A rapid calculation method and system for MPDB intrusion volume

Abstract

The present invention relates to the technical field of vehicle collision safety analysis, and particularly relates to a rapid calculation method for MPDB intrusion amount. The method includes selecting fixed points on a barrier trolley to form an initial coordinate system A; generating a grid on the surface of the barrier, and using the center point of the grid as the starting measurement point for calculating the intrusion amount; generating a spatial domain based on the center point of the grid; calculating the distances between each node in the spatial domain and the measurement point, and selecting the shortest distance as the intrusion amount; converting the coordinates of the barrier nodes after collision from the current coordinate system B to the initial coordinate system A, and obtaining the converted points. After coordinate conversion, the final distance is calculated. The technical solution of the present invention can improve the accuracy, flexibility and efficiency of intrusion amount measurement.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle collision safety analysis, and particularly to a method and system for quickly calculating the intrusion amount of an MPDB. Background Art

[0002] In the current field of automotive safety research, the frontal 50% offset moving progressive deformable barrier (MPDB) collision condition is one of the key means to evaluate vehicle collision compatibility. The calculation of the barrier intrusion amount of the MPDB is an essential part of the automotive safety index scoring system, which is used to quantify the degree of intrusion of the vehicle into the internal structure of the barrier during a collision, and then evaluate the occupant protection performance. However, the existing calculation methods and technologies face various challenges when accurately measuring and analyzing the barrier intrusion amount.

[0003] Traditional measurement methods rely on physically scanning the honeycomb aluminum structure on the surface of the barrier after the test to obtain the point cloud data after the collision, and based on this, compare the state before the collision to calculate the intrusion amount. Although this method can provide certain data support, it has significant limitations. First, during the disassembly and analysis of the barrier, its shape may change due to external forces, and this change cannot be accurately recorded, resulting in a difference between the measurement result and the actual situation. Second, the skin layer of the barrier may separate or adhere to the honeycomb aluminum structure during the collision, which will affect the true intrusion state of the barrier. However, the existing measurement methods do not fully consider the influence of the skin, making the calculation of the intrusion amount inaccurate. Third, the collision is a transient process, and the barrier will present different intrusion states at different time points during the collision. However, traditional measurement methods generally can only be carried out under static conditions after the collision, which limits the comprehensive understanding of the evolution of the barrier intrusion amount over time and may lead to incomplete evaluation.

[0004] Traditional technical solutions fail to fully consider the influence of barrier shape changes, skin state, and collision timing on the measurement results when dealing with the measurement of the MPDB barrier intrusion amount, which is the main shortcoming of the current measurement methods. Especially when the shape of the MPDB barrier is changed, for example, in order to meet the requirements of new collision tests, the size, shape, or material properties of the barrier change, how to flexibly adjust the measurement strategy to ensure the accuracy and effectiveness of the measurement becomes an urgent problem to be solved. In addition, due to the dynamic behavior of the barrier during the collision, how to accurately capture the intrusion state of the barrier at different collision moments for more detailed analysis and evaluation is also an important aspect that the existing technology has not properly handled. Summary of the Invention

[0005] The purpose of the present invention is to propose a method and system for quickly calculating the intrusion amount of an MPDB, which can improve the accuracy, flexibility, and efficiency of intrusion amount measurement.

[0006] To achieve the above object, in a first aspect, the present invention provides a method for quickly calculating the intrusion amount of MPDB, including: selecting fixed points on the barrier trolley to form an initial coordinate system A; generating a grid on the surface of the barrier, and using the center point of the grid as the starting measurement point for calculating the intrusion amount; generating a spatial domain based on the center point of the grid; calculating the distances between each node in the spatial domain and the measurement point, and selecting the shortest distance as the intrusion amount; converting the coordinates of the barrier nodes after collision from the current coordinate system B to the initial coordinate system A, and the coordinate transformation step includes calculating the translation vector P through the origin AB , and obtaining the rotation matrix R by calculating the rotation angles through the x-axis, y-axis, and z-axis respectively AB ;

[0007] Converting the coordinates of the intrusion amount measurement points within the domain to the A coordinate system n BA , and the calculation formula is:

[0008]

[0009] After obtaining the converted points through coordinate transformation, calculate the point ( , , ) and the final distance between the measurement point ( , , ) is :

[0010] .

