CN108210246B

CN108210246B - Four-degree-of-freedom rehabilitation mechanical arm device

Info

Publication number: CN108210246B
Application number: CN201810023630.9A
Authority: CN
Inventors: 李明爱; 刘帆; 孙炎珺; 杨金福
Original assignee: Beijing University of Technology
Current assignee: Beijing University of Technology
Priority date: 2018-01-10
Filing date: 2018-01-10
Publication date: 2020-04-03
Anticipated expiration: 2038-01-10
Also published as: CN108210246A

Abstract

The invention discloses a four-degree-of-freedom rehabilitation mechanical arm device which comprises a base and a rehabilitation mechanical arm, wherein the rehabilitation mechanical arm is arranged on the base. The rehabilitation mechanical arm consists of a shoulder abduction joint, a shoulder flexion and extension joint, an elbow flexion and extension joint and a wrist flexion and extension joint. After the motor imagery electroencephalogram signals are collected, two classification signals obtained through preprocessing, feature extraction and mode classification are used as input signals of the mechanical arm control unit. The control unit outputs PWM waves to control the shoulder abduction motor, the shoulder flexion and extension motor, the elbow flexion and extension motor and the wrist abduction motor to rotate. The classification of the operation imagination electroencephalogram signals is realized through an algorithm, and the signals are transmitted to a control unit. The control unit sends out corresponding control signals. The control signal controls the rotation of the servo motor. The mechanical arm is simple in structural design and convenient to mount and dismount.

Description

Four-degree-of-freedom rehabilitation mechanical arm device

Technical Field

The invention relates to the field of brain-computer interfaces and rehabilitation training, and mainly realizes active rehabilitation training of arms based on motor imagery electroencephalogram signals.

Background

With the aging of the global population becoming more and more serious, the elderly are mostly accompanied by the symptoms of apoplexy and hemiplegia. Rehabilitation training plays an important role in recovering and improving the limb movement function of the rehabilitation trainers. The motor function rehabilitation training robot can reduce the workload of a rehabilitation doctor, but has poor treatment effect. BCI (brain computer interface) technology offers a good alternative to this problem, and the main motivation for constructing BCI is its potential to restore lost sensory and motor abilities. The existing rehabilitation mechanical arm system platform is too large and complex, is difficult to move, and is not beneficial to the application and popularization of the rehabilitation system.

Aiming at the problems, the invention provides a four-degree-of-freedom rehabilitation mechanical arm device, which is a comfortable, flexible and convenient four-degree-of-freedom rehabilitation mechanical arm designed by self aiming at active rehabilitation training based on motor imagery electroencephalogram signals. The method has important scientific research value and application prospect for application of BCI technology in the field of rehabilitation robots and promotion of development of the existing motor function rehabilitation training field.

Disclosure of Invention

The invention aims to provide a mechanical arm capable of performing rehabilitation training of various upper limb conventional actions, and provides a hardware platform for clinical application and online experimental research of a rehabilitation system based on a brain-computer interface technology.

In order to achieve the purpose, the technical scheme adopted by the invention is a four-degree-of-freedom rehabilitation mechanical arm device which comprises a base and a rehabilitation mechanical arm, wherein the rehabilitation mechanical arm is arranged on the base.

The base comprises silence rubber wheel 1, chassis 2, support corner fittings 3, vertical guide rail 4, I shape slider, horizontal support side pipe 6, and four silence rubber wheels 1 are installed in the bottom on chassis 2, and vertical guide rail 4 is installed on chassis 2, and vertical guide rail 4 adopts support corner fittings 3 to fix. The I-shaped sliding block 5 is nested on the vertical guide rail 4, and the position of the I-shaped sliding block 5 and the vertical guide rail 4 can be manually adjusted up and down and locked. The transverse supporting square tube 6 is arranged between the two vertical guide rails 4 and used for maintaining the stability of the vertical guide rails 4.

