CN108858148B - A pneumatic muscle-driven upper-limb exoskeleton robot - Google Patents

Abstract

The invention relates to the technical field of robot system design, in particular to an upper limb exoskeleton robot driven by pneumatic muscles, comprising a back support and an upper arm. The upper arm is fixed on the back bracket through the shoulder-back connecting piece, and the back bracket plays the role of connecting and supporting the upper arm. The structure of the limb exoskeleton robot is symmetrical about the center line of the back support. The back support includes a frame structure, a pulley, a shoulder-back connector and a shoulder joint driving muscle, and the pulley is fixed on the upper side of the frame structure; the upper arm includes a locking ball joint, an upper arm outer splint, an upper arm medial splint, an upper arm pulley, and an elbow joint. The fixed wheel drives the muscles in series; the locking ball joint is fixed on the lower surface of the upper end of the shoulder-back connecting piece. The beneficial effects of the invention are as follows: the pneumatic muscle is used as the drive, which greatly reduces the structural complexity and cost compared with the motor and the hydraulic drive; the fixed wheel is installed at the elbow joint, which can ensure the series connection even under the condition of extreme angle. Muscles can output enough torque.

Description

A pneumatic muscle-driven upper-limb exoskeleton robot

technical field

The invention belongs to the technical field of robot system design, in particular to an upper limb exoskeleton robot driven by pneumatic muscles.

Background technique

An exoskeleton robot is essentially a wearable robot, that is, a mechanical mechanism that is worn outside the operator's body. Since exoskeleton robotics can enhance the ability of individuals to complete certain tasks, the human-exoskeleton system composed of exoskeletons and operators can have greater adaptability to the environment. Therefore, research on exoskeleton robots in recent years has caused Many researchers have paid attention to it, and it has been widely used in the fields of individual military combat equipment, auxiliary medical equipment, and assisting institutions.

Traditional exoskeletons mostly use electric motors and hydraulic drives. The cost of electric motors and hydraulic drives is too high, the output torque of motor drives is too small, and the structure is complex, while hydraulic drives are too noisy. The traditional upper limb exoskeleton shoulder joint three-degree-of-freedom drive is often realized separately, the structure is complex and scattered, and the bionic performance is low. At the same time, due to the small contraction rate of pneumatic muscles, the traditional pneumatic muscle-driven exoskeleton has the problem of a small range of motion.

SUMMARY OF THE INVENTION

In order to overcome the above-mentioned deficiencies of the prior art, the present invention provides a pneumatic muscle-driven upper limb exoskeleton robot, which is mainly used for assisting the upper limbs of the human body to bear weight and perform flexible movements.

To achieve the above object, the present invention adopts the following technical solutions:

A pneumatic muscle-driven upper-limb exoskeleton robot including a back support and an upper arm.

The upper arm is fixed on the back support through the shoulder-back connecting piece, and the back support connects and supports the upper arm; the structure of the limb exoskeleton robot is symmetrical along the center line of the back support.

The back support includes a frame structure, a pulley, a shoulder-back connector and a shoulder joint driving muscle, and six pulleys are fixed on the upper side of the frame structure at equal intervals; the six shoulder joint driving muscles are placed in parallel inside the frame structure and correspond to the six pulleys respectively. Its lower end is fixed with the lower side of the frame structure, and the upper end of the shoulder joint driving muscle is respectively connected with the driving rope of the locking ball joint through the wire rope bypassing the pulley located on the upper side of the frame structure, so as to realize the driving of the locking ball joint. The pulley realizes the flexible guidance of the output force direction of the shoulder joint driving muscle, reduces the friction force in the process of force conversion, and improves the transmission efficiency. The shoulder-back connecting piece has a V structure, the opening angle of the V shape is greater than 90 degrees, the lower end of the V shape is fixed on the right side of the frame structure, and the upper end is connected with the locking ball joint of the upper arm.

The upper arm includes a locking ball joint, an outer splint of the upper arm, an inner splint of the upper arm, an upper arm pulley, a fixed wheel of the elbow joint, and a series driving muscle; the locking ball joint is fixed on the lower surface of the shoulder-back connecting piece; The top plane is provided with three holes that are evenly distributed and the distance from the center of the top plane is R; The holes correspond one by one; the three driving ropes of the locking ball joint go around the shoulder guide pulley and connect with the steel wire rope respectively; The forearm is hinged to realize the rotation of the forearm, and the fixed wheel of the elbow joint is fixed on the forearm with the hinge point as the center of the circle;

The upper arm pulley is fixed on the outer side of the upper arm outer splint, the wire rope goes around the upper arm pulley and is connected with one end of the two elbow joint driving muscles respectively, and the other end of the two elbow joint driving muscles is respectively connected with the elbow joint fixed wheel on the forearm and the lower end of the upper arm outer splint, so that The amount of muscle contraction in series becomes larger, which can achieve a wider range of drive to the elbow joint while ensuring a certain output torque.

