A full-scene perception simulation method for automobile collision environment

Abstract

The present invention discloses a full-scene perception simulation method for a car collision environment, the method comprising: establishing a finite element model of participating objects, the participating objects including a car body, an obstacle and a ground matrix; in the process of constructing the finite element model of the car body, calibrating the car body mass Mb, and in the process of constructing the finite element model of the ground matrix, calibrating the ground friction coefficient μ; importing the finite element model into a full-scene model library, performing a collision simulation test, and using post-processing software to read the high-frequency acceleration signal at the collision point between the car body and the obstacle, and providing the high-frequency acceleration signal to the airbag test end. The present invention calibrates the car body mass, the ground friction coefficient and the car body finite element model, ensures that the finite element simulation test results are close to the real physical experiment results, improves the reliability of the simulation test results, and can cover multi-dimensional complex collision environments through full-scene model library simulation tests.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile collision safety, and in particular to a method for simulating full-scene perception of an automobile collision environment. Background Art

[0002] When a car is involved in a traffic accident, the accidental deployment of the airbag has always been the focus of consumers' attention on the safety performance of automobile products. When a car hits a telephone pole, a car runs into the rear of a truck, or a car crosses a railway track, if the airbag fails to function properly, and the collision accident is irreversible and cannot be reproduced, it will bring great challenges to after-sales troubleshooting.

[0003] There are two main reasons for the misoperation of airbags: one is hardware, where the hardware of the airbag controller itself fails; the other is software, where the amount of ambient signal information during a collision is insufficient, causing the airbag controller to be unable to make correct judgments after receiving this information.

[0004] In the first case, the hardware itself fails, and conventional testing equipment can be used to troubleshoot and quickly get the results. In the second case, the problem with the collision environment signal can be read from the inside of the airbag controller after the collision. The current mainstream practice is that car manufacturers return the signal reading data after the accident to the airbag controller supplier, and the supplier completes the troubleshooting. The supplier usually responds that there is no problem with the software, but the problem is that the scenario in which the customer has a traffic accident is not included in the software design scope.

[0005] In fact, this post-processing approach cannot fundamentally solve the problem. During the development and design stage, automobile manufacturers can only simulate traffic accident environments through a large number of real-car collision tests, collect acceleration signals, pressure signals and other information during the test, and provide them to airbag controller suppliers to complete the software design. On the one hand, a large number of real-car collision tests bring huge investment challenges to automobile manufacturers. On the other hand, these real-car collision tests contain limited traffic accident scenarios and cannot cover the multi-dimensional and more complex collision environment brought about by intelligence. Summary of the invention

[0006] Based on this, the purpose of the present invention is to provide a full-scene perception simulation method for a car collision environment, which establishes a full-scene finite element model library of car bodies, road surfaces, telephone poles, trees, walls, rails, earth slopes, flower beds, stone piers, pedestrians, bicycles, two-wheeled electric vehicles, two-wheeled motorcycles, etc., and calibrates the car body mass, ground friction coefficient and car body finite element model to ensure the reconstruction and reproduction of the real physical environment of the car collision in the computer simulation test, and further obtains the high-frequency acceleration signal at the collision point between the car body and the obstacle, and provides it to the airbag controller to carry out the next step of work, effectively solving the above-mentioned problems existing in the prior art.

[0007] To achieve the above object, the present invention provides the following technical solution: a method for simulating the full-scene perception of a car collision environment, the method comprising: establishing a finite element model of participating objects, the participating objects including a car body, obstacles and a ground substrate;

[0008] In the process of constructing the finite element model of the car body, the car body mass Mb is calibrated, and in the process of constructing the finite element model of the ground substrate, the ground friction coefficient μ is calibrated;

[0009] The finite element model is imported into the full-scene model library so that the pre-processing software can call the finite element model from the full-scene model library to perform collision simulation tests. The post-processing software is used to read the high-frequency acceleration signal at the collision point between the car body and the obstacle, and the high-frequency acceleration signal is provided to the airbag test end to determine whether the airbag system is working properly.

