CN111110409B

CN111110409B - Active-passive hybrid drive intelligent artificial limb knee joint structure

Info

Publication number: CN111110409B
Application number: CN202010045730.9A
Authority: CN
Inventors: 郑宏宇; 汪晓铭; 喻洪流; 孟巧玲; 张哲文; 孙金悦; 杨洁; 李科静; 蓝贺
Original assignee: University of Shanghai for Science and Technology
Current assignee: University of Shanghai for Science and Technology
Priority date: 2020-01-16
Filing date: 2020-01-16
Publication date: 2022-03-25
Anticipated expiration: 2040-01-16
Also published as: CN111110409A

Abstract

The invention relates to the field of wheelchairs, and discloses an active and passive hybrid drive intelligent artificial limb knee joint structure which is used for providing required damping and assistance for a user. The invention discloses an active and passive hybrid driving intelligent artificial limb knee joint structure, which comprises: a prosthesis body; the controller is arranged in the artificial limb body; a bi-directional damping cylinder having a first chamber and a second chamber isolated from each other by a pushrod; the damping adjusting seat is provided with an extension hydraulic channel and a buckling hydraulic channel which are respectively communicated with the first chamber and the second chamber; the first check valve is arranged in the extension hydraulic channel, and the second check valve is arranged in the flexion hydraulic channel; the damping adjusting valve is used for changing the flow direction of the hydraulic oil; the direct-current servo motor is used for driving the damping adjusting valve to rotate; the four-bar linkage mechanism is positioned at the top end of the artificial limb body and is used for realizing the squatting of a user; the driving mechanism is arranged on the artificial limb body and is electrically connected with the controller.

Description

Active-passive hybrid drive intelligent artificial limb knee joint structure

Technical Field

The embodiment of the invention relates to the field of wheelchairs, in particular to an active and passive hybrid driving intelligent artificial limb knee joint structure.

Background

With the increase of lower limb amputation patients and the continuous development of technologies such as micro-electronics and control, the intelligent lower limb prosthesis gradually becomes a research hotspot in the field of rehabilitation robots. As a core component of lower limb prosthesis systems, high performance knee prosthesis designs remain a major technical difficulty in current prosthesis designs. The existing intelligent artificial limb knee joint can be divided into a passive type and an active type according to a joint driving mode. When the passive artificial limb knee joint walks, the knee joint damping torque is adjusted according to the change of external conditions to realize gait adjustment, but the passive artificial limb knee joint cannot assist a patient to go upstairs because the active torque is not provided. The active artificial limb knee joint can replace leg muscles to provide torque, so that a wearer can better finish walking modes needing active torque, such as going upstairs and the like, but the active artificial limb knee joint has the defects of higher energy consumption, larger volume and weight of a battery, short endurance time and the like. At present, three ways of adjusting damping in the artificial limb knee joint mainly exist including magnetorheological, pneumatic and hydraulic. The magneto-rheological intelligent knee joint achieves the effect of adjusting damping by changing the magnetic field intensity through changing the current, but the viscosity change of the magneto-rheological fluid is closely related to the magnetic field, the requirements on magneto-rheological fluid materials are high, and the magneto-rheological intelligent knee joint is not easy to control and improve the productivity. The opening degree of the valve inside the damping cylinder is adjusted through the microprocessor driving motor in hydraulic pressure and air pressure, so that the aim of adjusting damping is achieved, but the stability of the supporting performance of the air pressure knee joint is unreliable, and safety accidents are easily caused.

Patent numbers US201100873391a1, 105769395A, 106726028B, 106539633a and 107035808A all propose electrically controlled hydraulic damping cylinder structures for intelligent knee prostheses, but they are essentially pure damping type and cannot provide active moment when climbing stairs and slopes.

Disclosure of Invention

The invention aims to provide an active and passive hybrid driving intelligent artificial limb knee joint structure which can provide required damping and assistance for a user.