Further, the locking ball joint includes a shoulder joint fixed platform, a shoulder joint movable platform, a joint ball, an upper arm rotation axis and a driving rope;

The shoulder joint fixing platform includes a top plane and a pillar, the top plane is provided with three evenly distributed holes and the distance from the center of the top plane is R, the top plane is fixed on the upper end of the pillar, the center of the lower end of the pillar is provided with a ball socket, and the joint ball It is placed in the ball socket; the lower end of the joint ball is connected with the upper arm rotating shaft; the upper arm rotating shaft is sheathed with the shoulder joint movable platform, and the shoulder joint movable platform is in the shape of a sleeve. The distance between the central axes is r; the three connecting ends of the shoulder joint movable platform are respectively fixed with three driving ropes, and the other ends of the three driving ropes are connected with the wire ropes after passing through the three holes on the top plane of the shoulder joint fixed platform.

Further, the exoskeleton robot also includes straps, the straps include shoulder straps, chest straps, waist straps, upper arm straps and forearm straps, and the shoulder straps are U-shaped hard materials, It is used to drag the upper limb exoskeleton and load weight. The shoulder straps are symmetrically fixed on the frame structure; the other straps are flexible straps, which can be made of nylon and other soft materials. The chest straps and waist straps are fixed on the frame structure. The upper arm strap is connected to the inner splint of the upper arm, the forearm strap is fixed on the forearm, and the upper arm strap and the forearm strap are used to ensure the human arm and the forearm For the relative fixation between exoskeletons, the main function of the flexible straps is to achieve both a fixation and a certain movement space between the human and the exoskeleton, so as to ensure the comfort of the human body wearing the exoskeleton.

Further, the above-mentioned pneumatic muscle-driven upper limb exoskeleton robot is characterized in that, the elbow joint fixed wheel is a fan-shaped grooved wheel, the elbow joint fixed wheel is fixed with the forearm, and the elbow joint fixed wheel is the same as the hinge. The function of the center of the circle and the fixed wheel of the elbow joint is: when the angle between the forearm and the upper arm is close to 180 degrees, the fixed wheel of the elbow joint ensures that the driving muscle of the elbow joint can output enough torque to drive the elbow joint.

Further, the frame structure adopts two horizontal brackets and two vertical brackets to form a frame structure; the horizontal brackets and the vertical brackets are cut and drilled from angle aluminum materials, and the brackets are fixed by bolts, which can be closely attached to the human body. On the back, the brace mainly plays the role of connecting and supporting the driving muscles of the shoulder joint.

The beneficial effects of the invention are as follows: the self-made pneumatic muscle is used as the drive, the pneumatic muscle has good flexibility and bionic performance, and the structure complexity and cost are greatly reduced compared with the motor and hydraulic drive. The shoulder joint adopts a parallel structure in the form of a ball joint, and the ball socket is inclined to the front right, which is consistent with the physiological performance of the human shoulder joint, with high bionicity and compact structure; the shoulder joint pneumatic muscle is placed on the back support, and the pulley is used to achieve the guiding effect, not only the structure It is compact and beautiful, and can also make up for the deficiency of the insufficient contraction rate of the pneumatic muscle to a certain extent. The elbow joint is driven by two pneumatic muscles in series, which increases the length of the pneumatic muscle, makes up for the deficiency of the insufficient contraction rate of the pneumatic muscle, and makes the elbow joint free. The range of motion is increased; a fixed wheel is installed at the elbow joint, which can ensure that the muscles in series can output sufficient torque even under extreme angles.

Description of drawings

FIG. 1 is a schematic structural diagram of the present invention.

FIG. 2 is a front view of FIG. 1 .

FIG. 3 is a right side view of FIG. 1 .

Figure 4 is a schematic diagram of the connection between the upper arm and the forearm.

5 is a schematic cross-sectional view of the assembly of the upper arm rotating shaft and the shoulder joint movable platform.