[0011] Advantages of the basic solution: The present invention can quickly obtain the intrusion amount of the MPDB finite element barrier after calculation. By generating a spatial domain, the nodes at the forefront of the domain are obtained for calculating the intrusion amount, and the actual object does not need to be considered.

[0012] This solution generates a grid on the surface of the barrier and uses the center point of the grid as the starting measurement point for calculating the intrusion amount, which can more carefully consider the situation of the barrier surface. Compared with some traditional calculation methods that take the overall barrier as the object, the grid-based method can more accurately locate the position where the intrusion occurs.

[0013] The basic solution constructs the initial coordinate system A and the spatial domain. This calculation method based on the coordinate system and the spatial domain has certain generality. Whether it is a barrier with different shapes or different collision scenarios, as long as the relevant parameters of the coordinate system and the spatial domain can be determined, the intrusion amount can be calculated according to the method of the present invention.

[0014] Taking the center point of the grid as the starting measurement point and generating the spatial domain, the method can be flexibly applied to calculations with different precision requirements. If more precise calculations are needed, the grid can be refined; if the precision requirement is slightly lower, the grid can also be appropriately coarsened, so as to balance the calculation precision and calculation cost.

[0015] As an implementable preferred solution, a selection function for the intrusion amount calculation object is provided, and the calculation object includes honeycomb aluminum or skin; a selection function for the collision time point is provided, and the value at the current time point is calculated according to the custom calculation time.

[0016] As an implementable preferred solution, the fixed points on the barrier trolley are selected to form the initial coordinate system A, including the following content:

[0017] Four points are selected on the barrier trolley, namely the origin (x0, y0, z0), the x-direction point (x1, y1, z1), the y-direction point (x2, y2, z2) and the z-direction point (x3, y3, z3);

[0018] The selected four points are used to construct the fixed coordinate system A, and its mathematical expression is in matrix form:

[0019] .

[0020] As an implementable preferred solution, the method for generating the spatial domain includes the following content:

[0021] Taking each grid plane as a reference, a detection spatial domain is generated with the barrier normal as the length direction, and the state of the detected spatial domain after the barrier deformation; a spatial domain perpendicular to the global y-direction is generated by the grid generation method, and the length is the length of the entire barrier. Eight corner points n1 - n8 of the spatial domain are obtained respectively, where n1 - n4 form the upper surface of the spatial domain , n5 - n8 form the lower surface of the spatial domain , and the expression is:

[0022] .

[0023] As an implementable preferred solution, the method for judging the points in the spatial domain includes:

[0024] By calculating the angles formed by any point in the spatial domain with three reference planes, if the three angles are all different, it is determined that the point is located inside the spatial domain, and non-related nodes are excluded.

[0025] As an implementable preferred solution, the calculation result of the intrusion amount is displayed in the form of a cloud map, and the color coding in the cloud map corresponds to different intrusion amount levels.

[0026] In a second aspect, embodiments of the present disclosure further provide a system for quickly calculating the intrusion amount of an MPDB, which is characterized in that it employs the above-mentioned method for quickly calculating the intrusion amount of an MPDB. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic logic diagram of a method for quickly calculating the intrusion amount of an MPDB.

[0028] Figure 2 It is a schematic diagram for obtaining the initial coordinate system of the wall barrier and its state.

[0029] Figure 3 It is a schematic diagram of setting a grid on the surface of the wall barrier.

[0030] Figure 4 It is a schematic diagram of the state of the spatial domain before deformation.

[0031] Figure 5 It is a schematic diagram of the state of the spatial domain after deformation.

[0032] Figure 6 It is a schematic diagram of the generation of the spatial domain.

[0033] Figure 7 It is a schematic diagram of the included angle for identifying points in the spatial domain.

[0034] Figure 8 It is a schematic diagram of the flow of the method for identifying points in the spatial domain.

[0035] Figure 9 Schematic diagram of the state of the cloud map of the calculated intrusion amount.

