Passive shoulder exoskeleton robot assisting head-passing task and design method

Abstract

The invention relates to the technical field of exoskeleton robots, in particular to a passive shoulder exoskeleton robot assisting a head task and a design method. The exoskeleton comprises a shoulder module, a passive driving module, a back supporting module and a flexible module. The shoulder module comprises a horizontal flexion and extension rod, a shoulder bending connecting rod, a sagittal flexion and extension rod and a front-back adjusting connecting rod; the passive driving module adopts a torque generator and is used for generating assisting torque, and the peak torque and the peak torque angle of the passive driving module can be adjusted; the back supporting module comprises a back sliding rail, a waist fixing plate, an upper back rod and a lower back rod; the flexible module comprises a shoulder strap, a waist strap and an arm binding part. The design method comprises the following steps: 1, designing a shoulder module, wherein parameters comprise a pitch angle phi, a vertical distance dv and a horizontal deviation db; 2, designing a passive driving module, wherein parameters comprise K, Li, alpha, beta, r1, r2, r3 and r; 3, designing a back supporting module; and 4, designing a flexible module. The human shoulder joint can be assisted, the load on the human shoulder is reduced, and the risk of shoulder diseases is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of exoskeleton robots, and in particular to a passive shoulder exoskeleton robot for assisting in overhead tasks and a design method thereof. Background Art

[0002] Work-related musculoskeletal disorders are the leading cause of health problems for workers worldwide, affecting 1.71 billion people. This is closely related to the high demand of labor-intensive industries. According to statistics, workers on assembly lines need to raise their arms up to 4,600 times a day, and the incidence of shoulder musculoskeletal diseases is high (accounting for 13%), resulting in long-term absences (average median of 25-37 days), resulting in reduced productivity and increased treatment costs. Overhead tasks have the greatest impact on shoulder injuries, which are usually associated with high physical loads and awkward and uncomfortable shoulder postures. Although factory automation technology seems to be a possible solution that can reduce the burden on workers while maintaining productivity, it is costly, requires the transformation of production lines, and is difficult to promote to multiple tasks. In addition, for many complex tasks that require human flexibility and cognitive ability, automated technology solutions cannot provide effective support. According to research, the shoulder exoskeletons involved in current invention patents are mainly focused on the field of rehabilitation, and most of the structures are large and bulky, which are not suitable for assisting workers in overhead operations. Considering the low cost of passive shoulder exoskeletons compared to active shoulder exoskeletons, they may be a cost-effective tool in the future to protect workers from shoulder injuries while assisting with multiple overhead tasks.

[0003] Since the shoulder is one of the most complex joints in the human body, the lack of kinematic compatibility between the exoskeleton and the user has become the main problem faced in the current design process of passive shoulder exoskeletons. Improving kinematic compatibility is crucial for users to accept the exoskeleton. At the same time, the shape of the power assist curve of the current passive shoulder exoskeleton is fixed, and the peak torque angle cannot be changed. The same shape of the power assist curve is used to adapt to a variety of tasks and people, which leads to insufficient task adaptability and individual adaptability of the exoskeleton, and it is difficult to achieve the optimal power assist effect. How to design a passive shoulder exoskeleton that can change the peak torque angle is crucial to improving the power assist efficiency and adaptability of the exoskeleton. Summary of the invention

[0004] In response to the above problems, the present invention provides a passive shoulder exoskeleton robot and design method for assisting overhead tasks, thereby assisting the human shoulder joint, reducing the load on the human shoulder, and alleviating the risk of shoulder musculoskeletal diseases.

[0005] To achieve the above object, the present invention adopts the following technical solution:

[0006] A passive shoulder exoskeleton robot for assisting head tasks, comprising a shoulder module, a passive drive module, a back support module and a flexible module; the shoulder module comprises a horizontal flexion and extension rod 1, a shoulder bending link 2, a sagittal flexion and extension rod 3 and a front and rear adjustment link 12, and the shoulder module is used to improve the shoulder motion range when a person wears the exoskeleton; the passive drive module adopts a torque generator 4 for generating an assist torque, and the peak torque and peak torque angle of the assist torque are adjustable; the back support module comprises a back slide rail 5, a waist fixing plate 7, an upper back rod 11 and a lower back rod 9, and the back support module is used to support the overall structure of the exoskeleton; the flexible module comprises a shoulder strap 6, a waist belt 8 and an arm binding 10, and the flexible module is used to connect the exoskeleton to the human body;

[0007] One end of the shoulder bending link 2 and the front and rear adjustment link 12 are connected through the horizontal flexion and extension rod 1 to form a horizontal flexion and extension degree of freedom, with the sagittal plane of the human body as the symmetry plane, one on each side; the other end of the shoulder bending link 2 and the torque generator 4 are connected through the sagittal flexion and extension rod 3 to form a sagittal flexion and extension degree of freedom, one on each side; one end of the lower back rod 9 is connected to the waist fixing plate 7 to form a waist rotation degree of freedom, and its rotation axis is perpendicular to the sagittal plane, and the other end of the lower back rod 9 is connected to the back slide rail 5; one end of the upper back rod 11 is connected to the front and rear adjustment link 12, and the other end is connected to the back slide rail 5; the arm binding 10 is fixed on the torque generator 4, one on each side; the shoulder strap 6 is connected to the back slide rail 5 and the waist belt 8 respectively; the waist belt 8 is connected to the waist fixing plate 7 and the shoulder strap 6 respectively.

[0008] Furthermore, the torque generator 4 is composed of a pulley block 13, a guide rail 14, a steel wire rope 15, a tensile elastic element 16, an eight-shaped ring 17, a pre-tightening bolt 18 and a housing 19; the pulley block (13) includes a No. 1 pulley (131), a No. 2 pulley (132), a No. 3 pulley (133), a No. 4 pulley (134) and a No. 5 pulley (135);

[0009] The tensile elastic element 16 is used as an energy storage element to provide power; one end of the wire rope 15 is fixed on pulley No. 131, and is wound around pulleys No. 2 132 and No. 3 133 in the middle, and is connected to the tensile elastic element 16 via pulleys No. 4 134 and No. 5 135, wherein pulleys No. 4 134 and No. 5 135 are placed side by side, and their function is to ensure that the direction of the wire rope 15 is in a straight line with the tensile elastic element 16; pulleys No. 2 132 and No. 3 133 are installed on a guide rail slider that cooperates with the guide rail 14, and can slide along the guide rail 14; the other end of the tensile elastic element 16 is connected to the figure-eight ring 17, and the other end of the figure-eight ring 17 is connected to the pre-tightening bolt 18, and the pre-tightening bolt 18 adjusts the pre-tightening length of the tensile elastic element 16; the figure-eight ring 17 contains a rotational freedom in the middle, and its function is to ensure that the tensile elastic element 16 does not rotate when the pre-tightening bolt 18 is rotated; the housing 19 provides protection and support.

[0010] Furthermore, the back slide rail 5 includes a back slide rail body 51, a back slider 52 and a back carbon fiber plate 53; the back slide rail body 51 is fixed on the back carbon fiber plate 53; the back slide rail body 51 has a groove, and the back slider 52 is placed in the groove and can slide left and right in the back slide rail body 51;

[0011] The upper back rod 11 comprises an upper back rod upper portion 111 and an upper back rod lower portion 112; the upper end of the upper back rod upper portion 111 is connected to the end of the front and rear adjustment connecting rod 12 by bolts, wherein the upper end of the upper back rod upper portion 111 has a prefabricated threaded hole, and the installation position of the upper back rod upper portion 111 and the front and rear adjustment connecting rod 12 can be changed; the lower end of the upper back rod upper portion 111 is connected to the upper end of the upper back rod lower portion 112 by bolts using a length adjustment hole 20, so as to adjust the overall length of the exoskeleton upper back rod 11; the lower end of the upper back rod lower portion 112 is connected to the back slider 52 by bolts;

[0012] The lower back rod 9 includes an upper portion 91 and a lower portion 92. The upper end of the upper portion 91 is fixedly connected to the back carbon fiber plate 53, and the lower end of the upper portion 91 is connected to the upper end of the lower portion 92 by bolts via a length adjustment hole 20, so as to adjust the overall length of the exoskeleton lower back rod 9; the lower end of the lower portion 92 is connected to the waist fixing plate 7 via a rotating joint.

