CN108836583B

CN108836583B - Active and passive ankle joint prosthesis with variable-rod-length gear five-rod mechanism

Info

Publication number: CN108836583B
Application number: CN201810475980.9A
Authority: CN
Inventors: 葛文杰; 王建停; 董典彪; 刘思哲; 赵振飞; 邵俊飞
Original assignee: Northwest University of Technology
Current assignee: Northwest University of Technology
Priority date: 2018-05-17
Filing date: 2018-05-17
Publication date: 2020-01-14
Anticipated expiration: 2038-05-17
Also published as: CN108836583A

Abstract

The invention relates to a variable-rod-length gear five-rod mechanism active and passive type ankle joint artificial limb, which adopts a mode of combining an active type artificial limb and a passive type artificial limb, and can effectively reduce the power and energy requirements of a motor through an energy storage spring and an elastic foot plate.

Description

Active and passive ankle joint prosthesis with variable-rod-length gear five-rod mechanism

Technical Field

The invention relates to an ankle joint prosthesis for single-leg or double-leg below-knee amputation, in particular to an active and passive ankle joint prosthesis with a variable-rod-length gear and a five-rod mechanism.

Background

The artificial limb is one of important means for solving the mobility disorder of the disabled, is different from an upper artificial limb, and the control of a lower artificial limb relates to the problem of human body motion balance, so that the artificial limb has a very important influence on the daily life of the disabled. The ankle joint prosthesis is used as a more core part of the lower limb prosthesis, and the quality of the function of the ankle joint prosthesis directly influences the overall performance of the lower limb prosthesis and the use feeling of a wearer. At present, the artificial limb sold on the market is mainly passive, a spring, an elastic element and a damping element for providing damping force are generally adopted, and due to effective control of damping, the running smoothness of the artificial limb is improved, but the adaptive gait is limited, particularly the adaptive rapid walking is not suitable, and the core problem of mismatching gait is not solved. A new generation of semi-active artificial limb is developed based on a passive artificial limb core technology, so that the elastic force or the damping force which is good at the passive artificial limb can be provided, necessary power assistance can be provided, and the controllable range of the ankle joint is expanded. The gait can be smoother due to the existence of the elastic force or the damping force, the artificial limb cannot rebound suddenly, and the fatigue of the disabled can be effectively relieved due to the existence of the power assisting force.

In chinese patent CN201814690U, an active bionic ankle joint prosthesis is disclosed, which adopts a combination of active control and passive control, so as to reduce energy loss, and implement a motion law close to the angle change of the ankle joint of a normal human body, but this mechanism cannot meet the requirement of the ankle joint on moment in the gait process, and cannot perform specific energy compensation.

In chinese patent CN102973338A, an active-passive type two-degree-of-freedom ankle joint prosthesis is disclosed, which may provide energy required by human body by energy compensation of the elastic potential energy stored by the carbon fiber foot plate in the early stage of gait and the potential energy stored by the ball screw compression spring in the middle stage of gait when the toes are off the ground in the later stage of gait, but the ankle joint prosthesis cannot be matched with the torque characteristic in the normal gait process in the gait process, and the problem of imbalance easily occurs in gait without solving the problem of gait mismatch.

Disclosure of Invention

Technical problem to be solved

In view of the defects in the prior art, the invention provides the active and passive type ankle joint prosthesis of the variable-rod-length gear five-rod mechanism based on the kinematics and the dynamic characteristics of the ankle joint, the bionic performance of the ankle joint prosthesis is realized through the human gait angle characteristic, the torque characteristic and the bionic design by utilizing the characteristic of rich motion rules of the variable-rod-length gear five-rod mechanism, meanwhile, the energy requirement of the ankle joint prosthesis is realized through the use of the parallel elastic driver, and the requirements of the lower limb amputation patient on better free walking and stable standing can be better met.

