Method for extracting head offset curve of test object in side collision test

Abstract

The embodiment of the invention discloses a method for extracting a head offset curve of a test object in a side collision test. The method comprises the steps of firstly obtaining a CAE simulation animation and a real vehicle test animation in a side collision test, and performing rotation adjustment on the CAE simulation animation based on a feature overlapping method to obtain a target simulation animation, so that the target simulation animation and the real vehicle test animation keep the same perspective view angle. Then, by constructing a projection plane and an image coordinate system, converting the space coordinates of the target head point into plane coordinates of the target head point and then converting the plane coordinates of the target head point into image coordinates of the target head point, the CAE 3D simulation is projected to equivalent 2D perspective coordinates, and the fitting degree and correlation of a simulated head offset curve and a real vehicle test head curve are effectively improved; errors with real result data are reduced, and the precision requirement of the virtual evaluation of the side collision safety of the automobile is further met.

Description

Technical Field

[0001] One or more embodiments of the present specification relate to the field of intelligent automobile manufacturing technology, and in particular, to a method for extracting a head displacement curve of a test object in a side impact test. Background Art

[0002] With the rapid development of the automobile industry, automobile collision safety performance has become a hot topic for major manufacturers. In a far-side collision, the occupant's head will move toward the impact side due to inertia. Relevant requirements stipulate that the maximum head offset score estimation should be based on the camera closest to the maximum head displacement. Correctly judging the lateral and forward movement trajectory of the head is extremely critical in reducing head injuries. However, in the test, the head movement trajectory can only be obtained through video analysis, and conventional Computer-Aided Engineering (CAE) test videos are all obtained based on perspective projection camera analysis. Perspective projection does not represent accurate 3D movement, so the offset obtained when participating in the head offset score will produce errors with the actual result.

[0003] At present, the head offset in a far-end side collision of a car is the key data for determining penalty points. The main method used is the virtual evaluation of the side collision safety of a car. The virtual evaluation of the side collision safety of a car is a benchmarking process based on the combination of computer CAE simulation and real vehicle tests. The CAE simulation animation is played based on parallel views. The head offset directly extracted from the CAE animation view will have a certain deviation from the real data due to the perspective problem, which will affect the score of the safety test. Summary of the invention

[0004] The embodiment of this specification provides a method for extracting a head offset curve of a test object in a side impact test, and its technical solution is as follows:

[0005] In a first aspect, an embodiment of the present specification provides a method for extracting a head displacement curve of a test object in a side impact test, the method comprising:

[0006] Obtaining a CAE simulation animation and a real vehicle test animation in a side impact test, rotating and adjusting the perspective angle of the CAE simulation animation based on a feature overlap method to obtain a target simulation animation, and extracting all observation point coordinates, camera coordinates, and vertical field of view angles in the target simulation animation, wherein the target simulation animation is an animation having the same perspective as the real vehicle test animation after the CAE simulation animation is adjusted;

[0007] For any frame of the target simulation animation, construct a projection plane equation based on the observation point coordinates and the camera coordinates, and determine the target head point plane coordinates corresponding to the target head point space coordinates based on the projection plane equation, the target head point being the center of mass of the test subject's head;

[0008] An image coordinate system is established in a projection plane based on the observation point coordinates, and in the image coordinate system, the plane coordinates of the target head point are converted into image coordinates of the target head point based on a field of view angle scaling factor, wherein the field of view angle scaling factor is calculated by the vertical field of view angle;

[0009] After obtaining all the target head point image coordinates corresponding to the target simulation animation, the head displacement curve of the test object is drawn according to all the target head point image coordinates.

[0010] In a second aspect, a device for extracting a head displacement curve of a test object in a side impact test is provided, the device comprising:

[0011] An adjustment module is used to obtain the CAE simulation animation and the real vehicle test animation in the side impact test, rotate and adjust the perspective angle of the CAE simulation animation based on the feature overlap method to obtain a target simulation animation, and extract all observation point coordinates, camera coordinates and vertical field of view angles in the target simulation animation, wherein the target simulation animation is the CAE simulation animation adjusted to have the same perspective as the real vehicle test animation;

[0012] A construction module, for constructing a projection plane equation for any frame of the target simulation animation based on the observation point coordinates and the camera coordinates, and determining the target head point plane coordinates corresponding to the target head point space coordinates based on the projection plane equation, wherein the target head point is the centroid point of the test subject's head;

[0013] A scaling module, for establishing an image coordinate system in a projection plane based on the observation point coordinates, and converting the target head point plane coordinates into the target head point image coordinates in the image coordinate system based on a field of view angle scaling factor, wherein the field of view angle scaling factor is calculated by the vertical field of view angle;

[0014] The drawing module is used to draw the head displacement curve of the test object according to all the target head point image coordinates after obtaining the target simulation animation corresponding to the target head point image coordinates.

