Pneumatic upper limb rehabilitation exoskeleton based on trapezoidal energy storage air bag

Abstract

The invention relates to a pneumatic upper limb rehabilitation exoskeleton based on a trapezoidal energy storage air bag. The pneumatic upper limb rehabilitation exoskeleton comprises shoulder, elbow and wrist joint drivers, a flexible exoskeleton suit and a connecting assembly. The shoulder-elbow-wrist joint driver comprises a shoulder joint driver, an elbow joint driver and a wrist joint driver; the shoulder joint driver comprises a shoulder joint forward flexion driver, a shoulder joint backward extension driver, a shoulder joint abduction driver and a shoulder joint adduction driver, the elbow joint driver comprises an elbow joint forward flexion driver and an elbow joint backward extension driver, and the wrist joint driver comprises a wrist joint forward flexion driver and a wrist joint backward extension driver; the shoulder elbow wrist joint driver is composed of a plurality of trapezoidal energy storage air bags. The flexible exoskeleton garment is used for connecting the shoulder-elbow-wrist joint driver and the upper limb of the human body and fixing the position of the shoulder-elbow-wrist joint driver. Compared with the prior art, the trapezoidal energy storage air bag in the pneumatic driver enables the upper limbs to move more flexibly and is matched with the upper limbs of the human body, and a patient is prevented from wearing discomfort or secondary injury.

Description

Technical Field

[0001] The present invention relates to the technical field of exoskeleton robots, and in particular to a pneumatic upper limb rehabilitation exoskeleton based on a trapezoidal energy storage airbag. Background Art

[0002] In recent years, the application of flexible robot technology in exoskeleton robots at home and abroad has been widely developed. Upper limb rehabilitation exoskeleton is a device used to assist patients with upper limb motor dysfunction in rehabilitation training. Pneumatic upper limb rehabilitation exoskeleton uses pneumatic muscle actuators (PMA) as a power source. These actuators generate force through compressed air to drive the exoskeleton to move. Pneumatic muscle actuators have the advantages of light weight, easy control, and relatively low cost, which makes them very popular in the field of rehabilitation exoskeletons. However, in actual applications, pneumatic upper limb rehabilitation exoskeletons still have problems such as insufficient driving force, complex control, and insufficient matching between the structure and the human body. Therefore, technicians in this field are committed to providing a pneumatic upper limb rehabilitation exoskeleton based on a trapezoidal energy storage airbag to provide the wearer with shoulder, elbow, and wrist joint movement assistance. Summary of the invention

[0003] The purpose of the present invention is to overcome the above-mentioned defects of the prior art and provide a pneumatic upper limb rehabilitation exoskeleton based on trapezoidal energy storage airbags. The trapezoidal energy storage airbags in the pneumatic drive adopt a bionic design to simulate the upper limb muscles to assist the shoulder, elbow and wrist joint movements. The upper limb movements that can be achieved are more flexible and match the upper limbs of the human body, avoiding discomfort or secondary injuries to patients.

[0004] The present invention provides a pneumatic upper limb rehabilitation exoskeleton based on a trapezoidal energy storage airbag, comprising: a shoulder, elbow and wrist joint driver, a flexible exoskeleton suit and a connection component;

[0005] The shoulder-elbow-wrist joint driver comprises: a shoulder joint driver, an elbow joint driver and a wrist joint driver; the shoulder joint driver comprises: a shoulder joint flexion driver, a shoulder joint extension driver, a shoulder joint abduction driver and a shoulder joint adduction driver; the elbow joint driver comprises: an elbow joint flexion driver and an elbow joint extension driver; the wrist joint driver comprises: a wrist joint flexion driver and a wrist joint extension driver; the shoulder-elbow-wrist joint driver is composed of a plurality of trapezoidal energy storage airbags;

[0006] The flexible exoskeleton suit is used to connect the shoulder, elbow and wrist joint actuators to the upper limbs of the human body and fix the position of the shoulder, elbow and wrist joint actuators;

[0007] The connection component is used to connect the shoulder, elbow and wrist joint drivers with the flexible exoskeleton suit.

[0008] Furthermore, the connecting component is composed of burr adhesive and Velcro straps; the velvet surface of the burr adhesive is connected to the back of the shoulder, elbow and wrist joint driver, the hook surface of the burr adhesive is connected to the flexible exoskeleton suit, and the Velcro straps pass through the pneumatic driver and are tied to the corresponding position of the upper limbs of the human body.