[0010] A further solution is to calculate the vehicle body mass M b Calibration specifically includes:

[0011] Get the actual mass M of the car body S and the centroid position X0 / Y0 / Z0;

[0012] Get the vehicle sub-assembly weight distribution table;

[0013] Refer to the automobile sub-assembly mass distribution table, balance the sub-assembly in the finite element model, and obtain the vehicle mass M in the finite element model. b and the centroid position X b ;

[0014] Compare M S and M b , X0 and X b The numerical value of

[0015] When |M S -M b |≤5kg and X0-X b ≤10mm, the automobile body finite element model meets the requirements, then the process ends; otherwise, the process returns to the reference automobile sub-assembly mass distribution table, performs mass weighting on the sub-assemblies in the automobile body finite element model, and adjusts the mass and center of mass position of the automobile body in the finite element model.

[0016] A further solution is to calibrate the ground friction coefficient μ, which specifically includes:

[0017] Assign friction coefficients or material information to different road surfaces. For rigid road surfaces, query the ground friction coefficient through the material manual and input it; for flexible road surfaces, obtain the corresponding material parameters and input them. The material parameters include material yield strength, Poisson's ratio and tensile strength.

[0018] A further solution is that before importing the finite element model into the full scene model library, it also includes:

[0019] According to the standard test conditions, finite element simulation test and real physical test of the collision between the car body and the car are carried out respectively;

[0020] The acceleration curve obtained from the simulation test is compared with the acceleration curve obtained from the real physical test;

[0021] If the acceleration curve morphology similarity WIF ≥ 98%, the car body finite element model is automatically imported into the full-scene model library through Python; if not, the car body finite element model is adjusted and the simulation test is performed again until the acceleration curve obtained by the simulation test meets the similarity requirements with the real physical test curve.

[0022] A further solution is to adjust the finite element model of the car body including:

[0023] Adjust the mesh unit size in the collision area, the normal of the mesh unit, the mesh type of the component, the material mechanical property curve of the component, and the connection relationship of the component.

[0024] A further solution is that the acceleration curve morphology similarity is calculated using the following formula:

[0025] Acceleration curve shape similarity

[0026]

[0027] Where f[t] is the acceleration curve obtained from the finite element simulation test; g[t] is the acceleration curve obtained from the real physical test, and t is time.

[0028] A further solution is to obtain the acceleration curve at the point where the vehicle body contacts the obstacle, specifically including:

[0029] After the simulation test, the animation of the simulation test is obtained through the d3plot processing software. The contact position between the car body and the obstacle is observed from the animation and the node number of its finite element grid unit is recorded. Then, the finite element model of the car body before the simulation test is opened, and the accelerometer is set at the node number position. The simulation test is repeated, and the acceleration curve at the contact position between the car body and the obstacle can be read through the post-processing software.

[0030] A further solution is that setting the accelerometer specifically includes:

[0031] Establish a small rigid cube at the position of the node number, the size and weight of the small cube being equivalent to the actual acceleration sensor;

[0032] The rigid small cube is rigidly connected to the non-deformed mesh on the car body;

[0033] The accelerometer is arranged at any corner of the small cube.

[0034] A further solution is that the obstacle finite element model includes a deformable mobile cart, a rigid mobile cart, a telephone pole, a tree, a wall, a railroad track, a soil slope, a flower bed, a stone pier, a pedestrian, a bicycle, a two-wheeled electric vehicle and a two-wheeled motorcycle.

[0035] A further solution is that the pre-processing software is any one of ANSA and Primer; the post-processing software is any one of this, Hyperview, 0asys, and Meta.

[0036] Compared with the prior art, the beneficial effects of the present invention are as follows: by establishing a full-scene finite element model library of automobile bodies, road surfaces, electric poles, trees, walls, rails, earth slopes, flower beds, stone piers, pedestrians, bicycles, two-wheeled electric vehicles, two-wheeled motorcycles, etc., the real physical environment of automobile collision is reconstructed and reproduced in computer simulation experiments, which is not restricted by the cost and scene constraints of real physical experiments, and the automobile body mass and ground friction coefficient are calibrated, and the automobile body finite element model is corrected, thereby improving the reliability of the simulation test results, ensuring that the finite element simulation test results are close to the real physical experiment results, and further obtaining the high-frequency acceleration signal at the collision point between the automobile body and the obstacle, and providing it to the airbag controller to carry out the next step of work, without the need to obtain these signals through a large number of real automobile collision tests, effectively solving the above-mentioned problems existing in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a flow chart of the full-scene perception simulation method of the automobile collision environment according to the first embodiment of the present invention;