The invention provides an active and passive hybrid drive intelligent artificial limb knee joint structure which is electrically connected with a controller and used for providing assistance for a user, and is characterized by comprising the following components: the interior of the artificial limb body is of a hollow structure; a bidirectional damping cylinder installed inside the prosthesis body, the bidirectional damping cylinder having a first chamber and a second chamber isolated from each other by a push rod; the damping adjusting seat is arranged on the bidirectional damping cylinder and is provided with an extension hydraulic channel and a buckling hydraulic channel which are respectively communicated with the first chamber and the second chamber; the first check valve is arranged in the extension hydraulic channel and used for preventing hydraulic oil in the second chamber from flowing backwards; the second one-way valve is arranged in the buckling hydraulic channel and used for preventing hydraulic oil in the first cavity from flowing backwards; the damping adjusting valve is rotationally connected with the damping adjusting seat and is provided with a first key-shaped groove communicated with the extension hydraulic channel and a second key-shaped groove communicated with the buckling hydraulic channel and used for changing the hydraulic oil flow areas of the extension hydraulic channel and the buckling hydraulic channel so as to adjust the extension damping and the buckling damping of the knee joint; the direct current servo motor is electrically connected with the controller and is used for driving the damping adjusting valve to rotate; the four-bar linkage mechanism is positioned at the top end of the artificial limb body and is provided with an upper connecting bar, the upper connecting bar is rotationally connected with the artificial limb body through a front connecting bar and a rear connecting bar, one end of a push rod connecting bar is connected with the upper connecting bar, and the other end of the push rod connecting bar is connected with a push rod of the bidirectional damping cylinder; and the driving mechanism is arranged on the artificial limb body, is electrically connected with the controller and is used for providing assistance for the bidirectional damping cylinder.

The active and passive hybrid driving intelligent artificial limb knee joint structure provided by the invention can also have the following characteristics: wherein, two-way damping cylinder has: a cylinder body; the cylinder cover is arranged at the top of the cylinder body, is used for sealing the cylinder body and is provided with a mounting hole; the bottom of the push rod is provided with a piston, the piston is positioned in the cylinder body and is in sliding connection with the cylinder body, and the top of the push rod penetrates through the cylinder cover through a mounting hole; and the extension assisting spring is positioned in the second chamber, one end of the extension assisting spring is propped against the piston, and the other end of the extension assisting spring is propped against the cylinder body.

The active and passive hybrid driving intelligent artificial limb knee joint structure provided by the invention can also have the following characteristics: wherein, the actuating mechanism has: the supporting seat is arranged in the artificial limb body; the ball screw is arranged on the supporting seat; the transmission nut is fixedly arranged on the upper part of the nut of the ball screw and is rotationally connected with the push rod of the bidirectional damping cylinder; a driven pulley mounted on the lower part of the ball screw; the driving motor is arranged in the artificial limb body and is electrically connected with the controller; and the driving belt wheel is arranged on a rotating shaft of the driving motor and is driven by the driving belt through a driving belt.

The active and passive hybrid driving intelligent artificial limb knee joint structure provided by the invention can also have the following characteristics: wherein, the magnetic ring fixer is arranged on the damping adjusting seat; and the encoder magnetic ring is arranged on the magnetic ring fixer and is electrically connected with the controller through the encoder reading head, and a rotating shaft of the encoder magnetic ring is fixedly connected with the direct-current servo motor.

The invention also provides an active and passive hybrid driving intelligent artificial limb knee joint structure, which is characterized by further comprising an energy accumulator, wherein the energy accumulator is installed on the damping adjusting seat and used for adjusting the pressure of the buckling hydraulic channel.

The active and passive hybrid driving intelligent artificial limb knee joint structure provided by the invention can also have the following characteristics: wherein, be equipped with the cylindrical notch that is used for holding damping control valve on the damping regulation seat, this cylindrical notch communicates with extension hydraulic channel and bucking hydraulic channel respectively, and the top of this cylindrical notch is equipped with the valve screw plug that is used for sealed cylindrical notch.

