A method for extracting the head deviation curve of a test object in a side impact test

Abstract

The embodiments of this specification disclose a method for extracting the head offset curve of a test subject in a side impact test. The method comprises first obtaining a CAE simulation animation and a real vehicle test animation in the side impact test, and then rotating and adjusting the CAE simulation animation based on a feature overlap method to obtain a 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 spatial coordinates of the target head point are converted into the plane coordinates of the target head point and then into the image coordinates of the target head point, thereby projecting the CAE 3D simulation into an equivalent 2D perspective coordinate, effectively improving the fit 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 automobile side impact safety.

Description

Technical Field

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

[0002] With the rapid development of the automotive industry, vehicle collision safety performance has become a hot topic for major manufacturers. In a far-side impact, the occupant's head will move toward the impacted side due to inertia. Relevant requirements stipulate that the maximum head excursion score should be estimated based on the camera closest to the point of maximum head displacement. Accurately determining the lateral and forward head motion trajectories is crucial for reducing head injuries. However, in testing, head motion trajectories can only be obtained through video analysis. Conventional Computer-Aided Engineering (CAE) test recordings are based on perspective projection camera analysis. Perspective projection does not represent precise 3D motion, so the offset value obtained when participating in head excursion scoring will differ from the actual result.

[0003] Currently, the head offset in a far-side collision of a car is the key data for determining penalty points. This is mainly determined by a virtual side collision safety assessment. The virtual side collision safety assessment is a benchmarking process based on the combination of computer CAE simulation and actual vehicle testing. The CAE simulation animation is played based on parallel views. The head offset directly extracted from the CAE animation view will deviate from the actual data due to perspective issues, which will affect the safety test score. Summary of the Invention

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

[0005] In a first aspect, an embodiment of this 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. The target simulation animation is the adjusted CAE simulation animation with the same perspective as the real vehicle test animation.

[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, where the target head point is the center of mass of the test subject's head;

[0008] Establishing an image coordinate system in a projection plane based on the observation point coordinates, and converting the target head point plane coordinates into 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 using the vertical field of view angle;

[0009] After obtaining all the target head point image coordinates corresponding to the target simulation animation, the head offset 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 for 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 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, where the target head point is the center of mass of the test subject's head;

[0013] a scaling module, configured to establish an image coordinate system in a projection plane based on the observation point coordinates, and convert the target head point plane coordinates into 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 using the vertical field of view angle;

[0014] The drawing module is used to draw the head deviation 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. When the instructions are executed on a computer or device processor, the computer or device processor executes the method provided in the first aspect or any possible implementation of the first aspect.

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

[0021] In one or more embodiments of this specification, a CAE simulation animation and an actual vehicle test animation from a side impact test can be first obtained. The CAE simulation animation is then rotated and adjusted based on a feature overlap method to obtain a target simulation animation, ensuring that the target simulation animation and the actual vehicle test animation maintain the same perspective. Next, by constructing a projection plane and image coordinate system, the target head point spatial coordinates are converted to target head point plane coordinates and then to target head point image coordinates, enabling the CAE 3D simulation to be projected into equivalent 2D perspective coordinates. This effectively improves the fit and correlation between the simulated head offset curve and the actual vehicle test head curve, reduces the error between the simulated head offset curve and the actual test data, and further meets the accuracy requirements of virtual vehicle side impact safety assessments. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. 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 creative work.

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

[0024] Figure 2 A flowchart of a method for extracting a head offset curve of a test subject 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 by an embodiment of this specification;

[0026] Figure 4This is a 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 described clearly and completely below in conjunction with the drawings in the embodiments of the present application.

[0028] Throughout this specification, the claims, and the accompanying drawings, the terms "first," "second," "third," and the like are used to distinguish between different items, not to describe a particular order. Furthermore, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements but may optionally include steps or elements not listed, or may include other steps or elements inherent to the process, method, product, or apparatus.

[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 this specification. Various examples may appropriately omit, replace, or add various processes or components. For example, the described methods may be performed in an order different from the order described, and various steps may be added, omitted, or combined. Furthermore, 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 offset curve of a test object in a side impact test provided by an embodiment of this specification is shown.