[0038] Figure 2 This is a schematic diagram of input and output of the full-scenario model library of a car collision according to the first embodiment of the present invention;

[0039] Figure 3 is a flow chart of a method for calibrating automobile body mass according to a first embodiment of the present invention;

[0040] Figure 4 is a schematic diagram of a finite element model of an obstacle in the first embodiment of the present invention;

[0041] Figure 5 This is a flow chart of a method for full-scene perception simulation of a vehicle collision environment according to a second embodiment of the present invention; DETAILED DESCRIPTION

[0042] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. Several embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0043] Example 1

[0044] See also Figure 1 , shown is a method for simulating full-scene perception of a car collision environment in a first embodiment of the present invention, including steps S101 to S103.

[0045] Step S101, establishing a finite element model of participating objects, where the participating objects include a car body, obstacles and a ground matrix;

[0046] Specifically, a three-dimensional geometric model of the car body, obstacles and ground base is established, and the shape of the three-dimensional geometric model is consistent with the shape of the actual object. Figure 4 The obstacles include the deformable mobile car specified in GB20071 "Occupant Protection in Side Collisions of Motor Vehicles", the rigid mobile car specified in GB20072 "Safety Requirements for Fuel Systems of Passenger Vehicles in Rear Collisions", as well as electric poles, trees, walls, rails, earth slopes, flower beds, stone piers, pedestrians, bicycles, two-wheeled electric vehicles and two-wheeled motorcycles, and the three-dimensional geometric model is meshed by finite element to obtain the finite element model of the vehicle body, obstacles and ground matrix.

[0047] In order to improve the reliability of the simulation test results and make them consistent with the real physical test results, in the process of constructing the finite element model of the car body, due to the mass M of the car b It is directly proportional to the energy generated during the collision, that is, Therefore, the vehicle mass M b The accuracy of the acceleration signal generated during the collision has a great impact on the high-frequency signal. b Calibration: In the process of constructing the finite element model of the ground matrix, for the collision test laboratory of the national testing agency, the ground condition μ is just a ground friction coefficient. However, for actual traffic accidents, the ground conditions are very complicated, and the ground friction coefficient μ needs to be calibrated before it can be imported into the full scene model library.

[0048] Among them, see Figure 3 , the calibration of the vehicle body mass Mb specifically includes:

[0049] S1001. Obtaining the actual mass M of the vehicle body S and the centroid position X0 / Y0 / Z0;

[0050] S1002, obtaining a weight distribution table of vehicle sub-assemblies;

[0051] S1003. Refer to the automobile sub-assembly mass distribution table, perform mass distribution on the sub-assembly in the finite element model, and obtain the vehicle mass Mb and the center of mass position X in the finite element model. b ;

[0052] S1004, Comparison M S and M b , X0 and X b The numerical value of

[0053] S1005, when M S -M b ≤5kg and |X0-X b |≤10mm, the finite element model of the car body meets the requirements, then the end is completed, indicating that the car body mass M b otherwise, return to step S1003, perform mass balancing on the sub-assemblies in the finite element model of the vehicle body, and adjust the mass and center of mass position of the vehicle body in the finite element model.

[0054] In addition, the calibration of the ground friction coefficient μ specifically includes:

[0055] Assign friction coefficients or material information to different road surfaces, see Table 1. For rigid road surfaces, query the ground friction coefficient through the material manual and input it; for flexible road surfaces, obtain the corresponding material parameters and input them. The material parameters include material yield strength, Poisson's ratio and tensile strength, etc.