In the picture: 1 vertical bracket; 2 forearm straps; 3 upper arm straps; 4 shoulder joint wire ropes; 5 shoulder guide pulleys; 6 back wire ropes; 7 horizontal brackets; 8 back guide pulleys; Joint pneumatic muscles; 10 shoulder joint pneumatic muscles; 11 waist straps; 12 chest straps; 13 shoulder straps; 14 shoulder joint fixed platform; 15 joint ball; ; 19 series pneumatic muscle; 20 upper arm lateral splint; 21 upper arm medial splint; 22 forearm; 23 elbow joint fixed wheel; 24 elbow joint hinge; 25 radial bearing A; 26 thrust bearing; 27 radial bearing B.

Detailed ways

A pneumatic muscle-driven upper limb exoskeleton robot of the present invention will be further described in detail below with reference to FIGS. 1 to 5 and specific embodiments.

As shown in Figures 1 to 5, a pneumatic muscle-driven upper limb exoskeleton robot mainly includes a back bracket, a shoulder-back connector 9, a parallel-driven shoulder joint, an upper arm, a series-driven elbow joint, a forearm 20, straps, etc. , the back support is composed of vertical support 1, horizontal support 7 and shoulder joint drive muscle 10, back support guide pulley 8 and steel wire rope 6, parallel drive shoulder joint is composed of steel wire rope 4, shoulder guide pulley 5, shoulder joint fixed platform 14, joint ball 15 and the shoulder joint movable platform 17, the upper arm is composed of the upper arm rotating shaft 16, the upper arm pulley 18, the upper arm outer splint 20 and the upper arm inner splint 21, and the series driven elbow joint is composed of the series pneumatic muscle 19 and the elbow joint fixed wheel 23. The part is composed of the forearm strap 2, the upper arm strap 3, the waist strap 11, the chest strap 12 and the shoulder strap 14. The upper arm rotating shaft 16 and the shoulder joint movable platform 14 pass through the radial bearing A25, the radial bearing The bearing B27 is connected to the thrust bearing 26 .

Taking the flexion and extension of the shoulder joint in the sagittal plane and the flexion and extension of the elbow joint as an example, the operation process of lifting the upper limb exoskeleton robot arm is explained.

wear

First of all, the human body needs to wear the upper limb exoskeleton. The shoulder strap 13 is a U-shaped hard strap, which is placed on the shoulder of the human body. The main function is to enable the human body to drag the upper limb exoskeleton from below. It is transmitted to the human body through the U-shaped straps on the shoulders, and soft objects such as sponges can be placed under it to improve wearing comfort. When wearing the exoskeleton, first place the shoulder straps on the shoulders of the human body, and then tie the chest straps. 12, waist The straps 11, the upper arm straps 2 and the forearm straps 3, and other straps except the shoulder straps are all flexible straps. The main function of the flexible straps is to achieve both a fixed and There must be a certain space for activities to ensure the comfort of the human body wearing the exoskeleton.

shoulder movement

Taking the right arm as an example, the control system sends a certain signal after detecting the intention of the human body to control the internal air pressure of the three shoulder joint driving muscles 10 respectively. The bracket and the shoulder are fixed on the pulley on the platform and connected to the shoulder joint movement platform 17. When the three pneumatic muscles contract or extend, the force and movement are transmitted to the shoulder joint movement platform through the pulley, and the shoulder joint movement platform transmits the force to the upper arm. The rotating shaft 16 can realize the swinging of the upper arm rotating shaft, that is, two degrees of freedom of abduction/adduction and flexion/extension. Since the shoulder joint movable platform and the upper arm rotating shaft are equipped with a thrust bearing 26 and a radial bearing A25 And the radial bearing B 27, can rotate flexibly, so the internal rotation/external rotation degree of freedom of the shoulder joint is in a non-driven state, and this degree of freedom can be actively driven by the upper limbs of the human body.

elbow joint movement

The pneumatic muscle 19 that drives the elbow joint is in the form of a series connection. The two muscles are connected by a wire rope. The series muscle bypasses the movable pulley 18, and one end is connected to the elbow joint fixed wheel 23 on the forearm. The wire rope bypasses the elbow joint fixed wheel. , one end is connected with the lower end of the outer splint 20, when the pneumatic muscle is inflated, the muscles in series contract together, when the pneumatic muscle contracts, the elbow joint fixed wheel 23 is pulled to move, and the elbow joint fixed wheel 23 is fixed on the forearm 22, This drives the forearm to rotate upwards around the hinge 24 . When the pneumatic muscle is deflated, the tandem muscle elongates, and the elbow joint rotates downward around the hinge under the condition of weight bearing or active driving of the human body.