Technical scheme

An active and passive ankle joint prosthesis of a variable-rod-length gear five-rod mechanism is characterized by comprising an elastic foot plate, a motor, a ball screw device, a motor fixing support, a synchronous belt transmission device, an energy storage spring device, a variable-rod-length gear five-rod mechanism, a shank structure, an ankle joint support seat and a spring support seat; the ankle joint supporting seat and the spring supporting seat are fixed on the elastic foot plate to jointly form a foot structure of the artificial limb; the shank structure comprises a shank side plate, a shank upper end plate and a shank lower end plate, the upper end of the shank side plate is connected with the shank upper end plate, the lower end of the shank side plate is connected with the shank lower end plate, and the shank structure is arranged on the ankle joint supporting seat through a rolling shaft and a rolling bearing and can rotate around the ankle joint supporting seat structure; the motor is fixedly connected with a motor fixing support, and the motor fixing support is fixed on the shank side plate; the synchronous belt device comprises a No. 1 synchronous belt wheel, a synchronous belt and a No. 2 synchronous belt wheel, wherein the No. 1 synchronous belt wheel is fixed on an output shaft of the motor, and the No. 2 synchronous belt wheel is fixed on a lead screw of the ball screw device; the ball screw device comprises a screw, a screw flange connecting block and a screw flange, wherein the upper end and the lower end of the screw are respectively fixed with an upper crus end plate and a lower crus end plate through angular contact bearings, the screw flange connecting block is fixedly connected with the screw flange, and a No. 2 synchronous belt pulley is fixedly connected on the screw; the variable-rod-length gear five-rod mechanism comprises a shank structure, a ball screw device, a No. 1 connecting rod, a No. 2 connecting rod, a No. 3 connecting rod, a No. 1 gear, a No. 2 gear and a foot structure; the No. 2 gear is fixedly connected on the lower end plate of the shank, and the No. 1 gear is fixedly connected with the No. 3 connecting rod and is connected on the spring support through a rolling shaft; the No. 2 connecting rod is connected with the No. 3 connecting rod through a rolling shaft, and is connected with the No. 1 connecting rod through the rolling shaft and a rolling bearing, and in addition, the No. 1 connecting rod is connected with a screw rod flange connecting block through the rolling shaft and the rolling bearing; the energy storage spring device comprises an energy storage spring, an upper spring end block and a lower spring end block, wherein two ends of the energy storage spring are respectively connected with the upper spring end block and the lower spring end block, the upper spring end block is installed on the No. 2 connecting rod through a rolling shaft and a rolling bearing, and the lower spring end block is installed on a spring supporting seat through the rolling shaft and the rolling bearing.

Advantageous effects

The invention relates to a driving and passive type ankle joint artificial limb of a variable-rod long-gear five-rod mechanism capable of conveniently providing driving force, which adopts a mode of combining an active type artificial limb and a passive type artificial limb and can effectively reduce the power and energy requirements of a motor through an energy storage spring and an elastic foot plate.

Drawings

FIG. 1 is a schematic view of an active and passive ankle prosthesis fitting assembly of the variable length gear five bar mechanism of the present invention;

fig. 2 is a schematic view of the variable-rod-length gear five-rod mechanism of the invention.

Detailed Description

The invention will now be further described with reference to the following examples and drawings:

referring to fig. 1-2, the active and passive type ankle joint prosthesis with the variable-rod long-gear five-rod mechanism comprises: no. 1-1 synchronous belt wheel; 2-synchronous belt; 3, fixing a support of the motor; 4-a motor; 5-a lead screw flange connecting block; 6-shank lateral plate; 7-a lead screw; 8-upper plate of shank; 9-a screw flange; a No. 10-1 connecting rod; 11-spring upper end block; connecting rod number 12.2; 13-an energy storage spring; a No. 14-3 connecting rod; 15-spring lower end block; 16-a spring support seat; 17-a resilient foot plate; gear number 18-1; gear number 19-2; 20-ankle joint support seat; 21-lower calf endplate; no. 22-2 synchronous pulley.

The invention provides a driving and passive type ankle joint prosthesis of a variable-rod-length gear five-rod mechanism, which comprises an elastic foot plate 17, a motor 4, a ball screw device, a motor fixing support 3, a synchronous belt transmission device, an energy storage spring device, a variable-rod-length gear five-rod mechanism, a shank structure, an ankle joint support seat 20 and a spring support seat 16.

The elastic foot plate 17, the ankle joint supporting seat 20 and the spring supporting seat 16 are connected through screws, and a foot structure of the artificial limb is jointly manufactured;

the shank structure mainly comprises a shank side plate 6, a shank upper end plate 8 and a shank lower end plate 21, is fixedly connected through screws and serves as a main frame of a shank, and is also a main frame for fixing a motor and fixing a ball screw device, and is arranged on the ankle joint support seat 20 (connected through a rolling shaft and a rolling bearing, which are not marked in the figure) and can rotate around the ankle joint support seat 20;

the motor 4 is connected with the motor fixing support 3 through a screw, the motor fixing support 3 is fixed on the shank side plate 6 through a screw, and in addition, the No. 1 synchronous pulley 1 is fixed on an output shaft of the motor through a set screw;

the synchronous belt device consists of a No. 1 synchronous belt pulley 1, a synchronous belt 2 and a No. 2 synchronous belt pulley 22, wherein the No. 1 synchronous belt pulley 1 is fixed on an output shaft of the motor through a set screw, and the No. 2 synchronous belt pulley 22 is fixed on a lead screw 7 of the ball screw device through a set screw;