Action and Effect of the invention

According to the active-passive hybrid driving intelligent artificial limb knee joint structure, because the two hydraulic oil channels respectively provided with the one-way valve, the damping adjusting valve provided with the key groove, the direct current servo motor connected with the damping adjusting valve and the driving mechanism for providing power for the two-way damping cylinder are arranged, when the active-passive hybrid driving intelligent artificial limb knee joint structure is used, the driving mechanism can be used for providing power for the two-way damping cylinder, and the required damping degree is adjusted through the two hydraulic oil channels provided with the one-way valve, the damping adjusting valve and the direct current servo motor, so that the use requirements of users are met.

Drawings

FIG. 1 is a perspective view of an active-passive hybrid driven intelligent prosthetic knee joint structure according to an embodiment of the present invention;

FIG. 2 is a schematic diagram illustrating an internal structure of an active-passive hybrid driven intelligent prosthetic knee joint structure according to an embodiment of the present invention;

FIG. 3 is a schematic view of a bi-directional damping cylinder in an embodiment of the present invention;

FIG. 4 is a schematic view of a drive mechanism in an embodiment of the present invention;

FIG. 5 is a schematic view of the bi-directional damping cylinder and the damping adjustment mount according to an embodiment of the present invention;

FIG. 6 is a schematic view at A-A in an embodiment of the present invention; and

FIG. 7 is a sectional view taken at B-B in an example of the present invention.

Detailed Description

In order to make the technical means, the creation features, the achievement purposes and the effects of the invention easy to understand, the invention is specifically described below by combining the embodiment and the attached drawings.

< example >

Fig. 1 is a perspective view of an active-passive hybrid driven intelligent prosthetic knee joint structure according to an embodiment of the present invention. Fig. 2 is a schematic diagram of an internal structure of an active-passive hybrid driven intelligent prosthetic knee joint structure according to an embodiment of the present invention. FIG. 3 is a schematic diagram of a bi-directional damping cylinder in an embodiment of the present invention. Fig. 4 is a schematic view of a driving mechanism in an embodiment of the present invention. FIG. 5 is a schematic diagram of the bi-directional damping cylinder and the damping adjustment seat in the embodiment of the present invention. FIG. 6 is a schematic view at A-A in the example of the present invention. FIG. 7 is a sectional view taken at B-B in an example of the present invention.

As shown in fig. 1 to 7, the active-passive hybrid driving intelligent prosthetic knee joint structure 100 provided by the present embodiment includes: the artificial limb comprises an artificial limb body 1, a bidirectional damping cylinder 2, a damping adjusting seat 3, a first one-way valve 4, a second one-way valve 5, a damping adjusting valve 6, a direct-current servo motor 7, a four-bar mechanism 8, a driving mechanism 9, a magnetic ring fixer 10, an encoder magnetic ring 11, an encoder reading head 12 and an energy accumulator 13.

The interior of the prosthesis body 1 is a hollow structure, and the interior is used for accommodating the controller, the bidirectional damping cylinder 2 and the driving mechanism 9. The four-bar linkage 8 has an upper link 801, a front link 802, a rear link 803 and a push rod link 804, wherein the upper part and the upper connection of the prosthesis body 1 are provided with a plurality of mounting holes, and the front link 802 and the rear link 803 are matched with the mounting holes to realize the rotary connection of the upper link 801 and the prosthesis body 1. One end of the push rod link 804 is rotatably connected to the upper link 801, and the other end is connected to the driving mechanism 9.

The bidirectional damping cylinder 2 comprises a cylinder body 201, a cylinder cover 202, a push rod 203 and an extension assisting spring 204. The cylinder cover 202 is installed on the top of the cylinder body 201 in a threaded connection manner, and is used for sealing the cylinder body 201. The bottom of the push rod 203 is provided with a piston which is positioned inside the cylinder 201 and is connected with the cylinder 201 in a sliding way, the cylinder cover 202 is provided with a mounting hole, and the top of the push rod 203 penetrates through the cylinder cover 202 through the mounting hole. The cylinder 201 divides the inner cavity into a first chamber and a second chamber which are isolated from each other by a push rod 203. The extension assisting spring 204 is located in the first chamber, one end of the extension assisting spring 204 abuts against the piston, and the other end of the extension assisting spring abuts against the cylinder 201.

