Large-angle zero-gravity seat damage risk assessment method

Abstract

The invention provides a large-angle zero-gravity seat damage risk assessment method, and the method comprises the following steps: S1, collecting the pressure and comfort data of a dummy at different angles and under different supporting point configurations through an experiment, and building a dummy simulation model suitable for a large-angle zero-gravity seat; s2, on the basis of the dummy simulation model of the large-angle zero-gravity seat, vehicle collision and impact tests are added, acceleration and impact force data under different seat adjusting angles are obtained, a large-angle zero-gravity seat passenger injury prediction simulation model is established, and therefore a injury prediction value is obtained; and S3, calculating a damage risk score according to the damage predicted value.

Description

Technical Field

[0001] The present invention relates to the technical field of injury risk assessment, and in particular to an injury risk assessment method for a large-angle zero-gravity chair. Background Art

[0002] As more and more consumers expect a more comfortable driving experience, zero-gravity seats that allow for greater seat angle adjustment and retractable leg rests have gradually become a market hotspot in recent years, and more and more car companies have begun to equip new cars with zero-gravity seat configurations. The zero-gravity posture that can be achieved by a large-angle zero-gravity seat presents a nearly lying sitting posture. Under the premise of also providing good support to the body, the human torso and thighs form an angle of about 130° to make the spine naturally relaxed, thereby dispersing and balancing the pressure on the body as much as possible, reducing muscle wear, and keeping blood flow in a constant state, thus creating a sense of weightlessness and relaxation. The emergence of zero-gravity seats has greatly improved the seat comfort of passengers.

[0003] However, since the posture of passengers in a large-angle zero-gravity seat is significantly different from the traditional sitting posture, it exceeds the protection range of the existing passenger restraint system developed for the traditional sitting posture. Therefore, the safety of passengers in a zero-gravity seat cannot be fully protected even if they wear seat belts. In addition, with the development of autonomous driving and intelligent transportation technology, when passengers in the car no longer need to perform driving tasks, their demands for the in-car environment and sitting posture will also tend to be diversified, and this diversification will also make it increasingly difficult to protect the safety of passengers in the event of a collision. Therefore, it is particularly important to find an injury risk assessment for passengers in a large-angle zero-gravity seat in various postures. Summary of the invention

[0004] The purpose of the present invention is to provide a large-angle zero-gravity seat injury risk assessment method to solve the problems raised in the above-mentioned background technology.

[0005] The present invention is implemented by the following technical solution: a large-angle zero-gravity seat injury risk assessment method, the method comprising the following steps:

[0006] Step S1: collecting pressure and comfort data of the dummy at different angles and different support point configurations through experiments, and establishing a dummy simulation model suitable for a large-angle zero-gravity seat;

[0007] Step S2: Based on the dummy simulation model of the large-angle zero-gravity seat, vehicle collision and impact tests are added to obtain acceleration and impact force data at different seat adjustment angles, and a large-angle zero-gravity seat occupant injury prediction simulation model is established to obtain injury prediction values;

[0008] Step S3: Calculate the injury risk score according to the injury prediction value.

[0009] Specifically, the specific process of establishing the dummy simulation model suitable for the large-angle zero-gravity seat in step S1 is as follows:

[0010] Step S11: Assuming that the seat can be adjusted to a specific angle θ ranging from 120 degrees to 180 degrees, when the dummy sits on the seat, the change of the center of gravity of the dummy's body is expressed by the following formula:

[0011] h′=h·cos(θ)

[0012] Wherein, h′ is the height of the new center of gravity after adjustment, h is the height of the center of gravity before adjustment, and cos(θ) is the cosine value of the angle;

[0013] Step S12: The force state of the dummy on the seat is still based on gravity and support force:

[0014] F net =m·g·sin(θ)-F support

[0015] Among them, F net is the comprehensive force state of the dummy on the seat, m is the mass of the dummy, g is the acceleration of gravity, sin(θ) is the sine value of the angle, F support The support force provided by each supporting point of the dummy is used to offset the gravity of the dummy;