[0015] In a third aspect, an electronic device is provided, including a device processor and a memory;

[0016] The device processor is connected to the memory;

[0017] The memory is used to store executable program code;

[0018] The device processor runs a program corresponding to the executable program code by reading the executable program code stored in the memory, so as to execute the steps of the method provided in the first aspect or any possible implementation manner of the first aspect.

[0019] In a fourth aspect, a computer-readable storage medium is provided, on which a computer program is stored, and the computer-readable storage medium stores instructions, which, when the instructions are executed on a computer or a device processor, cause the computer or the device processor to execute the method provided in the first aspect or any possible implementation of the first aspect.

[0020] The beneficial effects brought by the technical solutions provided by some embodiments of this specification include at least:

[0021] In one or more embodiments of the present specification, the CAE simulation animation and the real vehicle test animation in the side impact test can be obtained first, and the CAE simulation animation can be rotated and adjusted based on the feature overlap method to obtain the target simulation animation, so that the target simulation animation and the real vehicle test animation maintain the same perspective. Then, by constructing a projection plane and an image coordinate system, the target head point space coordinates are converted into the target head point plane coordinates and then converted into the target head point image coordinates, so as to realize the projection of the CAE 3D simulation into the equivalent 2D perspective coordinates, effectively improving the fitting degree and correlation between the simulated head offset curve and the real vehicle test head curve, reducing the error between the real result data, and further meeting the accuracy requirements of the virtual evaluation of the side impact safety of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 A schematic diagram of the system architecture of a method for extracting a head displacement curve of a test object in a side impact test provided in an embodiment of this specification;

[0024] Figure 2 A flowchart of a method for extracting a head deviation curve of a test object in a side impact test provided in an embodiment of this specification;

[0025] Figure 3 A schematic diagram of the structure of a device for extracting a head displacement curve of a test object in a side impact test provided in an embodiment of this specification;

[0026] Figure 4A schematic diagram of the structure of an electronic device provided in an embodiment of this specification. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0028] The terms "first", "second", "third", etc. in the description and claims of this specification and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0029] The following description provides examples and does not limit the scope, applicability or examples set forth in the claims. Changes may be made to the functions and arrangements of the elements described without departing from the scope of the present specification. Various processes or components may be appropriately omitted, substituted or added to each example. For example, the described method may be performed in an order different from the order described, and various steps may be added, omitted or combined. In addition, features described with respect to some examples may be combined in other examples.

[0030] See also Figure 1 , Figure 1 A schematic diagram of the system architecture of a method for extracting a head displacement curve of a test object in a side impact test provided by an embodiment of the present specification is shown.

[0031] like Figure 1 As shown, the system architecture of the method for extracting the head displacement curve of the test object in the side impact test may at least include a terminal 10 , a server 20 and a network 30 .

[0032] The terminal 10 includes but is not limited to electronic devices such as smart phones, desktop computers, tablet computers, laptops, smart speakers, digital assistants, and smart wearable devices, and may also be software running on the above electronic devices, such as applications. Optionally, the operating system running on the electronic device may include but is not limited to Android, IOS, Linux, Windows, etc. Optionally, the terminal 10 provides a head offset curve extraction service to the user, and the terminal 10 may obtain a head offset curve extraction instruction of an application program interface, and send a head offset curve extraction request to the server 20.

[0033] The server 20 can provide background services for the terminal 10. According to the head offset curve extraction request sent by the terminal 10, the server 20 will obtain a series of head offset curve extraction instructions, and the server 20 transmits the head offset curve extraction instructions to other terminals 10 through the network 30. Specifically, the server 20 can be an independent physical server, or a server cluster or distributed system composed of multiple physical servers, or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, CDN (Content Delivery Network), and big data and artificial intelligence platforms.

[0034] The network 30 is used to provide a medium for a communication link between the terminal 10 and the server 20. The network 30 may include various connection types, such as wired or wireless communication links or optical fiber cables.

[0035] In addition, it should be noted that Figure 1 What is shown is only one system provided by the present disclosure. In practical applications, other systems may also be included, for example, more terminals may be included.

[0036] In the embodiments of the present specification, the terminal 10 and the server 20 may be directly or indirectly connected via wired or wireless communication, which is not limited in the present disclosure.

[0037] See next Figure 2 , Figure 2 An overall flow chart of a method for extracting a head displacement curve of a test object in a side impact test provided by an embodiment of the present specification is shown. The method for extracting a head displacement curve of a test object in a side impact test can be used in the server 20 .

[0038] like Figure 2 As shown, the method for extracting the head displacement curve of the test object in the side impact test may at least include the following steps:

[0039] Step 201: obtain CAE simulation animation and real vehicle test animation in the side impact test, rotate and adjust the perspective angle of the CAE simulation animation based on the feature overlap method to obtain the target simulation animation, and extract all observation point coordinates, camera coordinates and vertical field of view angles in the target simulation animation.