[0056] Table 1. Ground matrix friction coefficient of the full scene perception model library

[0057]

[0058]

[0059] Step S102: importing the finite element models of the vehicle body, obstacles and ground matrix into the full-scene model library, calling the finite element model from the full-scene model library through the pre-processing software, and performing a collision simulation test;

[0060] It should be noted that before conducting a collision simulation test, it is necessary to set parameters such as the vehicle body speed V1 and the obstacle speed V2, the collision angle θ1, the obstacle angle θ2, the wind speed and the rainfall, and conduct simulation tests of different collision conditions.

[0061] The pre-processing software is any one of ANSA and Primer.

[0062] Step S103: Use post-processing software to read the high-frequency acceleration signal at the collision point between the vehicle body and the obstacle, and provide the high-frequency acceleration signal to the airbag test end to determine whether the airbag system is working normally.

[0063] In order to obtain the high-frequency acceleration signal at the point where the car body collides with the obstacle. After the simulation test, firstly use the d3plot processing software to obtain the animation of the simulation test, observe the contact position between the car body and the obstacle from the animation and record the node number of the finite element grid unit, then open the finite element model of the car body before the simulation test, and build a rigid small cube at the position of the node number. The size and weight of the small cube are equivalent to the actual acceleration sensor; the rigid small cube is rigidly connected to the non-deformed grid on the car body, and an accelerometer is set at any corner of the small cube. Re-carry out the simulation test, use LS-DYNA software to calculate and process the simulation results, and then read the acceleration curve signal RAX / RAY / RAZ at the contact position between the car body and the obstacle through the post-processing software, see Figure 2 , where RAX represents the signal in the X direction, RAY represents the signal in the Y direction, and RAZ represents the signal in the Z direction.

[0064] Among them, the post-processing software is any one of this, Hyperview, Oasys, and Meta.

[0065] Example 2

[0066] See also Figure 5 , shown is a method for simulating full-scene perception of a car collision environment in a second embodiment of the present invention, including steps S111 to S114.

[0067] Step S111, establishing a finite element model of participating objects, where the participating objects include a vehicle body, obstacles, and a ground matrix;

[0068] Specifically, a three-dimensional geometric model of a car body, an obstacle and a ground substrate is established. The shape of the three-dimensional geometric model is consistent with the shape of the actual object. The obstacles include but are not limited to the deformable mobile car specified in GB20071 "Occupant Protection in Side Collisions of Automobiles", the rigid mobile car specified in GB20072 "Safety Requirements for Fuel Systems of Passenger Cars in Rear Collisions", and telephone poles, trees, walls, rails, earth slopes, flower beds, stone piers, pedestrians, bicycles, two-wheeled electric vehicles and two-wheeled motorcycles. Solid and shaped objects that may appear in actual traffic accidents should be included in the obstacles of the present invention, and the three-dimensional geometric model is divided into finite element grids, and the grid unit size, normal direction of the grid unit, grid type of components, material mechanical property curves of components and connection relationship of components in the collision area are set to obtain finite element models of the car body, obstacles and ground substrate.

[0069] In order to improve the reliability of the simulation test results and make them consistent with the real physical test results, the mass M of the car body needs to be calculated in the process of constructing the finite element model of the car body. b Calibration; In the process of constructing the finite element model of the ground matrix, it is necessary to calibrate the friction coefficient μ of the ground matrix. Among them, the mass of the car body M b The method for calibrating the ground substrate friction coefficient μ is the same as in Example 1.

[0070] Step S112: modifying the finite element model of the automobile body:

[0071] According to the standard test conditions, finite element simulation test and real physical test of the collision between the car body and the car are carried out respectively;

[0072] And compare the acceleration curve obtained from the simulation test with the acceleration curve obtained from the real physical test;

[0073] If the acceleration curve morphology similarity WIF≥98%, the car body finite element model is automatically imported into the full-scene model library through Python; if not, return to step S111 to adjust the car body finite element model, adjust the grid unit size in the collision area, the normal of the grid unit, the grid type of the component, the material mechanical property curve of the component and the connection relationship of the component, and perform the simulation test again until the acceleration curve obtained by the simulation test meets the similarity requirement with the real physical test curve.