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

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

[0033] The server 20 can provide background services for the terminal 10. Based on 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 will transmit the head offset curve extraction instructions to other terminals 10 via 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. It can also be 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 fiber optic cables.

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

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

[0037] See next Figure 2 , Figure 2 The 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 an embodiment of this specification, when conducting a side impact test of a vehicle, a certain perspective angle is selected and the collision process is simulated on a computer, resulting in a CAE simulation animation. A real vehicle side impact test is then conducted while maintaining the same test parameters to produce a real vehicle test animation. Both animations include multiple frames from the collision test, and the two animation frames at the same test moment correspond one-to-one. To ensure that the perspective angle of the CAE simulation animation remains the same as the test angle of the real vehicle test animation, multiple feature points or feature lines can be determined in the initial animation frame before the side impact. Next, using the initial animation frame in the real vehicle test animation as a reference, 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. Simulation is then performed while maintaining this perspective angle to produce the target simulation image. Furthermore, Meta can be used to extract all observation point coordinates, camera coordinates, and vertical field of view angles corresponding to all animation frames in the target simulation animation. The vertical field of view angle is the maximum angle range that can be seen upward and downward from the center of the observer's line of sight in the vertical direction.

[0042] In one possible implementation, the step 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:

[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 is adjusted until the corresponding feature points in the CAE simulation animation and the actual vehicle test animation coincide with each other, 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's posture, seat belt positioning, and airbag deployment, to ensure that the calibration is accurate. 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, and the test object dummy's 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 and the calibrated feature points in the actual vehicle test animation overlap as much as possible, and the simulation is performed while maintaining this perspective angle 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 this specification, for any frame of the target simulated animation, the orientation of the projection plane is determined by first determining the observation point coordinates and camera coordinates in that frame. The projection plane equation is then constructed based on the projection plane parameters. Furthermore, the spatial coordinates of the target head point at that moment are mapped onto the determined projection plane. Multiple multivariate equations are then constructed and solved based on the positional relationships between the point and the line, and between the point and the plane. The corresponding plane coordinates of the target head point are determined using the solutions to these equations.

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

[0050] Determining 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 using observation point coordinates and camera coordinates, the projection plane is first defined by overlapping target simulation animations and real-vehicle test animations. The projection plane orientation is determined by selecting the plane azimuth closest to these feature points and perpendicular to the line of sight using previously determined sets of corresponding feature points, such as the perimeter and center of the seat, and the test dummy's shoulder and seatbelt positioning points. Next, the projection plane parameters are determined using the observation point coordinate parameters and the camera coordinate parameters, and the projection plane equation is further constructed based on 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 embodiment, 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 target straight line corresponding equation group are jointly solved, and the target head point plane coordinates corresponding to the target head point space coordinates are determined based on the equation solution of the equation group.

[0057] In the embodiment of the present specification, in order to determine the target head point plane coordinates corresponding to the target head point space coordinates, the center of mass point of the test subject's head, that is, the space coordinates of 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 target head point space coordinates in the initial state. Since the target head space point, the camera coordinate point and the corresponding projection plane point are on a straight line, the target head point space coordinates and the camera coordinates can be processed by the straight line slope principle, and assuming that the target head point plane coordinates 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 previously determined are combined to obtain a set of three 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] Among them, the 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 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 this specification, to convert the plane coordinates of the target head point to the target head point coordinates, the initial image coordinate system orientation is first determined in the determined projection plane. The origin of the coordinate system is then determined to establish the image coordinate system. The corresponding field of view angle scaling factor is then calculated using the vertical field of view angle and camera distance. Furthermore, the width and height scaling ratios of the CAE image are calculated based on the field of view angle scaling factor. The plane coordinates of the target head point are then converted in the image coordinate system based on the vector components and the width and height scaling ratios 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 coordinate orientations 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 using observation point coordinates, the horizontal and vertical axis orientations of the initial image coordinate system are first determined using the determined projection plane equations. Generally, the determined horizontal axis orientation is parallel to the horizontal line of the live vehicle test animation. Next, the initial image coordinate system is translated to move the coordinate axis to the observation point coordinates. Alternatively, the image coordinate system can be established directly on the projection plane using the observation point coordinates as the coordinate axis.

