An automobile airbag type active energy absorbing device and method

Abstract

The present application relates to the field of automobile safety technology, and particularly relates to an automobile airbag type active energy absorption device and method, first calculating a safety threshold of pedestrian and automobile collision, then constructing a numerical simulation model of pedestrian and vehicle collision, and then carrying out numerical simulation analysis of pedestrian-vehicle collision, analyzing the HIC value of pedestrian and vehicle collision under different impact scenarios (with / without airbag), verifying the buffering effect of the airbag type active energy absorption device, finally carrying out safety airbag trigger circuit design of pedestrian and automobile collision and completing circuit simulation, and finally realizing that when the speed exceeds the safety threshold, the safety airbag can be successfully triggered, and the collision impact force is slowed down through the airbag to protect the safety of pedestrians.

Description

Technical Field

[0001] This invention relates to the field of automotive safety technology, and in particular to an active energy absorption device and method for automotive airbags. Background Technology

[0002] Currently, car-pedestrian collisions are frequent, posing a serious threat to pedestrian safety. To mitigate pedestrian injuries during collisions, various active pedestrian protection devices have been developed. However, existing active pedestrian protection devices still have many shortcomings in improving collision safety performance. Although the focus of automotive safety technology research is shifting towards intelligent driver assistance systems, research into passive safety technologies continues to advance. Passive safety technologies primarily achieve energy absorption and cushioning by altering the vehicle's external structure, material stiffness, and structural spatial arrangement, thereby reducing the severity of pedestrian injuries in collisions.

[0003] Meanwhile, active safety technologies are gaining increasing attention, including traditional active safety systems such as ABS and ESP, as well as currently popular technologies like pedestrian braking, intelligent collision avoidance, and blind spot monitoring. Their role is to prevent collisions between pedestrians and vehicles, thus avoiding traffic accidents at their source. At the same time, well-known passive energy-absorbing devices such as airbags and seat belts are widely used to protect the safety of vehicle occupants. Active safety technologies such as anti-lock braking systems, blind spot detection, and intelligent obstacle avoidance are also becoming increasingly common, improving vehicle safety performance and occupant safety. However, as a vulnerable group among road users, pedestrians still suffer from high rates of fatality and serious injury in collision accidents.

[0004] However, research on pedestrian protection in China is relatively lagging behind. Most studies are still in the stage of research on passive devices. When pedestrians collide with vehicles, it is usually the car's engine hood and windshield that cause the most serious injuries to pedestrians. Existing technologies cannot reduce the injuries caused to pedestrians by vehicles when they collide with pedestrians, thus reducing the overall safety of the vehicle. Summary of the Invention

[0005] The purpose of this invention is to provide an active energy absorption device and method for automobiles with airbags, which solves the problem of significant head injuries to pedestrians caused by the car's engine hood and windshield during collisions with vehicles.

[0006] To achieve the above objectives, the present invention provides an active energy absorption method for automobile airbags, comprising the following steps:

[0007] Calculate the safety threshold for pedestrian-vehicle collisions;

[0008] Construction of a numerical simulation model for pedestrian-vehicle collisions;

[0009] Numerical simulation analysis of pedestrian-vehicle collision;

[0010] HIC value analysis of pedestrian and vehicle collisions in different impact scenarios with and without airbags;

[0011] Design and simulation of the airbag triggering circuit for pedestrian-vehicle collision.

[0012] The calculation of the safety threshold for pedestrian-vehicle collisions includes:

[0013] The reaction time to detect the pedestrian is t1, the braking delay time is t2, and the car moves at a constant speed during this period.

[0014] During the acceleration growth time t3, the car undergoes variable deceleration motion.

[0015] In time t4, the car travels a distance of x3.

[0016] The construction of the numerical simulation model for pedestrian-vehicle collisions includes:

[0017] When constructing a car front-end model, the car front-end model can be divided into three types based on the actual geometry and size of the structure: one-dimensional units, two-dimensional units, and three-dimensional units.