[0040] The target simulation animation is the CAE simulation animation adjusted to have the same viewing angle as the real vehicle test animation.

[0041] In the embodiment of the present specification, when performing a side collision test of a car, a certain perspective angle is selected to simulate the collision process on a computer, and a CAE simulation animation result can be obtained. The same test parameters are maintained for the side collision test of the real car to obtain the real car test animation. Among them, both animations include multiple process frames in the collision test, and the two animation frames at the same test time correspond one to one. In order to ensure that the perspective angle of the CAE simulation animation is the same as the test angle of the real car test animation, multiple feature points or feature lines can be determined in the initial animation frame when no side collision is performed. Then, based on the initial animation frame in the real car test animation, the perspective angle of the CAE simulation animation is rotated so that the previously determined feature points or feature lines overlap in the two initial images, and the perspective angle is maintained for simulation to obtain the target simulation image. Further, Meta can be used to extract all the observation point coordinates, camera coordinates and vertical field angles corresponding to all animation frames in the target simulation animation. Among them, the vertical field angle is the maximum angle range that can be seen upward and downward from the center point of the observer's line of sight in the vertical direction.

[0042] In one possible implementation, the perspective angle of the CAE simulation animation is rotated and adjusted based on the feature overlap method to obtain a target simulation animation, including:

[0043] Establishing at least one set of corresponding feature points in the CAE simulation animation and the real vehicle test animation;

[0044] The perspective angle of the CAE simulation animation is rotated based on the corresponding feature points, and adjusted until the corresponding feature points in the CAE simulation animation and the actual vehicle test animation overlap, thereby obtaining a target simulation animation.

[0045] In the embodiments of this specification, it is possible to first check whether the various parts of the restraint system and the positioning of the test object dummy in the CAE simulation animation are consistent with the actual vehicle test animation, including the test object dummy posture, seat belt positioning, and airbag extension, to ensure accurate calibration. Then, in the CAE simulation animation and the actual vehicle test animation, multiple groups of corresponding feature points are established, which may include the positioning points of the seats around and in the middle, the test object dummy shoulders and seat belts. Furthermore, based on the actual vehicle test animation, the perspective angle of the CAE simulation animation is rotated and the CAE simulation animation is adaptively scaled, so that the calibrated feature points in the CAE simulation animation coincide with the calibrated feature points in the actual vehicle test animation as much as possible, and the perspective angle is maintained for simulation to obtain the target simulation image.

[0046] Step 202: for any frame of the target simulation animation, construct a projection plane equation based on the observation point coordinates and the camera coordinates, and determine the target head point plane coordinates corresponding to the target head point space coordinates based on the projection plane equation.

[0047] The target head point is the center of mass of the test subject's head.

[0048] In the embodiments of the present specification, for any frame of the obtained target simulation animation, the orientation of the projection plane can be determined by first determining the observation point coordinates and camera coordinates in the frame, and then the projection plane equation is constructed according to the projection plane parameters. Further, the spatial coordinates of the target head point at this time are mapped to the determined projection plane, and then multiple multivariate equations are constructed and solved according to the positional relationship between the point and the line, and the point and the plane, and the corresponding plane coordinates of the target head point are determined by the obtained equation solutions.

[0049] In one possible implementation, constructing a projection plane equation based on the observation point coordinates and the camera coordinates includes:

[0050] Determine the orientation of the projection plane based on the distribution position of each of the feature points;

[0051] The projection plane parameters are determined based on the observation point coordinates and the camera coordinates, and the projection plane equation is constructed in combination with the projection plane orientation and the projection plane parameters.

[0052] In the embodiments of this specification, when constructing the projection plane equation through the observation point coordinates and the camera coordinates, the projection plane can be first defined through the overlapping target simulation animation and the real vehicle test animation, and the corresponding feature points previously determined therein, such as the periphery and middle of the seat, the test object dummy shoulder and the seat belt positioning points, select the plane azimuth closest to these feature points and perpendicular to the line of sight to locate the projection plane orientation. Then, the projection plane parameters of the projection plane are determined through the observation point coordinate parameters and the camera coordinate parameters, and the projection plane equation is further constructed in combination with the projection plane orientation.

[0053] As an example, the camera coordinates are p1(x1, y1, z1), the observation point coordinates are p2(x2, y2, z2), and the equation of the projection plane can be constructed as aX+bY+cZ+d=0, where a, b, c and d are the corresponding parameters of the projection plane equation.

[0054] In one possible implementation, the determining the target head point plane coordinates corresponding to the target head point space coordinates based on the projection plane equation, where the target head point is the center of mass of the test subject's head, includes:

[0055] Processing the target head point space coordinates and the camera coordinates based on the slope principle to obtain the target straight line equation;

[0056] The projection plane equation and the equation group corresponding to the target straight line are combined, and the plane coordinates of the target head point corresponding to the spatial coordinates of the target head point are determined based on the solution of the equation group.

