CN114211523B

CN114211523B - Variable damping compliant driving exoskeleton joint

Info

Publication number: CN114211523B
Application number: CN202111349905.6A
Authority: CN
Inventors: 朱爱斌; 邹佳峻; 宋纪元
Original assignee: Xian Jiaotong University
Current assignee: Xian Jiaotong University
Priority date: 2021-11-15
Filing date: 2021-11-15
Publication date: 2023-07-14
Anticipated expiration: 2041-11-15
Also published as: CN114211523A

Abstract

The invention discloses a variable damping compliant driving exoskeleton joint, which comprises a crank block, an elastic driver, an exoskeleton joint shell and a magneto-rheological damper, wherein the crank block is connected in series; two joint rolling bearings are arranged in the outer skeleton joint shell and used for supporting a joint center rotating body in a crank block serial elastic driver, other rod pieces or joints are connected through joint connecting pieces, elastic elements are respectively connected with the outer skeleton joint shell and the joint center rotating body, a first magnetorheological damper connecting block in the magnetorheological damper is connected with the outer skeleton joint shell, a second magnetorheological damper connecting block in the magnetorheological damper is connected with the joint center rotating body, and the crank block serial elastic driver, the magnetorheological damper and the elastic elements are connected in parallel. The invention can realize flexible driving of the mechanism and resist external impact, thereby improving wearing comfort of the exoskeleton.

Description

Variable damping compliant driving exoskeleton joint

Technical Field

The invention belongs to the technical field of mechanical joint units, and particularly relates to a variable damping compliant driving exoskeleton joint.

Background

The joint of the exoskeleton mainly provides power for the joint movement of a wearer, and the traditional exoskeleton joint adopts a scheme that a motor and a speed reducer are connected in series and then are directly connected with an executing part, so that the exoskeleton joint has high rigidity, and the flexibility and the comfort level of the wearer are limited; the scheme of adopting the serial elastic driver to drive is also adopted, the impact influence generated during the collision of the robot can be well reduced by the scheme, but the rigidity of the serial elastic driver is fixed and cannot adapt to different working conditions, and the added elastic element inevitably vibrates, so that the control precision is low. The existing scheme for reducing the defects of the serial elastic driver by adding the damping cannot quickly change the damping, the energy consumption is high, continuous adjustment cannot be realized, and the damping control precision is low; in addition, the average power of the existing exoskeleton joint is too high, and the overall energy consumption is high.

Disclosure of Invention

In order to overcome the technical problems, the invention aims to provide the exoskeleton joint with the variable damping compliant drive, so that the mechanism can realize compliant drive and resist external impact, thereby improving the wearing comfort of the exoskeleton.

In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:

a variable damping compliant driving exoskeleton joint comprises a crank block, a serial elastic driver 1, an exoskeleton joint shell 2 and a magneto-rheological damper 3;

two joint rolling bearings 8 are placed inside the exoskeleton joint shell 2 and used for supporting a joint center rotating body 22 in the crank slider serial elastic driver 1, other rods or joints are connected through joint connecting pieces 9, the elastic elements 10 are respectively connected with the exoskeleton joint shell 2 and the joint center rotating body 22, a first magnetorheological damper connecting block 42 in the magnetorheological damper 3 is connected with the exoskeleton joint shell 2, a second magnetorheological damper connecting block 51 in the magnetorheological damper 3 is connected with the joint center rotating body 22, and the crank slider serial elastic driver 1, the magnetorheological damper 3 and the elastic elements 10 are connected in parallel.

The center of the joint center rotating body 22 is of a hollow structure and is used for placing the

magnetorheological damper

3, 4 arc-shaped bosses are arranged on the end face, the axial circumferential limit and connecting holes are provided for the second connecting block 51 of the magnetorheological damper while bearing is carried, in addition, the end face is provided with holes in an array, the connecting piece 9 and the crank 23 are connected, and the holes in the circumferential array are used for adjusting the relative positions of the crank 23 and the joint center rotating body 22, so that the range of joint output angles is adjusted.

The first magnetorheological damper connecting block 42 is connected with the exoskeleton joint housing 2, and adopts a flower-shaped structure, so that in order to reduce the overall weight, other shapes can be adopted, in addition, the first magnetorheological damper connecting block 42 plays a role of an end cover, and the mandrel 39 is limited.