[0018] Head-shaped impactor model construction; pedestrian head-shaped impactors are divided into adult head-shaped impactors and child head-shaped impactors.

[0019] The airbag model is constructed by weaving warp and weft threads at a certain angle into the fabric material of the pedestrian airbag.

[0020] The numerical simulation analysis of pedestrian-vehicle collisions includes:

[0021] Conduct pedestrian-engine hood collision simulations, including both scenarios with and without airbags;

[0022] Conduct pedestrian collision simulations with the windshield, including both scenarios with and without airbags.

[0023] The analysis of HIC values ​​for pedestrian-vehicle collisions under different impact scenarios with and without airbags includes:

[0024] The Hip Injury Criterion (HIC) value was used to evaluate the degree of head injury in people under different impact scenarios.

[0025] The design and simulation of the airbag triggering circuit in a pedestrian-vehicle collision includes:

[0026] The design and simulation verification of the triggering system were completed based on the key conditions of accurately predicting the occurrence of accidents and outputting trigger signals in a timely manner.

[0027] An active energy absorption device for automobiles with an airbag, comprising an inflatable airbag and a control mechanism;

[0028] The control mechanism is mounted on the inflatable airbag and located on one side of the inflatable airbag.

[0029] The present invention discloses an active energy absorption device and method for automobile airbags. First, the safety threshold for pedestrian-vehicle collision is calculated. Then, a numerical simulation model of pedestrian-vehicle collision is constructed. Subsequently, a pedestrian-vehicle collision numerical simulation analysis is carried out to analyze the HIC value of pedestrian-vehicle collision under different impact scenarios (with / without airbags) to verify the buffering effect of the active energy absorption device. Finally, the design of the safety airbag triggering circuit for pedestrian-vehicle collision is carried out and the circuit simulation is completed. Ultimately, when the speed exceeds the safety threshold, the safety airbag can be successfully triggered and the collision impact force is reduced by the airbag to protect the safety of pedestrians. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0031] Figure 1 This is a flowchart illustrating the steps of the automotive airbag-type active energy absorption method according to the first embodiment of the present invention.

[0032] Figure 2 This is a flowchart illustrating the analysis of pedestrian-vehicle collisions according to the first embodiment of the present invention.

[0033] Figure 3 This is a schematic diagram of the structure of the automotive airbag-type active energy absorption device according to the second embodiment of the present invention.

[0034] Figure 4 This is a schematic diagram of the structure of the inflatable airbag according to the second embodiment of the present invention.

[0035] Figure 5 This is a schematic diagram of the control mechanism according to the second embodiment of the present invention. Detailed Implementation

[0036] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0037] The first embodiment of this application is as follows:

[0038] Please see Figure 1 , Figure 1 This is a flowchart illustrating the steps of the active energy absorption method for automotive airbags according to the present invention. Figure 2 This is a flowchart illustrating the analysis of pedestrian-vehicle collisions according to the first embodiment of the present invention.

[0039] This invention provides an active energy absorption method for automotive airbags, comprising the following steps:

[0040] S101: Calculate the safety threshold for pedestrian-vehicle collisions.

[0041] Specifically, in the actual braking process, the braking distance consists of three parts: the first part is the reaction time t1 when the pedestrian is detected and the braking delay time t2. During this stage, the car moves at a constant speed x1 = v1(t1 + t2), where v1 is the initial speed of the car (m / s) and x1 is the distance traveled in the first stage (m). The second part is the acceleration increase time t3, during which the car undergoes variable deceleration. In the formula, x2 represents the distance traveled during the variable deceleration phase (m); v(t) is a function of the velocity during time t3, and the increase in acceleration can be approximated as linear, as follows: Therefore: ∫dv=∫ktdt is the expression where a is the value of ∫dv=∫ktdt. max Maximum acceleration of the car (m / s²) 2 k is the average acceleration coefficient. At t=0, v=v1, so: In time t3, the car travels a distance of x2, and we have: In the formula, v2 is the vehicle speed after deceleration (m / s). The third part, in time t4, shows the distance the vehicle travels, x3, which is given by: When the acceleration reaches its maximum value, the car undergoes uniform deceleration during time t4, with an initial velocity of v2 and a final velocity of 0, at which point the car comes to a standstill. Therefore: X = x1 + x2 + x3, The results show that when the distance S between the car and the pedestrian is greater than X, the car and the pedestrian will not collide, and this distance is considered a safe distance; when S is less than X, a collision is inevitable, and the control system will deploy the pedestrian airbag.