The damping adjusting seat 3 is installed on the bidirectional damping cylinder 2, and the damping adjusting seat 3 is provided with an extension hydraulic channel and a buckling hydraulic channel which are respectively communicated with the first chamber and the second chamber. A first check valve 4 is installed in the extension hydraulic passage for preventing the hydraulic oil in the second chamber from flowing backwards. And a second one-way valve 5 is arranged on the buckling hydraulic channel and used for preventing the hydraulic oil in the first chamber from flowing backwards. The damping adjusting seat 3 is provided with a cylindrical notch for accommodating the damping adjusting valve 6, the cylindrical notch is communicated with the extension hydraulic channel and the buckling hydraulic channel respectively, and the top of the cylindrical notch is provided with a valve thread plug for sealing the cylindrical notch. Still have the cylindrical recess that is linked together with bucking hydraulic passage on the seat 3 is adjusted in damping, accumulator 13 includes energy storage ejector pad 1301, accumulator spring 1303, sealing washer 1302 and screw gland 1304, energy storage ejector pad 1301 is located cylindrical recess, sealing washer 1302 is installed on energy storage ejector pad 1301, be used for preventing that hydraulic oil from oozing, screw gland 1304 threaded connection is on cylindrical recess, be used for sealed cylindrical recess, accumulator spring 1303's one end offsets with energy storage ejector pad 1301, the other end offsets with screw gland 1304. When the knee joint is bent, the push rod moves downwards to enable the space of the hydraulic cylinder chamber to be small, redundant hydraulic oil can enter the energy accumulator through the bent hydraulic oil duct, the energy accumulator push block 1301 is pushed to move, the energy accumulator push block 1301 pushes the energy accumulator spring 1303 to compress and store energy, and therefore the pressure of the hydraulic oil of the bent hydraulic passage is absorbed. And an oil filling port 1305 is arranged on the damping adjusting seat 3, is communicated with the buckling hydraulic channel and is used for filling hydraulic oil into the hydraulic cylinder, and is provided with a plug and used for sealing the oil filling port after oil is filled.

DC servo motor 7 installs and adjusts seat 3 at the damping, and DC servo motor 7's pivot is stretched into cylindrical notch and is connected with damping control valve 6 for drive damping control valve 6, change extend hydraulic passage and bucking hydraulic passage's hydraulic oil flow area, thereby adjust the extension damping and the bucking damping of knee joint.

The drive mechanism 9 includes a support base 901, a ball screw 902, a transmission nut 903, a driven pulley 905, a drive motor 907, a drive pulley 904, and a transmission belt 906. The supporting seat is installed in the prosthesis body 1, a threaded hole matched with the ball screw 902 is formed in the supporting seat 901, and the ball screw 902 is installed on the supporting seat 901 through the threaded hole and is rotatably connected with the supporting seat 901. The drive nut 903 is fixedly mounted on the upper part of the nut of the ball screw 902 and is rotatably connected to the push rod 203 of the bidirectional damping cylinder 2. A driven pulley 905 is mounted on a lower portion of the ball screw 902. The driving motor 907 is installed in the prosthesis body 1 and electrically connected with the controller. The driving pulley 904 is mounted on the shaft of a driving motor 907 and drives a driven pulley 905 via a belt 906. When assisting power, the transmission nut 903 converts the circular motion of the ball screw 902 into a linear motion, the transmission nut 903 pushes or pulls the push rod 203 to move up or down in the linear motion process, and the other end of the push rod 203 is connected with the push rod connecting rod 804, so as to drive the four-bar mechanism 8 to move.

The magnetic ring fixer 10 is arranged on the damping adjusting seat 3. The encoder magnetic ring 11 is installed on the magnetic ring fixer 10 and is electrically connected with the controller through the encoder reading head 12, and the rotating shaft of the encoder magnetic ring 11 is fixedly connected with the direct current servo motor. The rotating angle of the motor shaft of the direct current servo motor 7 can be accurately read through the encoder magnetic ring 11, so that the controller can accurately control the rotating angle of the damping adjusting valve 6 conveniently.