the ball screw device mainly comprises a screw 7, a screw flange connecting block 5 and a screw flange 9, wherein the upper end and the lower end of the screw 7 are respectively fixedly installed with the upper end 8 of a shank and the lower end 21 of the shank through angular contact bearings (not marked in the figure), the screw flange connecting block 5 is fixedly connected with the screw flange 9 through screws, and a No. 2 synchronous belt pulley is fixedly connected on the screw 7 through a set screw;

the variable-rod-length gear five-rod mechanism mainly comprises a shank structure, a ball screw device, a No. 1 connecting rod 10, a No. 2 connecting rod 12, a No. 3 connecting rod 14, a No. 1 gear 18, a No. 2 gear 19 and a foot structure. The gear No. 2 is fixedly connected to the lower end plate 21 of the lower leg through a pin shaft. The No. 1 gear 19 is fixedly connected with the No. 3 connecting rod 14 through a pin shaft and is connected to the spring support 16 through a rolling shaft. The No. 2 connecting rod 12 is connected with the No. 3 connecting rod 14 through a rolling shaft, and is connected with the No. 1 connecting rod 10 through the rolling shaft and a rolling bearing. In addition, the No. 1 connecting rod is connected with a screw flange connecting block 9 through a rolling shaft and a rolling bearing;

the energy storage spring device consists of an energy storage spring 13, an upper spring end block 11 and a lower spring end block 15, wherein the energy storage spring 13 is connected with the upper spring end block 11 and the lower spring end block 15 through screws, the upper spring end block 11 is installed on the No. 2 connecting rod 12 through a rolling shaft and a rolling bearing, and the lower spring end block 15 is installed on a spring supporting seat 16 through the rolling shaft and the rolling bearing.

In the control plantar flexion stage (early stage of gait support), when the heel lands, the human body starts to move downwards and forwards to convert gravitational potential energy into elastic potential energy of the elastic foot plate 17, and at the moment, the motor 4 rotates the synchronous belt transmission device, the rolling screw rod device and the five-rod gear mechanism to move;

in a stage of controlling dorsiflexion (gait support middle stage), the motor 4 continues to rotate and drives the synchronous belt transmission device, the ball screw device and the five-rod gear device to compress the energy storage spring 13 for energy storage, and at the moment, the gravity center of the human body continues to move downwards and forwards to convert gravitational potential energy into elastic potential energy of the elastic foot plate 17 and elastic potential energy of the energy storage spring 13;

in the active plantar flexion stage (later stage of gait support), the human body starts to move upwards and forwards at the center of gravity, at the moment, the elastic potential energy stored in the elastic foot plate 17 and the elastic potential energy of the energy storage spring 13 start to be released outwards to provide forward driving energy for the user, and the motor 4 continues to rotate to compensate the insufficient energy of the elastic foot plate 17 and the energy storage spring 13;

in the swing stage (gait swing stage), at the moment, the foot leaves the ground, the elastic foot plate 17 and the energy storage spring 13 are in the relaxation stage, no potential energy exists, and the motor 4 rotates to enable the driving and driven type ankle joint artificial limb of the gear five-bar mechanism to realize initial position reset so as to prepare for the posture of the foot landing in the next stage.

The variable-rod-length gear five-rod mechanism active and passive type ankle joint prosthesis can better realize the energy combination of the active type ankle joint prosthesis and the passive type ankle joint prosthesis, the variable-rod-length gear five-rod mechanism active and passive type ankle joint prosthesis drives a user to move forwards, and the energy source comprises two parts, wherein one part is derived from the driving energy provided by the motor 4, and the other part is derived from the energy stored by the deformation of the energy storage spring 13 and the elastic foot plate 17.

In order to realize the gait motion and the angle torque characteristic of the ankle joint of the user, the active driving motor 4 is added to carry out energy compensation and pose adjustment. In the stage of controlling plantarflexion (earlier stage of gait support), when the heel lands, the motor rotates 4 to drive the synchronous belt transmission device, the rolling screw rod device and the gear five-rod mechanism to move, so that the energy storage spring 13 is stretched, and the matching of the angular torque characteristics of the ankle joint is realized; in a dorsiflexion control stage (gait support middle stage), the motor 4 continues to rotate, and the synchronous belt transmission device, the ball screw device and the gear five-bar mechanism are driven to compress the energy storage spring 13 for energy storage; in the active plantar flexion stage (later stage of gait support), the motor 4 continues to rotate to drive the synchronous belt transmission device, the ball screw device and the five-rod gear device to move, so that the energy stored in the energy storage spring 13 is released, and the driving energy caused by insufficient energy stored in the elastic foot plate 17 and the energy storage spring 13 is compensated; in the swing stage (gait swing period), at the moment, the foot is lifted off the ground, the motor 4 rotates to drive the synchronous belt transmission device, the rolling screw rod device and the five-rod gear mechanism to move, so that the driving and driven type ankle joint artificial limb of the five-rod gear mechanism realizes initial position reset, and posture preparation is carried out for the foot landing in the next stage.