[0042] S102: Construction of numerical simulation model for pedestrian-vehicle collision.

[0043] Specifically, the analysis of the automotive front-end model involves finite element analysis (FEM), a commonly used engineering analysis method typically consisting of three stages: preprocessing, solution calculation, and post-processing. Geometric cleanup is a crucial step in the preprocessing stage, aiming to regularize the geometry, improve mesh quality, and increase meshing efficiency. Geometric cleanup achieves this by repairing the imported CAD model. First, defects are checked on the geometric surfaces, and problematic faces are repaired or deleted. Additionally, small geometric features such as chamfers and small holes are eliminated. After geometric cleanup by HyperMesh, finite element analysis is performed. When meshing the automotive front-end model, based on the actual structure's geometry and dimensions, it can be divided into three types: one-dimensional elements, two-dimensional elements, and three-dimensional elements. This model employs both 2D and 3D meshing techniques. After optimizing the mesh quality map, material property parameters are defined. The "Materials" command allows creating new materials for components or modifying commonly used materials in automotive front-end structures, such as MAT24, MAT20, and MAT1. In the automotive front-end structure model, most components belong to shell elements, which are elasto-plastic; therefore, MAT24 is selected as the material model. Only a very few components are classified as kinematic pairs; the rest remain relatively stationary. In modeling component connections, they can be categorized into three types: connections between deformable bodies, connections between a deformable body and a rigid body, and connections between rigid bodies. Common methods for connecting deformable bodies include the common node connection method and the addition of rigid bodies. However, to achieve a common node connection, the nodes at both ends of the added rigid body must coincide with the nodes of the connected flexible body. Additionally, connections can be achieved by defining the weld contact type using the "interface" function. Connections between deformable and rigid bodies can be achieved by defining XtraNod type contacts using the "interfaces" function in the control panel. Connections between rigid bodies can also be achieved by defining ConstRigidRbody type contacts using the "interfaces" function in the control panel. Head-shaped impactor model: Pedestrian head-shaped impactors are divided into adult head-shaped impactors and child head-shaped impactors. Typically, head-shaped impactors employ a homogeneous spherical structure, consisting of four parts: a sphere, a skin layer, a base plate, and an acceleration sensor. In head impact tests, the sphere and base plate must not deform significantly during the collision; therefore, they are typically made of aluminum, a material known for its rigidity and high strength. The skin layer, on the other hand, needs to realistically simulate the characteristics of human tissue and is usually made of polyethylene, which is highly elastic and must cover more than half of the sphere's area. The accelerometer is located inside the sphere and consists of a rigid support and three unidirectional sensors or one tridirectional sensor. In pedestrian head impact tests, the deformation of the base plate and sphere is negligible; the characteristics of the skin layer are the primary factor affecting the impact outcome.Therefore, in the model, the skin layer is given suitable material properties using MATL181 material properties, with a density of 1.15 × 10^(-6) kg•mm^3. The base plate and sphere are given MAT20 rigid material properties, with a density of 2.559 × 10^(-6) kg•mm^3, an elastic modulus of 70 GPa, and a Poisson's ratio of 0.33. Airbag Model Analysis: The pedestrian airbag is installed at the bottom of the windshield to meet the requirements of the windshield pedestrian protection regulations' collision test area. To simulate the airbag inflation process, air pressure (Jet) was used as an influencing factor, and the uniform pressure method was used for simulation. After mesh generation, the correct material properties were assigned to the airbag. The fabric material of the pedestrian airbag is woven from warp and weft threads at a certain angle. Since changes in the warp and weft direction lead to changes in the fabric's mechanical properties, the angle between the warp and weft threads also changes during large deformations. Therefore, the fabric material is a non-orthogonal anisotropic material. MAT34, developed in LS-DYNA, was chosen as the material model for the airbag fabric, as it can effectively simulate large deformations of fabric materials. The material properties of MAT34 were defined for the airbag using the `materials` command in HyperMesh software. To simulate the airbag inflation process, the *AIRBAG_WANG_NEFSKE uniform pressure method was employed. By simulating parameters such as the mass, flow rate, and temperature of the gas generator, the process of gas being inflated into the airbag can be simulated. In the model, the isochoric heat capacity parameter CV was defined as 461.086 J, the isobaric heat capacity parameter CP as 699.928 J, and the initial value of the initial filling volume parameter VINI was 0.