The rehabilitation mechanical arm consists of a shoulder abduction joint I, a shoulder flexion and extension joint II, an elbow flexion and extension joint III and a wrist flexion and extension joint IV. Wherein the shoulder abduction joint I is connected with the shoulder flexion and extension joint II, and the shoulder flexion and extension joint II is connected with the wrist flexion and extension joint IV through the elbow flexion and extension joint III; the shoulder abduction joint I consists of a shoulder abduction motor fixing part 7, a shoulder connecting rod 8, a shoulder abduction motor 14 and a shoulder abduction motor coupler 15, the shoulder abduction motor 14 is installed on the shoulder abduction motor fixing part 7, and an output shaft of the shoulder abduction motor 14 is connected with the shoulder connecting rod 8 through the shoulder abduction motor coupler 15. The shoulder flexion and extension joint II is composed of a large arm support 9, a large arm connecting rod 10, a shoulder flexion and extension motor 16 and a shoulder flexion and extension motor coupler 17, the large arm support 9 is connected with the large arm connecting rod 10, and the shoulder flexion and extension motor 16 is connected with the large arm connecting rod 10 through the shoulder flexion and extension motor coupler 17. The elbow bending and stretching joint III is composed of a small arm connecting rod 11, an elbow arm support 12, an elbow bending and stretching motor 18 and an elbow bending and stretching motor coupler 19, the small arm connecting rod 11 is connected with the elbow arm support 12, and the elbow bending and stretching motor 18 is connected with the small arm connecting rod 11 through the elbow bending and stretching motor coupler 19. The wrist flexion-extension joint IV is composed of a hand swing part 13, a wrist extension motor coupler 20 and a wrist extension motor 21, and the wrist extension motor 21 is connected with the hand swing part 13 through the wrist extension motor coupler 20.

After the motor imagery electroencephalogram signals are collected, two classification signals obtained through preprocessing, feature extraction and mode classification are used as input signals of the mechanical arm control unit. The control unit outputs PWM waves to control the shoulder abduction motor 14, the shoulder flexion and extension motor 16, the elbow flexion and extension motor 18 and the wrist abduction motor 21 to rotate. The classification of the operation imagination electroencephalogram signals is realized through an algorithm, and the signals are transmitted to a control unit. The control unit sends out corresponding control signals. The control signal controls the rotation of the servo motor.

The large arm support 9, the elbow arm support 12 and the hand swing part 13 are all made of PLA materials, so that the weight of the mechanical arm is reduced.

The shoulder connecting rod 8, the large arm connecting rod 10 and the small arm connecting rod 11 are all made of high-strength aluminum alloy materials, and the overall light weight of the rehabilitation mechanical arm is guaranteed.

Drawings

FIG. 1 is a schematic structural diagram of a four-degree-of-freedom rehabilitation arm device;

FIG. 2 is a schematic structural diagram of a four-DOF rehabilitation robot device joint;

FIG. 3 is a schematic structural diagram of a shoulder abduction joint of a four-degree-of-freedom rehabilitation robot arm device;

FIG. 4 is a schematic diagram of a four-degree-of-freedom rehabilitation robot device with shoulder flexion-extension joints;

FIG. 5 is a schematic diagram of a four-DOF rehabilitation arm device with an elbow flexion-extension joint;

FIG. 6 is a schematic structural diagram of a wrist abduction joint of a four-degree-of-freedom rehabilitation mechanical arm device;

in the figure: 1. the device comprises a mute rubber wheel, 2, a chassis, 3, a supporting corner fitting, 4, a vertical guide rail square tube, 5, an I-shaped sliding block, 6, a transverse supporting square tube, 7, a shoulder abduction motor fixing part, 8, a shoulder connecting rod, 9, a big arm support, 10, a big arm connecting rod, 11, a small arm connecting rod, 12, an elbow arm support, 13, a hand swing part, 14, a shoulder abduction motor, 15, a shoulder abduction motor coupler, 16, a shoulder flexion and extension motor, 17, a shoulder flexion and extension motor coupler, 18, an elbow flexion and extension motor, 19, an elbow flexion and extension motor coupler, 20, a wrist abduction motor coupler, 21 and a wrist abduction motor.

I. Shoulder abduction joints, shoulder flexion and extension joints, III elbow flexion and extension joints, IV and wrist abduction joints.

Detailed Description

The invention is further described with reference to the following figures and detailed description.

