biomechanics.

The hinge parts of the proximal knuckle J are positioned in the hinge parts of the connecting block, the two hinge parts are in clearance fit, a pin shaft penetrates through the two hinge parts, and a torsion spring is sleeved on the pin shaft; the edge of the hinged part of the connecting block is arc-shaped. The rounded edges avoid interference during hinge movement.

As shown in fig. 15 and 16, the motor mounting positions of the index finger driving motor, the middle finger 3 driving motor, the ring finger 4 driving motor and the little finger 5 driving motor are respectively aligned with the respective connecting blocks, and the position of each motor mounting position is used as the position of the motor output shaft, as shown in fig. 17, when the lead shaft a is optimally distributed, the motor mounting positions are listed as the lead shaft a of the proximal knuckle-metacarpal joint in the palm in the optimal distribution scheme. As shown in fig. 18, the motor mounting position is used as a wire axis a on the force output line B, after the position distribution optimization, the bending action of the finger can be accurately controlled through the length of the force output line B, and the bending form of the finger is determined in the process of optimizing the distribution, so that the finger is prevented from generating discordant movement which does not accord with biomechanics.

As shown in fig. 19, each motor mounting position includes a pair of side plates 14 and a far-end baffle 15, the side plates are perpendicular to the palm skeleton and connected with the palm skeleton, the through holes K are arranged on the far-end baffle 15, and the near end of the motor mounting position is open; the finger drive motor is a close fit with the side plate 14.

The advantages of this finger and palm construction are: only need with finger driving motor installation position, the wire guide K on the hand core skeleton is directly passed to power output line B, again pass between wire guide A and the finger skeleton in proper order can, the arrangement of power output line B is simple.

Thumb structure

The object of the present embodiment is to provide a structure of a highly integrated thumb 1 capable of achieving finger bending and metacarpal swing of the thumb 1.

As shown in fig. 20, the thumb 1 has thumb fingers and scaphoid, the thumb fingers comprise metacarpal bones of the thumb 1, a proximal knuckle J and a distal knuckle Y, the metacarpal bones of the thumb 1 are hinged with the proximal knuckle J through an elastic hinge, and the proximal knuckle J is hinged with the distal knuckle Y through an elastic hinge; a wire guide shaft A is arranged on the thumb finger, the thumb finger is provided with a corresponding thumb 1 driving motor, a force output line B is led out from the thumb 1 driving motor and then sequentially passes through the wire guide shaft A, and the far end of the force output line B is fixed on the far knuckle Y; the scaphoid is hinged with the palm 7 and is provided with a scaphoid driving motor.

The scaphoid driving motor enables the scaphoid to rotate around the hinge shaft, so that the motion that the thumb 1 approaches to other four fingers is realized, and the thumb 1 is matched with other fingers to realize the grasping motion.

The palm bone of the thumb 1 is connected with the hand back framework 71A through the hand scaphoid, the hand back framework 71A is provided with a scaphoid connecting seat, the scaphoid comprises a first connecting part hinged with the scaphoid connecting seat and a second connecting part hinged with the palm bone of the thumb 1, and the force output line B of the scaphoid is bound on the second connecting part.

In the first structure in which the thumb is connected to the palm, as shown in fig. 21, the scaphoid drive motor is configured as follows: the near end of the force output line B of the scaphoid penetrates through the output shaft of the scaphoid driving motor, and the far end is arranged on the scaphoid; the palm skeleton 72A is provided with an opening in the area of which the thumb 1 is located. The scaphoid driving motor enables the force output lines B to be mutually wound or loosened, so that the distance between the force output lines B is changed, the purpose of adjusting the angle of the scaphoid and controlling the motion angle of the thumb 1 relative to the palm is achieved. The structure has the advantages that the structure is simple, the scaphoid motor can be inherited in the palm, the requirement on the motor R is relatively low, and the motor of the same type as the finger driving motor can be adopted.