[0044] S103: Numerical simulation analysis of pedestrian-vehicle collision.

[0045] Specifically, the pedestrian-engine hood collision simulation: Based on the C-NCAP (China New Car Assessment Program) requirements for the head impact test, a location at the rear of the engine hood was selected for the collision simulation test. When the head impactor contacts the engine hood, the acceleration increases sharply within a very short time, reaching a peak value, and then gradually decreases to a stable value. The pedestrian-engine hood collision test shows that the engine hood exhibits significant dent, absorbing some of the energy. According to the simulated acceleration curve, the peak acceleration during the collision did not exceed 165g. According to C-NCAP's injury assessment standards, this level of acceleration is insufficient to cause head injury fatality. Therefore, it can be concluded that such injury is insufficient to cause fatal head injury in pedestrians. The pedestrian-windshield collision simulation: After the head collides with the windshield, the head tends to tilt backward. The initial contact occurs approximately 25ms, therefore a 10ms airbag inflation time was set. According to the C-NCAP pedestrian protection test collision point requirements, the airbag is installed at the bottom of the windshield to cover the bottom of the windshield and the rear of the hood. The following observations can be made: Without an airbag, the stress increases rapidly after the head impactor contacts the windshield, reaching a maximum value of 1.699 × 10^(-1) GPa. With an airbag, the airbag acts as a buffer, allowing the head impactor to make soft contact with the airbag, avoiding a violent collision. After the head impactor contacts the airbag, the stress change is relatively slow, with a maximum value of 5.764 × 10^(-2) GPa, far less than the maximum value without an airbag. By observing the total energy change curve, it can be found that without an airbag, the total energy shows a nearly horizontal trend, with the change in total energy not exceeding 25 J after the collision begins, conforming to the law of conservation of energy. However, with an airbag, once the head contacts the airbag, the total energy begins to rise. This is because the energy state of the airbag is constantly changing, leading to a gradual increase in total energy. The kinetic energy change curves show that in both cases, the kinetic energy decreases rapidly once the head makes contact with the windshield or airbag. A comparison reveals that without an airbag, the kinetic energy reaches its lowest point in approximately 35 ms, while with an airbag, this decrease takes approximately 30 ms. The internal energy change curves reveal that in both cases, kinetic energy is converted into internal energy upon head contact with the impact object, leading to a rapid increase in internal energy. However, with an airbag, the internal energy continues to rise. Further analysis shows that after the head contacts and the airbag inflates, the airbag contains a certain amount of internal energy, causing the kinetic energy to fluctuate within a certain range, while the internal energy continues to rise. Regardless of whether there is an airbag or not, the hourglass energy indicator remains at an extremely low level with almost no change. Moreover, the maximum value of the hourglass energy indicator accounts for far less than 5% of the total energy, indicating the reliability of the simulation results.

[0046] S104: HIC value analysis of pedestrian-vehicle collisions in different impact scenarios with and without airbags.