[0074] It should be noted that the acceleration curve morphology similarity is calculated using the following formula:

[0075] Acceleration curve shape similarity

[0076]

[0077] Where f[t] is the acceleration curve obtained from the finite element simulation test; g[t] is the acceleration curve obtained from the real physical test, t is the time, and the acceleration curve is the relationship curve between acceleration and time.

[0078] Step S113, importing the finite element models of the vehicle body, obstacles and ground matrix into the full-scene model library, calling the finite element model from the full-scene model library through the pre-processing software, and performing a collision simulation test;

[0079] It should be noted that before conducting a collision simulation test, it is necessary to set parameters such as the vehicle body speed V1 and the obstacle speed V2, the collision angle θ1, the obstacle angle θ2, the wind speed and the rainfall, and conduct simulation tests under different working conditions.

[0080] The pre-processing software is any one of ANSA and Primer.

[0081] Step S114: Use post-processing software to read the high-frequency acceleration signal at the collision point between the vehicle body and the obstacle, and provide the high-frequency acceleration signal to the airbag test end to determine whether the airbag system is working normally.

[0082] In order to obtain the high-frequency acceleration signal at the collision point between the car body and the obstacle, after the simulation test, the animation of the simulation test is first obtained through the d3plot processing software, the contact position between the car body and the obstacle is observed from the animation and the node number of its finite element grid unit is recorded, and then the finite element model of the car body before the simulation test is opened, and a rigid small cube is established at the node number position, and the size and weight of the small cube are equivalent to the actual acceleration sensor; the rigid small cube is rigidly connected to the non-deformed grid on the car body, and the accelerometer is set at any corner of the small cube. The simulation test is repeated, and the simulation results are calculated and processed using the LS-DYNA software, and the acceleration curve at the contact position between the car body and the obstacle can be read through the post-processing software. Compared with real physical test experiments, since the number of acceleration sensors installed on a car body does not exceed 7, namely 2 front collision sensors, 2 side collision sensors, 2 rear collision sensors and 1 airbag controller built-in sensor, when the car is involved in a traffic accident, the amount of information transmitted by the sensor signal to the airbag controller software is also limited. Through the full-scenario model library simulation experiment, it is possible to cover multi-dimensional and more complex collision environments.

[0083] Among them, the post-processing software is any one of this, Hyperview, 0asys, and Meta.

[0084] In summary, the present invention establishes a full-scene finite element model library of automobile bodies, road surfaces, telephone poles, trees, walls, rails, earth slopes, flower beds, stone piers, pedestrians, bicycles, two-wheeled electric vehicles, two-wheeled motorcycles, etc., to reconstruct and reproduce the real physical environment of automobile collision in computer simulation experiments, without being restricted by the cost and scene constraints of real physical experiments, and calibrates the automobile body mass and the ground friction coefficient, and corrects the automobile body finite element model, thereby improving the reliability of the simulation test results, ensuring that the finite element simulation test results are close to the real physical experiment results, and further obtaining the acceleration high-frequency signal at the collision point between the automobile body and the obstacle, and providing it to the airbag controller to carry out the next step of work, without the need to obtain these signals through a large number of real automobile collision tests, effectively solving the above-mentioned problems existing in the prior art.

[0085] It should be pointed out that the automobiles described in the present invention include traditional fuel vehicles, new energy electric vehicles, etc., not only M1 passenger cars, but also N tool pickups and M2 and above light passenger cars.

[0086] Although the description of the present invention has been quite detailed and specifically describes several described embodiments, it is not intended to be limited to any of these details or embodiments or any particular embodiment, but should be regarded as providing a broad possible interpretation of these claims in view of the prior art by reference to the appended claims, thereby effectively covering the intended scope of the present invention. In addition, the above description of the present invention is based on the embodiments foreseeable by the inventor, and its purpose is to provide a useful description, and those non-substantial changes to the present invention that have not yet been foreseen may still represent equivalent changes to the present invention.