[0013] Furthermore, the size of the exoskeleton robot is adjustable, wherein the front and rear adjustment links 12 are adjustable in length to accommodate people with different back thicknesses, with the back thickness range being 5 to 10 cm; the upper back rod 11 and the lower back rod 9 are adjustable in length to accommodate people with different back lengths, with the back length range being 43.6 to 66.6 cm; the upper back rod can slide left and right along the back slide rail 5 to accommodate people with different shoulder widths, with the shoulder width range being 29.6 to 45.6 cm; the arm straps 10, waist belt 8 and shoulder straps 6 are adjustable in length.

[0014] Furthermore, the method of using the exoskeleton robot is as follows: before using the exoskeleton, the user can adjust the position of pulley No. 131 and the positions of pulleys No. 2 132 and No. 3 133 on the guide rail 14 according to the actual overhead task height and the need for a safety limit angle; during the use of the exoskeleton, the user adjusts the size of the exoskeleton through the arm straps 10, waist belt 8, shoulder straps 6, front and rear adjustment links 12, upper back rod 11, lower back rod 9 and back slide rail 5 to make it fit his or her body size; after putting it on, the peak torque of the torque generator 4 is changed by adjusting the pre-tightening bolts 18 to meet his or her own needs.

[0015] Based on the above technical solution, the present invention also provides a design method for a passive shoulder exoskeleton robot that assists with head tasks, which is used to design the above passive shoulder exoskeleton robot that assists with head tasks, comprising the following steps:

[0016] Step 1: Design the shoulder module. The design parameters of the shoulder module include the pitch angle φ, the vertical distance d v and horizontal deviation d b ; Among them, the pitch angle φ is the angle between the front and rear adjustment links and the horizontal plane of the human body, and the vertical distance d v Defined as the vertical distance between the user's shoulder rotation center and the front and rear adjustment links, horizontal deviation d b is the horizontal distance between the user's shoulder rotation center and the exoskeleton's shoulder rotation center; the pitch angle φ and the vertical distance d v Used to adjust the space between the acromion and the exoskeleton horizontal flexion and extension bar above it, horizontal deviation d b Used to adjust the deviation distance between the exoskeleton shoulder rotation center and the user's shoulder rotation center.

[0017] Step 2: Design a passive drive module. The passive drive module uses a torque generator. The torque generator design parameters include K, L i , α, β, r 1 、r 2 、r 3 r, used to adjust the peak torque and peak torque angle; where K is the stiffness of the tensile elastic element, L i is the initial stretch of the stretching elastic element, α is the angle of pulley No. 1, β is the angle of pulley No. 2, r 1 is the distance between the sagittal flexion bar and pulley No. 1, r 2 is the distance between the sagittal flexion and extension rod and the guide rail, r 3 is the radius of the sagittal flexion and extension bar, r is the radius of pulleys 1, 2, and 3;

[0018] Step 3: Design a back support module to fit wearers of different body sizes;

[0019] Step 4: Design flexible modules for fixing the exoskeleton to the human body.

[0020] Furthermore, in step 2, the torque generator design parameters include K, L i , α, β, r 1 、r 2 、r 3 r, used to adjust the peak torque and peak torque angle, specifically: K, L i and r 1It mainly affects the peak torque of the power-assist torque curve. As the parameter increases, the peak torque increases; r 2 The overall length of the impact moment generator housing; r 3 The main influence of the assist torque in stage 1, r 3 The assist torque of stage 1 increases, but the peak torque of stage 2 remains basically unchanged; r has some influence on the peak torque of the assist torque curve and the boundary angle between stage 1 and stage 2. The increase of r will cause the peak torque to increase slightly and the boundary angle between stage 1 and stage 2 to decrease slightly; α and β mainly affect the peak torque, peak torque angle and boundary angle of the assist torque curve. If α increases or β decreases, the peak torque of the assist torque curve decreases, the peak torque angle increases, and the boundary angle between stage 1 and stage 2 increases;

[0021] The definitions of stage 1 and stage 2 are as follows: depending on whether the wire rope is in contact with the sagittal flexion and extension bar, the entire assistance process can be divided into two stages: stage 1 is the low assistance area, in which the wire rope is in contact with the sagittal flexion and extension bar, and the lever arm is very small; stage 2 is the high assistance area, in which the wire rope is separated from the sagittal flexion and extension bar, and the lever arm first increases and then decreases.

[0022] Furthermore, in step 2, the boost torque τ generated by the torque generator 4 exo , the calculation method is:

[0023] τ exo =F s L exo (1)

[0024] Where F s and L exo They represent the stored elastic potential energy and the lever arm, respectively. The lever arm is the vertical distance from the center of the exoskeleton sagittal flexion and extension rod to the wire rope between pulleys 1 and 2. F s By formula (2) we can obtain

[0025] F s =kΔL (2)

[0026] Where K is the stiffness of the tensile elastic element and ΔL is the stretch of the tensile elastic element.

[0027] Furthermore, the calculation formula of the stretching amount ΔL of the stretching elastic element is:

[0028] ΔL=ΔL(θ s，exo )=L A′B′ (θ s，exo )-L A′B′ (mmax(θ s，exo ))+L i (3) Where L A′B′is the change in the length of the wire rope between pulley No. 1 and pulley No. 3. s，exo When it reaches the maximum value, L A′B′ The shortest length, L i is the initial stretch of the stretch elastic element.

[0029] Compared with the prior art, the present invention has the following beneficial technical effects:

[0030] 1. In view of the fact that existing rigid upper limb exoskeletons are difficult to achieve good human-machine compatible kinematic performance, a shoulder structure is designed that can simultaneously meet the sagittal flexion and extension and horizontal flexion and extension range of motion of the human shoulder.

[0031] 2. Aiming at the problem that the existing passive upper limb exoskeleton cannot change the peak torque angle, a torque generator that can change the peak torque angle is designed. The torque generator can reconstruct the assisting torque curve at both the peak and phase levels, thereby improving the assisting effect of the exoskeleton.

[0032] 3. The invention can effectively assist the shoulders during overhead tasks, reduce the physical burden on the shoulders, reduce related muscle activation, and thus delay muscle fatigue and reduce the risk of musculoskeletal diseases. The performance verification experiment of the invention shows that in the case of exoskeleton matching, the relative percentage of muscle activation reduction can reach about 40%.

[0033] 4. Compared with the active exoskeleton, the passive shoulder exoskeleton in the present invention has low cost and good economy.

[0034] 5. The passive shoulder exoskeleton of the present invention is also light in weight, easy to use and comfortable to wear. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the overall structure of the exoskeleton;

[0036] Figure 2 This is the definition diagram of the exoskeleton shoulder structure design parameters.

[0037] in, Figure 2 (a) is the ψ plane viewing angle, Figure 2 (b) is a top view perspective;

[0038] Figure 3 is a schematic diagram of the kinematic model of the user and the exoskeleton.