Claims (3)

1. an upper limb exoskeleton robot driven by a pneumatic muscle, is characterized in that, comprises back support and upper arm; Described upper arm is fixed on the back support by shoulder-back connector (9); The structure of the upper limb exoskeleton robot is symmetrical along the center line of the back support; The back support includes a frame structure, a pulley (8), a shoulder-back connector (9) and a shoulder joint driving muscle (10), and six pulleys (8) are fixed on the upper side of the frame structure at equal intervals; six shoulder joint driving muscles ( 10) Parallel to the inside of the frame structure and corresponding to the six pulleys (8), the lower ends of which are fixed to the lower side of the frame structure, and the upper ends of the shoulder joint driving muscles (10) bypass the pulleys located on the upper side of the frame structure through wire ropes (6). The pulley (8) is connected with the driving rope of the locking ball joint to realize the driving of the locking ball joint; the shoulder and back connecting piece (9) is a V structure, the opening angle of the V shape is greater than 90 degrees, and the lower end of the V shape is fixed at the On the right side of the frame structure, the upper end is connected with the locking ball joint of the upper arm; The upper arm comprises a locking ball joint, an upper arm outer splint (20), an upper arm inner splint (21), an upper arm pulley (18), an elbow joint fixed wheel (23), and a series driving muscle (19); the locking ball The joint is fixed on the lower surface of the shoulder and back connecting piece (9); the top plane of the closed ball joint is provided with three holes that are evenly distributed and the distances from the center of the top plane are all R; the three shoulder guide pulleys (5) are fixed on the shoulder and back On the upper surface of the connecting piece (9), the three shoulder guide pulleys (5) are in one-to-one correspondence with the holes on the top plane of the locking ball joint; the three driving ropes of the locking ball joint respectively pass around the shoulder guide pulleys (5) is connected with the wire rope (6); the lower end of the locking ball joint is fixed between the upper arm outer splint (20) and the upper arm inner splint (21), and the lower ends of the upper arm inner and outer splints are hinged with the forearm (22) to realize the forearm (22). ) rotation, the elbow joint fixed wheel (23) is fixed on the forearm (22) with the hinge point as the center; the upper arm pulley (18) is fixed on the outer side of the upper arm outer splint (20), and the wire rope goes around the upper arm pulley (18) and two One end of the elbow joint driving muscle (19) is connected, and the other ends of the two elbow joint driving muscles (19) are respectively connected with the elbow joint fixed wheel (23) on the forearm (22) and the lower end of the upper arm outer splint (20). A locking ball joint, comprising a shoulder joint fixing platform (14), a shoulder joint moving platform (17), a joint ball (15), an upper arm rotating shaft (16) and a driving rope; The shoulder joint fixing platform (14) includes a top plane and a support column, the top plane is provided with three holes that are evenly distributed and the distance from the center of the top plane is R, the top plane is fixed on the upper end of the support column, and the center of the lower end of the support column is provided with a ball socket , the joint ball (15) is placed in the ball socket; the lower end of the joint ball (15) is connected with the upper arm rotation shaft (16); the upper arm rotation shaft (16) covers the shoulder joint movement platform (17), and the shoulder joint movement platform (17) is The shape of the sleeve, the outer wall of the sleeve is evenly distributed with three connecting ends on the same section, and the distance between the connecting end and the central axis of the sleeve is r; the three connecting ends of the shoulder joint movable platform (17) are respectively fixed with three driving ropes, and the The other end is connected with the wire rope (6) after passing through the three holes on the top plane of the shoulder joint fixing platform (14), the exoskeleton robot further comprises a strap, and the strap includes a shoulder strap (13), a chest strap The straps (12), waist straps (11), upper arm straps (3) and forearm straps (2), the shoulder straps (13) are U-shaped hard materials, and the shoulder straps (13) are symmetrical Fixed on the frame structure; the rest of the straps are flexible straps, made of soft materials, the chest straps (12) and waist straps (11) are fixed on the frame structure for matching between the human torso and the exoskeleton The upper arm strap (3) is connected to the inner splint (21) of the upper arm, and the forearm strap (2) is fixed on the forearm (22). 2. the upper limb exoskeleton robot driven by a kind of pneumatic muscle as claimed in claim 1, is characterized in that, described elbow joint fixed wheel (23) is sector-shaped grooved wheel, elbow joint fixed wheel (23) and forearm (23) 22) Fixed, the fixed wheel (23) of the elbow joint and the hinge (24) are concentric. 3. The upper limb exoskeleton robot driven by a pneumatic muscle according to claim 1 or 2, wherein the frame structure adopts two horizontal supports (7) and two vertical supports (1) to form a frame structure .

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