[0009] Furthermore, the shoulder, elbow and wrist joint driver is fixed to the corresponding position of the flexible exoskeleton suit through a connecting component; the shoulder joint flexion driver is placed on the front side of the upper arm, parallel to the coronal plane; the shoulder joint extension driver is placed on the back side of the upper arm, parallel to the coronal plane; the shoulder joint abduction driver is placed on the outside of the shoulder joint, parallel to the sagittal plane; the shoulder joint abduction driver is placed under the armpit, parallel to the sagittal plane.

[0010] Furthermore, the elbow flexion driver is placed on the inner side of the elbow joint, the elbow extension driver is placed on the outer side of the elbow joint, the wrist flexion driver is placed on the inner side of the wrist joint, and the wrist flexion driver is placed on the outer side of the wrist joint.

[0011] Furthermore, the shoulder, elbow and wrist joint driver is a pneumatic driver that conforms to the structure and length of the three joints of the human shoulder, elbow and wrist. The pneumatic driver is formed by connecting several trapezoidal energy storage airbags. The sides of the trapezoidal energy storage airbags overlap and are connected by glue. The bottom surface is connected to the bottom plastic film by glue. Adjacent trapezoidal energy storage airbags are closely arranged. The length of the bottom plastic film is equal to the product of the bottom length of a single trapezoidal energy storage airbag and the number of trapezoidal energy storage airbags. The bottom plastic film is connected to the suede surface of the burr adhesive by double-sided tape.

[0012] Furthermore, the trapezoidal energy storage airbag is a deformable three-dimensional trapezoidal structure. When the air pressure inside the trapezoidal energy storage airbag reaches the maximum value, the trapezoidal energy storage airbag is a three-dimensional trapezoid. The pneumatic driver is formed by connecting several trapezoidal energy storage airbags. A circular hole for connecting the left and right airbags is provided in the middle position of the side of the trapezoidal energy storage airbag. There is only one circular hole on the side of the first and rear airbags of the pneumatic driver. An air source vent is provided at the tail of the pneumatic driver for connecting the air pipe and thus connecting the air source.

[0013] Furthermore, the trapezoidal energy storage airbag is made of 0.1 mm thick thermoplastic polyurethane TPU fabric, which is soft, light and highly fatigue-resistant.

[0014] Furthermore, the trapezoidal energy storage airbag is formed into a single trapezoidal air chamber by heat-pressing sealing, and a circular vent hole is provided at the center of the side of the single airbag to form a connected air chamber.

[0015] Furthermore, the trapezoidal energy storage airbag changes the air pressure inside the airbag by connecting to an air source, causing the airbag to deform and generate pressure, simulating human muscle-assisted joint movement. When the air pressure inside the airbag reaches the maximum value, the bending angle generated by the entire driver is the largest.

[0016] Furthermore, the parameter calculation of the bending angle of the pneumatic actuator includes the following steps:

[0017] S1. When the air pressure of the trapezoidal energy storage airbag reaches the maximum value, the bending angle of the entire driver is the largest; suppose that when the airbag is inflated, the angle between the short side extension line of the first airbag and the short side of the second airbag in the adjacent trapezoidal energy storage airbag is θ n When the number of airbags n is 2, the maximum bending angle of the entire actuator is θ 1 ; When n is 3, the maximum bending angle produced by the entire driver is θ 1 +θ 2 ; Similarly, when the driver has n trapezoidal energy storage airbags, the maximum bending angle it can produce is:

[0018]

[0019] S2. Under ideal conditions, when each trapezoidal energy storage airbag reaches its maximum internal pressure, the shape of each trapezoidal energy storage airbag remains uniform. Therefore, the angles between each pair of adjacent trapezoidal energy storage airbags are consistent, then:

[0020] θ sum =(n-1)θ 1 ;

[0021] S3. Let the short side of a single bag be a s , the long side is a l , the height is h, and the base angle of the short side is but:

[0022]

[0023] S4, from S3, we can get the first maximum bending angle θ 1 for:

[0024]

[0025] S5. By analogy with S4, when the number of trapezoidal energy storage airbags in the driver is n, the maximum bending angle value of the driver is:

[0026]

[0027] Compared with the prior art, the present invention has the following advantages:

[0028] (1) The pneumatic upper limb exoskeleton provided by the present invention has a trapezoidal energy storage airbag in the pneumatic drive that adopts a bionic design to simulate the upper limb muscles to assist the shoulder, elbow, and wrist joint movements.