The end face of the second connecting block 51 of the magneto-rheological damper is provided with 4 bosses which are used for corresponding to the 4 arc bosses of the central rotating body 22 of the joint, so that circumferential and axial limiting is realized, the whole flower-shaped structure is only used for reducing weight, other shapes can be adopted, the center of the connecting block is provided with 4 circumferential holes which are used for being connected with the mandrel 39, and the holes in the center are used for better guiding out of the coil.

The exoskeleton joint housing 2 is divided into an upper part and a lower part, and the upper part and the lower part of the exoskeleton joint housing 2 are connected through a copper column 4, a first shell supporting plate 5, a second shell supporting plate 6 and a third shell supporting plate 7.

The crank block serial elastic driver 1 comprises an encoder 11, the encoder 11 is connected with a motor 13, the motor 13 is placed on a motor seat 12 and is connected with a guide rail base 30 through a motor fixing seat 14, a motor shaft of the motor 13 is connected with a small synchronous pulley 15, the small synchronous pulley 15 and a large synchronous pulley 17 are driven by a synchronous belt 16, the large synchronous pulley 17 is connected with a lead screw 24, an elastic slider 26 is connected on the lead screw 24, two ends of the lead screw 24 are supported by lead screw end flange bearings 25, the lead screw end flange bearings 25 are embedded into lead screw end stop blocks 18, the lead screw end stop blocks 18 are connected with an exoskeleton joint shell 2, and the fixed connection of the lead screw 24 and the exoskeleton joint shell 2 is realized.

The elastic slider 26 is connected with an elastic slider base 27, further connected with an elastic slider connecting piece 28, the elastic slider connecting piece 28 can slide on a guide rail 29, the guide rail 29 is connected with a guide rail base 30, the guide rail base 30 is connected with the exoskeleton joint housing 2, and the top of the guide rail base 30 is provided with a motor base 12 and a motor fixing base 14.

The elastic sliding block 26 comprises a sliding block 36, the sliding block 36 is connected with the screw rod 24, four sliding block optical axes 35 penetrate through the sliding block 36 and are connected to a sliding block front end connecting block 38 and a sliding block rear end connecting block 38, the sliding block optical axes 35 are connected with the sliding block elastic element 34, a sliding block left end connecting block 37 and a sliding block right end connecting block 37 are connected with the sliding block front end connecting block 38, a crank 23 is mounted on the sliding block left end connecting block 37 and the sliding block end flange bearing 33 is mounted in the crank 23, and the sliding block is fixed through a bolt 31 and a gasket 32.

The elastic sliding block 26 is connected with the crank 23, the elastic sliding block 26 is fixed between the crank 23 and the crank through the bolt 31, the sliding block end flange bearing 33 supports the elastic sliding block 26, the crank 23 is connected with the joint center rotating body 22, the joint center rotating body 22 is meshed with the encoder output end gear 20, the encoder output end gear 20 is connected with the encoder 21, and the encoder output end gear 20 is connected with the exoskeleton joint housing 2 through the encoder connecting piece 19.

The magnetorheological damper 3 comprises a mandrel 39, the mandrel 39 is coaxial with a central hole of a first magnetorheological damper connecting block 42 and is supported by an input end bearing 61, a first sealing ring 41 is arranged between the mandrel 39 and the first magnetorheological damper connecting block 42 to seal, a sealing gasket 60 is arranged between the first magnetorheological damper connecting block 42 and a magnetorheological damper housing 45 to seal, a coil 57 is wound on the mandrel 39, magnetorheological fluid 48 and the coil 57 are separated by the spacer 58, the second sealing ring 56 is used for sealing, and then the spacer 58 is axially positioned by a side plate 43. The magnetorheological damper housing 45 and the spacer 58 are respectively provided with 4 grooves, the input end disc 46 and the output end disc 47 are respectively fixed in the circumferential direction, and then are respectively fixed in the axial direction through the outer end gasket 44 and the inner end gasket 49, so that the input end disc 46 and the output end disc 47 can be alternately arranged to form a serpentine loop.