[0057] In the embodiment of the present specification, in order to determine the plane coordinates of the target head point corresponding to the spatial coordinates of the target head point, the spatial coordinates of the center of mass of the test object's head, that is, the target head point, can be first obtained. Among them, when the perspective angle of the CAE simulation animation is initially adjusted, the extracted observation point coordinates are the spatial coordinates of the target head point in the initial state. Since the target head spatial point, the camera coordinate point and the corresponding projection plane point are on a straight line, the target head point spatial coordinates and the camera coordinates can be processed by the straight line slope principle, and assuming that the plane coordinates of the target head point are p0 (x0, y0, z0), each coordinate value is substituted into the slope equation to obtain two target straight line equations. Then, the target head point on the projection plane is substituted into the projection plane equation, and the two target straight line equations determined previously are combined to obtain a set of three-variable linear equations. Finally, the equation is solved, and the plane coordinates of the target head point can be determined by the solution of the system of equations obtained.

[0058] The system of simultaneous equations can be expressed as:

[0059] ax0+by0+cz0+d=0

[0060] (x2-x1) / (y2-y1)=(x0-x2) / (y0-y2)

[0061] (z2-z1) / (x2-x1)=(z0-z2) / (x0-x2)

[0062] Step 203: establish an image coordinate system in the projection plane based on the observation point coordinates, and convert the target head point plane coordinates into the target head point image coordinates in the image coordinate system based on the field of view angle scaling factor.

[0063] The field of view angle scaling factor is calculated by the vertical field of view angle.

[0064] In the embodiments of the present specification, in order to convert the plane coordinates of the target head point into the target head point coordinates, the initial image coordinate system orientation can be first determined in the determined projection plane, and then the origin position of the coordinate system can be determined to establish the image coordinate system, and then the corresponding field of view angle scaling factor can be calculated first by the vertical field of view angle and the camera distance. Further, the width and height scaling ratio of the CAE image is calculated based on the field of view angle scaling factor, and then the plane coordinates of the target head point are transformed in the image coordinate system based on the vector components and the width and height scaling ratio to obtain the corresponding image coordinates of the target head point.

[0065] In one possible implementation, establishing an image coordinate system in a projection plane based on the observation point coordinates includes:

[0066] Determine the horizontal and vertical coordinates of the initial image coordinate system based on the projection plane equation;

[0067] The coordinate axis center coordinates of the initial image coordinate system are moved to the observation point coordinates to obtain the image coordinate system.

[0068] In the embodiments of this specification, when establishing an image coordinate system through observation point coordinates, the horizontal and vertical axis orientations of the initial image coordinate system can be determined by first determining the projection plane equation. In general, the determined horizontal axis orientation is parallel to the horizontal line of the screen of the real vehicle test animation. Then, the initial image coordinate system is translated, and the coordinate axis is moved to the observation point coordinates, that is, the observation point coordinates can be directly used as the coordinate axis to establish the image coordinate system on the projection plane.

[0069] In one possible implementation, the converting the target head point plane coordinates into the target head point image coordinates based on the field of view angle scaling factor in the image coordinate system, wherein the field of view angle scaling factor is calculated by the vertical field of view angle, comprises:

[0070] Determine a minimum distance from the camera to the projection plane, and determine a field of view angle scaling factor based on the minimum distance and the vertical field of view angle;

[0071] Determine the horizontal axis vector component and the vertical axis vector component of the target head point plane coordinate in the image coordinate system;

[0072] The target head point image coordinates are determined based on the field of view angle scaling factor, the horizontal axis vector component and the vertical axis vector component.

[0073] In the embodiment of this specification, when converting the target head point plane coordinates to the target head point image coordinates, the minimum distance lookAtLen from the shooting camera to the determined projection plane can be determined first, which can be calculated by the camera coordinates and the projection plane equation. Then, the calculation formula of the field of view angle scaling factor H0 is The field of view angle scaling factor is calculated. Wherein, FOV is the vertical field of view angle extracted previously. Further, the image coordinates corresponding to the target head plane point p0 in the image coordinate system are set to (u, v), and the horizontal axis vector component Vx=V*cos(θ) of the target head point plane coordinates in the image coordinate system can be determined. Wherein, V is the vector from the camera coordinate p1 to the observation point p2, and θ is the angle between V and the X-axis. The vertical axis vector component Vy=V*cos(ε) of the target head point plane coordinates in the image coordinate system. Wherein, V is the vector from the camera coordinate p1 to the observation point p2, and ε is the angle between V and the Y-axis. Further, after obtaining the field of view angle scaling factor, the horizontal axis vector component, and the vertical axis vector component, the horizontal coordinate u and the vertical coordinate v of the image coordinates are calculated respectively to determine the image coordinates of the target head point.