[0039] in, Figure 3 (a) is the kinematic model of the user, Figure 3 (b) is the kinematic model of the exoskeleton;

[0040] Figure 4This is the simulation result diagram of the range of motion of the shoulder structure;

[0041] Figure 5 It is a schematic diagram of the overall structure of the torque generator;

[0042] Figure 6 is a schematic diagram of the moment generator arm;

[0043] Figure 7 It is a schematic diagram of the torque generator assist curve;

[0044] Figure 8 It is a schematic diagram of the design parameters of the torque generator;

[0045] in Figure 8 (a) is a schematic diagram of the design parameters for stage 1. Figure 8 (b) is a schematic diagram of the design parameters for stage 2;

[0046] Fig. 9 is the relationship between the peak torque angle and β in the torque generator;

[0047] Fig.10 is the simulation auxiliary torque curve of the torque generator, where

[0048] Fig.10 (a) is L i Impact diagram on auxiliary torque curve, Fig.10 (b) is r 1 Impact diagram on auxiliary torque curve,

[0049] Fig.10 (c) is r 2 Impact diagram on auxiliary torque curve, Fig.10 (d) is r 3 Impact diagram on auxiliary torque curve,

[0050] Fig.10 (e) is the influence diagram of α on the auxiliary torque curve, Fig.10 (f) is the influence diagram of β on the auxiliary torque curve,

[0051] Fig.10 (g) is the influence diagram of r on the auxiliary torque curve; Fig.10 (h) is the influence diagram of K on the auxiliary torque curve;

[0052] Fig.11 This is a diagram of the exoskeleton experiment task.

[0053] in Fig.11 (a) Corresponding motion range experiment, Fig.11 (b) Corresponding performance verification experiment;

[0054] Fig.12It is the height definition diagram of the exoskeleton performance verification experiment;

[0055] Fig.13 This is the muscle activation diagram of the exoskeleton performance verification experiment.

[0056] in Fig.13 (a) For low height screwing, Fig.13 (b) Tighten screws corresponding to high heights.

[0057] Reference numerals:

[0058] 1. Horizontal flexion and extension rod; 2. Shoulder bending link; 3. Sagittal flexion and extension rod; 4. Torque generator;

[0059] 5. back slide rail, 51. back slide rail body, 52. back slider, 53. back carbon fiber plate;

[0060] 6. Shoulder straps; 7. Waist fixing plate; 8. Waist belt;

[0061] 9. Lower back bar, 91 upper part of lower back bar, 92 lower part of lower back bar; 10. Arm tie;

[0062] 11. upper back bar, 111. upper part of upper back bar, 112. lower part of upper back bar;

[0063] 13. Pulley block, 131, pulley No. 1, 132, pulley No. 2, 133, pulley No. 3,

[0064] 134, pulley No. 4, 135, pulley No. 5;

[0065] 14. Guide rail; 15. Steel wire rope; 16. Tensile elastic element; 17. Figure-eight ring;

[0066] 18. Pre-tightening bolt; 19. Housing; 20. Length adjustment hole. DETAILED DESCRIPTION

[0067] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0068] The present invention provides a passive shoulder exoskeleton robot for assisting head tasks, such as Figure 1As shown, it includes a shoulder module, a passive drive module, a back support module and a flexible module; the shoulder module includes a horizontal flexion and extension rod 1, a shoulder bending link 2, a sagittal flexion and extension rod 3 and a front and rear adjustment link 12, and the shoulder module is used to improve the shoulder movement range when a person wears the exoskeleton; the passive drive module adopts a torque generator 4 to generate an assist torque, and the peak torque and peak torque angle of the assist torque are adjustable; the back support module includes a back slide rail 5, a waist fixing plate 7, an upper back rod 11 and a lower back rod 9, and the back support module is used to support the overall structure of the exoskeleton; the flexible module includes a shoulder strap 6, a waist belt 8 and an arm strap 10, and the flexible module is used to connect the exoskeleton to the human body.

[0069] The exoskeleton robot has a total of 5 degrees of freedom. One end of the shoulder bending link 2 and the front and rear adjustment link 12 are connected through the horizontal flexion and extension rod 1 to form a horizontal flexion and extension degree of freedom, with the sagittal plane of the human body as the symmetry plane, one on each side; the other end of the shoulder bending link 2 and the torque generator 4 are connected through the sagittal flexion and extension rod 3 to form a sagittal flexion and extension degree of freedom, one on each side; one end of the lower back rod 9 is connected to the waist fixing plate 7 to form a waist rotation degree of freedom, and its rotation axis is perpendicular to the sagittal plane, and the other end of the lower back rod 9 is connected to the back slide rail 5; one end of the upper back rod 11 is connected to the front and rear adjustment link 12, and the other end is connected to the back slide rail 5; the arm binding 10 is fixed on the torque generator 4, one on each side; the shoulder strap 6 is respectively connected to the back slide rail 5 and the waist belt 8; the waist belt 8 is respectively connected to the waist fixing plate 7 and the shoulder strap 6.

[0070] The following are descriptions of the four modules:

[0071] 1. Shoulder Module

[0072] (I) Overall introduction of shoulder module

[0073] As one of the most complex joints in the human body, the shoulder has the characteristic of flexible movement. In order to ensure that the normal range of motion of a person is not affected when wearing a shoulder exoskeleton, it is necessary to design an ergonomic shoulder structure. The center of the glenohumeral joint is considered to be the center of rotation of the user's shoulder (the center of the shoulder of the user, CSU). The intersection of the rotation axes of the sagittal flexion and extension rod 3 and the horizontal flexion and extension rod 1 is considered to be the center of rotation of the exoskeleton shoulder (The center of the shoulder of the exoskeleton, CSE). The center of rotation of the exoskeleton shoulder is close to the center of rotation of the user's shoulder, which enables the torque generator 4 to better track the shoulder movement. However, the positions of the two do not coincide, and the shoulder movement is accompanied by the lifting and posterior movement of the humerus, causing the center of rotation of the user's shoulder to shift, so it is necessary to extract the structural design parameters and find the optimal solution. For this purpose, the present invention defines the following structural design parameters: pitch angle φ, vertical distance d vand horizontal deviation d b ,like Figure 2 As shown. The plane including the front and rear adjustment link 12 and perpendicular to the horizontal plane of the human body is defined as the ψ plane. The pitch angle φ is the angle between the front and rear adjustment link 12 and the horizontal plane of the human body; the vertical distance d v Defined as the vertical distance between the user's shoulder rotation center and the front and rear adjustment link 12; horizontal deviation d b is the horizontal distance between the user's shoulder rotation center and the exoskeleton's shoulder rotation center. Φ and d v The configuration of the front and rear adjustment link 12 can be defined, d b It can be adjusted by adjusting the front and rear connecting rod 12. Increase Φ and d v The space between the user and the exoskeleton shoulder can be enlarged, which is used for humeral elevation to avoid collision between the exoskeleton and the user at high elevation angles. b The exoskeleton shoulder rotation center can be moved backward toward the user's shoulder to compensate for the displacement of the user's shoulder rotation center during the user's shoulder movement.

[0074] 2. Shoulder joint kinematic modeling and design parameter analysis

[0075] In order to better explore the impact of shoulder design parameters on the range of motion, kinematic analysis is required. Here, only two degrees of freedom of the user are considered, namely the horizontal flexion and extension degree of freedom and the sagittal flexion and extension degree of freedom, respectively θ h，user and θ s，user , respectively, represent the horizontal flexion and extension angles and sagittal flexion and extension angles of the human body. Correspondingly, the horizontal flexion and extension degrees of freedom and sagittal flexion and extension degrees of freedom of the exoskeleton are expressed as θ h，exo and θ s，exo , respectively represent the horizontal flexion and extension angle and sagittal flexion and extension angle of the exoskeleton. user and D exo Respectively represent the distance between the user's shoulder rotation center and the exoskeleton's shoulder rotation center to the arm binding 10 center of mass, Figure 3 is a diagram of the kinematic model of the user and the exoskeleton. Table 1 and Table 2 are the Denavit-Hartenberg (DH) parameters of the user kinematic model and the exoskeleton kinematic model, respectively. The connection between the two models is that their coordinate origins are both the user's shoulder rotation center, and the arm strap 10 is in the same position. Using this feature, the simulation is carried out to calculate the shoulder motion range of the user when wearing the exoskeleton. The simulation process is shown in Table 3. Figure 4 Seven selected sets of design parameters and their corresponding ranges of motion are shown.