[0036] Figure 10 It is a schematic diagram of the architecture of the electronic device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0037] To make the technical solutions of the present application and their advantages clearer, the technical solutions of the present invention will be further described in detail below with reference to the accompanying drawings. It can be understood that the specific embodiments described herein are only partial embodiments of the present invention, which are only used to explain the present application and are not intended to limit the present application. It should be noted that the technical features or combinations of technical features described in the following embodiments should not be considered isolated, and they can be combined with each other to achieve better technical effects. The same reference numerals in the accompanying drawings of the following embodiments represent the same features or components, which can be applied to different embodiments.

[0038] In addition, unless otherwise defined, the technical terms or scientific terms used in the description of the present invention should have the ordinary meanings understood by those of ordinary skill in the art to which the present invention pertains.

[0039] The present invention will be further described in detail below with reference to the accompanying drawings:

[0040] Reference numerals: electronic device 500, processor 501, communication interface 502, memory 503, bus 504.

[0041] Referring to Figure 1 , an embodiment of the present disclosure provides a method for quickly calculating the MPDB intrusion amount, including:

[0042] Step S100, establishing a coordinate system for the barrier trolley, including:

[0043] Step S101, referring to Figure 2 , pick non-deformable points on the barrier trolley as the original coordinate system A. The original coordinate system includes an origin, and the x-direction point, y-direction point, and z-direction point together form the original coordinate system A. Specifically, the barrier trolley does not deform during the entire collision process. Four points are selected on the barrier trolley as the origin (x0, y0, z0), the x-direction point (x1, y1, z1), the y-direction point (x2, y2, z2), and the z-direction point (x3, y3, z3).

[0044] Step S102, using the selected 4 points to construct a fixed coordinate system A, and its mathematical expression is in matrix form:

[0045]

[0046] Each row of this matrix represents the coordinate differences in the x, y, and z directions from the origin to the corresponding direction points. Through this matrix, the direction and scale of the coordinate system A in space can be accurately described, providing a stable reference framework for subsequent calculations.

[0047] Step S200, dividing the barrier surface mesh and determining the measurement points, including:

[0048] Step S201, set at the front position of the barrier before deformation according to the in-plane dimension requirements of the MPDB regulations. A total of 1400 meshes are generated according to the current MPDB in the regulations. Referring to Figure 3 as shown, during the mesh generation process, it is necessary to closely monitor the quality of the meshes, including indicators such as the aspect ratio and distortion of the meshes, to ensure that the mesh quality meets the calculation requirements.

[0049] Step S202, obtain the coordinates of the measurement points. After the grid points are generated, use the center point of each grid as the starting point for measurement, and obtain the coordinates of the measurement points (x i , y i , z i ) at the position of the grid center point.

[0050] Step 300, generate a spatial domain, referring to Figure 4, taking each grid plane as a reference, a detection space domain is generated with the wall barrier normal as the length direction. The state of the detected space domain after the wall barrier deformation is as Figure 5 shown. A space domain with the normal of the grid generation perpendicular to the global y-direction is generated, where the height and width are 20 mm and 20 mm respectively, and the length is the length of the entire wall barrier. Eight corner points n1 - n8 of the space domain are obtained respectively. Among them, n1 - n4 form the upper surface of the space domain, and n5 - n8 form the lower surface of the space domain. In one embodiment, the planes formed by n1 - n4 and the planes formed by n5 - n8 have vectors and respectively (note the directionality):

[0051] .

[0052] The vector cross product operation of the above expressions is based on the mathematical definition of vectors. The vectors and calculated not only contain the direction information of the plane but can also be used to determine whether a point is within the space domain subsequently.

[0053] Step S400: Determine the points within the space domain. The generation of the detection space domain is based on the grid, and the length and normal are based on the length and normal of the honeycomb aluminum of the wall barrier. The generation reference and plane state are as Figure 6 shown, and then the detection of points within the space is implemented according to the Figure 8 process. If a point is within the space, the normal angles of the planes are different. The state within the space points is as Figure 7 shown. For a point (x ii , y ii , z ii ) within the space domain and the vectors of the current plane are nn2 and nn6 respectively, and then the angles of the remaining other planes are judged. It is judged whether a point is within the space domain by judging whether the included angles within three pairs of planes in the space domain are different; the theoretical basis is that if a point is within the space domain, then its included angle relationship with different planes has specific geometric characteristics; conversely, if the point is outside the space domain, the included angle relationship will be different.