[0029] (2) In the pneumatic upper limb exoskeleton provided by the present invention, the eight actuators of the shoulder, elbow and wrist joints are all provided with separate air source channels, so each pneumatic actuator can be driven separately, making the upper limb movements achievable by the present invention more flexible.

[0030] (3) The pneumatic upper limb exoskeleton provided by the present invention has shoulder, elbow and wrist joint drivers that are pneumatic drivers that conform to the structure and length of the three joints of the human shoulder, elbow and wrist, and match the human upper limbs to avoid discomfort or secondary injuries to patients. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 Schematic diagram of the wearing effect of the pneumatic upper limb exoskeleton provided by the present invention;

[0032] Figure 2 It is a schematic diagram of the shoulder, elbow and wrist joint driver provided by the present invention;

[0033] Figure 3 It is a schematic diagram of the shoulder, elbow and wrist joint driver provided by the present invention;

[0034] Figure 4 is a schematic diagram of a single pneumatic actuator provided by the present invention;

[0035] Figure 5 yes Figure 4 Schematic diagram of the tail trapezoidal energy storage airbag;

[0036] Figure 6 yes Figure 4 Schematic diagram of the intermediate trapezoidal energy storage airbag;

[0037] Figure 7 It is a schematic diagram of the contraction of the trapezoidal energy storage airbag;

[0038] Figure 8 It is a schematic diagram of the expansion of a trapezoidal energy storage airbag;

[0039] Fig. 9 It is a parameter annotation diagram of the pneumatic actuator;

[0040] Figure markings: 1-shoulder, elbow and wrist joint driver, 100-shoulder joint flexion driver, 110-trapezoidal energy storage airbag, 1100-first circular connecting hole, 1101-second circular connecting hole, 1102-third circular connecting hole, 1103-air source vent, 1001-bottom plastic film, 101-shoulder joint extension driver, 102-shoulder joint abduction driver, 103-shoulder joint adduction driver, 104-elbow joint flexion driver, 105-elbow joint extension driver, 106-wrist joint flexion driver, 107-wrist joint extension driver; 2-flexible exoskeleton suit. DETAILED DESCRIPTION

[0041] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. Component models, material names, connection structures, control methods, algorithms and other features not clearly described in this technical solution are all considered to be common technical features disclosed in the prior art.

[0042] Example 1

[0043] This embodiment provides a pneumatic upper limb rehabilitation exoskeleton based on a trapezoidal energy storage airbag. Figure 1 As shown, it includes: a shoulder, elbow and wrist joint driver 1, a flexible exoskeleton suit 2 and a connection component;

[0044] like Figure 2 , 3 As shown, the shoulder-elbow-wrist joint driver 1 includes: a shoulder joint driver, an elbow joint driver and a wrist joint driver; the shoulder joint driver includes: a shoulder joint flexion driver 100, a shoulder joint extension driver 101, a shoulder joint abduction driver 102 and a shoulder joint adduction driver 103; the elbow joint driver includes: an elbow joint flexion driver 104 and an elbow joint extension driver 105; the wrist joint driver includes: a wrist joint flexion driver 106 and a wrist joint extension driver 107; the shoulder-elbow-wrist joint driver 1 is composed of a plurality of trapezoidal energy storage airbags;

[0045] The flexible exoskeleton suit 2 is used to connect the shoulder, elbow and wrist joint driver 1 with the upper limbs of the human body, and fix the position of the shoulder, elbow and wrist joint driver 1;

[0046] The connection component is used to connect the shoulder, elbow and wrist joint driver 1 and the flexible exoskeleton suit 2.

[0047] In a specific embodiment, the connecting component is composed of burr adhesive and Velcro straps; the velvet surface of the burr adhesive is connected to the back of the shoulder, elbow and wrist joint driver 1, the hook surface of the burr adhesive is connected to the flexible exoskeleton suit 2, and the Velcro straps pass through the pneumatic driver and are tied to the corresponding position of the upper limbs of the human body.