The invention relates to a four-degree-of-freedom mechanical arm for active upper limb rehabilitation training based on motor imagery electroencephalogram signals, which is mainly applied to a BCI (brain computer interface) online rehabilitation platform. After the motor imagery electroencephalogram signals are collected, two classification signals obtained through preprocessing, feature extraction and mode classification are used as input signals of the mechanical arm control unit. The control unit outputs PWM waves to control the corresponding servo motor to rotate. The mechanical arm transmission device adopts a motor, a speed reducer, a Hall sensor integrated mode and a direct transmission mode so as to achieve the simplification of the structural design of the mechanical arm, facilitate the installation and the disassembly and the replacement of parts in the future.

The rehabilitation mechanical arm is fixed on the base with the lockable rubber wheel, and is flexible and convenient to move. The height of the mechanical arm can be adjusted up and down, and training requirements of different requirements are met. The shoulder joint has the functions of abduction/adduction and flexion/extension. As shown in FIG. 4, the large arm connecting rod is fixed by adopting threaded holes, and the length of the large arm connecting rod can be adjusted by designing a plurality of rows of threaded holes. Big arm holds in palm device adopts the design of U type, and the structure is stronger to the parcel nature of arm to the accessible installation elastic bandage is fixed the arm. As shown in fig. 5, the small arm connecting rod is also fixed by threaded holes, and the length of the small arm connecting rod can be adjusted according to requirements by designing multiple rows of threaded holes. The edges of the small arm support devices are designed with chamfers, elastic sponges are additionally arranged, a comfortable training mechanism is built, and the small arm support devices can fix the arms through installing elastic bandages. As shown in fig. 6, the hand swing can be held by hand, and the rehabilitation training of the wrist can be realized under the traction of the servo motor.

The invention mainly comprises a base and a rehabilitation mechanical arm. The base is as shown in figure 1, and assembly and disassembly are simple, and four silence rubber wheels can move and lock in the two-dimensional direction, realize the quick nimble removal and the position locking of whole device, and applicable in multiple occasion. The balance weight can be filled below the chassis, and the stability of the whole device can be adjusted. The height of the adjustable arm of the vertical guide rail square tube of the base is locked at a comfortable position convenient for exercise according to requirements.

As can be seen in fig. 2, the rehabilitation arm consists of a shoulder abduction joint I, a shoulder flexion and extension joint II, an elbow flexion and extension joint III and a wrist flexion and extension joint IV. Each joint of the mechanical arm adopts a direct driving mode, so that the power transmission path is shortened, and the structural design of the mechanical arm can be simplified. Shoulder abduction joint: the motor fixing frame is fixed on an I-shaped sliding block of the vertical guide rail square tube. The shoulder abduction motor is fixed on the motor fixing frame, a transmission shaft of the shoulder abduction motor is matched and connected with the coupler in a key groove mode, the coupler is fixed by screws above the coupler along the direction of the transmission shaft, the coupler is fixed with one end of the shoulder connecting rod, and the shoulder joint abduction can be changed from 0 to 90 degrees (assuming that the upper arm naturally droops to be 0 degrees, and the direction far away from the body side is positive). Shoulder flexion and extension joints: the shoulder bending and stretching motor is fixed on the shoulder connecting rod, a transmission shaft of the shoulder bending and stretching motor is matched and connected with the coupler in a key groove mode, and screws are fixed above the coupler along the direction of the transmission shaft. The coupler is fixed with one end of the big arm connecting rod through a threaded hole, and the flexion and extension of the shoulder joint can be changed from 90 degrees to-45 degrees (assuming that the forward swing of the upper arm is positive). The big arm connecting rod is provided with a U-shaped arm support which is made of PLA material to reduce the weight of the mechanical arm. Elbow flexion and extension joints: the elbow bending and stretching motor is fixed on the large arm connecting rod, a transmission shaft of the elbow bending and stretching motor is matched and connected with the coupler in a key slot mode, and screws are fixed above the coupler along the direction of the transmission shaft. The coupler is fixed with one end of the forearm connecting rod through a threaded hole, so that the flexion and extension of the elbow joint can be changed from 0 degree to 125 degrees (assuming that the forearm naturally droops to 0 degree). The small arm support device is fixed with the small arm connecting rod, and is made of PLA materials for reducing weight. Wrist abduction joint: the wrist extending motor is fixed on the small arm connecting rod, the transmission shaft of the wrist extending motor is matched and connected with the coupler in a key groove mode, and screws are fixed above the coupler along the direction of the transmission shaft. The coupling is fixed with the hand swing through the screw hole. The rehabilitation trainee can hold the hand on the direction guide rod of the hand swing part, thereby achieving the purpose of wrist rehabilitation training. The hand goods of furniture for display rather than for use PLA material weight reduction to promote the terminal load weight of arm. The transmission structure of arm all adopts high strength aluminum alloy material preparation, guarantees the holistic lightweight of arm.