[0016] Step S13: For multi-point support, the distribution of the dummy's weight at each support point needs to be adjusted with a distance factor related to the angle:

[0017]

[0018] Among them, P i is the pressure of the ith support point, F net is the comprehensive stress state of the dummy on the seat, d i (θ) is the distance between the dummy and the i-th support point considering the angle effect, ∑d i (θ) is the sum of the distances of all support points;

[0019] Specifically, the following formula is used to calculate the comfort of the dummy interacting with the large-angle zero-gravity seat:

[0020]

[0021] Among them, E represents the comfort score of the dummy, n is the number of support points, λ is a constant, and γ is an adjustment factor.

[0022] Specifically, the comfort score of the dummy is normalized:

[0023]

[0024] Among them, E′ represents the normalized comfort score, E min represents the minimum value of the expected comfort score, E max Indicates the maximum value of the expected comfort score.

[0025] Specifically, the process of establishing the large-angle zero-gravity seat occupant injury prediction simulation model in step S2 specifically includes: calculating the acceleration of the dummy at different seat adjustment angles, and the specific formula is as follows:

[0026]

[0027] Where a represents acceleration, F external Indicates external impact force;

[0028] Specifically, the potential damage value is predicted based on acceleration and contact time, and the formula is as follows:

[0029]

[0030] Among them, H represents the damage prediction value, K represents the dynamic response coefficient, t represents the contact time, C represents the basic risk score, and D represents the correction factor.

[0031] Specifically, the specific process of calculating the injury risk score according to the injury prediction value in step S3 is as follows:

[0032] A dynamic risk assessment model is introduced, with time and impact force as variables, considering the strain response of occupants in different sitting postures. The specific formula is as follows:

[0033]

[0034] Among them, R is the risk score, k and X are constants, and α and β are model parameters.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] The present invention provides a method for assessing the injury risk of a large-angle zero-gravity seat. By establishing a dummy simulation model and an injury prediction simulation model suitable for a large-angle zero-gravity seat, the injury risk score of the occupant in a specific situation is calculated. The obtained injury risk score will provide real-time and objective data support for improving the seat design and formulating occupant protection measures, thereby optimizing the seat design and improving the safety and comfort of the occupant in various situations. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only preferred embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0038] Figure 1 A structural diagram of a large-angle zero-gravity seat injury risk assessment method provided by the present invention. DETAILED DESCRIPTION

[0039] In order to make the purpose, technical scheme and advantages of the present invention more obvious, the exemplary embodiments according to the present invention will be described in detail with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments of the present invention, and it should be understood that the present invention is not limited to the exemplary embodiments described herein. Based on the embodiments of the present invention described in the present invention, all other embodiments obtained by those skilled in the art without creative work should fall within the protection scope of the present invention.

[0040] In the following description, a large number of specific details are provided to provide a more thorough understanding of the present invention. However, it is apparent to those skilled in the art that the present invention can be implemented without one or more of these details. In other examples, in order to avoid confusion with the present invention, some technical features well known in the art are not described.

[0041] It should be understood that the present invention can be implemented in different forms and should not be interpreted as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to make the disclosure thorough and complete and to fully convey the scope of the present invention to those skilled in the art.

[0042] The purpose of the terms used herein is only to describe specific embodiments and is not intended to be limiting of the present invention. When used herein, the singular forms "one", "an" and "said / the" are also intended to include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "consisting of" and / or "comprising", when used in this specification, determine the presence of the features, integers, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, parts and / or groups. When used herein, the term "and / or" includes any and all combinations of the relevant listed items.

[0043] In order to fully understand the present invention, a detailed structure will be proposed in the following description to illustrate the technical solution proposed by the present invention. The optional embodiments of the present invention are described in detail as follows, but in addition to these detailed descriptions, the present invention may also have other implementations.