[0054] Step S500: Calculate the intrusion amount. All nodes within each grid space domain are obtained, and the distance d ii between the point n(x ii , y ii , z i ) within the domain and the measurement point (x i , y i ) is calculated. The calculation formula is; i

[0055] ​

[0056] The above formula calculates the square root of the sum of the squares of the coordinate differences between two points in three-dimensional space to obtain the distance between the two points. The point with the minimum distance is the point with the minimum intrusion amount, and the distance d i is the intrusion amount of the current measurement grid point.

[0057] Step S600: Convert the coordinate system. Since the coordinate state after the collision has changed, it is necessary to perform a coordinate system conversion to transform the coordinates of the deformed barrier nodes and obtain the coordinates of the deformed barrier under the current initial coordinate A, including:

[0058] Step S601: Obtain the coordinate system B after the collision through the points picked up in step S100 (i.e., the 4 points that construct the coordinate system A).

[0059] Step S602: Calculate the translation vector P through the origin AB , and the translation vector reflects the translational change of the coordinate system B relative to the coordinate system A in terms of spatial position. Calculate the rotation angles through the x-axis, y-axis, and z-axis respectively to obtain the rotation matrix R AB , and the rotation matrix describes the rotational change of the coordinate system B relative to the coordinate system A in terms of spatial orientation.

[0060] Step S603: Convert the coordinates of the intrusion amount measurement point n B in the domain to the A coordinate system n BA under the following formula:

[0061]

[0062] After obtaining the converted point through coordinate conversion, calculate the final distance between the point ( , , ) and the measurement point ( , , ) is:

[0063]

[0064] By selecting an object, the object that needs to calculate the intrusion amount can be automatically recognized. If the skin structure needs to be included, the skin should also be included during selection. If the skin is not selected, only the honeycomb aluminum will be considered during the calculation. By adjusting the time, the moment closest to the calculation time history can be automatically obtained for calculation. By default, the values at each moment are calculated according to the entire collision process. It is also possible to customize the calculation moments, and the program calculates the values at the current time point according to the defined moments. Through object picking and moment picking, the selection of the actual intrusion amount object and the collision time can be carried out more freely. Even if the shape of the barrier changes, the calculation method is still applicable, and the scheme screening can be carried out more quickly.

[0065] It should be noted that this technical solution uses a finite element simulation software to simulate the collision process between the whole vehicle and the barrier. The entire analyzed collision process is obtained from the calculation file. The finite element simulation software can generate detailed collision process data, track the dynamic deformation of the barrier during the collision through numerical simulation, including the position information of each node of the barrier during the collision, record the node coordinate data at each time step in real time, and divide the collision time points according to the time interval set in the calculation file, and then freely select the moments that need to be calculated according to the collision time points.

[0066] This technical solution utilizes the finite element simulation result data, which includes information such as the position coordinates of each node of the barrier at different collision moments, so that the positions of each node in the spatial domain at different moments can be obtained without actually disassembling the barrier, in order to evaluate the intrusion amount state of the barrier during the entire collision process.

[0067] The intrusion amounts of all grids are plotted into an intrusion amount cloud map in the form of a cloud map, and the intrusion amount cloud map as shown in Figure 9 can be obtained. The color coding in the cloud map corresponds to different intrusion amount levels, which is convenient for users to intuitively understand and analyze the dynamic changes and intrusion amount distribution of the honeycomb aluminum structure of the barrier during the collision process, and strengthens the visualization effect of the data presentation.

[0068] This embodiment also provides an MPDB intrusion amount rapid calculation system, which applies the above-mentioned MPDB intrusion amount rapid calculation method.

[0069] Those of ordinary skill in the art can understand that all or part of the processes in implementing a fast calculation method for MPDB intrusion volume can be completed by instructing relevant hardware through a computer program. The program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of various embodiments of a fast calculation method for MPDB intrusion volume. Among them, any reference to a memory, storage, database, or other medium used in the various embodiments provided in this application can include non-volatile and / or volatile memories. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in many forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0070] An embodiment of this application also provides a fast calculation device for MPDB intrusion volume, which uses the above-mentioned fast calculation system for MPDB intrusion volume, including a memory, a processor, and a computer program stored on the memory and executable on the processor. When the processor executes the program, it implements the steps of the above-mentioned fast calculation method for MPDB intrusion volume. In the embodiment of this application, the processor is the control center of the computer method, which can be the processor of a physical machine or the processor of a virtual machine.