The lengths of the outer end gasket 44 and the inner end gasket 49 can be adjusted so as to adapt to different working conditions, the output end of the mandrel 39 is coaxial with the outer end flange 50 of the magnetorheological damper, the mandrel 39 is supported by the bearing 53 of the output end of the magnetorheological damper and is sealed by the sealing gasket 60 and the sealing ring 41, the mandrel 39 is connected with the second connecting block 51 of the magnetorheological damper, the second connecting block 51 of the magnetorheological damper is connected with the joint center rotator 22, the input end disc 46 is connected with the first connecting block 42 of the magnetorheological damper, and the mandrel is further connected with the outer skeleton joint shell 2.

The inner wall of the magnetorheological damper housing 45 is provided with 4 guide grooves and 4 spline grooves, the four spline grooves are arranged at equal intervals, the guide grooves are arranged on two sides of a group of spline grooves which are arranged oppositely, the guide grooves are used for enabling magnetorheological fluid to be injected better, and the spline grooves are used for achieving circumferential fixation of the input end disc 46.

The core shaft 39 adopts a hollow structure, so that the coil is led out more conveniently, the coil adopts an arc structure, so that the magnetic field distribution is more uniform, and the magnetic field intensity at the serpentine circuit is higher.

The input end disc 46 is of an annular structure, four bulges are arranged on the outer side of the annular structure, the bulges are arranged at equal intervals, the outer side edges of the bulges are larger than the contact ends with the annular structure, the output end disc 47 is of an annular structure, four bulges are arranged on the inner side of the annular structure, the bulges are arranged at equal intervals, and the inner side edges of the bulges are larger than the contact ends with the annular structure.

The invention has the beneficial effects that:

the invention designs a compact and exquisite variable damping flexible driving exoskeleton joint. The adopted serial elastic driver driven by the crank sliding block has an elastic element in the transmission chain, so that the mechanism can realize flexible driving and resist external impact, thereby improving the wearing comfort of the exoskeleton. Moreover, by incorporating the resilient element in the drive train, the resilient element compresses when impacted, stores energy, and releases the stored energy after the impact force is dissipated, thereby reducing the energy consumption of the system. In addition, the tooth-shaped structure is arranged at the joint rotating body and meshed with the encoders, so that the measurement of the joint angle change is realized, the rotation angle of the motor is measured through the encoders at the motor, and finally, the output force can be accurately calculated through the difference value of the two encoders, so that the exoskeleton force control is convenient to realize, and a foundation is laid for the compliant control and man-machine follow-up control of the exoskeleton.

The parallel magnetorheological damper is adopted to provide damping, vibration is reduced, compared with a traditional damping generation mode, the damping range is larger, the damping generation and interruption speed is higher, and the consumed energy is less, so that the method is related to high responsiveness and low energy consumption of the magnetorheological fluid. The designed magnetorheological damper adopts a snake-shaped loop, expands the effective contact area of magnetorheological fluid, and can generate larger resistance moment. In addition, the diversion trench is designed at the shell, so that the injection of the magnetorheological fluid is easier. The designed mode of isolating the input board and the output board by using the gasket enables the gap between the input board and the output board to be adjustable, and the size of the gap can be further adjusted by adjusting the thickness of the gasket, so that the maximum value of the resistance moment can be changed according to the requirement. The designed unique coil leading-out mode ensures that the whole sealing performance of the magnetorheological damper is better.

The parallel magneto-rheological damper is adopted to provide a resistance moment, so that the joint can be locked at any angle, and the load transmission can be better realized.

The torsion spring connected in parallel with the transmission chain is adopted to realize gravity compensation, reduce average power, reduce energy consumption, reduce vibration, make output force more gentle and resist external impact. Taking this as an example of a hip joint, the torsion spring provides an upward lifting moment to the thigh when the thigh is in a vertical position, and provides a reverse moment to the thigh when the thigh has been lifted. The torsion spring plays a role in balancing the gravity of the thigh in the whole process, so that the average power of the exoskeleton joint is reduced during movement, and the energy consumption is reduced in the whole process. In addition, the magnetorheological damper is connected with the torsion spring in parallel, which is equivalent to the dynamic vibration absorber, so that a good vibration reduction effect can be achieved, the output force can be more gentle, and the wearing comfort is improved.

Drawings

FIG. 1 is an overall structure of a variable damping compliant drive joint of the present invention.

FIG. 2 is an exploded view of the overall structure of a compliant drive joint with variable damping.