The hand back framework 71A is provided with a first part of the scaphoid connecting seat, the hand back framework 71A is provided with a second part of the scaphoid connecting seat, the first part and the second part of the scaphoid connecting seat are hinged with a first connecting part of the scaphoid through a pin shaft, and the pin shaft is provided with a torsion spring 12; a scaphoid driving motor is arranged in the palm 7. The motion of the scaphoid approaching or leaving the palm is realized by controlling the scaphoid through the scaphoid driving motor, so as to realize grasping. In the natural state, the thumb 1 is substantially flush with the four fingers, similar to the natural open state of a human hand.

As shown in fig. 26, a cavity for driving the motor of the thumb 1 is formed in the metacarpal bone of the thumb 1. And a force output line B of the thumb 1 finger is led out from the thumb 1 driving motor, sequentially passes through the wire guide shaft A and is finally fixed on the far knuckle Y. The thumb 1 driving motor is integrated in the thumb 1, and the bending movement of the fingers of the thumb is realized.

According to the scheme for arranging the scaphoid, all force is concentrated on the direction from the thumb 1 to the palm of the hand through the matching of the scaphoid driving motor and the thumb 1 driving motor, and the finger tip force output by the thumb 1 and the gripping force on the whole hand are greatly improved.

The pin shaft of the scaphoid connecting seat hinged with the scaphoid faces to the direction of four fingers, and the pin shaft of the scaphoid hinged with the metacarpal of the thumb 1 is parallel to the pin shaft of the metacarpal of the thumb 1 hinged with the proximal knuckle J. Like this the navicular bone realizes drawing close to the palm direction, if with 1 driving motor of thumb integrated in the palm, 1 driving motor of thumb can control 1 to four fingers of thumb and draw close and crooked, realizes gripping, promotes the gripping power.

The second thumb-to-palm connection, in some embodiments, the scaphoid-to-palm connection: the axial direction of the pin shaft in the first connecting part and the axial direction of the pin shaft in the second connecting part form an included angle. The first connecting part faces to the direction of the four fingers, and the second connecting part faces to the direction of the palm, so that the scaphoid driving motor controls the length of the force output line B, and the thumb 1 moves towards the four fingers.

The scaphoid connecting seat comprises a base and a hinge part connected with the scaphoid, the hinge part is positioned on the base surface of the base, and the base surface is an inclined surface with a low outer part and a high inner part. Outer means near the edge of the palm. The slope gives the thumb 1a natural slope.

Third structure for connecting thumb 1 to palm 7 in some embodiments, the scaphoid driving motor further comprises: the output shaft of the scaphoid motor is used as a hinge pin shaft of the scaphoid and the palm. A fixed seat is arranged on the palm 7 and is fixed with the scaphoid motor shell; one end of the scaphoid close to the fixed seat is provided with a through hole K which is in clearance fit with the motor shell of the scaphoid; the other end of the scaphoid is fixed with an output shaft of the scaphoid motor. Therefore, the shell of the scaphoid motor is fixed by the fixing seat, the fixing seat is fixed with the palm 7, and the output shaft of the scaphoid motor outputs torque to realize the rotation of the scaphoid relative to the palm 7. The rotation angle of the output of the scaphoid motor is controlled, namely, the angle of the thumb 1 relatively close to or far away from the palm 7 can be controlled, the control is simple and accurate, but the requirement on the volume of the motor R is high, and the motor capable of being integrated on the palm must be selected.

The opening on the palm skeleton provides the activity space of the thumb 1. Among the bone structures of thumb 1, proximal and distal knuckles J and Y are included, as well as the metacarpal bone of thumb 1 located in the palm of the hand. However, the metacarpal bones of the thumb 1 are different from those of the other four fingers, and the metacarpal bones of the thumb 1 have a movement function in a natural palm, so that the metacarpal bones of the thumb 1 are arranged outside the palm in the scheme so as to realize the biological movement function of the metacarpal bones of the thumb 1. The thumb 1 driving motor drives the swing of the thumb 1 to approach or depart from the palm of the hand and the bending motion of the thumb 1 through the force output line B.