[0048] In a specific embodiment, the shoulder, elbow and wrist joint driver 1 is fixed to the corresponding position of the flexible exoskeleton suit 2 through a connecting assembly; the shoulder joint flexion driver 100 is placed on the front side of the upper arm, parallel to the coronal plane; the shoulder joint extension driver 101 is placed on the back side of the upper arm, parallel to the coronal plane; the shoulder joint abduction driver 102 is placed on the outside of the shoulder joint, parallel to the sagittal plane; the shoulder joint abduction driver 103 is placed under the armpit, parallel to the sagittal plane.

[0049] In a specific implementation, the elbow flexion driver 104 is placed on the inner side of the elbow joint, the elbow extension driver 105 is placed on the outer side of the elbow joint, the wrist flexion driver 106 is placed on the inner side of the wrist joint, and the wrist flexion driver 107 is placed on the outer side of the wrist joint.

[0050] like Figure 4 , 5 , 6, 7, and 8, in a specific embodiment, the shoulder-elbow-wrist joint driver 1 is a pneumatic driver that conforms to the structure and length of the three joints of the human shoulder-elbow-wrist joint. The pneumatic driver is formed by connecting several trapezoidal energy storage airbags 110. The sides of the trapezoidal energy storage airbags 110 overlap and are connected by glue. The bottom surface is connected to the bottom plastic film 1001 by glue. Adjacent trapezoidal energy storage airbags 110 are closely arranged. The length of the bottom plastic film 1001 is equal to the product of the bottom length of a single trapezoidal energy storage airbag 110 and the number of trapezoidal energy storage airbags 110. The bottom plastic film 1001 is connected to the suede surface of the burr adhesive by double-sided tape.

[0051] In a specific embodiment, the trapezoidal energy storage airbag 110 is a deformable three-dimensional trapezoidal structure. When the internal air pressure of the trapezoidal energy storage airbag 110 reaches a maximum value, the trapezoidal energy storage airbag 110 is a three-dimensional trapezoid. The pneumatic driver is formed by connecting several trapezoidal energy storage airbags 110. A circular hole for connecting the left and right airbags is provided in the middle position of the side of the trapezoidal energy storage airbag 110, namely, a first circular connecting hole 1100 and a second circular connecting hole 1101. There is only one circular hole on the side of the first and rear airbags of the pneumatic driver, namely, a third circular connecting hole 1102. The tail of the pneumatic driver is provided with an air source vent 1103 for connecting the air pipe and thus connecting the air source.

[0052] In a specific implementation, the trapezoidal energy storage airbag 110 is made of 0.1 mm thick thermoplastic polyurethane TPU fabric, which is soft, light and highly fatigue-resistant.

[0053] In a specific embodiment, the trapezoidal energy storage airbag 110 is formed into a single trapezoidal air chamber by heat-pressing and sealing, and a circular vent hole is provided at the center of the side of the single airbag to form a connected air chamber.

[0054] In a specific embodiment, the trapezoidal energy storage airbag 110 changes the air pressure inside the airbag by connecting to an air source, causing the airbag to deform and generate pressure, simulating human muscle-assisted joint movement. When the air pressure inside the airbag reaches the maximum value, the bending angle generated by the entire actuator is the largest.

[0055] like Fig. 9 As shown, in a specific embodiment, the parameter calculation of the bending angle of the pneumatic actuator includes the following steps:

[0056] S1. When the air pressure of the trapezoidal energy storage airbag 110 reaches the maximum value, the bending angle of the entire driver is the largest; assuming that in the airbag expansion state, the angle between the short side extension line of the front airbag and the short side of the rear airbag in the adjacent two trapezoidal energy storage airbags is θ n When the number of airbags n is 2, the maximum bending angle of the entire actuator is θ 1 ; When n is 3, the maximum bending angle produced by the entire driver is θ 1 +θ 2 Similarly, when the driver has n trapezoidal energy storage airbags 110, the maximum bending angle that can be generated is:

[0057]

[0058] S2. Under ideal conditions, when each trapezoidal energy storage airbag 110 reaches its maximum internal pressure, the shape of each trapezoidal energy storage airbag 110 remains uniform. Therefore, the angles between each pair of adjacent trapezoidal energy storage airbags 110 are consistent, then:

[0059] θ sum =(n-1)θ 1 ;

[0060] S3. Let the short side of a single bag be a s , the long side is a l , the height is h, and the base angle of the short side is but:

[0061]

[0062] S4, from S3, we can get the first maximum bending angle θ 1 for:

[0063]

[0064] S5. By analogy with S4, when the number of trapezoidal energy storage airbags 110 in the driver is n, the maximum bending angle value of the driver is:

[0065]

[0066] The working principle is as follows: First, the 8 drivers included in the shoulder, elbow and wrist joint driver 1 are all provided with a separate air source channel, so each pneumatic driver can be driven separately, and the air pressure inside the single pneumatic driver is changed to generate force, so as to realize the corresponding movement of the joint corresponding to the pneumatic driver. Take the extension movement of the elbow joint as an example: when performing the extension movement of the elbow joint, gas is introduced into the source channel of the elbow joint extension driver 105 to increase the air pressure inside the elbow joint extension driver 105. When the internal air pressure reaches the maximum value, the maximum bending angle that can be achieved by the elbow joint extension movement is completed. The working principle of each pneumatic driver is the same, and each pneumatic driver can be driven separately, so that the upper limb movement that can be realized by the present invention is more flexible. Secondly, the shoulder, elbow and wrist joint drivers 1 are pneumatic drivers that conform to the structure and length of the three joints of the shoulder, elbow and wrist of the human body, and match the upper limbs of the human body to avoid discomfort or secondary injury to the patient.

[0067] The trapezoidal energy storage airbag 110 of the present invention adopts a bionic design to imitate the contraction and relaxation of the upper limb muscles of the human body to achieve corresponding movements of the shoulder and elbow joints.

[0068] Components not described in detail in this embodiment are all existing components that can be purchased through public channels.

[0069] The above description of the embodiments is to facilitate the understanding and use of the invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the scope of protection of the present invention.

Claims

1. A pneumatic upper limb rehabilitation exoskeleton based on a trapezoidal energy storage airbag, characterized in that: include: Shoulder, elbow and wrist joint actuators (1), flexible exoskeleton suits (2) and connection components; The shoulder-elbow-wrist joint driver (1) comprises: a shoulder joint driver, an elbow joint driver and a wrist joint driver; the shoulder joint driver comprises: a shoulder joint flexion driver (100), a shoulder joint extension driver (101), a shoulder joint abduction driver (102) and a shoulder joint adduction driver (103); the elbow joint driver comprises: an elbow joint flexion driver (104) and an elbow joint extension driver (105); the wrist joint driver comprises: a wrist joint flexion driver (106) and a wrist joint extension driver (107); the shoulder-elbow-wrist joint driver (1) is composed of a plurality of trapezoidal energy storage airbags; The flexible exoskeleton suit (2) is used to connect the shoulder, elbow and wrist joint driver (1) to the upper limbs of the human body, and fix the position of the shoulder, elbow and wrist joint driver (1); The connection component is used to connect the shoulder, elbow and wrist joint driver (1) and the flexible exoskeleton suit (2).

2. A pneumatic upper limb rehabilitation exoskeleton based on a trapezoidal energy storage airbag according to claim 1, characterized in that: The connection component is composed of burr adhesive and Velcro straps; the velvet surface of the burr adhesive is connected to the back of the shoulder, elbow and wrist joint driver (1), the hook surface of the burr adhesive is connected to the flexible exoskeleton suit (2), and the Velcro straps pass through the pneumatic driver and are tied to the corresponding position of the upper limb of the human body.

3. A pneumatic upper limb rehabilitation exoskeleton based on a trapezoidal energy storage airbag according to claim 1, characterized in that: The shoulder, elbow and wrist joint driver (1) is fixed to a corresponding position of the flexible exoskeleton suit (2) via a connecting assembly; the shoulder joint flexion driver (100) is placed on the front side of the upper arm, parallel to the coronal plane; the shoulder joint extension driver (101) is placed on the back side of the upper arm, parallel to the coronal plane; the shoulder joint abduction driver (102) is placed on the outside of the shoulder joint, parallel to the sagittal plane; and the shoulder joint abduction driver (103) is placed under the armpit, parallel to the sagittal plane.