Fig. 3 is a block diagram of the crank block series elastic driving part.

FIG. 4 is a cross-sectional view of a magnetorheological damper.

FIG. 5 is an exploded view of a magnetorheological damper.

Fig. 6 is an exploded view of the elastic slider.

FIG. 7 is a magnetorheological damper housing.

Fig. 8 is a schematic diagram of a mandrel structure.

Fig. 9 is a schematic diagram of the structure of the input end disc and the output end disc.

Reference numerals: 1 crank block serial elastic driver, 2 exoskeleton joint shell, 3 magneto-rheological damper, 4 copper column, 5 shell support plate I, 6 shell support plate II, 7 shell support plate III, 8 joint rolling bearing, 9 joint connecting piece, 10 elastic element, 11 encoder, 12 motor base, 13 motor, 14 motor fixing base, 15 small synchronous pulley, 16 synchronous belt, 17 big synchronous pulley, 18 lead screw two end stop, 19 encoder connecting piece, 20 encoder output end gear, 21 encoder, 22 joint center rotating body, 23 crank, 24 lead screw, 25 lead screw end flange bearing, 26 elastic slider, 27 elastic slider base, 28 elastic slider connecting piece, 29 guide rail, 30 guide rail base, 31 bolt, 32 gaskets, 33 sliding block end flange bearings, 34 sliding block elastic elements, 35 sliding block optical axes, 36 sliding blocks, 37 sliding block left and right end connecting blocks, 38 sliding block front and rear end connecting blocks, 39 mandrel, 40 first sealing ring, 41 first sealing ring, 42 first magneto-rheological damper connecting block, 43 side plates, 44 outer end gaskets, 45 magneto-rheological damper shell, 46 input end disc, 47 output end disc, 48 magneto-rheological fluid, 49 inner end gaskets, 50 magneto-rheological damper outer end flange, 51 magneto-rheological damper connecting block two, 52 second sealing ring, 53 magneto-rheological damper output end bearing, 54 third sealing ring, 55 fourth sealing ring, 56 second sealing ring, 57 coil, 58 spacer sleeve, 59 fifth sealing ring, 60 sealing gasket and 61 input end bearing.

Detailed Description

The invention is described in further detail below with reference to the accompanying drawings.

As shown in fig. 1: the present invention is designed for a variable damping compliant drive exoskeleton joint, which is the most important part of the exoskeleton. The overall structure of the variable damping compliant drive joint unit is shown in fig. 1. Mainly comprises a crank sliding block serial elastic driver 1, an exoskeleton joint shell 2 and a magneto-rheological damper 3. In the overall structural exploded view of the variable damping compliant drive joint of fig. 2, the interrelationship between the various parts is seen: the whole joint unit takes an exoskeleton joint shell 2 as a fixed basis, a copper column 4, a first shell supporting plate 5, a second shell supporting plate 6 and a third shell supporting plate 7 are used for connecting an upper exoskeleton joint shell 2 and a lower exoskeleton joint shell 2, two joint rolling bearings 8 are placed in the exoskeleton joint shell 2 and used for supporting a joint center rotating body 22 in a crank sliding block serial elastic driver 1, other rods or joints are connected through an inter-joint connecting piece 9, an elastic element 10 is respectively connected with the exoskeleton joint shell 2 and the joint center rotating body 22, a first magnetorheological damper connecting block 42 in a magnetorheological damper 3 is connected with the exoskeleton joint shell 2, and a second magnetorheological damper connecting block in the magnetorheological damper 3 is connected with the joint center rotating body 22. Finally, the parallel connection among the crank block serial elastic driver 1, the magneto-rheological damper 3 and the elastic element 10 is realized.