[0071] Refer to Figure 10 , the electronic device 500 includes: at least one processor 501, at least one communication interface 502, at least one memory 503, and at least one bus 504. Among them, the bus 504 is used to realize the connection communication between these components, the communication interface 502 is used to communicate signaling or data with other node devices, and the memory 503 stores machine-readable instructions executable by the processor 501. When the electronic device 500 runs, the processor 501 communicates with the memory 503 through the bus 504, and when the machine-readable instructions are called by the processor 501, they execute the steps of the above-mentioned fast calculation method for MPDB intrusion volume.

[0072] The above content is only an embodiment of the present invention. Specific structures and common knowledge such as characteristics that are well-known in the art are not described in detail herein. Those of ordinary skill in the art know all the general technical knowledge in the technical field to which the invention pertains before the filing date or the priority date, are able to learn all the prior art in this field, and have the ability to apply conventional experimental means before this date. Those of ordinary skill in the art can, under the inspiration given in this application, combine their own abilities to complete and implement this solution. Some typical well-known structures or well-known methods should not become an obstacle for those of ordinary skill in the art to implement this application. It should be noted that for those skilled in the art, without departing from the structure of the present invention, several modifications and improvements can still be made, and these should also be regarded as the protection scope of the present invention, and these will not affect the implementation effect of the present invention and the practicality of the patent. The protection scope claimed in this application shall be subject to the content of its claims, and the specific implementation manners and the like recorded in the specification can be used to interpret the content of the claims.

Claims

1. A method for quickly calculating the MPDB intrusion amount, characterized in that: include: Select fixed points on the barrier trolley to form the initial coordinate system A; Generating a grid on the surface of the barrier, and using the center point of the grid as the starting measurement point for intrusion calculation; Generate a detection spatial domain based on the center point of the grid, each grid plane as a reference, and the normal direction of the barrier as the length direction, and the state of the detection spatial domain after the barrier is deformed; The spatial domain with the normal perpendicular to the global y direction is generated by the grid, and the length is the length of the entire barrier. The eight corner points n1-n8 of the spatial domain are obtained, of which n1-n4 constitute the upper surface of the spatial domain. , n5-n8 form the lower surface of the space domain , the expression is: ； Calculate the distance between each node in the spatial domain and the measurement point, and select the shortest distance as the intrusion amount; transform the coordinates of the barrier node after collision from the current coordinate system B to the initial coordinate system A. The coordinate transformation step includes calculating the translation vector P through the origin AB , calculate the rotation angles by x-axis, y-axis and z-axis respectively to obtain the rotation matrix R AB ; The intrusion measurement points in the domain The coordinates are transformed into the A coordinate system n BA The calculation formula is: After the coordinate transformation is completed, the point is calculated. ( , , ) and measuring points ( , , ) for: 。 2. A method for quickly calculating MPDB intrusion according to claim 1, characterized in that: Provides a function for selecting the object for intrusion calculation, including honeycomb aluminum or skin; provides a function for selecting the collision time point, and calculates the value at the current time point according to the customized calculation moment.

3. The MPDB intrusion amount rapid calculation method according to claim 1, characterized in that: Select fixed points on the barrier trolley to form the initial coordinate system A, including the following: Select four points on the barrier trolley: the origin (x0, y0, z0), the x-direction point (x1, y1, z1), the y-direction point (x2, y2, z2), and the z-direction point (x3, y3, z3); The fixed coordinate system A is constructed using the selected 4 points. Its mathematical expression is in matrix form: 。 4. The MPDB intrusion amount rapid calculation method according to claim 1, characterized in that: The method for determining points in the spatial domain includes: By calculating the angles formed by any point in the spatial domain and the three reference planes, if the three angles are all different, the point is deemed to be located inside the spatial domain, and non-relevant nodes are eliminated.

5. The MPDB intrusion amount rapid calculation method according to claim 1, characterized in that: The intrusion calculation results are displayed in the form of a cloud map, where color codes correspond to different intrusion levels.

6. A MPDB intrusion amount rapid calculation system, characterized in that: A fast calculation method for MPDB intrusion amount according to any one of claims 1 to 5 is used.

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