[0044] See also Figure 1 , a large-angle zero-gravity seat injury risk assessment method, the method comprising the following steps:

[0045] Step S1: collecting pressure and comfort data of the dummy at different angles and different support point configurations through experiments, and establishing a dummy simulation model suitable for a large-angle zero-gravity seat;

[0046] Step S2: Based on the dummy simulation model of the large-angle zero-gravity seat, vehicle collision and impact tests are added to obtain acceleration and impact force data at different seat adjustment angles, and a large-angle zero-gravity seat occupant injury prediction simulation model is established to obtain injury prediction values;

[0047] Step S3: Calculate the injury risk score based on the injury prediction value.

[0048] Exemplarily, the present invention provides a method for assessing the risk of injury of a large-angle zero-gravity seat. First, the pressure and comfort data of the dummy at different angles and support point configurations are collected through experiments. These data will be used to establish a dummy simulation model suitable for a large-angle zero-gravity seat to simulate the performance of the human body on the seat, and the subsequent analysis and experiments provide necessary parameters and data support. Secondly, on the basis of the established dummy simulation model, simulation tests on vehicle collision and impact are added. These tests will cover different seat adjustment angles to obtain the acceleration and impact force data experienced by the occupants in different situations. Using the above data, an injury prediction simulation model is established, which will calculate the degree of injury that the occupants may suffer under various conditions. Predict potential injury risks and provide a basis for subsequent design improvements. Finally, based on the injury prediction value obtained in the previous step, the injury risk score of the occupant in a specific situation is calculated to perform a risk assessment. The injury risk score obtained will provide real-time and objective data support for seat design improvements and the formulation of occupant protection measures, thereby optimizing seat design and improving the safety and comfort of occupants in various situations.

[0049] For example, assume that the mass of the dummy is m=75 kg (the mass of an adult), and the acceleration due to gravity is g=9.81 m / s 2 , the initial center of gravity height of the dummy is h = 1.8m, the adjustment angle θ = 150°, the number of support points where the dummy sits is n = 4, and the distances of each support point under the influence of the angle are d 1 =0.5,d 2 =0.6, d 3 =0.4,d 4 =0.5, adjustment constant λ=0.1, adjustment factor γ=0.05;

[0050] When the dummy sits on the seat, the center of gravity of its body changes as follows:

[0051] h′=h·cos(θ)=1.8×cos(150°)=-1.557m

[0052] The force state of the dummy in the seat is still based on gravity and support force:

[0053] F net =m·g·sin(θ)-F support =75×9.81×0.5=294.15N

[0054] For multiple points of support, the distribution of the dummy's weight at each support point needs to be adjusted by the distance factor related to the angle: d i (θ)=(0.5,0.6,0.4,0.5), then ∑d i (θ) = 0.5 + 0.6 + 0.4 + 0.5 = 2.0, then:

[0055]

[0056]

[0057]

[0058]

[0059] The comfort level of the dummy interacting with the large-angle zero-gravity seat is calculated as follows:

[0060]

[0061] Assume E min =-50, E max =50, the comfort score of the dummy is normalized as follows:

[0062]

[0063] The result indicates that the comfort score under each condition is 30.49, which is a lower-middle level of comfort. It can be seen that the dummy's sitting posture is not comfortable at a seat angle of 150° and may cause excessive pressure.

[0064] Assume that the external impact force F external =500N, contact time t=0.1S, dynamic response coefficient K=3.0, basic risk score C=10, correction factor D=6, seat adjustment angle θ=150°.

[0065] Calculate the acceleration of the dummy at different seat adjustment angles as follows:

[0066]

[0067] Based on the acceleration and contact time, the potential damage value is predicted as follows:

[0068]

[0069] A dynamic risk assessment model is introduced, with time and impact force as variables, considering the strain response of occupants in different sitting postures. The specific calculation is as follows: C is set to 6000 to control the final result between 0 and 100, and the model parameters α=2, β=0.1, k=1.5; then:

[0070]

[0071] The result shows that when the seat angle is 150°, the injury risk value is 15.54. Through the normalized dynamic risk model, the risk score calculated is 96.66, which indicates that in this sitting posture and condition, the occupant may face a higher risk of injury.