[0076] Table 1. DH parameters of user kinematic model

[0077]

[0078] In Table 1, a i-1 Along x i Axis, from z i Rotate to z i+1 Angle of i-1 For x i Axis, from z i Move to z i+1 Distance; d i For along z i Axis, from x i-1 Move to x i The distance; θ i For along z i Axis, from x i-1 Rotate to x i angle.

[0079] Table 2. DH parameters of the exoskeleton kinematic model

[0080]

[0081] Table 3 Calculation of the range of motion simulation when the user wears the exoskeleton

[0082]

[0083] In Table 3 (p x , p y , p z ) represent the x-axis coordinate, y-axis coordinate and z-axis coordinate of the center of mass of the arm binding respectively.

[0084] 2. Passive drive module

[0085] (I) Overall introduction of torque generator

[0086] The passive drive module uses a torque generator, such as Figure 5 As shown, the torque generator 4 is composed of a pulley block 13, a guide rail 14, a steel wire rope 15, a tensile elastic element 16, an eight-shaped ring 17, a pre-tightening bolt 18 and a housing 19. The pulley block 13 includes a No. 1 pulley 131, a No. 2 pulley 132, a No. 3 pulley 133, a No. 4 pulley 134 and a No. 5 pulley 135; wherein the No. 1 pulley 131, the No. 2 pulley 132 and the No. 3 pulley 133 have the same radius.

[0087] The tensile elastic element 16 is used as an energy storage element to provide power; one end of the wire rope 15 is fixed on pulley No. 131, and is wound around pulleys No. 2 132 and No. 3 133 in the middle, and is connected to the tensile elastic element 16 via pulleys No. 4 134 and No. 5 135, wherein pulleys No. 4 134 and No. 5 135 are placed side by side, and their function is to ensure that the direction of the wire rope 15 is in a straight line with the tensile elastic element 16; pulleys No. 2 132 and No. 3 133 are installed on a guide rail slider that cooperates with the guide rail 14 and can slide along the guide rail 14; the other end of the tensile elastic element 16 is connected to the figure-eight ring 17, and the other end of the figure-eight ring 17 is connected to the pre-tightening bolt 18, and the pre-tightening bolt 18 can adjust the pre-tightening length of the tensile elastic element 16, and the figure-eight ring 17 contains a rotational freedom in the middle, and its function is to ensure that the tensile elastic element 16 does not rotate when the pre-tightening bolt 18 is rotated; the housing 19 provides protection and support.

[0088] The tensile elastic element 16 is one of a parallel spring group, an elastic rope, and a tension spring.

[0089] Since the torque generator 4 is fixed to the user's upper arm by the arm strap 10, it can be assumed that the flexion and extension angles of the exoskeleton and the user are consistent. The assisting principle of the torque generator 4 is to store the elastic potential energy of the stretching elastic element 16 when the arm is lowered, and release the elastic potential energy of the stretching elastic element 16 when the arm is raised upward. Its characteristics are that the peak torque and peak torque angle (Peak assistive torque angle, PATA) of the assisting torque can be adjusted.

[0090] (II) Description of assist torque

[0091] The assist torque τ generated by the torque generator 4 exo , the calculation method is:

[0092] τ exo =F s L exo (1)

[0093] Where F s and L exo They represent the stored elastic potential energy and the lever arm respectively. The lever arm is the vertical distance of the wire rope from the center of the exoskeleton sagittal flexion and extension rod 3 to the pulley No. 1 and the pulley No. 2, as shown in Figure 6 As shown, F s It can be obtained through formula (2)

[0094] F s =KΔL (2)

[0095] Where K is the stiffness of the tensile elastic element 16, and ΔL is the stretching amount of the tensile elastic element 16. During the shoulder movement, because the steel wire rope 15 is connected in series with the tensile elastic element 16, the stretching amount of the tensile elastic element 16 is the same as the change in the length of the steel wire rope 15 between the No. 1 pulley and the No. 3 pulley (i.e. Figure 8 = (the length of the cable between midpoint A' and point B'). ΔL can be constructed as the sagittal flexion and extension angle of the exoskeleton (θ s，exo ),

[0096] ΔL=ΔL(θ s，exo )=L A′B′ (θ s，exo )-L A′B′ (max(θ s，exo ))+L i (3)

[0097] Where L A′B′ is the change in the length of the wire rope between pulley No. 1 and pulley No. 3. s，exo When it reaches the maximum value, L A′B′ The shortest length, L i is the initial stretching amount of the stretching elastic element 16 , which can be adjusted by the pre-tightening bolt 18 .

[0098] Figure 7 The change of the force arm and the torque curve are shown. The gray part in the figure represents stage 1, and the white part represents stage 2. It can be seen that the force arm L exo The change process is that it increases first and then decreases, while the stretching amount ΔL of the stretching elastic element 16 is monotonically decreasing. Therefore, it can be known that the force arm L exo It will affect the assist torque peak torque angle while ΔL affects the peak torque.

[0099] In order to better identify the assist torque curve, six design parameters (α, β, r 1 , r 2 , r 3 , r), whose meanings are shown in Table 4.

[0100] Table 4. Torque generator design parameter definitions

[0101]

[0102] Impact exo The main parameters are α and β. When α increases or β decreases, L exo The peak angle of the power assist curve will shift to the left, which causes the peak torque angle of the power assist curve to shift to the left accordingly. In order to explore the changing trend of the peak torque angle, when α=β=0, the peak torque angle at this time is defined as the reference value, and θ 0 Indicates. Peak torque angle (θPATA ) can be expressed by equations (4)-(5):

[0103] θ PATA =θ 0 +α-kβ (4)

[0104]

[0105] Where r is the radius of the No. 2 pulley 132, r 2 is the distance between the sagittal flexion and extension rod and the guide rail; due to ΔL on τ exo The nonlinear effect of k is a variable positive value close to 1. From formulas (4)-(5), we can see that increasing r or decreasing r 2 Can make θ 0 The decrease leads to a decrease in the peak torque angle. The simulation results show that this effect is very weak. Fig.10 (c) and Fig.10 (g). In order to make the peak torque angle adjustable to suit different tasks and people, β can be adjusted by changing the positions of the No. 2 pulley 132 and the No. 3 pulley 133 on the guide rail 14. The relationship between the peak torque angle and β is as follows: Fig. 9 shown.

[0106] (III) The influence of analysis parameters on torque curve by stage

[0107] According to whether the steel wire rope 15 is in contact with the sagittal flexion and extension rod 3, the whole assisting process can be divided into two stages: Stage 1 is the low assisting area, corresponding to Figure 8 (a), in this stage, the wire rope 15 is in contact with the sagittal flexion and extension rod 3, resulting in a very small force arm, so the assist torque is low to prevent the user from being hindered from exercising normally; stage 2 is the high assist area, corresponding to Figure 8 (b), in this stage, the steel wire 15 is separated from the sagittal flexion and extension rod 3, and the force arm increases first and then decreases, so that the torque increases first and then decreases. The contact between the steel wire 15 and the sagittal flexion and extension rod 3 can ensure that the assist torque is always positive. If the steel wire 15 is not placed on the sagittal flexion and extension rod 3 at a low angle, a negative torque will be caused, stretching the arm to the back of the body, causing a safety hazard.

[0108] The shoulder flexion and extension angle corresponding to the critical state of phase 1 and phase 2 is defined as θ c , whose size is related to α and β. When α increases or β decreases, θ c The following is a phased introduction to the effect of various parameters on the assist torque. Fig. 9 The simulation results of the influence of various design parameters on the assist torque are shown in Figure 2. It is worth noting that no matter at which stage, the stiffness K of the stretching elastic element 16 and the initial stretching amount L iThey are all positively correlated with the peak torque and have nothing to do with the peak torque angle.