Claims

1. The four-degree-of-freedom rehabilitation mechanical arm device is characterized in that: the device consists of a base and a rehabilitation mechanical arm, wherein the rehabilitation mechanical arm is arranged on the base;

the base comprises four silent rubber wheels (1), a chassis (2), supporting corner fittings (3), vertical guide rails (4), an I-shaped sliding block and a transverse supporting square tube (6), wherein the four silent rubber wheels (1) are installed at the bottom of the chassis (2), the vertical guide rails (4) are installed on the chassis (2), and the vertical guide rails (4) are fixed by the supporting corner fittings (3); the I-shaped sliding block (5) is nested on the vertical guide rail (4), and the positions of the I-shaped sliding block (5) and the vertical guide rail (4) can be manually adjusted up and down and locked; the transverse supporting square pipe (6) is arranged between the two vertical guide rails (4) and is used for maintaining the stability of the vertical guide rails (4);

the rehabilitation mechanical arm consists of a shoulder abduction joint (I), a shoulder flexion and extension joint (II), an elbow flexion and extension joint (III) and a wrist flexion and extension joint (IV); wherein the shoulder abduction joint (I) is connected with the shoulder flexion and extension joint (II), and the shoulder flexion and extension joint (II) is connected with the wrist flexion and extension joint (IV) through the elbow flexion and extension joint (III); the shoulder abduction joint (I) consists of a shoulder abduction motor fixing part (7), a shoulder connecting rod (8), a shoulder abduction motor (14) and a shoulder abduction motor coupler (15), wherein the shoulder abduction motor (14) is arranged on the shoulder abduction motor fixing part (7), and an output shaft of the shoulder abduction motor (14) is connected with the shoulder connecting rod (8) through the shoulder abduction motor coupler (15); the shoulder flexion and extension joint (II) consists of a large arm support (9), a large arm connecting rod (10), a shoulder flexion and extension motor (16) and a shoulder flexion and extension motor coupler (17), the large arm support (9) is connected with the large arm connecting rod (10), and the shoulder flexion and extension motor (16) is connected with the large arm connecting rod (10) through the shoulder flexion and extension motor coupler (17); the elbow bending and stretching joint (III) consists of a small arm connecting rod (11), an elbow arm support (12), an elbow bending and stretching motor (18) and an elbow bending and stretching motor coupler (19), the small arm connecting rod (11) is connected with the elbow arm support (12), and the elbow bending and stretching motor (18) is connected with the small arm connecting rod (11) through the elbow bending and stretching motor coupler (19); the wrist flexion-extension joint (IV) consists of a hand swing part (13), a wrist extension motor coupler (20) and a wrist extension motor (21), wherein the wrist extension motor (21) is connected with the hand swing part (13) through the wrist extension motor coupler (20);

after the motor imagery electroencephalogram signals are collected, two classification signals obtained through preprocessing, feature extraction and mode classification are used as input signals of a mechanical arm control unit; the control unit outputs PWM waves to control the shoulder abduction motor (14), the shoulder flexion and extension motor (16), the elbow flexion and extension motor (18) and the wrist abduction motor (21) to rotate; the classification of the motor imagery electroencephalogram signals is realized through an algorithm, and the signals are transmitted to a control unit; the control unit sends out a corresponding control signal; the control signal controls the rotation of the servo motor.

2. The four-degree-of-freedom rehabilitation mechanical arm device according to claim 1, wherein: the big arm support (9), the elbow arm support (12) and the hand swing (13) are all made of PLA materials.

3. The four-degree-of-freedom rehabilitation mechanical arm device according to claim 1, wherein: the shoulder connecting rod (8), the large arm connecting rod (10) and the small arm connecting rod (11) are all made of high-strength aluminum alloy materials.