The primary source of drive for the motion of the prosthesis in the sagittal plane is stored in the stored energy spring 13 and the flexible foot plate 17. In the control plantar flexion stage (early stage of gait support), when the heel touches the ground, the human body then starts to move down and tilt forward the center of gravity to convert the gravitational potential energy into the elastic potential energy of the elastic foot plate 17; in the stage of controlling dorsiflexion (middle stage of gait support), the human body continues to move downwards and forwards to convert the gravitational potential energy into the elastic potential energy of the elastic foot plate 17 and the elastic potential energy of the energy storage spring 13; in the active plantar flexion stage (later stage of gait support), the human body starts to move the gravity center upwards and forwards, and the elastic potential energy stored in the elastic foot plate 17 and the elastic potential energy of the energy storage spring 13 start to be released outwards to provide forward driving energy for the user; in the swing phase (gait swing phase), when the foot is off the ground, the elastic foot plate 17 and the energy storage spring 13 are in the relaxation phase, and no potential energy is generated.

Claims

1. An active and passive ankle joint prosthesis of a variable-rod-length gear five-rod mechanism is characterized by comprising an elastic foot plate (17), a motor (4), a ball screw device, a motor fixing support (3), a synchronous belt transmission device, an energy storage spring device, a variable-rod-length gear five-rod mechanism, a shank structure, an ankle joint support seat (20) and a spring support seat (16); the ankle joint supporting seat (20) and the spring supporting seat (16) are fixed on the elastic foot plate (17) to jointly form a foot structure of the artificial limb; the shank structure comprises a shank side plate (6), a shank upper end plate (8) and a shank lower end plate (21), the upper end of the shank side plate (6) is connected with the shank upper end plate (8), the lower end of the shank side plate (6) is connected with the shank lower end plate (21), and the shank structure is installed on the ankle joint support seat (20) through a rolling shaft and a rolling bearing and can rotate around the ankle joint support seat (20) structure; the motor (4) is fixedly connected with the motor fixing support (3), and the motor fixing support (3) is fixed on the shank side plate (6); the synchronous belt transmission device comprises a No. 1 synchronous belt wheel (1), a synchronous belt (2) and a No. 2 synchronous belt wheel (22), wherein the No. 1 synchronous belt wheel (1) is fixed on an output shaft of a motor, and the No. 2 synchronous belt wheel (22) is fixed on a lead screw (7) of the ball screw device; the ball screw device comprises a screw (7), a screw flange connecting block (5) and a screw flange (9), wherein the upper end and the lower end of the screw (7) are respectively fixed with an upper crus end plate (8) and a lower crus end plate (21) through angular contact bearings, the screw flange connecting block (5) is fixedly connected with the screw flange (9), and a No. 2 synchronous belt pulley is fixedly connected on the screw (7); the variable-rod-length gear five-rod mechanism comprises a shank structure, a ball screw device, a No. 1 connecting rod (10), a No. 2 connecting rod (12), a No. 3 connecting rod (14), a No. 1 gear (18), a No. 2 gear (19) and a foot structure; the No. 2 gear (19) is fixedly connected on the lower end plate (21) of the shank, and the No. 1 gear (18) is fixedly connected with the No. 3 connecting rod (14) and is connected on the spring supporting seat (16) through a rolling shaft; the No. 2 connecting rod (12) is connected with the No. 3 connecting rod (14) through a rolling shaft, and is connected with the No. 1 connecting rod (10) through the rolling shaft and a rolling bearing, and in addition, the No. 1 connecting rod (10) is connected with the screw flange connecting block (5) through the rolling shaft and the rolling bearing; the energy storage spring device comprises an energy storage spring (13), an upper spring end block (11) and a lower spring end block (15), two ends of the energy storage spring (13) are respectively connected with the upper spring end block (11) and the lower spring end block (15), the upper spring end block (11) is installed on a No. 2 connecting rod (12) through a rolling shaft and a rolling bearing, and the lower spring end block (15) is installed on a spring supporting seat (16) through the rolling shaft and the rolling bearing.