The connection relation between each part can be seen in the structure diagram of the crank block serial elastic driver 1 in fig. 3: the encoder 11 is connected with the motor 13, the motor 13 is placed in the motor seat 12 and is connected with the guide rail base 30 through the motor fixing seat 14, the motor shaft of the motor 13 is connected with the small synchronous pulley 15, the small synchronous pulley 15 and the large synchronous pulley 17 are driven through the synchronous belt 16, the large synchronous pulley 17 is connected with the lead screw 24, the lead screw 24 is connected with the elastic sliding block 26, the two ends of the lead screw 24 are supported by the lead screw end flange bearings 25, the lead screw end flange bearings 25 are embedded in the lead screw end baffle blocks 18, the lead screw end baffle blocks 18 are connected with the outer skeleton joint shell 2, the fixed connection of the lead screw and the outer skeleton joint shell 2 is finally realized, the elastic sliding block 26 is connected with the elastic sliding block base 27 and further connected with the elastic sliding block connecting piece 28, the elastic sliding block connecting piece 28 can slide on the guide rail 29, the guide rail 29 is connected with the guide rail base 30, and the guide rail base is connected with the outer skeleton joint shell 2. The elastic slider 26 is connected with the crank 23, the elastic slider 26 is supported by the flange bearing 33 at the slider end through the bolt 31, the crank 23 is connected with the joint center rotating body 22, the joint center rotating body 22 is meshed with the gear 20 at the output end of the encoder, the gear 20 at the output end of the encoder is connected with the encoder 21, and the encoder is connected with the exoskeleton joint housing 2 through the encoder connecting piece 19. The whole transmission process is that the motor 13 drives the small synchronous pulley 15 to rotate, the large synchronous pulley 17 is further driven to rotate through the synchronous belt 16, so that the lead screw 24 connected with the large synchronous pulley 17 is driven, when the lead screw 24 rotates, the sliding block 36 in the elastic sliding block 26 is driven to move, the sliding block 36 pushes the sliding block front end connecting block 38 and the sliding block rear end connecting block 38 through the elastic element 34 sleeved on the optical axis 35 at the sliding block, the sliding block left end connecting block and the sliding block right end connecting block 37 are further driven to move, the crank 23 is further driven to move, and finally, the joint center rotating body 22 is enabled to rotate.

Referring to fig. 4, which is a cross-sectional view of the magnetorheological damper 3, the mandrel 39 is coaxial with a central hole of the first connecting block 42 of the magnetorheological damper and is supported by the input end bearing 61, a first sealing ring 41 is arranged between the mandrel 39 and the first connecting block 42 of the magnetorheological damper, and a sealing gasket 60 is arranged between the first connecting block 42 of the magnetorheological damper and the housing 45 of the magnetorheological damper. The core shaft 39 is wound with a coil 57, the magnetorheological fluid 48 is separated from the coil 57 by a spacer 58, the magnetorheological fluid is sealed by a second sealing ring 56, and then the spacer 58 is axially positioned by the side plate 43. The magnetorheological damper housing 45 and the spacer 58 are respectively provided with 4 grooves, so that the input end disc 46 and the output end disc 47 can be respectively fixed in the circumferential direction, then the input end disc 46 and the output end disc 47 are respectively fixed in the axial direction through the outer end gasket 44 and the inner end gasket 49, and finally, the effect that the input end disc 46 and the output end disc 47 alternately appear to form a snake-shaped loop and the effect of increasing the acting area is realized. The length of both the outer end pad 44 and the inner end pad 49 can be adjusted to accommodate different operating conditions. The output end of the mandrel 39 is then coaxial with the magnetorheological damper outer end flange 50, supported by the magnetorheological damper output end bearing 53, and sealed by the sealing gasket 60 and the first seal ring 41. Finally, the spindle 39 is connected with the second magnetorheological damper connecting block 51, the second magnetorheological damper connecting block 51 is connected with the joint center rotating body 22, the input end disc 46 is connected with the first magnetorheological damper connecting block 42 and further connected with the exoskeleton joint housing 2, so that when the coil 57 is electrified, a magnetic field loop is formed, the magnetorheological fluid 48 between the input end disc 46 and the output end disc 47 is changed into a Bingham fluid by Newtonian fluid under the action of a magnetic field, and finally damping is generated in the exoskeleton joint.

Referring to fig. 6, which is an exploded view of the elastic slider 26, the slider 36 is connected with the screw 24, the optical axes 35 at four sliders penetrate through the slider 36 and are connected to the slider front and rear end connecting blocks 38, the optical axes 35 at the sliders are connected with the elastic elements 34 at the sliders, the slider left and right end connecting blocks 37 are connected with the slider front and rear end connecting blocks 38, the crank 23 is mounted on the slider left and right end connecting blocks 37, the slider end flange bearing 33 is mounted in the crank 23, and the slider is fixed by the bolts 31 and the gaskets 32.