[0109] Phase 1: The parameter that affects the assist torque in this phase is mainly the radius r of the sagittal flexion and extension rod 3 3 When r 3 When increasing, L A′B′ and L exo This increases, which causes the assist torque in the low assist area to become larger.

[0110] Stage 2: The parameters that affect the assist torque in this stage are mainly the angle α of the No. 1 pulley 131, the angle β of the No. 2 pulley 132, and the distance r between the sagittal flexion and extension rod 3 and the No. 1 pulley 131. 1 When r 1 When L increases A′B′ and L exo increases, which in turn leads to a larger peak torque. When α increases or β decreases, L exo The peak angle of the power assist curve will shift to the left, which causes the peak torque angle of the power assist curve to shift to the left accordingly. α also has a limiting function, and different positions correspond to different maximum flexion and extension angles, with a maximum of 170° and a minimum of 140°. 2 The results showed that it had little effect on the peak torque and peak torque angle.

[0111] 3. Back support module

[0112] like Figure 1 As shown, the back support module includes a back slide rail 5 , a waist fixing plate 7 , an upper back rod 11 and a lower back rod 9 .

[0113] The back slide rail 5 includes a back slide rail body 51, a back slider 52 and a back carbon fiber plate 53; the back slide rail body 51 is fixed on the back carbon fiber plate 53; there is a groove on the back slide rail body 51, and the back slider 52 is placed in the groove and can slide left and right in the back slide rail body 51.

[0114] The upper back rod 11 includes an upper back rod upper portion 111 and an upper back rod lower portion 112. The upper end of the upper back rod upper portion 111 is connected to the end of the front and rear adjustment connecting rod 12 by bolts, wherein the upper end of the upper back rod upper portion 111 has a prefabricated threaded hole, which can change its installation position with the front and rear adjustment connecting rod 12. The lower end of the upper back rod upper portion 111 is connected to the upper end of the upper back rod lower portion 112 by bolts using the length adjustment hole 20, so as to adjust the overall length of the exoskeleton upper back rod 11. The lower end of the upper back rod lower portion 112 is connected to the back slider 52 by bolts.

[0115] The lower back bar 9 includes an upper lower back bar portion 91 and a lower lower back bar portion 92. The upper end of the upper lower back bar portion 91 is fixedly connected to the back carbon fiber plate 53. The lower end of the upper lower back bar portion 91 is connected to the upper end of the lower lower back bar portion 92 by bolts using a length adjustment hole 20 to adjust the overall length of the lower back bar 9 of the exoskeleton. The length adjustment hole 20 for adjusting the lower back bar 11 is on the side. The lower end of the lower lower back bar portion 92 is connected to the waist fixing plate 7 through a rotating joint, so that the exoskeleton fits the human body movement better.

[0116] 4. Flexible Module

[0117] The flexible module includes shoulder straps 6, waist belts 8 and arm straps 10. The shoulder straps 6 and waist belts 8 are used to fix the exoskeleton structure to the human body, and the lengths of the shoulder straps 6 and waist belts 8 are adjustable. The arm straps 10 are used to connect the torque generator 4 to the human arm to achieve the effect that the torque generator 4 follows the movement of the human arm; the arm straps 10 can be made by 3D printing, and the material is resin or nylon.

[0118] The size of the exoskeleton robot of the present invention is adjustable to adapt to people of different body shapes, wherein the front and rear adjustment connecting rods 12 are adjustable in length to adapt to people of different back thicknesses (i.e., the thickness of the front and back of the body), and the adapted back thickness range is 5 to 10 cm; the upper back rod 11 and the lower back rod 9 are adjustable in length to adapt to people of different back lengths (i.e., the length of the upper body), and the adapted back length range is 43.6 to 66.6 cm; the upper back rod can slide left and right along the back slide rail 5 to adapt to people of different shoulder widths, and the adapted shoulder width range is 29.6 to 45.6 cm: the flexible module (arm binding 10, waist belt 8 and shoulder strap 6) is adjustable in length to adapt to people of different body shapes and ensure comfortable wearing.

[0119] The method of using the exoskeleton robot is as follows: before using the exoskeleton, the user can adjust the position of the No. 1 pulley 131 and the positions of the No. 2 pulley 132 and the No. 3 pulley 133 on the guide rail 14 according to the actual overhead task height and the requirements for the safety limit angle. During the use of the exoskeleton, the user can adjust the size of the exoskeleton to match the size of his body through the arm straps 10, waist belt 8, shoulder straps 6, front and rear adjustment links 12, upper back rod 11, lower back rod 9 and back slide rail 5. After wearing, the peak torque of the torque generator 4 can be changed by adjusting the pre-tightening bolts 18 to meet his needs.

[0120] Based on the above technical solution, the present invention also provides a design method for a passive shoulder exoskeleton robot that assists in head tasks, comprising the following steps:

[0121] Step 1: Design the shoulder module. The design parameters of the shoulder module include the pitch angle φ, the vertical distance d v and horizontal deviation d b ;

[0122] Among them, the pitch angle φ is the angle between the front and rear adjustment links and the horizontal plane of the human body, and the vertical distance d v Defined as the vertical distance between the user's shoulder rotation center and the front and rear adjustment links, horizontal deviation d b is the horizontal distance between the user's shoulder rotation center and the exoskeleton's shoulder rotation center; the pitch angle φ and the vertical distance d v Used to adjust the space between the acromion and the exoskeleton horizontal flexion and extension bar above it, horizontal deviation d b Used to adjust the deviation distance between the exoskeleton shoulder rotation center and the user's shoulder rotation center.

[0123] Step 2: Design a passive drive module. The passive drive module uses a torque generator. The torque generator design parameters include K, L i , α, β, r 1 、r 2 、r 3 r, used to adjust the peak torque and peak torque angle; where K is the stiffness of the tensile elastic element, L i is the initial stretch of the stretching elastic element, α is the angle of pulley No. 1, β is the angle of pulley No. 2, r 1 is the distance between the sagittal flexion bar and pulley No. 1, r 2 is the distance between the sagittal flexion and extension rod and the guide rail, r 3 is the radius of the sagittal flexion and extension bar, and r is the radius of pulleys No. 1, 2, and 3.

[0124] The influence of the above design parameters on the auxiliary torque curve is as follows: Fig.10 K, L i and r 1 It mainly affects the peak torque of the power-assist torque curve. As the parameter increases, the peak torque increases; r 2 It has little effect on the assist torque curve, but due to r 2 is the distance between the sagittal flexion and extension rod and the guide rail, so r 2 The overall length of the impact moment generator housing; r 3 The main influence of the assist torque in stage 1, r 3 As α increases, the assist torque of stage 1 increases, but the peak torque of stage 2 remains basically unchanged; r has some influence on the peak torque of the assist torque curve and the dividing angle between stage 1 and stage 2. An increase in r will cause a slight increase in the peak torque and a slight decrease in the dividing angle between stage 1 and stage 2; α and β mainly affect the peak torque, peak torque angle and dividing angle between stage 1 and stage 2 of the assist torque curve. If α increases or β decreases, the peak torque of the assist torque curve decreases, the peak torque angle increases, and the dividing angle between stage 1 and stage 2 increases.

[0125] Among the above parameters, r 1 、r 2 、r 3 and r are parameters that need to be determined in the design phase. Once the exoskeleton entity is determined and constructed, these parameters can no longer be changed unless the exoskeleton is reconstructed; but L i The four parameters, K, α and β, can still be changed after the exoskeleton is constructed. i It can be adjusted by pre-tightening bolts, K can be adjusted by replacing elastic elements, and α can be adjusted by changing the installation position of pulley No. 1 (there is a prefabricated installation hole at the end of the shoulder bending connecting rod, such as Fig. 9 As shown), β can be adjusted by changing the position of pulley No. 2 and pulley No. 3 on the slide rail.

[0126] Step 3: Design a back support module to fit wearers of different body sizes.