[0074] In one possible implementation, determining the target head point image coordinates based on the field of view angle scaling factor, the horizontal axis vector component, and the vertical axis vector component includes:

[0075] Determine a height scaling ratio and a width scaling ratio corresponding to the vertical field of view angle based on the field of view angle scaling factor;

[0076] Determine the image horizontal coordinate value corresponding to the horizontal axis vector component and the width scaling ratio;

[0077] Determine the image ordinate value corresponding to the ordinate vector component and the height scaling ratio;

[0078] The target head point image coordinates are determined based on the image abscissa value and the image ordinate value.

[0079] In the embodiment of the present specification, the height scaling ratio and width scaling ratio corresponding to the vertical field of view angle can be determined by first determining the field of view angle scaling factor. The calculation formula for calculating the height scaling ratio HScaling is: Where H is the actual height of the CAE image, and H0 is the field of view scaling factor. The calculation formula for the width scaling ratio Wscaling is: Among them, aspect_ratio is the aspect ratio, which is numerically equal to the ratio of the actual width of the CAE image divided by the actual height, and w is the actual width of the CAE image. Then, the corresponding image horizontal coordinate value is determined by the horizontal axis vector component and the width scaling ratio, that is, u = |V x |·(1,0)·du / W Scaling .in, Similarly, the corresponding image horizontal coordinate value is determined by the vertical axis vector component and the height scaling ratio, that is, v = |V y |·(0,1)·dv / H Scaling .in, Finally, after obtaining the image abscissa value u and the image ordinate value v, the image coordinates (u, v) of the target head point can be determined.

[0080] Step 204: after obtaining all the target head point image coordinates corresponding to the target simulation animation, draw the head deviation curve of the test object according to all the target head point image coordinates.

[0081] In an embodiment of the present specification, the spatial point coordinates of the target head point in the target simulation animation are converted through the above method for determining image coordinates to obtain the target head point image coordinates of all animation frames, and all the target head point image points are connected in the determined image coordinate system based on the time sequence of the animation frames to extract the offset curve of the test object's head in the entire side impact test.

[0082] The above is a description of a specific embodiment of the specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0083] See next Figure 3 , Figure 3 The schematic diagram of the structure of a device for extracting the head displacement curve of a test object in a side impact test provided by an embodiment of the present specification is shown. It should be noted that: Figure 3 The device for extracting the head displacement curve of the test object in the side impact test is used to implement the present application Figure 2 For the convenience of explanation, only the part related to the embodiment of the present application is shown. For the specific technical details not disclosed, please refer to the present application. Figure 2 The embodiment shown.

[0084] like Figure 3 As shown, the device for extracting the head displacement curve of the test object in the side impact test may at least include:

[0085] The adjustment module 301 is used to obtain the CAE simulation animation and the real vehicle test animation in the side impact test, rotate and adjust the perspective angle of the CAE simulation animation based on the feature overlap method to obtain the target simulation animation, and extract all the observation point coordinates, camera coordinates and vertical field of view angles in the target simulation animation, wherein the target simulation animation is the CAE simulation animation adjusted to have the same perspective as the real vehicle test animation;

[0086] A construction module 302 is used to construct a projection plane equation for any frame of the target simulation animation based on the observation point coordinates and the camera coordinates, and determine the target head point plane coordinates corresponding to the target head point space coordinates based on the projection plane equation, where the target head point is the centroid point of the test subject's head;

[0087] A scaling module 303 is used to establish an image coordinate system in a projection plane based on the observation point coordinates, and to convert the target head point plane coordinates into the target head point image coordinates in the image coordinate system based on a field of view angle scaling factor, wherein the field of view angle scaling factor is calculated by the vertical field of view angle;

[0088] The drawing module 304 is used to draw the head deviation curve of the test object according to all the target head point image coordinates after obtaining all the target head point image coordinates corresponding to the target simulation animation.

[0089] In one possible implementation, the adjustment module 301 is specifically used for:

[0090] Establishing at least one set of corresponding feature points in the CAE simulation animation and the real vehicle test animation;

[0091] The perspective angle of the CAE simulation animation is rotated based on the corresponding feature points, and adjusted until the corresponding feature points in the CAE simulation animation and the actual vehicle test animation overlap, thereby obtaining a target simulation animation.

[0092] In one possible implementation, the construction module 302 is specifically used to:

[0093] Determine the orientation of the projection plane based on the distribution position of each of the feature points;

[0094] The projection plane parameters are determined based on the observation point coordinates and the camera coordinates, and the projection plane equation is constructed in combination with the projection plane orientation and the projection plane parameters.

[0095] In one possible implementation, the construction module 302 is further configured to:

[0096] Processing the target head point space coordinates and the camera coordinates based on the slope principle to obtain the target straight line equation;

[0097] The projection plane equation and the equation group corresponding to the target straight line are combined, and the plane coordinates of the target head point corresponding to the spatial coordinates of the target head point are determined based on the solution of the equation group.