When a user is on an uphill slope or an upstairs, the driving mechanism 9 can generate assistance, and the specific implementation process is as follows:

1. the driving motor 907 is electrified to rotate by the motor, the driving wheel 904 is driven to rotate in the rotating process, the driven wheel 905 is driven to rotate by the driving belt 906, and the driven wheel 905 is fixedly connected with the ball screw 902, so that the ball screw 902 is driven to rotate by the driven wheel 905 in the rotating process.

2. The transmission nut 903 is screwed to the ball screw 902, and converts the circular motion of the ball screw 902 into linear motion. The driving nut 903 drives the push rod 203 to move up or down in the process of moving up or down, and the other end of the push rod 203 is connected with the four-bar mechanism 8, so that the push rod 203 drives the four-bar mechanism 8 to operate in the process of moving up or down, and assistance is provided for a user.

When adjusting the damping degree:

when the knee joint extends, the four-bar linkage 8 drives the push rod 203 to move downwards, meanwhile, the compression extension assisting spring 204 stores energy, the second one-way valve 5 in the buckling hydraulic oil channel is closed, hydraulic oil flows upwards from the extension hydraulic oil channel through the oil hole of the cylinder body 201, the direct-current servo motor drives the damping adjusting valve 6 to rotate, the first key-shaped groove and the overlapping area of the extension hydraulic oil channel further change the flow area of the hydraulic oil, and the damping force applied to the knee joint during extension changes.

When the knee joint is in flexion, the energy stored in the extension assisting spring 204 is released to provide assistance for the upward movement of the push rod 203, the first one-way valve 4 in the hydraulic oil channel is extended, the hydraulic oil flows downwards from the flexion hydraulic oil channel, and the direct-current servo motor drives the damping adjusting valve 6 to rotate, so that the overlapping area of the second key-shaped groove and the flexion hydraulic oil channel is changed, the flow area of the hydraulic oil is further changed, and the damping force applied to the knee joint during flexion is changed.

In summary, the invention provides an active-passive hybrid driving intelligent artificial limb knee joint structure, wherein a motor 907 is used for providing an active moment, a ball screw 902 is driven in a belt transmission manner, and the knee joint is controlled to perform yielding/extending movement through the up-and-down movement of a transmission nut 903. In the case where the knee joint active torque is not required for flat ground, downstairs, downhill, or the like, the angle of the damping control valve 6 is controlled by the dc servo motor 7, the magnitude of the damping of the hydraulic cylinder is controlled, and the drive motor 907 that supplies the active torque does not operate. In the situations such as ascending slopes and stairs where the knee joint needs to provide the active moment, the driving motor 907 provides the active moment for the knee joint, so that the patient can obtain the required damping or driving moment in various use occasions, and meanwhile, the electric consumption of the motor can be reduced, and the working endurance of the intelligent artificial limb is improved.

Effects and effects of the embodiments

According to the active-passive hybrid driving intelligent artificial limb knee joint structure provided by the embodiment, because the two hydraulic oil channels respectively provided with the one-way valve, the damping adjusting valve provided with the key groove, the direct current servo motor connected with the damping adjusting valve and the driving mechanism for providing power for the two-way damping cylinder are arranged, when the active-passive hybrid driving intelligent artificial limb knee joint structure is used, the driving mechanism can provide power for the two-way damping cylinder, and the two hydraulic oil channels provided with the one-way valve, the damping adjusting valve and the direct current servo motor are arranged to adjust the required damping degree, so that the use requirements of users are met.

The driving mechanism is driven by the ball screw mechanism and the synchronous belt, so that the transmission distance of the driving motor is greatly increased, the transmission efficiency of the ball screw mechanism and the synchronous belt is higher, and the transmission efficiency and the transmission precision of the whole mechanism are improved.

The driving motor is a direct current servo motor, the design of a clutch device is omitted, and the driving is driven by hydraulic pressure, so that the stability is greatly improved compared with a supporting mode of a pneumatic cylinder.

The encoder is added at the position of the direct current servo motor, so that the rotating angle of a direct current servo motor shaft can be accurately read, and meanwhile, the angle of the damping adjusting valve can be accurately controlled.