[0127] Step 4: Design flexible modules for fixing the exoskeleton to the human body.

[0128] Example:

[0129] A passive shoulder exoskeleton robot for assisting over-the-head tasks comprises a shoulder module, a passive drive module, a back support module and a flexible module; the shoulder module comprises a horizontal flexion and extension rod 1, a shoulder bending link 2, a sagittal flexion and extension rod 3 and a front-rear adjustment link 12, for improving the range of shoulder motion when a person wears the exoskeleton; the passive drive module adopts a torque generator 4 for generating an assist torque, and the peak torque and peak torque angle of the assist torque are adjustable; the back support module comprises a back slide rail 5, a waist fixing plate 7, an upper back rod 11 and a lower back rod 9, for supporting the overall structure of the exoskeleton; the flexible module comprises a shoulder strap 6, a waist belt 8 and an arm strap 10, for connecting the exoskeleton to the human body.

[0130] The exoskeleton robot has a total of 5 degrees of freedom. One end of the shoulder bending link 2 and the front and rear adjustment link 12 are connected through the horizontal flexion and extension rod 1 to form a horizontal flexion and extension degree of freedom, with the sagittal plane of the human body as the symmetry plane, one on each side; the other end of the shoulder bending link 2 and the torque generator 4 are connected through the sagittal flexion and extension rod 3 to form a sagittal flexion and extension degree of freedom, one on each side; one end of the lower back rod 9 is connected to the waist fixing plate 7 to form a waist rotation degree of freedom, and its rotation axis is perpendicular to the sagittal plane, and the other end of the lower back rod 9 is connected to the back slide rail 5; one end of the upper back rod 11 is connected to the front and rear adjustment link 12, and the other end is connected to the back slide rail 5; the arm binding 10 is fixed on the torque generator 4, one on each side; the shoulder strap 6 is respectively connected to the back slide rail 5 and the waist belt 8; the waist belt 8 is respectively connected to the waist fixing plate 7 and the shoulder strap 6.

[0131] The shoulder module includes the pitch angle φ, vertical distance d vand horizontal deviation d b Three design parameters, the specific design parameters in this embodiment are φ = 15°, d v =80mm,d b =10mm, the range of motion obtained by this group has ensured that the user can complete the task over the head while exercising normally.

[0132] The passive drive module adopts a torque generator, and the torque generator 4 is composed of a pulley block 13, a guide rail 14, a steel wire rope 15, a tensile elastic element 16, an eight-shaped ring 17, a pre-tightening bolt 18 and a housing 19. The pulley block 13 includes a No. 1 pulley 131, a No. 2 pulley 132, a No. 3 pulley 133, a No. 4 pulley 134 and a No. 5 pulley 135; in this embodiment, the No. 1 pulley 131, the No. 2 pulley 132, the No. 3 pulley 133, the No. 4 pulley 134 and the No. 5 pulley 135 use pulleys with the same radius.

[0133] In this embodiment, the tensile elastic element 16 adopts a parallel spring group; one end of the wire rope 15 is fixed on pulley No. 131, and is wound around pulleys No. 2 132 and No. 3 133 in the middle, and is connected to the parallel spring group via pulleys No. 4 134 and No. 5 135, wherein pulleys No. 4 134 and No. 5 135 are placed side by side to ensure that the direction of the wire rope 15 is in a straight line with the parallel spring group; pulleys No. 2 132 and No. 3 133 are installed on a guide rail slider that cooperates with the guide rail 14 and can slide along the guide rail 14; the other end of the parallel spring group is connected to the figure-eight ring 17, and the other end of the figure-eight ring 17 is connected to the pre-tightening bolt 18, which can adjust the pre-tightening length of the parallel spring group, and the figure-eight ring 17 contains a rotational freedom in the middle, and its function is to ensure that the parallel spring group does not rotate when the pre-tightening bolt 18 is rotated; the housing 19 provides protection and support.

[0134] The torque generator design parameters include K, L i , α, β, r 1 、r 2 、r 3 r is used to adjust the peak torque and the peak torque angle. The specific design parameter values ​​of the torque generator in this embodiment are shown in the following table.

[0135] Table 5 Value table of torque generator design parameters

[0136]

[0137]

[0138] The back support module comprises a back slide rail 5 , a waist fixing plate 7 , an upper back rod 11 and a lower back rod 9 .

[0139] The back slide rail 5 includes a back slide rail body 51, a back slider 52 and a back carbon fiber plate 53; the back slide rail body 51 is fixed on the back carbon fiber plate 53; there is a groove on the back slide rail body 51, and the back slider 52 is placed in the groove and can slide left and right in the back slide rail body 51.

[0140] The upper back rod 11 includes an upper back rod upper portion 111 and an upper back rod lower portion 112. The upper end of the upper back rod upper portion 111 is connected to the end of the front and rear adjustment connecting rod 12 by bolts, wherein the upper end of the upper back rod upper portion 111 has a prefabricated threaded hole, which can change its installation position with the front and rear adjustment connecting rod 12. The lower end of the upper back rod upper portion 111 is connected to the upper end of the upper back rod lower portion 112 by bolts using the length adjustment hole 20, so as to adjust the overall length of the exoskeleton upper back rod 11. The lower end of the upper back rod lower portion 112 is connected to the back slider 52 by bolts.

[0141] The lower back bar 9 includes an upper lower back bar portion 91 and a lower lower back bar portion 92, the upper end of the upper lower back bar portion 91 is fixedly connected to the back carbon fiber plate 53, and the lower end of the upper lower back bar portion 91 is connected to the upper end of the lower lower back bar portion 92 by bolts using a length adjustment hole 20, so as to adjust the overall length of the exoskeleton lower back bar 9, wherein the length adjustment hole 20 for adjusting the lower back bar 11 is on the side. The lower end of the lower lower back bar portion 92 is connected to the waist fixing plate 7 through a rotating joint.

[0142] The flexible module includes a shoulder strap 6, a waist belt 8 and an arm strap 10. The lengths of the shoulder strap 6 and the waist belt 8 are adjustable. The arm strap 10 is used to connect the torque generator 4 to the human arm. The arm strap 10 can be made by 3D printing and the material is resin. Performance verification:

[0143] In order to further verify the rationality of the present invention, a motion range experiment and a performance verification experiment were carried out.

[0144] 1. Experimental content

[0145] The range of motion experiment involved 5 healthy male participants (age ± standard deviation: 24.1 ± 1.64 years, height ± standard deviation: 173.8 ± 3.27 cm, weight ± standard deviation: 70 ± 9.06 kg). Each subject was required to perform horizontal flexion and extension and sagittal flexion and extension to the maximum extent at a suitable speed of their own choice, 5 times each. Each person's experimental configuration included wearing and not wearing an exoskeleton. The data of the range of motion experiment was collected by optical motion capture (sampling frequency 100 Hz, VICON, UK).