Claims

1. A full-scene perception simulation method for a car collision environment, characterized in that: The method comprises: Establishing finite element models of participating objects, including vehicle body, obstacles and ground substrate; In the process of constructing the finite element model of the automobile body, the automobile body mass Mb is calibrated. In the process of constructing the finite element model of the ground substrate, the ground friction coefficient μ is calibrated. The calibration of the automobile body mass Mb specifically includes: Get the actual car body mass Ms and center of mass position X0 / Y0 / Z0, Get the vehicle sub-assembly weight distribution table, Refer to the automobile sub-assembly mass distribution table, balance the sub-assembly in the finite element model, and obtain the vehicle mass M in the finite element model. b and the centroid position X b , Compare M s and M b , X0 and X b The numerical size of When |M s -M b |≤5kg and |X0-X b |≤10mm, the automobile body finite element model meets the requirements, then the process ends; otherwise, the process returns to the reference automobile sub-assembly mass distribution table, performs mass weighting on the sub-assemblies in the automobile body finite element model, and adjusts the mass and center of mass position of the automobile body in the finite element model; Calibration of the ground friction coefficient μ specifically includes: Assign friction coefficients or material information to different road surfaces. For rigid road surfaces, query the ground friction coefficient through the material manual and input it; for flexible road surfaces, obtain the corresponding material parameters and input them. The material parameters include material yield strength, Poisson's ratio and tensile strength. The finite element model is imported into the full-scene model library so that the pre-processing software can call the finite element model from the full-scene model library to perform collision simulation tests. The post-processing software is used to read the high-frequency acceleration signal at the collision point between the car body and the obstacle, and the high-frequency acceleration signal is provided to the airbag test end to determine whether the airbag system is working properly.

2. The method for simulating the full scene perception of a vehicle collision environment according to claim 1, characterized in that: Before importing the finite element model into the full scene model library, it also includes: According to the standard test conditions, finite element simulation test and real physical test of the collision between the car body and the car are carried out respectively; The acceleration curve obtained from the simulation test is compared with the acceleration curve obtained from the real physical test; If the acceleration curve morphology similarity WIF ≥ 98%, the car body finite element model is automatically imported into the full-scene model library through Python; if not, the car body finite element model is adjusted and the simulation test is performed again until the acceleration curve obtained by the simulation test meets the similarity requirements with the real physical test curve.

3. The method for simulating the full scene perception of a vehicle collision environment according to claim 2, characterized in that: Adjusting the finite element model of the car body specifically includes: Adjust the mesh unit size in the collision area, the normal of the mesh unit, the mesh type of the component, the material mechanical property curve of the component, and the connection relationship of the component.

4. The method for simulating the full scene perception of a vehicle collision environment according to claim 2, characterized in that: The acceleration curve morphology similarity is calculated using the following formula: Acceleration curve shape similarity Where f[t] is the acceleration curve obtained from the finite element simulation test; g[t] is the acceleration curve obtained from the real physical test, and t is time.

5. The method for simulating the full scene perception of a vehicle collision environment according to claim 1, characterized in that: Obtaining the acceleration curve at the point where the vehicle body contacts the obstacle specifically includes: After the simulation test, the animation of the simulation test is obtained through the d3plot processing software. The contact position between the car body and the obstacle is observed from the animation and the node number of its finite element grid unit is recorded. Then, the finite element model of the car body before the simulation test is opened, and the accelerometer is set at the node number position. The simulation test is repeated, and the acceleration curve at the contact position between the car body and the obstacle can be read through the post-processing software.

6. The method for simulating the full scene perception of a vehicle collision environment according to claim 5, characterized in that: Setting up the accelerometer involves: Establish a small rigid cube at the position of the node number, the size and weight of the small cube being equivalent to the actual acceleration sensor; The rigid small cube is rigidly connected to the non-deformed mesh on the car body; The accelerometer is arranged at any corner of the small cube.

7. The method for simulating the full scene perception of a vehicle collision environment according to claim 1, characterized in that: The obstacles in the finite element model include a deformable mobile car, a rigid mobile car, a telephone pole, a tree, a wall, a rail, a soil slope, a flower bed, a stone pier, a pedestrian, a bicycle, a two-wheeled electric vehicle and a two-wheeled motorcycle.

8. The method for simulating the full scene perception of a vehicle collision environment according to claim 1, characterized in that: The pre-processing software is any one of ANSA and Primer; the post-processing software is any one of this, Hyperview, Oasys, and Meta.

Images