The invention shown and described herein may be practiced in the absence of any element or elements, limitation or limitations, which is specifically disclosed herein. The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, and it is recognized that various modifications are possible within the scope of the invention. It should therefore be understood that although the present invention has been specifically disclosed by various embodiments and optional features, modification and variation of the concepts herein described may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention as defined by the appended claims.

The contents of the articles, patents, patent applications, and all other documents and electronically available information described or cited herein are hereby incorporated by reference in their entirety to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference. Applicants reserve the right to incorporate into this application any and all materials and information from any such articles, patents, patent applications, or other documents.

Claims

1. The utility model provides a bionical manipulator of no shake which characterized in that: the device comprises at least one driving motor, a plurality of wire guiding shafts and a plurality of driving motors, wherein each driving motor is provided with a traction part, a force output line and a plurality of wire guiding shafts are arranged between each driving motor and each traction part, each force output line comprises at least two segments which can be wound mutually, one end of each force output line is fixed with the traction part, and the other end of each force output line is fixed with the output end of each driving motor; the path through which the force output line passes is provided with a beam splitting piece, and the line segments wound by the force output line are separated at the beam splitting piece;

each joint of the manipulator is provided with a pair of wire guide shafts and a spring positioned between insertion points; the insertion point and the rigidity of the spring are determined by an optimization method, and the driving motor is used as a driver of a first principal component direction obtained by a PCA analysis method; the optimization method comprises the following operations: obtaining a natural limb movement database, establishing a movement model for natural limbs, wherein in the movement model for natural limbs, bones are used as connecting rods, joints are used as elastic hinges, tendons are used as force output lines, parameters of each joint comprise tendon length l and joint rigidity, and a relation delta l ═ f (theta) between movement quantity delta l of the tendons of the natural limbs and joint angle theta is obtained by utilizing positive and negative kinematics_i) (ii) a Obtaining the dimension direction of the first principal component of the natural limb and the relation between the tendon exercise quantity delta l and the joint angle theta in the dimension direction by using a PCA (principal component analysis) algorithm; wherein theta is_iThe joint angle of the joint i of the manipulator is shown, i is any one of a proximal knuckle-metacarpal bone, a proximal knuckle-middle knuckle and a middle knuckle-distal knuckle;

taking the spring stiffness and the tendon length as input, taking the angle of each joint as output, continuously adjusting the position of an insertion point and the spring stiffness by taking the minimum difference between the relation between the tendon exercise amount delta l and the joint angle theta in the exercise model and the relation between the tendon exercise amount delta l and the joint angle theta in natural limbs as a target, and carrying out iterative calculation until the target is achieved; and outputting the position of the insertion point and the spring stiffness, and finishing the optimization of the position of the lead shaft and the spring stiffness.

2. The biomimetic manipulator without jitter of claim 1, wherein: the beam splitting piece is arranged at the proximal knuckle; or the beam splitting piece is arranged on the palm, each finger is provided with the respective beam splitting piece, and the beam splitting pieces are rigid pieces.

3. The biomimetic manipulator without shaking of claim 1 or 2, wherein: each finger is provided with a wire groove for containing a force output wire, the beam splitting piece is positioned in the wire groove close to the knuckle, and a gap is formed between the beam splitting piece and the wall of the wire groove.

4. The biomimetic manipulator without jitter of claim 3, wherein: the splitter is a streamlined body partition centered with the axial centerline of the trunking.

5. The biomimetic manipulator without jitter of claim 4, wherein: the far end and the near end of the beam splitting component are respectively smooth curved surfaces.

6. The biomimetic manipulator without jitter of claim 5, wherein: the proximal and distal ends of the splitter are both domes.

7. The biomimetic manipulator without jitter of claim 6, wherein: the wire groove of the proximal knuckle is internally provided with two wire guide shafts, and the beam splitting piece is positioned between the two wire guide shafts.

8. The biomimetic manipulator without jitter of claim 7, wherein: the beam splitter is equidistant from both guide axes, or the beam splitter is near the proximal guide axis.

9. The biomimetic manipulator without jitter of claim 1, wherein: the proximal knuckle is integral with a beam splitter that is higher than the guide axis.