[0146] Ten healthy males participated in the performance verification experiment (age ± standard deviation: 25.1 ± 2.0 years old, height ± standard deviation: 177 ± 4.3 cm, weight ± standard deviation: 68.3 ± 9.3 kg). Each experimental subject was required to perform screwing tasks at two working heights on an adjustable height aluminum alloy frame. The low height was defined as the hand height when the shoulder was raised 90°, and the high height was defined as the hand height when the shoulder was raised 120°. There are two types of exoskeleton configurations: one with a peak torque angle of 90° and one with a peak torque angle of 120°. It should be noted that this experiment only took two peak torque angles as the experimental configuration of the exoskeleton. In actual situations, the exoskeleton can achieve any peak torque angle configuration between 90° and 150°. When the peak torque angle of the exoskeleton matches the shoulder lifting angle, the experimental configuration is defined as exoskeleton matching, otherwise it is exoskeleton mismatching. In summary, the task heights are low and high, and the experimental configurations are no exoskeleton, exoskeleton matching, and exoskeleton mismatching. Each experimental subject needs to perform six experiments, each experiment lasts for 2 minutes, and the task height and experimental configuration are randomly assigned. The experimental process is shown in the figure below. The data collected in the performance verification experiment include electromyographic data and inertial measurement unit data (hereinafter referred to as IMU data). The electromyographic data is used to evaluate the performance of the exoskeleton with a sampling frequency of 1111Hz, and the IMU data is used to divide the task interval of the data with a sampling frequency of 148Hz. The electromyographic data collects the muscles on the right side of the human body, specifically: anterior deltoid (AD), middle deltoid (MD), posterior deltoid (PD), biceps brachii (BB), pectoralis major (PM), trapezius (TR), latissimus dorsi (LD), erector spinae (ES). The IMU data is resampled to 1111Hz, and then the acceleration variance is calculated through a non-overlapping sliding time window of 30ms. The variance mean plus two times the standard deviation is selected as the threshold to divide the movement interval. The EMG data within the movement interval were preprocessed to obtain the envelope, including zero mean, bandpass filtering (4th order, 20-350 Hz), full-wave rectification, low-pass filtering (6 Hz) and normalization. For the high-height and low-height screw-tightening tasks, the maximum amplitude of each muscle of each experimental subject without wearing an exoskeleton was selected to normalize the EMG data. The root mean square of the envelope of each muscle of each experimental subject was calculated using a non-overlapping sliding time window of 30 ms. The results of the experiment were statistically analyzed. The Shapiro-Wilk test was used to test the normality of the data. If the normal distribution was not satisfied, a nonparametric analysis of variance (ANOVA) was performed to check for differences across conditions, otherwise a parametric ANOVA was applied. When a significant effect was observed, a post hoc analysis was performed. When the significant p value was less than 0.05, a statistically significant conclusion was drawn.

[0147] 2. Experimental results

[0148] (1) Range of motion test

[0149] According to the data collected by VICON, the maximum sagittal flexion and extension angle and the maximum horizontal flexion and extension angle of each person in each experimental configuration were obtained, and the mean of five people in each experimental configuration was calculated, as shown in Table 6. There was no significant difference in the results under the two experimental configurations, and it can be concluded that wearing an exoskeleton can still meet the user's range of motion.

[0150] Table 6 Shoulder range of motion with and without exoskeleton

[0151]

[0152] (2) Performance verification experiment

[0153] The ANOVA results for the screw tightening at two heights are shown in Table 7. All muscles monitored showed statistically significant effects. Fig.13 Results of pairwise comparisons of muscle activation are shown. In the exoskeleton-matched condition for both tasks, muscle activation was found to be significantly reduced for all monitored muscles compared to not wearing an exoskeleton.

[0154] Table 7. F and p values ​​of analysis of variance (ANOVA) of muscle activation in two tasks

[0155]

[0156] When screwing at a low height, the muscle activation of MD, PD, BB, PM, and LD in the exoskeleton-matching condition was significantly reduced compared with that in the exoskeleton-mismatching condition; in addition, the muscle activation of BB in the exoskeleton-mismatching condition was also significantly lower than that in the condition without an exoskeleton.

[0157] Compared with the exoskeleton mismatch condition, when screwing at high height, the muscle activation of AD, MD, PD and PM in the exoskeleton matching condition was significantly reduced; the muscle activation of BB and TR in the exoskeleton mismatch condition was significantly lower than when not wearing an exoskeleton.

[0158] As shown in Table 8, under the exoskeleton matching condition, the absolute percentage reductions for both tasks were above 15% (the highest for AD was 22.9% and 23.8% when screwing at low and high heights, respectively), and the relative percentage reductions were above 30% (the highest for AD was 48.3% when screwing at low heights, and the highest for BB was 49.6% when screwing at high heights). For both tasks under the exoskeleton mismatching condition, the absolute percentage reductions were above 5% (the highest for AD was 11.9% when screwing at low heights, and the highest for BB and TR was 11.3% when screwing at high heights), and the relative percentage reductions were above 9% (the highest for AD was 24.3% when screwing at high heights, and the highest for BB was 27.7% when screwing at low heights). For the same muscle in the same task, the absolute and relative reductions under the exoskeleton matching condition were approximately twice the reductions under the exoskeleton mismatching condition.

[0159] Table 8. Percentage of muscle activation reduction when wearing an exoskeleton

[0160]

[0161] Note: A|B represents the absolute and relative percentage decrease in muscle activation compared to not wearing an exoskeleton.

[0162] The above results verify the effectiveness of the exoskeleton, indicating that the passive shoulder exoskeleton robot provided by the present invention can reduce the burden on the shoulder and the muscle force of the corresponding muscles, thereby delaying fatigue and reducing the risk of shoulder musculoskeletal diseases.

[0163] It should be noted that the embodiments of the present invention are preferred implementations rather than limiting the present invention. It should be noted that, for those skilled in the art, without departing from the principles of the present invention, the specific implementations may be modified or some technical features may be replaced by equivalents, which shall all be deemed to be within the scope of the present invention.

Claims

1. A passive shoulder exoskeleton robot for assisting head tasks, characterized in that: The exoskeleton comprises a shoulder module, a passive drive module, a back support module and a flexible module; the shoulder module comprises a horizontal flexion and extension rod (1), a shoulder bending connecting rod (2), a sagittal flexion and extension rod (3) and a front and rear adjustment connecting rod (12); the shoulder module is used to improve the range of shoulder movement when a person wears the exoskeleton; the passive drive module adopts a torque generator (4) for generating a power-assisting torque, and the peak torque and peak torque angle of the power-assisting torque are adjustable; The back support module comprises a back slide rail (5), a waist fixing plate (7), an upper back rod (11) and a lower back rod (9), and the back support module is used to support the overall structure of the exoskeleton; the flexible module comprises a shoulder belt (6), a waist belt (8) and an arm strap (10), and the flexible module is used to connect the exoskeleton to the human body; One end of the shoulder bending link (2) and the front and rear adjustment link (12) are connected through a horizontal flexion and extension rod (1) to form a horizontal flexion and extension degree of freedom, with the sagittal plane of the human body as the symmetry plane, one on each side; the other end of the shoulder bending link (2) and the torque generator (4) are connected through a sagittal flexion and extension rod (3) to form a sagittal flexion and extension degree of freedom, one on each side; one end of the lower back rod (9) is connected to a waist fixing plate (7) to form a waist rotation degree of freedom, whose rotation axis is perpendicular to the sagittal plane, and the other end of the lower back rod (9) is connected to a back slide rail (5); one end of the upper back rod (11) is connected to the front and rear adjustment link (12), and the other end is connected to the back slide rail (5); the arm binding (10) is fixed on the torque generator (4), one on each side; the shoulder strap (6) is respectively connected to the back slide rail (5) and the waist belt (8); the waist belt (8) is respectively connected to the waist fixing plate (7) and the shoulder strap (6).

2. The passive shoulder exoskeleton robot for assisting over-the-head tasks according to claim 1, characterized in that: The torque generator (4) is composed of a pulley block (13), a guide rail (14), a steel wire rope (15), a tensile elastic element (16), an eight-shaped ring (17), a pre-tightening bolt (18) and a housing (19); the pulley block (13) includes a No. 1 pulley (131), a No. 2 pulley (132), a No. 3 pulley (133), a No. 4 pulley (134) and a No. 5 pulley (135); The tensile elastic element (16) is used as an energy storage element to provide power; one end of the steel wire rope (15) is fixed on the No. 1 pulley (131), and is wound around the No. 2 pulley (132) and the No. 3 pulley (133) in the middle, and is connected to the tensile elastic element (16) via the No. 4 pulley (134) and the No. 5 pulley (135). The No. 4 pulley (134) and the No. 5 pulley (135) are placed side by side, and their function is to ensure that the direction of the steel wire rope (15) and the tensile elastic element (16) are in a straight line; the No. 2 pulley (132) and the No. 3 pulley are connected to the tensile elastic element (16) in the middle. The wheel (133) is installed on a guide rail slider matched with the guide rail (14) and can slide along the guide rail (14); the other end of the stretching elastic element (16) is connected to the eight-shaped ring (17), and the other end of the eight-shaped ring (17) is connected to the pre-tightening bolt (18), and the pre-tightening bolt (18) adjusts the pre-tightening length of the stretching elastic element (16); the eight-shaped ring (17) contains a rotational freedom in the middle, and its function is to ensure that the stretching elastic element (16) does not rotate when the pre-tightening bolt (18) is rotated; the housing (19) provides protection and support.