Further, in the active-passive hybrid driving intelligent artificial limb knee joint structure provided by the embodiment, the damping adjusting seat is provided with the energy accumulator,

in addition, when the patient does not need the assistance, the driving motor is powered off, and the adopted servo motor is not provided with a brake, so that the power-off torque is small, and the adjustment of the damping degree cannot be influenced.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An active and passive hybrid drive intelligent artificial limb knee joint structure is connected with controller electric connection for provide required damping and helping hand for the user, its characterized in that includes:

the interior of the artificial limb body is of a hollow structure;

a bidirectional damping cylinder installed inside the prosthesis body, the bidirectional damping cylinder having a first chamber and a second chamber isolated from each other by a push rod;

the damping adjusting seat is installed on the bidirectional damping cylinder and is provided with an extension hydraulic channel and a buckling hydraulic channel which are respectively communicated with the first chamber and the second chamber;

the first check valve is arranged in the extension hydraulic channel and used for preventing hydraulic oil in the second chamber from flowing backwards;

the second one-way valve is arranged in the buckling hydraulic channel and used for preventing the hydraulic oil in the first cavity from flowing backwards;

the damping adjusting valve is rotationally connected with the damping adjusting seat, is provided with a first key-shaped groove communicated with the extension hydraulic channel and a second key-shaped groove communicated with the buckling hydraulic channel, and is used for changing the hydraulic oil flow areas of the extension hydraulic channel and the buckling hydraulic channel so as to adjust the extension damping and the buckling damping of the knee joint;

the direct current servo motor is electrically connected with the controller and is used for driving the damping adjusting valve to rotate;

the four-bar linkage mechanism is positioned at the top end of the artificial limb body and is provided with an upper connecting bar, the upper connecting bar is rotatably connected with the artificial limb body through a front connecting bar and a rear connecting bar, one end of a push rod connecting bar is connected with the upper connecting bar, and the other end of the push rod connecting bar is connected with a push rod of the bidirectional damping cylinder;

the driving mechanism is arranged on the artificial limb body, is electrically connected with the controller and is used for providing assistance for the bidirectional damping cylinder;

the magnetic ring fixer is arranged on the damping adjusting seat; and

and the encoder magnetic ring is arranged on the magnetic ring fixer and is electrically connected with the controller through an encoder reading head, and a rotating shaft of the encoder magnetic ring is fixedly connected with the direct-current servo motor.

2. The active-passive hybrid driven intelligent prosthetic knee joint structure according to claim 1, wherein:

wherein the bidirectional damping cylinder has:

a cylinder body;

the cylinder cover is arranged at the top of the cylinder body, is used for sealing the cylinder body and is provided with a mounting hole;

the bottom of the push rod is provided with a piston, the piston is positioned in the cylinder body and is in sliding connection with the cylinder body, and the top of the push rod penetrates through the cylinder cover through the mounting hole;

and the extension assisting spring is positioned in the second cavity, one end of the extension assisting spring is abutted against the piston, and the other end of the extension assisting spring is abutted against the cylinder body.

3. The active-passive hybrid driven intelligent prosthetic knee joint structure according to claim 1, wherein:

wherein the drive mechanism has:

the supporting seat is arranged in the artificial limb body;

the ball screw is arranged on the supporting seat;

the transmission nut is fixedly arranged on the upper part of the nut of the ball screw and is rotationally connected with the push rod of the bidirectional damping cylinder;

a driven pulley mounted on a lower portion of the ball screw;

the driving motor is arranged in the artificial limb body and is electrically connected with the controller;

and the driving belt wheel is arranged on a rotating shaft of the driving motor and drives the driven belt wheel through a transmission belt.

4. An active-passive hybrid drive intelligent prosthetic knee joint structure according to claim 1, further comprising:

and the energy accumulator is arranged on the damping adjusting seat and is used for adjusting the pressure of the buckling hydraulic channel.

5. The active-passive hybrid driven intelligent prosthetic knee joint structure according to claim 1, wherein:

the damping adjusting seat is provided with a cylindrical notch used for accommodating the damping adjusting valve, the cylindrical notch is communicated with the extension hydraulic channel and the buckling hydraulic channel respectively, and the top of the cylindrical notch is provided with a valve thread plug used for sealing the cylindrical notch.