[0072] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for assessing the risk of injury to a large-angle zero-gravity seat, characterized in that: The method comprises the following steps: Step S1: collecting pressure and comfort data of the dummy at different angles and different support point configurations through experiments, and establishing a dummy simulation model suitable for a large-angle zero-gravity seat; Step S2: Based on the dummy simulation model of the large-angle zero-gravity seat, vehicle collision and impact tests are added to obtain acceleration and impact force data at different seat adjustment angles, and a large-angle zero-gravity seat occupant injury prediction simulation model is established to obtain injury prediction values; Step S3: Calculate the injury risk score based on the injury prediction value.

2. A method for assessing the risk of injury to a large-angle zero-gravity chair according to claim 1, characterized in that: The specific process of establishing the dummy simulation model suitable for the large-angle zero-gravity seat in step S1 is as follows: Step S11: Assuming that the seat can be adjusted to a specific angle θ ranging from 120 degrees to 180 degrees, when the dummy sits on the seat, the change of its body center of gravity is expressed by the following formula: h′=h·cos(θ) Wherein, h′ is the height of the new center of gravity after adjustment, h is the height of the center of gravity before adjustment, and cos(θ) is the cosine value of the angle; Step S12: The force state of the dummy on the seat is still based on gravity and support force: F net =m·g·sin(θ)-F support Among them, F net is the comprehensive force state of the dummy on the seat, m is the mass of the dummy, g is the acceleration of gravity, sin(θ) is the sine value of the angle, F support The support force provided by each supporting point of the dummy is used to offset the gravity of the dummy; Step S13: For multi-point support, the distribution of the dummy's weight at each support point needs to be adjusted with a distance factor related to the angle: Among them, P i is the pressure of the ith support point, F net is the comprehensive stress state of the dummy on the seat, d i (θ) is the distance between the dummy and the i-th support point considering the angle effect, ∑d i (θ) is the sum of the distances of all support points.

3. A method for assessing the risk of injury to a large-angle zero-gravity chair according to claim 2, characterized in that: The following formula is used to calculate the comfort of the dummy interacting with the large-angle zero-gravity seat: Among them, E represents the comfort score of the dummy, n is the number of support points, λ is a constant, and γ is an adjustment factor.

4. A method for assessing the risk of injury to a large-angle zero-gravity chair according to claim 3, characterized in that: Normalize the comfort rating of the dummy: Among them, E ′ represents the normalized comfort score, E min represents the minimum value of the expected comfort score, E max Indicates the maximum value of the expected comfort score.

5. A method for assessing the risk of injury to a large-angle zero-gravity chair according to claim 4, characterized in that: The process of establishing the large-angle zero-gravity seat occupant injury prediction simulation model in step S2 specifically includes: calculating the acceleration of the dummy at different seat adjustment angles, and the specific formula is as follows: Where a represents acceleration, F external Indicates external impact force.

6. A method for assessing the risk of injury to a large-angle zero-gravity chair according to claim 5, characterized in that: Based on acceleration and contact time, the potential damage value is predicted using the following formula: Among them, H represents the damage prediction value, K represents the dynamic response coefficient, t represents the contact time, C represents the basic risk score, and D represents the correction factor.

7. A method for assessing the risk of injury to a large-angle zero-gravity chair according to claim 6, characterized in that: The specific process of calculating the injury risk score according to the injury prediction value in step S3 is as follows: A dynamic risk assessment model is introduced, with time and impact force as variables, considering the strain response of occupants in different sitting postures. The specific formula is as follows: Among them, R is the risk score, k and X are constants, and α and β are model parameters.

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