3. The passive shoulder exoskeleton robot for assisting over-the-head tasks according to claim 1, characterized in that: The back slide rail (5) comprises a back slide rail body (51), a back slider (52) and a back carbon fiber plate (53); the back slide rail body (51) is fixed on the back carbon fiber plate (53); a groove is provided on the back slide rail body (51), and the back slider (52) is placed in the groove and can slide left and right in the back slide rail body (51); The upper back rod (11) comprises an upper back rod upper part (111) and an upper back rod lower part (112); the upper end of the upper back rod upper part (111) is connected to the end of the front and rear adjustment connecting rod (12) by bolts, wherein the upper end of the upper back rod upper part (111) has a prefabricated threaded hole, which can change the installation position of the upper back rod upper part (111) and the front and rear adjustment connecting rod (12); the lower end of the upper back rod upper part (111) is connected to the upper end of the lower back rod (112) by bolts using a length adjustment hole 20, so as to adjust the overall length of the exoskeleton upper back rod (11); the lower end of the upper back rod lower part (112) is connected to the back slider (52) by bolts; The lower back rod (9) comprises an upper portion (91) and a lower portion (92). The upper end of the upper portion (91) is fixedly connected to the back carbon fiber plate (53). The lower end of the upper portion (91) is connected to the upper end of the lower portion (92) by bolts through a length adjustment hole 20, so as to adjust the overall length of the exoskeleton lower back rod (9). The lower end of the lower portion (92) is connected to the waist fixing plate (7) through a rotating joint.

4. The passive shoulder exoskeleton robot for assisting over-the-head tasks according to claim 3, characterized in that: The size of the exoskeleton robot is adjustable, wherein the front and rear adjustment connecting rods (12) are adjustable in length to accommodate people with different back thicknesses, with the back thickness range being 5 to 10 cm; the upper back rod (11) and the lower back rod (9) are adjustable in length to accommodate people with different back lengths, with the back length range being 43.6 to 66.6 cm; the upper back rod can slide left and right along the back slide rail (5) to accommodate people with different shoulder widths, with the shoulder width range being 29.6 to 45.6 cm; the arm straps (10), waist belts (8) and shoulder straps (6) are adjustable in length.

5. The passive shoulder exoskeleton robot for assisting over-the-head tasks according to claim 2, characterized in that: The method for using the exoskeleton robot is as follows: before using the exoskeleton, the user adjusts the position of the No. 1 pulley (131) and the positions of the No. 2 pulley (132) and the No. 3 pulley (133) on the guide rail (14) according to the actual overhead task height and the requirements for the safety limit angle; during the use of the exoskeleton, the user adjusts the size of the exoskeleton through the arm binding (10), the waist belt (8), the shoulder strap (6), the front and rear adjustment connecting rods (12), the upper back rod (11), the lower back rod (9) and the back slide rail (5) to make it conform to the size of the user's body; after putting on the exoskeleton, the user changes the peak torque of the torque generator (4) by adjusting the pre-tightening bolt (18) to meet the user's own needs.

6. A method for designing a passive shoulder exoskeleton robot for assisting head tasks, used to design the passive shoulder exoskeleton robot for assisting head tasks as claimed in claim 2, characterized in that: The following steps are involved: Step 1: Design the shoulder module. The design parameters of the shoulder module include the pitch angle φ, the vertical distance d v and horizontal deviation d b ; Among them, the pitch angle φ is the angle between the front and rear adjustment links and the horizontal plane of the human body, and the vertical distance d v Defined as the vertical distance between the user's shoulder rotation center and the front and rear adjustment links, horizontal deviation d b is the horizontal distance between the user's shoulder rotation center and the exoskeleton's shoulder rotation center; the pitch angle φ and the vertical distance d v Used to adjust the space between the acromion and the exoskeleton horizontal flexion and extension bar above it, horizontal deviation d b Used to adjust the deviation distance between the exoskeleton shoulder rotation center and the user's shoulder rotation center; Step 2: Design a passive drive module. The passive drive module uses a torque generator. The torque generator design parameters include K, L i , α, β, r1, r2, r3 r, are used to adjust the peak torque and peak torque angle; where K is the stiffness of the tensile elastic element, L i is the initial stretch of the stretch elastic element, α is the angle of pulley No. 1, β is the angle of pulley No. 2, r1 is the distance between the sagittal flexion and extension bar and pulley No. 1, r2 is the distance between the sagittal flexion and extension bar and the guide rail, r3 is the radius of the sagittal flexion and extension bar, and r is the radius of pulley No. 1, pulley No. 2, and pulley No. 3; Step 3: Design a back support module to fit wearers of different body sizes; Step 4: Design flexible modules for fixing the exoskeleton to the human body.

7. The design method of a passive shoulder exoskeleton robot for assisting over-the-head tasks according to claim 6, characterized in that: In step 2, the torque generator design parameters include K, L i , α, β, r1, r2, r3r, used to adjust the peak torque and peak torque angle, specifically: K, L i and r1 mainly affect the peak torque of the power-assist torque curve. As the parameters increase, the peak torque increases. r2 affects the overall length of the torque generator housing. r3 mainly affects the power-assist torque of stage 1. As r3 increases, the power-assist torque of stage 1 increases, but the peak torque of stage 2 remains basically unchanged. r has some influence on the peak torque of the power-assist torque curve and the boundary angle between stage 1 and stage 2. As r increases, the peak torque increases slightly and the boundary angle between stage 1 and stage 2 decreases slightly. α and β mainly affect the peak torque, peak torque angle and boundary angle between stage 1 and stage 2 of the power-assist torque curve. If α increases or β decreases, the peak torque of the power-assist torque curve decreases, the peak torque angle increases, and the boundary angle between stage 1 and stage 2 increases. The definitions of stage 1 and stage 2 are as follows: depending on whether the wire rope is in contact with the sagittal flexion and extension bar, the entire assistance process is divided into two stages: stage 1 is a low-assistance area, in which the wire rope is in contact with the sagittal flexion and extension bar, and the lever arm is very small; stage 2 is a high-assistance area, in which the wire rope is separated from the sagittal flexion and extension bar, and the lever arm first increases and then decreases.

8. The design method of a passive shoulder exoskeleton robot for assisting over-the-head tasks according to claim 6, characterized in that: In step 2, the torque generator generates a boost torque τ exo , the calculation method is: t exo =F s L exo (1) Where F s and L exo They represent the stored elastic potential energy and the lever arm, respectively. The lever arm is the vertical distance from the center of the exoskeleton sagittal flexion and extension rod to the wire rope between pulleys 1 and 2. F s By formula (2) we can obtain F s =KΔL (2) Where K is the stiffness of the tensile elastic element and ΔL is the stretch of the tensile elastic element.

9. The design method of a passive shoulder exoskeleton robot for assisting over-the-head tasks according to claim 8, characterized in that: The calculation formula of the stretching amount ΔL of the stretching elastic element is: ΔL=ΔL(θ s，exo )=L A′，B′ (i s，exo )-L A′B′ (max(θ s，exo ))+L i (3) Where L A′B′ is the change in the length of the wire rope between pulley No. 1 and pulley No.

3. s，exo When it reaches the maximum value, L A′B′ The shortest length, L i is the initial stretch of the stretch elastic element.

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