Fig. 7 shows a magnetorheological damper housing 45 having 4 channels and 4 spline grooves therein, wherein the channels are configured for better injection of magnetorheological fluid and the spline grooves are configured for circumferential fixation of the input disc 46.

As shown in fig. 8, for the core shaft 39, in order to avoid the concentration of the magnetic field at the corners, the coil is in an arc structure to make the magnetic field distribution more uniform, so that the magnetic field intensity at the serpentine loop is higher, and the resistance moment generated by the magnetorheological damper is increased. In addition, the mandrel adopts a hollow structure, so that the coil is more conveniently guided out, and the tightness is better.

Fig. 9 shows the input end disks 46 and the output end disks 47, respectively. They are specially shaped and the input disc 46 and the outer end pad 44 are circumferentially positioned within the magnetorheological damper housing 45. The outer end spacer 44, the inner end spacer 49 can be positioned circumferentially within the spacer 58.

The invention designs a variable damping flexible driving exoskeleton joint, so that the exoskeleton can flexibly move; variable damping can be provided, vibration is reduced, and comfort of a wearer is improved; the joint can be locked at any angle, so that the joint can conduct load better; by connecting the elastic elements in parallel in the transmission chain, gravity compensation is performed, the average power consumption of the motor is reduced, and the cruising ability is enhanced.

The working principle of the invention is as follows:

the series elastic driver is a flexible driver, and by adding an elastic element in a transmission chain, the impact of ground contact on a machine body during landing can be alleviated, and the energy consumption of the system can be reduced by storing and releasing energy. According to the invention, the elastic element 34 at the sliding block is added into the transmission chain, when the transmission chain is subjected to external impact, the elastic element 34 at the sliding block is compressed, energy is stored and the external impact is buffered, and after the impact force is eliminated, the elastic element 34 at the sliding block is restored to the original state through the elastic force and releases the energy, so that the energy loss of the system is reduced. In addition, the invention can detect the rotation angle of the joint center rotator 22 by arranging the encoder 21, then detect the rotation angle change of the motor by the encoder 11 behind the motor to obtain the difference value of the two, finally obtain the magnitude of man-machine interaction force, feed back the man-machine interaction force to the motor, control the magnitude of output moment, reduce the man-machine interaction force and finally realize flexible driving.

The magnetorheological fluid is a novel intelligent material, has good fluidity under the action of no magnetic field, and can be continuously and reversibly converted into a guest-han fluid with high viscosity and low fluidity in millisecond time under the action of strong magnetic field, so that the surface viscosity of the magnetorheological fluid is increased by more than two orders of magnitude, and the magnetorheological fluid presents similar mechanical properties of solids. The magnetorheological damper is a damper using magnetorheological fluid as a working medium, in the patent, by electrifying a coil 57 to generate a magnetic field, a mandrel 39, a side plate 43, an input end disc 46 and an output end disc 47 are made of magnetic conductive materials to form a magnetic field loop, so that magnetic force lines vertically penetrate the input end disc 46 and the output end disc 47, the magnetorheological fluid 48 between the input end disc 46 and the output end disc 47 is distributed along the magnetic field direction under the action of the magnetic field, and is converted from low-viscosity high-fluidity fluid into high-viscosity low-fluidity guest-han fluid, so that damping is generated between the input end disc 46 and the output end disc 47, the input end disc 46 and the output end disc 47 are respectively connected with a magnetorheological damper shell 45 and the mandrel 39, the magnetorheological damper shell 45 and the mandrel 39 are respectively connected with a joint center rotating body 22 and an exoskeleton joint shell 2, damping is finally generated between the joint center rotating body 22 and the exoskeleton joint shell 2, the magnitude of the magnetic field generated by controlling the magnitude of current input into the coil 57 can be changed, the magnitude of the joint damping is further changed, and thus the joint damping is formed, and the complex environment can be reduced. In addition, when the joint needs to transmit load, the damping of the magneto-rheological damper can be maximized, so that the aim of locking the joint is fulfilled, and the load is better transmitted.