[0069] In one embodiment, converting the target head point plane coordinates into the target head point image coordinates based on a 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:

[0070] Determining a minimum distance from the camera to the projection plane, and determining 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 field of view scaling factor H0 is calculated by the formula The field of view scaling factor is calculated. Wherein, FOV is the vertical field of view extracted previously. Further, the image coordinates of the target head plane point p0 corresponding to 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 coordinate 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 coordinate 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 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 coordinate are calculated respectively to determine the target head point image coordinates.

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

[0077] Determining an 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 this 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 scaling factor. The calculation formula for calculating the height scaling ratio HScaling is: Where H is the actual height of the CAE image, 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 offset curve of the test subject according to all the target head point image coordinates.

[0081] In the 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 foregoing description of this specification describes specific embodiments. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in an order different from that described in the embodiments and still achieve the desired results. Furthermore, the processes depicted in the accompanying drawings do not necessarily require the specific order shown or the sequential order to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0083] See next Figure 3 , Figure 3 The following is a schematic diagram showing the structure of a device for extracting the head deviation curve of a test object in a side impact test provided by an embodiment of this specification. Figure 3 The device for extracting the head deviation curve of the test object in the side impact test is used to perform 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] An adjustment module 301 is configured to obtain a CAE simulation animation and a real vehicle test animation in a side impact test, rotate and adjust the perspective angle of the CAE simulation animation based on a 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. The target simulation animation is the adjusted CAE simulation animation with the same perspective as the real vehicle test animation.

[0086] A construction module 302 is configured 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 plane coordinates of a target head point corresponding to the spatial coordinates of the target head point based on the projection plane equation, where the target head point is the center of mass of the test subject's head;

[0087] a scaling module 303 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 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 using the vertical field of view angle;

[0088] The drawing module 304 is configured to draw the head displacement curve of the test subject 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 embodiment, the adjustment module 301 is specifically configured to:

[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 is adjusted until the corresponding feature points in the CAE simulation animation and the actual vehicle test animation coincide with each other, thereby obtaining a target simulation animation.

[0092] In one embodiment, the construction module 302 is specifically configured to:

[0093] Determining 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 embodiment, 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 target straight line corresponding equation group are jointly solved, and the target head point plane coordinates corresponding to the target head point space coordinates are determined based on the equation solution of the equation group.

[0098] In one embodiment, the scaling module 303 is specifically configured to:

[0099] Determine the horizontal and vertical coordinate orientations 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 embodiment, the scaling module 303 is further configured to:

[0102] Determining a minimum distance from the camera to the projection plane, and determining 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 embodiment, the scaling module 303 is further configured to:

[0106] Determining 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] Determining an image horizontal coordinate value corresponding to the horizontal axis vector component and the width scaling ratio;

[0108] Determining an 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 will clearly understand that the technical solutions of the embodiments of the present application can be implemented with the help of software and / or hardware. "Unit" and "module" in this specification refer to software and / or hardware that can independently perform or cooperate with other components to perform specific functions, where the hardware can be, for example, a field programmable gate array (FPGA), an integrated circuit (IC), etc.

[0111] Each processing unit and / or module in 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 structural diagram 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 implement the connection and communication between the above 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, and the like.

[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 the various parts of the entire electronic device 400, and executes various functions of the electronic device 400 and processes data 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, and modem. 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; and the modem is used to handle wireless communications. It is understandable that the above-mentioned modem may not be integrated into the device processor 401, but may be implemented separately through a chip.

[0118] Among them, the memory 405 may include RAM and 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 various method embodiments, etc.; the data storage area may store data involved in the above-mentioned various method embodiments, etc. The memory 405 may also be optionally 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 configured to call the application for extracting the head displacement curve of the test subject 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. The target simulation animation is the adjusted CAE simulation animation with the same perspective as the real vehicle test animation.

[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, where the target head point is the center of mass of the test subject's head;

[0122] Establishing an image coordinate system in a projection plane based on the observation point coordinates, and converting the target head point plane coordinates into 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 using the vertical field of view angle;

[0123] After obtaining all the target head point image coordinates corresponding to the target simulation animation, the head offset 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 is adjusted until the corresponding feature points in the CAE simulation animation and the actual vehicle test animation coincide with each other, thereby obtaining a target simulation animation.