4. A pneumatic upper limb rehabilitation exoskeleton based on a trapezoidal energy storage airbag according to claim 1, characterized in that: The elbow joint flexion driver (104) is placed on the inner side of the elbow joint, the elbow joint extension driver (105) is placed on the outer side of the elbow joint, the wrist joint flexion driver (106) is placed on the inner side of the wrist joint, and the wrist joint flexion driver (107) is placed on the outer side of the wrist joint.

5. The pneumatic upper limb rehabilitation exoskeleton based on a trapezoidal energy storage airbag according to claim 1, characterized in that: The shoulder, elbow and wrist joint driver (1) is a pneumatic driver that conforms to the structure and length of the three joints of the human shoulder, elbow and wrist. The pneumatic driver is formed by connecting a plurality of trapezoidal energy storage airbags (110). The side surfaces of the trapezoidal energy storage airbags (110) overlap and are connected by glue. The bottom surface is connected to the bottom plastic film (1001) by glue. Adjacent trapezoidal energy storage airbags (110) are closely arranged. The length of the bottom plastic film (1001) is equal to the product of the bottom surface length of a single trapezoidal energy storage airbag (110) and the number of trapezoidal energy storage airbags (110).

6. A pneumatic upper limb rehabilitation exoskeleton based on a trapezoidal energy storage airbag according to claim 5, characterized in that: The trapezoidal energy storage airbag (110) is a deformable three-dimensional trapezoidal structure. When the air pressure inside the trapezoidal energy storage airbag (110) reaches a maximum value, the trapezoidal energy storage airbag (110) is a three-dimensional trapezoidal shape. The pneumatic driver is formed by connecting a plurality of trapezoidal energy storage airbags (110). A circular hole for connecting the left and right airbags is provided in the middle of the side of the trapezoidal energy storage airbag (110). The side of the first and last airbags of the pneumatic driver has only one circular hole. The tail of the pneumatic driver is provided with an air source vent (1103) for connecting an air pipe and thus connecting an air source.

7. A pneumatic upper limb rehabilitation exoskeleton based on a trapezoidal energy storage airbag according to claim 5, characterized in that: The trapezoidal energy storage airbag (110) is made of a 0.1 mm thick thermoplastic polyurethane TPU fabric, which is soft, light and highly fatigue-resistant.

8. The pneumatic upper limb rehabilitation exoskeleton based on a trapezoidal energy storage airbag according to claim 5, characterized in that: The trapezoidal energy storage airbag (110) is formed into a single trapezoidal air chamber by heat-pressing and sealing, and a circular vent hole is provided at the center of the side of the single airbag to form a connected air chamber.

9. The pneumatic upper limb rehabilitation exoskeleton based on a trapezoidal energy storage airbag according to claim 5, characterized in that: The trapezoidal energy storage airbag (110) changes the air pressure inside the airbag by connecting to an air source, causing the airbag to deform and thus generate pressure, thereby simulating human muscle-assisted joint movement.

10. The pneumatic upper limb rehabilitation exoskeleton based on a trapezoidal energy storage airbag according to claim 5, characterized in that: The parameter calculation of the bending angle of the pneumatic actuator includes the following steps: S1. When the air pressure of the trapezoidal energy storage airbag (110) reaches the maximum value, the bending angle generated by the entire driver is the largest; assuming that in the airbag expansion state, the angle between the extension line of the short side of the front airbag and the short side of the rear airbag in two adjacent trapezoidal energy storage airbags is θ n When the number of airbags n is 2, the maximum bending angle generated by the entire driver is θ1; when n is 3, the maximum bending angle generated by the entire driver is θ1+θ2; and so on, when the driver has n trapezoidal energy storage airbags (110), the maximum bending angle it can generate is S2. Under ideal conditions, when each trapezoidal energy storage airbag (110) reaches its maximum internal pressure, the shape of each trapezoidal energy storage airbag (110) remains uniform; therefore, the angles between each pair of adjacent trapezoidal energy storage airbags (110) are consistent, then: i sum =(n-1)θ1; S3. Let the short side of a single bag be a s , the long side is a l , the height is h, and the base angle of the short side is but: S4. From S3, we can get the first maximum bending angle θ1: S5. By analogy with S4, when the number of trapezoidal energy storage airbags (110) in the driver is n, the maximum bending angle value of the driver is:

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