Gravity compensation is the maintenance of the sum of gravitational potential energy and elastic potential energy of the system by means of elastic elements. In this patent, take the hip joint as the example, when the thigh is in vertical state, the torsional spring provides the moment of upwards lifting for the thigh, and when the thigh had lifted, the torsional spring provides reverse moment for the thigh, and this accords with the motion law of human body in the walking process, promptly in the early stage of swing phase, needs to provide the moment of upwards lifting for the thigh, at the end of swing phase, needs to provide the moment of resistance backward for the thigh, slows down the velocity of movement of thigh, can make the exoskeleton joint average power reduce when moving like this to reduce the energy consumption in whole in-process.

Dynamic vibration absorbers refer to devices that utilize a resonant system to absorb vibrational energy of an object to reduce vibration of the object. The principle is that a mass spring resonance system is added on the vibrating object, and the reaction force generated by the added system at resonance can reduce the vibration of the vibrating object. In this application, establish ties elastic drive ware, magneto rheological damper, torsional spring three and connect in parallel, formed dynamic vibration absorber to can deal with more complicated environment, reduce the vibration, improve the travelling comfort of ectoskeleton.

Claims

1. The exoskeleton joint driven flexibly by variable damping is characterized by comprising a crank block, a serial elastic driver (1), an exoskeleton joint shell (2) and a magneto-rheological damper (3);

two joint rolling bearings (8) are arranged in the exoskeleton joint shell (2) and used for supporting a joint center rotating body (22) in a crank slider serial elastic driver (1), other rods or joints are connected through inter-joint connectors (9), an elastic element (10) is respectively connected with the exoskeleton joint shell (2) and the joint center rotating body (22), a first magnetorheological damper connecting block (42) in the magnetorheological damper (3) is connected with the exoskeleton joint shell (2), a second magnetorheological damper connecting block (51) in the magnetorheological damper (3) is connected with the joint center rotating body (22), and the crank slider serial elastic driver (1), the magnetorheological damper (3) and the elastic element (10) are connected in parallel;

the center of the joint center rotating body (22) is of a hollow structure and is used for placing the magnetorheological damper (3), 4 arc-shaped bosses are arranged on the end face, the axial circumferential limit and connecting holes are provided for the second connecting block (51) of the magnetorheological damper while bearing is carried, in addition, the end face is provided with an array of holes which are used for connecting the joint connecting piece (9) and the crank (23), and the holes of the circumferential array are used for adjusting the relative positions of the crank (23) and the joint center rotating body (22), so that the range of joint output angles is adjusted;

the first magnetorheological damper connecting block (42) is connected with the exoskeleton joint shell (2), and adopts a flower-shaped structure, the first magnetorheological damper connecting block (42) plays a role of an end cover and limits the mandrel (39);

the end face of the second magnetorheological damper connecting block (51) is provided with 4 bosses which are used for corresponding to 4 arc bosses of the joint center rotating body (22), so that circumferential and axial limiting is realized, and 4 circumferential holes are formed in the center of the second magnetorheological damper connecting block and are used for being connected with the mandrel (39); the exoskeleton joint housing (2) is divided into an upper part and a lower part, and the upper part and the lower part of the exoskeleton joint housing (2) are connected through a copper column (4), a first shell supporting plate (5), a second shell supporting plate (6) and a third shell supporting plate (7).

2. The variable damping compliant driving exoskeleton joint as claimed in claim 1, wherein the crank block serial elastic driver (1) comprises a first encoder (11), the first encoder (11) is connected with a motor (13), the motor (13) is placed on a motor base (12) and is connected with a guide rail base (30) through a motor fixing seat (14), a motor shaft of the motor (13) is connected with a small synchronous pulley (15), the small synchronous pulley (15) is driven by a large synchronous pulley (17) through a synchronous belt (16), the large synchronous pulley (17) is connected with a screw (24), an elastic slider (26) is connected on the screw (24), screw end flange bearings (25) are supported at two ends of the screw (24), the screw end flange bearings (25) are embedded into screw end baffle blocks (18), and the screw end baffle blocks (18) are connected with the exoskeleton joint housing (2), so that the screw (24) is fixedly connected with the exoskeleton joint housing (2).