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

[0128] Determining 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 optional embodiment of this specification, 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:

[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 target straight line corresponding equation group are jointly solved, and the target head point plane coordinates corresponding to the target head point space coordinates are determined based on the equation solution of the equation group.

[0133] As an optional 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 coordinate orientations 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 a 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] Determining a minimum distance from the camera to the projection plane, and determining 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, 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] Determining 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] Determining an image horizontal coordinate value corresponding to the horizontal axis vector component and the width scaling ratio;

[0143] Determining an 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 having a computer program stored thereon, which, when executed by a processor, implements the steps of the above method. 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 microdrive, a magneto-optical disk, a ROM, a RAM, an EPROM, an EEPROM, a DRAM, a VRAM, a flash memory device, a magnetic or 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 this application is not limited by the order of the actions described, because according to this 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 this application.

[0147] In the above embodiments, the description of each embodiment has its own focus. 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 this application, it should be understood that the disclosed devices can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the units is merely a logical function division. In actual implementation, there may be other division methods, 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 interface, and the indirect coupling or communication connection of the device or unit can be electrical or other forms.

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

[0150] In addition, the functional units in the various embodiments of the present application may be integrated into a single processing unit, or each unit may exist physically separately, or two or more units may be integrated into a single unit. The aforementioned integrated units may be implemented in the form of hardware or 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 for enabling a computer device (which can be a personal computer, server or network device, etc.) to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned memory includes: various media that can store program codes, such as a USB flash drive, a read-only memory (ROM), a random access memory (RAM), a mobile hard disk, a magnetic disk or an optical disk.

[0152] Those skilled in the art will appreciate that all or part of the steps in the various methods of the above embodiments can be completed by instructing related hardware through a program, and the program can 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 foregoing description of this specification describes specific embodiments. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in an order different from that described in the embodiments and still achieve the desired results. Furthermore, the processes depicted in the accompanying drawings do not necessarily require the specific order shown or the sequential order to achieve the desired results. In certain 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. The target simulation animation is the adjusted CAE simulation animation with the same perspective as the real vehicle test animation. 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, where the target head point is the center of mass of the test subject's head; Establishing an image coordinate system in a projection plane based on the observation point coordinates, and converting the target head point plane coordinates into 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 using the vertical field of view angle; After obtaining all the target head point image coordinates corresponding to the target simulation animation, drawing the head displacement curve of the test object according to all the target head point image coordinates; 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: Determining a minimum distance from the camera to the projection plane, and determining 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.

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 is adjusted until the corresponding feature points in the CAE simulation animation and the actual vehicle test animation coincide with each other, thereby obtaining a target simulation animation.

3. The method according to claim 2, characterized in that The constructing of the projection plane equation based on the observation point coordinates and the camera coordinates includes: Determining 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, wherein The determining, based on the projection plane equation, the target head point plane coordinates corresponding to the target head point space coordinates 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 target straight line corresponding equation group are jointly solved, and the target head point plane coordinates corresponding to the target head point space coordinates are determined based on the equation solution of the equation group.

5. The method according to claim 1, wherein The establishing of an image coordinate system in a projection plane based on the observation point coordinates includes: Determine the horizontal and vertical coordinate orientations 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, wherein The determining of 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: Determining 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; Determining an image horizontal coordinate value corresponding to the horizontal axis vector component and the width scaling ratio; Determining an 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.

7. 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 for 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 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, where the target head point is the center of mass of the test subject's head; a scaling module, configured to establish an image coordinate system in a projection plane based on the observation point coordinates, and convert the target head point plane coordinates into 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 using the vertical field of view angle; a drawing module, configured to draw a head displacement curve of the test subject according to all the target head point image coordinates after obtaining the target simulation animation corresponding to the target head point image coordinates; The scaling module is further configured to: Determining a minimum distance from the camera to the projection plane, and determining 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.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 6 are implemented.

9. A computer-readable storage medium having a computer program stored thereon, wherein the computer-readable storage medium stores instructions, which, when the instructions are executed on a computer or a processor, cause the computer or processor to execute the steps of the method according to any one of claims 1 to 6.

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