[0047] Specifically, the severity of head injury is typically assessed using the Head Injury Evaluation Index (HII), and its calculation formula is as follows: In the formula: t1 to t2 is the time interval between the peak HIC value during the collision, generally taken as 15ms or 36ms; a(t) represents the composite acceleration of the head center of mass, in g. By analyzing the curve and calculating the HIC value, the effectiveness of the airbag can be evaluated. Under different collision conditions, the composite acceleration of the pedestrian's head center of mass shows significant differences. Without an airbag, the composite acceleration of the pedestrian's head center of mass increases rapidly, reaching a maximum of 281.24g in 23–28ms. With an airbag, the composite acceleration of the head center of mass increases slowly in 10–28ms, with a maximum value of 144.08g, a decrease of 48.77%. Data shows that airbags can provide a certain degree of buffering and energy absorption. Under airbag conditions, the acceleration change curve of the head is relatively flat, and the peak point of the curve is smoothed out. Airbags prolong the time of head impact contact, and the head makes soft contact with the airbag. This allows the energy generated by the collision to be evenly distributed over a relatively long period of time, reducing the force on the head and achieving the purpose of buffering and energy absorption, thereby reducing head injury. A collision index (HIC) greater than 650 indicates a head injury, while a value greater than 1700 indicates a serious head injury.

[0048] The calculation results show that the HIC value without airbags is 2123, while the HIC value with airbags is 845, a reduction of 60.2%. This meets the requirements of pedestrian protection standards and can effectively protect the head safety of pedestrians. Based on simulation analysis of pedestrian-vehicle collision accidents with and without pedestrian airbags, the following conclusions are drawn: with airbags, when the head impacts the windshield at a speed of 40 km / h, the resultant acceleration of the head's center of mass is reduced by 48.7%, and the HIC value is reduced by 60.2%. Therefore, pedestrian airbags, to a certain extent, mitigate the head injury to pedestrians in collision accidents. The adult head impactor used in this invention underwent collision simulation analysis, and the materials and parameters of the child head impactor are the same, only the size is different. Therefore, if airbags can effectively reduce head injuries to adults, they can also reduce head injuries to children. According to the simulation analysis results, pedestrian airbags have a good protective effect on the adult head. To protect children's heads, it is only necessary to increase the size and coverage area of ​​the airbag.

[0049] S105: Design and simulation of airbag triggering circuit for pedestrian-vehicle collision.