[0098] In one possible implementation, the scaling module 303 is specifically used for:

[0099] Determine the horizontal and vertical coordinates of the initial image coordinate system based on the projection plane equation;

[0100] The coordinate axis center coordinates of the initial image coordinate system are moved to the observation point coordinates to obtain the image coordinate system.

[0101] In one possible implementation, the scaling module 303 is further configured to:

[0102] Determine a minimum distance from the camera to the projection plane, and determine a field of view angle scaling factor based on the minimum distance and the vertical field of view angle;

[0103] Determine the horizontal axis vector component and the vertical axis vector component of the target head point plane coordinate in the image coordinate system;

[0104] The target head point image coordinates are determined based on the field of view angle scaling factor, the horizontal axis vector component and the vertical axis vector component.

[0105] In one possible implementation, the scaling module 303 is further configured to:

[0106] Determine a height scaling ratio and a width scaling ratio corresponding to the vertical field of view angle based on the field of view angle scaling factor;

[0107] Determine the image horizontal coordinate value corresponding to the horizontal axis vector component and the width scaling ratio;

[0108] Determine the image ordinate value corresponding to the ordinate vector component and the height scaling ratio;

[0109] The target head point image coordinates are determined based on the image abscissa value and the image ordinate value.

[0110] Those skilled in the art can clearly understand that the technical solutions of the embodiments of the present application can be implemented with the help of software and / or hardware. The "unit" and "module" in this specification refer to software and / or hardware that can independently complete or cooperate with other components to complete specific functions, where the hardware can be, for example, a field programmable gate array (Field-Programmable Gate Array, FPGA), an integrated circuit (Integrated Circuit, IC), etc.

[0111] Each processing unit and / or module of the embodiments of the present application may be implemented by an analog circuit that implements the functions described in the embodiments of the present application, or may be implemented by software that executes the functions described in the embodiments of the present application.

[0112] See next Figure 4 , Figure 4 A schematic diagram of the structure of an electronic device provided in an embodiment of this specification is shown.

[0113] like Figure 4 As shown, the electronic device 400 may include: at least one device processor 401 , at least one network interface 404 , a user interface 403 , a memory 405 , and at least one communication bus 402 .

[0114] The communication bus 402 may be used to realize the connection and communication among the above-mentioned components.

[0115] The user interface 403 may include buttons, and the optional user interface may also include a standard wired interface or a wireless interface.

[0116] The network interface 404 may include, but is not limited to, a Bluetooth module, an NFC module, a Wi-Fi module, etc.

[0117] Among them, the device processor 401 may include one or more processing cores. The device processor 401 uses various interfaces and lines to connect various parts within the entire electronic device 400, and executes various functions and processes data of the electronic device 400 by running or executing instructions, programs, code sets or instruction sets stored in the memory 405, and calling data stored in the memory 405. Optionally, the device processor 401 can be implemented in at least one hardware form of DSP, FPGA, and PLA. The device processor 401 can integrate one or a combination of CPU, GPU, modem, etc. Among them, the CPU mainly processes the operating system, user interface, and application programs; the GPU is responsible for rendering and drawing the content to be displayed on the display screen; the modem is used to handle wireless communications. It can be understood that the above-mentioned modem may not be integrated into the device processor 401, and it can be implemented separately through a chip.

[0118] The memory 405 may include RAM or ROM. Optionally, the memory 405 includes a non-transitory computer-readable medium. The memory 405 can be used to store instructions, programs, codes, code sets or instruction sets. The memory 405 may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function (such as a touch function, a sound playback function, an image playback function, etc.), instructions for implementing the above-mentioned method embodiments, etc.; the data storage area may store data involved in the above-mentioned method embodiments, etc. The memory 405 may optionally be at least one storage device located away from the aforementioned device processor 401. As Figure 4 As shown, the memory 405 as a computer storage medium may include an operating system, a network communication module, a user interface module, and program instructions.

[0119] Specifically, the device processor 401 may be used to call the application for extracting the head displacement curve of the test object in the side impact test stored in the memory 405, and specifically perform the following operations:

[0120] Obtaining a CAE simulation animation and a real vehicle test animation in a side impact test, rotating and adjusting the perspective angle of the CAE simulation animation based on a feature overlap method to obtain a target simulation animation, and extracting all observation point coordinates, camera coordinates, and vertical field of view angles in the target simulation animation, wherein the target simulation animation is an animation having the same perspective as the real vehicle test animation after the CAE simulation animation is adjusted;

[0121] For any frame of the target simulation animation, construct a projection plane equation based on the observation point coordinates and the camera coordinates, and determine the target head point plane coordinates corresponding to the target head point space coordinates based on the projection plane equation, the target head point being the center of mass of the test subject's head;

[0122] An image coordinate system is established in a projection plane based on the observation point coordinates, and in the image coordinate system, the plane coordinates of the target head point are converted into image coordinates of the target head point based on a field of view angle scaling factor, wherein the field of view angle scaling factor is calculated by the vertical field of view angle;

[0123] After obtaining all the target head point image coordinates corresponding to the target simulation animation, the head displacement curve of the test object is drawn according to all the target head point image coordinates.