3. The variable damping compliant drive exoskeleton joint as claimed in claim 2, wherein said elastic slider (26) is connected to an elastic slider base (27), the elastic slider base (27) is connected to an elastic slider connector (28), the elastic slider connector (28) is capable of sliding on a guide rail (29), the guide rail (29) is connected to a guide rail base (30), the guide rail base (30) is connected to the exoskeleton joint housing (2), and a motor base (12) and a motor fixing base (14) are provided on top of the guide rail base (30);

the elastic sliding block (26) comprises a sliding block (36), the sliding block (36) is connected with a screw rod (24), optical axes (35) at four sliding blocks penetrate through the sliding block (36) and are connected to a connecting block (38) at the front end and the rear end of the sliding block, the optical axes (35) at the sliding block are connected with elastic elements (34) at the sliding block, a connecting block (37) at the left end and the right end of the sliding block is connected with a connecting block (38) at the front end and the rear end of the sliding block, a crank (23) is arranged on the connecting block (37) at the left end and the right end of the sliding block, a flange bearing (33) at the end of the sliding block is arranged in the crank (23), and the sliding block is fixed through bolts (31) and gaskets (32).

4. A variable damping compliant drive exoskeleton joint as claimed in claim 2 wherein said resilient slider (26) is connected to a crank (23) with a bolt (31) fixed therebetween, a slider end flange bearing (33) supports the resilient slider (26), the crank (23) is connected to a joint center rotator (22), the joint center rotator (22) is in turn meshed with an encoder output gear (20), the encoder output gear (20) is connected to an encoder two (21) and to the exoskeleton joint housing (2) via an encoder connection (19).

5. The variable damping compliant driving exoskeleton joint as claimed in claim 1, wherein the magnetorheological damper (3) comprises a mandrel (39), the mandrel (39) is coaxial with the central hole of the first magnetorheological damper connecting block (42) and is supported by an input end bearing (61), a sealing ring (41) is arranged between the mandrel (39) and the first magnetorheological damper connecting block (42), a sealing gasket (60) is arranged between the first magnetorheological damper connecting block (42) and the first magnetorheological damper housing (45) for sealing, a coil (57) is wound on the mandrel (39), the magnetorheological fluid (48) is separated from the coil (57) by a spacer (58), the second sealing ring (56) is used for sealing, then the spacer (58) is axially positioned by a side plate (43), 4 grooves are respectively arranged on the first magnetorheological damper housing (45) and the spacer (58), the first output end disc (47) is circumferentially fixed, then the first magnetorheological damper connecting block (42) and the second magnetorheological damper housing (45) are axially fixed by an outer end gasket (44) and an inner end gasket (49) respectively, and finally the first magnetorheological damper housing (46) is axially fixed, and the second magnetorheological damper housing (46) is axially fixed.

6. The flexible driving exoskeleton joint of claim 5, wherein the lengths of the outer end pad (44) and the inner end pad (49) are adjustable to adapt to different working conditions, the output end of the mandrel (39) is coaxial with the outer end flange (50) of the magnetorheological damper, the mandrel (39) is supported by the output end bearing (53) of the magnetorheological damper, and the mandrel (39) is sealed by the sealing pad (60) and the first sealing ring (41) to realize the connection of the mandrel (39) with the second connecting block (51) of the magnetorheological damper, the second connecting block (51) of the magnetorheological damper is connected with the central rotating body (22) of the joint, and the input end disc (46) is connected with the first connecting block (42) of the magnetorheological damper and further connected with the outer shell (2) of the exoskeleton joint.

7. The variable damping compliant actuated exoskeleton joint as claimed in claim 5 wherein said magnetorheological damper housing (45) has 4 channels and 4 spline grooves on its inner wall, four spline grooves being equally spaced, a set of oppositely disposed spline grooves having channels on both sides for better injection of magnetorheological fluid, the spline grooves for circumferential fixation of the input disc (46).

8. The variable damping compliant drive exoskeleton joint of claim 5 wherein said mandrel (39) is hollow to facilitate the guiding out of the coil, and a circular arc structure at the coil to provide a more uniform magnetic field distribution and thus a higher magnetic field strength at the serpentine circuit.

9. The variable damping compliant drive exoskeleton joint of claim 5 wherein said input disc (46) is of annular configuration with four protrusions disposed on the outside of the annular configuration, said protrusions being disposed at equal intervals with the outside edges of the protrusions being larger than the contact ends with the annular configuration, and said output disc (47) is of annular configuration with four protrusions disposed on the inside of the annular configuration, said protrusions being disposed at equal intervals with the inside edges of the protrusions being larger than the contact ends with the annular configuration.