[0050] Specifically, the control system of an automotive airbag-type active energy absorption device needs to meet two key conditions: accurately predicting accidents and promptly outputting trigger signals. Therefore, the microcontroller control system needs to possess high computational accuracy and fast response speed. To meet these requirements, the AT89C52 microcontroller was selected as the control system, as it features low power consumption, high performance, high precision, and ease of programming. The microcontroller determines whether a collision between the car and a pedestrian has occurred based on signals such as vehicle speed, acceleration, and distance detected by sensors. If an accident is unavoidable, the microcontroller will control the airbag to deploy rapidly. The hardware circuit mainly includes the following modules: voltage regulator module, radar ranging module, inflation module, motor drive module, vehicle speed acquisition module, and acceleration acquisition module. The circuit was built using AD software and simulated using Proteus and Keil to verify the rationality of the circuit schematic. Since automotive batteries typically operate at 12V, while the microcontroller requires 5V, a voltage reduction step-down process is necessary. The voltage regulator module uses an LM2596-5 current-voltage regulator and an IN5824 Schottky diode. The current-voltage regulator controls the output voltage within a specified range to prevent damage or operational limitations caused by excessively high or low voltage. The Schottky diode limits its reverse breakdown current through a series current-limiting resistor, thus achieving voltage regulation. The microcontroller requires a clock circuit for normal operation, necessitating an external crystal oscillator. For the AT89C52 microcontroller, with a maximum operating frequency of 24MHz, 12MHz or 11.0592MHz crystal oscillators are commonly used. Using an 11.0592MHz crystal oscillator in a serial communication circuit reduces the error to zero; a 12MHz crystal oscillator is used for more accurate timers and delay timing. Microcontroller reset is achieved by generating a high-level signal (above 2µs) on the RESET pin, causing the microcontroller to reset and change the resistance value in the circuit. Given the complex and ever-changing road traffic conditions, the selected sensor should have good environmental adaptability. The active energy-absorbing device for automotive airbags requires high accuracy in vehicle speed detection. Therefore, this invention selected the AH3144L Hall sensor, which is small in size, highly sensitive, and has a fast response speed, enabling accurate detection of vehicle speed. Typically, the Hall sensor is installed near the wheel or motor, measuring the rotational speed to obtain vehicle speed information. The inflation module consists of a relay, a PNP transistor, and an inflation pump. The PNP transistor functions as a switch to control the deployment of the airbag. The relay controls the switching of the circuit, enabling circuit control and automatic operation. Furthermore, the LED light facilitates observation of its on / off state during simulation to determine the operation of the inflation pump, thereby controlling the inflation of the airbag. Since the active energy-absorbing device for automotive airbags operates before a collision occurs, the ranging sensor must have long-distance measurement capabilities and be minimally affected by environmental factors.The ranging module uses the HB100 microwave radar sensor, which features small size, long-range measurement, high accuracy, fast response, strong environmental adaptability, and strong anti-interference performance. The microwave radar sensor measures the target's position by emitting microwaves and receiving the returned signals, utilizing the time difference. Two operational amplifiers amplify the received minute signals and output digital signals for microcontroller processing. Multiple sawtooth resistors are used to adjust the current and voltage. After completing the circuit schematic design, circuit simulation was performed using Proteus and Keil5 software. Since Proteus software lacks components such as microwave radar sensors and speed sensors, devices with similar functions were used for simulation substitution. During simulation, a sliding rheostat replaces the speed sensor to adjust the speed change, and an ultrasonic ranging module replaces the microwave radar sensor. Simulation results show that when the distance between the car and pedestrian is 10m, the speed reaches 11.5m / s, exceeding the 8.5m / s threshold. Therefore, the airbag should deploy and inflate. Observing the state of the LEDs in the simulation circuit confirms that the airbag is inflated. When the distance between the car and the pedestrian is 10m, the speed is 11.5m / s, which exceeds the threshold of 8.5m / s, thus triggering the deployment of the airbag.

[0051] This invention discloses an active energy absorption method for automobiles using airbags. First, the safety threshold for pedestrian-vehicle collisions is calculated. Then, a numerical simulation model of pedestrian-vehicle collisions is constructed. Subsequently, a numerical simulation analysis of pedestrian-vehicle collisions is conducted to analyze the HIC values ​​of pedestrian-vehicle collisions under different impact scenarios (with and without airbags), verifying the buffering effect of the active energy absorption device using airbags. Finally, the design of the airbag triggering circuit for pedestrian-vehicle collisions is carried out and the circuit simulation is completed. Ultimately, when the speed exceeds the safety threshold, the airbag can be successfully triggered, and the airbag can reduce the impact force of the collision to protect the safety of pedestrians.

[0052] The second embodiment of this application is as follows:

[0053] Based on the first embodiment, please refer to Figures 3 to 5 , Figure 3 This is a schematic diagram of the structure of the automotive airbag-type active energy absorption device according to the second embodiment of the present invention. Figure 4 This is a schematic diagram of the structure of the inflatable airbag according to the second embodiment of the present invention. Figure 5 This is a schematic diagram of the control mechanism according to the second embodiment of the present invention.

[0054] An active energy absorption device for automobiles using an airbag, as described in this embodiment, includes an inflatable airbag 201 and a control mechanism 202.