[0124] As an optional embodiment of this specification, the perspective angle of the CAE simulation animation is rotated and adjusted based on the feature overlap method to obtain the target simulation animation, including:

[0125] Establishing at least one set of corresponding feature points in the CAE simulation animation and the real vehicle test animation;

[0126] The perspective angle of the CAE simulation animation is rotated based on the corresponding feature points, and adjusted until the corresponding feature points in the CAE simulation animation and the actual vehicle test animation overlap, thereby obtaining a target simulation animation.

[0127] As an option of the embodiment of this specification, constructing the projection plane equation based on the observation point coordinates and the camera coordinates includes:

[0128] Determine the orientation of the projection plane based on the distribution position of each of the feature points;

[0129] The projection plane parameters are determined based on the observation point coordinates and the camera coordinates, and the projection plane equation is constructed in combination with the projection plane orientation and the projection plane parameters.

[0130] As an option of the embodiment of this specification, the determining the plane coordinates of the target head point corresponding to the space coordinates of the target head point based on the projection plane equation includes:

[0131] Processing the target head point space coordinates and the camera coordinates based on the slope principle to obtain the target straight line equation;

[0132] The projection plane equation and the equation group corresponding to the target straight line are combined, and the plane coordinates of the target head point corresponding to the spatial coordinates of the target head point are determined based on the solution of the equation group.

[0133] As an option of the embodiment of this specification, establishing an image coordinate system in the projection plane based on the observation point coordinates includes:

[0134] Determine the horizontal and vertical coordinates of the initial image coordinate system based on the projection plane equation;

[0135] The coordinate axis center coordinates of the initial image coordinate system are moved to the observation point coordinates to obtain the image coordinate system.

[0136] As an optional embodiment of this specification, the converting of the target head point plane coordinates into the target head point image coordinates based on the field of view angle scaling factor in the image coordinate system, wherein the field of view angle scaling factor is calculated by the vertical field of view angle, includes:

[0137] Determine a minimum distance from the camera to the projection plane, and determine a field of view angle scaling factor based on the minimum distance and the vertical field of view angle;

[0138] Determine the horizontal axis vector component and the vertical axis vector component of the target head point plane coordinate in the image coordinate system;

[0139] The target head point image coordinates are determined based on the field of view angle scaling factor, the horizontal axis vector component and the vertical axis vector component.

[0140] As an optional embodiment of this specification, the determining the target head point image coordinates based on the field of view angle scaling factor, the horizontal axis vector component and the vertical axis vector component includes:

[0141] Determine a height scaling ratio and a width scaling ratio corresponding to the vertical field of view angle based on the field of view angle scaling factor;

[0142] Determine the image horizontal coordinate value corresponding to the horizontal axis vector component and the width scaling ratio;

[0143] Determine the image ordinate value corresponding to the ordinate vector component and the height scaling ratio;

[0144] The target head point image coordinates are determined based on the image abscissa value and the image ordinate value.

[0145] The embodiments of this specification also provide a computer-readable storage medium, on which a computer program is stored, and when the program is executed by a processor, the steps of the above method are implemented. The computer-readable storage medium may include, but is not limited to, any type of disk, including a floppy disk, an optical disk, a DVD, a CD-ROM, a micro drive, and a magneto-optical disk, a ROM, a RAM, an EPROM, an EEPROM, a DRAM, a VRAM, a flash memory device, a magnetic card or an optical card, a nanosystem (including a molecular memory IC), or any type of medium or device suitable for storing instructions and / or data.

[0146] It should be noted that, for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described order of actions, because according to the present application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0147] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0148] In the several embodiments provided in the present application, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are only schematic, such as the division of the units, which is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some service interfaces, and the indirect coupling or communication connection of devices or units can be electrical or other forms.

[0149] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0150] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0151] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable memory. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a memory, including a number of instructions to enable a computer device (which can be a personal computer, server or network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned memory includes: U disk, read-only memory (ROM), random access memory (RAM), mobile hard disk, disk or optical disk and other media that can store program code.

[0152] A person skilled in the art may understand that all or part of the steps in the various methods of the above embodiments may be completed by entering a program to instruct related hardware, and the program may be stored in a computer-readable memory, which may include a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, etc.

[0153] The above is a description of a specific embodiment of the specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

Claims

1. A method for extracting a head displacement curve of a test object in a side impact test, characterized in that: The method comprises: Obtaining a CAE simulation animation and a real vehicle test animation in a side impact test, rotating and adjusting the perspective angle of the CAE simulation animation based on a feature overlap method to obtain a target simulation animation, and extracting all observation point coordinates, camera coordinates, and vertical field of view angles in the target simulation animation, wherein the target simulation animation is an animation having the same perspective as the real vehicle test animation after the CAE simulation animation is adjusted; For any frame of the target simulation animation, construct a projection plane equation based on the observation point coordinates and the camera coordinates, and determine the target head point plane coordinates corresponding to the target head point space coordinates based on the projection plane equation, the target head point being the center of mass of the test subject's head; An image coordinate system is established in a projection plane based on the observation point coordinates, and in the image coordinate system, the plane coordinates of the target head point are converted into image coordinates of the target head point based on a field of view angle scaling factor, wherein the field of view angle scaling factor is calculated by the vertical field of view angle; After obtaining all the target head point image coordinates corresponding to the target simulation animation, the head displacement curve of the test object is drawn according to all the target head point image coordinates.

2. The method according to claim 1, characterized in that The method of rotating and adjusting the perspective angle of the CAE simulation animation based on the feature overlap method to obtain the target simulation animation includes: Establishing at least one set of corresponding feature points in the CAE simulation animation and the real vehicle test animation; The perspective angle of the CAE simulation animation is rotated based on the corresponding feature points, and adjusted until the corresponding feature points in the CAE simulation animation and the actual vehicle test animation overlap, thereby obtaining a target simulation animation.

3. The method according to claim 1, characterized in that The constructing of the projection plane equation based on the observation point coordinates and the camera coordinates includes: Determine the orientation of the projection plane based on the distribution position of each of the feature points; The projection plane parameters are determined based on the observation point coordinates and the camera coordinates, and the projection plane equation is constructed in combination with the projection plane orientation and the projection plane parameters.

4. The method according to claim 1, characterized in that: The step of determining the plane coordinates of the target head point corresponding to the spatial coordinates of the target head point based on the projection plane equation includes: Processing the target head point space coordinates and the camera coordinates based on the slope principle to obtain the target straight line equation; The projection plane equation and the equation group corresponding to the target straight line are combined, and the plane coordinates of the target head point corresponding to the spatial coordinates of the target head point are determined based on the solution of the equation group.

5. The method according to claim 1, characterized in that The establishing of an image coordinate system in a projection plane based on the observation point coordinates comprises: Determine the horizontal and vertical coordinates of the initial image coordinate system based on the projection plane equation; The coordinate axis center coordinates of the initial image coordinate system are moved to the observation point coordinates to obtain the image coordinate system.

6. The method according to claim 1, characterized in that The step of converting the target head point plane coordinates into the target head point image coordinates based on the field of view angle scaling factor in the image coordinate system, wherein the field of view angle scaling factor is calculated by the vertical field of view angle, comprises: Determine a minimum distance from the camera to the projection plane, and determine a field of view angle scaling factor based on the minimum distance and the vertical field of view angle; Determine the horizontal axis vector component and the vertical axis vector component of the target head point plane coordinate in the image coordinate system; The target head point image coordinates are determined based on the field of view angle scaling factor, the horizontal axis vector component and the vertical axis vector component.

7. The method according to claim 6, characterized in that The determining the target head point image coordinates based on the field of view angle scaling factor, the horizontal axis vector component and the vertical axis vector component comprises: Determine a height scaling ratio and a width scaling ratio corresponding to the vertical field of view angle based on the field of view angle scaling factor; Determine the image horizontal coordinate value corresponding to the horizontal axis vector component and the width scaling ratio; Determine the image ordinate value corresponding to the ordinate vector component and the height scaling ratio; The target head point image coordinates are determined based on the image abscissa value and the image ordinate value.

8. A device for extracting a head displacement curve of a test object in a side impact test, characterized in that: The device comprises: An adjustment module is used to obtain the CAE simulation animation and the real vehicle test animation in the side impact test, rotate and adjust the perspective angle of the CAE simulation animation based on the feature overlap method to obtain a target simulation animation, and extract all observation point coordinates, camera coordinates and vertical field of view angles in the target simulation animation, wherein the target simulation animation is the CAE simulation animation adjusted to have the same perspective as the real vehicle test animation; A construction module, for constructing a projection plane equation for any frame of the target simulation animation based on the observation point coordinates and the camera coordinates, and determining the target head point plane coordinates corresponding to the target head point space coordinates based on the projection plane equation, wherein the target head point is the centroid point of the test subject's head; A scaling module, for establishing an image coordinate system in a projection plane based on the observation point coordinates, and converting the target head point plane coordinates into the target head point image coordinates in the image coordinate system based on a field of view angle scaling factor, wherein the field of view angle scaling factor is calculated by the vertical field of view angle; The drawing module is used to draw the head displacement curve of the test object according to all the target head point image coordinates after obtaining the target simulation animation corresponding to the target head point image coordinates.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, wherein the computer-readable storage medium has instructions stored therein, and when the instructions are executed on a computer or a processor, the computer or the processor executes the steps of the method according to any one of claims 1 to 7.

Images