[0055] The control mechanism 202 is mounted on the inflatable airbag 201 and located on one side of it. The inflatable airbag 201 consists of a gas generator and an airbag. The gas generated by the gas generator inflates the airbag. The control mechanism 202 is an AT89C52 microcontroller, which is connected to a voltage regulator module, a radar ranging module, an inflation module, a motor drive module, a vehicle speed acquisition module, and an acceleration acquisition module. The voltage regulator module uses an LM2596-5 current-voltage regulator and an IN5824 Schottky diode. The function of the current-voltage regulator is to control the output voltage within a specified range to prevent damage to the equipment or limitation of operation due to excessively high or low voltage. The Schottky diode limits its reverse breakdown current value through a series current-limiting resistor, thereby achieving voltage regulation. The sensor ranging module uses an HB100 microwave radar sensor, which has the following characteristics: small size, long-distance measurement, high accuracy, fast response, strong environmental adaptability, and strong anti-interference performance. The microwave radar sensor measures the target's position by emitting microwaves and receiving the returned signals, utilizing the time difference. Two operational amplifiers amplify the received minute signals and output digital signals for processing by the microcontroller. The inflation module consists of relays, PNP transistors, and an air pump. The PNP transistors function as switches to control the airbag deployment. The relays control the circuit's switching, enabling automatic control. The vehicle speed acquisition module uses an AH3144L Hall sensor, which is small, highly sensitive, and has a fast response time, accurately detecting vehicle speed. Typically, the Hall sensor is installed near the wheels or motor, measuring rotational speed to obtain vehicle speed information. When the sensor detects a distance of 10m between the car and a pedestrian with a speed of 11.5m / s, exceeding the 8.5m / s threshold, it triggers the airbag deployment. The inflated airbag 201 then absorbs the impact force of the collision, protecting the pedestrian's safety.

[0056] The above-disclosed embodiments are merely one or more preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art can understand that all or part of the processes for implementing the above embodiments and equivalent changes made in accordance with the claims of this application still fall within the scope of this application.

Claims

1. A method for active energy absorption in automobiles using airbags, characterized in that, Includes the following steps: Calculating the safety threshold for pedestrian-vehicle collisions includes reaction time to detect a pedestrian. Braking delay time During this phase, the car moves at a constant speed; the acceleration increases over time. Inside, during this stage, the car undergoes variable deceleration; The distance the car traveled within the given time was ; Construction of a numerical simulation model for pedestrian-vehicle collisions; Numerical simulation analysis of pedestrian-vehicle collisions includes: construction of the vehicle front-end model; when meshing the vehicle front-end model, it can be divided into three types according to the actual structure's geometry and size: one-dimensional elements, two-dimensional elements, and three-dimensional elements; construction of the head impactor model; pedestrian head impactors are divided into adult head impactors and child head impactors; and construction of the airbag model; the fabric material of pedestrian airbags is woven from warp and weft threads at a certain angle. HIC value analysis of pedestrian and vehicle collisions in different impact scenarios with and without airbags, including using the head injury assessment index HIC value to evaluate the degree of head injury of pedestrians in different impact scenarios. Design and simulation of the airbag triggering circuit for pedestrian-vehicle collision.

2. The active energy absorption method for automobile airbags as described in claim 1, characterized in that, Numerical simulation analysis of pedestrian-vehicle collisions, including: Conduct pedestrian-engine hood collision simulations, including both scenarios with and without airbags; Conduct pedestrian collision simulations with the windshield, including both scenarios with and without airbags.

3. The active energy absorption method for automobile airbags as described in claim 1, characterized in that, The design and simulation of the airbag triggering circuit in a pedestrian-vehicle collision included: The design and simulation verification of the triggering system were completed based on the key conditions of accurately predicting the occurrence of accidents and outputting trigger signals in a timely manner.

4. A car airbag-type active energy absorption device, characterized in that, The method for active energy absorption of automobile airbags as described in any one of claims 1 to 3 is characterized in that it includes an inflatable airbag and a control mechanism; The control mechanism is mounted on the inflatable airbag and located on one side of the inflatable airbag.

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