A method and device for measuring the trajectory of a test subject's head during automobile travel

Abstract

The embodiment of the specification discloses a kind of automobile driving test object head movement trajectory measurement method and device.The method includes first by obtaining the head test data of target test object to determine the rotation matrix of each time corresponding angular velocity data, then the angular velocity data and relative acceleration data are translated, the head centroid acceleration of target test object is obtained, and the absolute acceleration is obtained based on the correction processing of gravity factor to head centroid acceleration, finally, the integral algorithm is based on the integral operation of absolute acceleration, and the head movement trajectory of target test object is obtained.The sampling data is converted into the head movement trajectory curve under global coordinate system by combining head centroid and gravity factor, the requirement that measurement point and target test object head centroid point coincide and eliminate gravity acceleration influence is met, relatively accurate target test object head displacement trajectory calculation is realized, and the effectiveness and accuracy of virtual evaluation are guaranteed.

Description

Technical Field

[0001] This specification relates to the field of intelligent vehicle technology, and in particular to a method and apparatus for measuring the head movement trajectory of a test subject while the vehicle is in motion. Background Technology

[0002] With the rapid development of intelligent vehicle technology, the trajectory of the test subject's head is crucial in vehicle driving tests, particularly in determining head injury values. Currently, traditional methods for determining the trajectory of a test subject's head typically involve first obtaining the absolute acceleration of the head and then directly integrating this acceleration to arrive at the trajectory. However, this method generally includes the influence of gravitational acceleration in the absolute acceleration measurement, and it cannot guarantee that the absolute acceleration measurement point coincides with the center of mass of the test subject's head. This results in a significant difference between the final trajectory curve and the actual curve, affecting subsequent testing and failing to meet high-precision requirements. Summary of the Invention

[0003] This specification provides a method and apparatus for measuring the head movement trajectory of a test subject while the vehicle is in motion, the technical solution of which is as follows:

[0004] Firstly, embodiments of this specification provide a method for measuring the head movement trajectory of a test object while the vehicle is in motion, the method comprising:

[0005] The head test data of the target test object is obtained, and the rotation matrix corresponding to each moment of the angular velocity data is determined based on the angle change method. The head test data includes angular velocity data and relative acceleration data.

[0006] The angular velocity data and relative acceleration data are translated based on the point overlap to obtain the head center of mass acceleration of the target test object. The point overlap is the degree of overlap between the measurement point of the head test data and the head center of mass of the target test object.

[0007] The acceleration of the head's center of mass is corrected based on the gravity factor and the rotation matrix at each time point to obtain the absolute acceleration.

[0008] The absolute acceleration is integrated using an integral algorithm, and the integration results are combined to obtain the head motion trajectory of the target test object.

[0009] Secondly, a device for measuring the head movement trajectory of a test subject during vehicle operation is provided, the device comprising:

[0010] The acquisition module is used to acquire the head test data of the target test object and determine the rotation matrix corresponding to each moment of the angular velocity data based on the angle change method. The head test data includes angular velocity data and relative acceleration data.

[0011] The translation module is used to translate the angular velocity data and relative acceleration data based on the point coincidence degree to obtain the head center of mass acceleration of the target test object. The point coincidence degree is the degree of coincidence between the measurement point of the head test data and the head center of mass of the target test object.

[0012] The correction module is used to correct the acceleration of the head's center of mass based on the gravity factor and the rotation matrix at each time point to obtain the absolute acceleration.

[0013] The integration module is used to perform integration calculations on the absolute acceleration based on the integration algorithm, and integrate the integration results to obtain the head motion trajectory of the target test object.

[0014] Thirdly, an electronic device is provided, including a device processor and a memory;

[0015] The device processor is connected to the memory;

[0016] The memory is used to store executable program code;

[0017] The device processor runs a program corresponding to the executable program code stored in the memory to perform the steps of the method provided as in the first aspect or any possible implementation thereof.

[0018] Fourthly, a computer-readable storage medium is provided having a computer program stored thereon, the computer-readable storage medium storing instructions that, when executed on a computer or device processor, cause the computer or device processor to perform the method provided as in the first aspect or any possible implementation thereof.

[0019] The beneficial effects of the technical solutions provided in some embodiments of this specification include at least the following:

[0020] In one or more embodiments of this specification, the rotation matrix corresponding to the angular velocity data at each moment is first determined by acquiring the head test data of the target test object. Then, the angular velocity data and relative acceleration data are translated to obtain the head centroid acceleration of the target test object. The head centroid acceleration is then corrected based on the gravity factor to obtain the absolute acceleration. Finally, the absolute acceleration is integrated using an integral algorithm to obtain the head motion trajectory of the target test object. By combining the sampled data with the head centroid and gravity factor to convert it into a head motion trajectory curve in a global coordinate system, the requirements of the measurement point coinciding with the head centroid of the target test object and eliminating the influence of gravitational acceleration are met. This achieves a relatively accurate calculation of the head displacement trajectory of the target test object, ensuring the effectiveness and accuracy of the virtual evaluation. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This specification provides a schematic diagram of the system architecture for a method of measuring the head motion trajectory of a test object while the vehicle is in motion, as illustrated in an embodiment of this specification.

[0023] Figure 2 A flowchart illustrating a method for measuring the head movement trajectory of a test subject while the vehicle is in motion, provided in an embodiment of this specification;

[0024] Figure 3 This is a schematic diagram of the structure of a device for measuring the head movement trajectory of a test object during vehicle movement, provided in an embodiment of this specification.

[0025] Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this specification. Detailed Implementation

[0026] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0027] The terms "first," "second," "third," etc., in the description, claims, and accompanying drawings are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such processes, methods, products, or apparatus.

[0028] 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 function and arrangement of the described elements without departing from the scope of this specification. Various processes or components may be appropriately omitted, substituted, or added to the examples. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Furthermore, features described with respect to some examples may be combined into other examples.

[0029] Please see Figure 1 , Figure 1 This document illustrates a system architecture diagram of a method for measuring the head movement trajectory of a test subject while the vehicle is in motion, as provided in an embodiment of this specification.

[0030] like Figure 1 As shown, the system architecture of this method for measuring the head movement trajectory of a test subject while the vehicle is in motion may include at least a terminal 10, a server 20, and a network 30.

[0031] Terminal 10 includes, but is not limited to, electronic devices such as smartphones, desktop computers, tablets, laptops, smart speakers, digital assistants, and smart wearable devices, and may also be software running on the aforementioned electronic devices, such as applications. 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 head motion trajectory measurement services to the user. Terminal 10 can obtain head motion trajectory measurement instructions from the application programming interface and send a head motion trajectory measurement request to server 20.

[0032] Server 20 can provide background services for terminal 10. Based on the head motion trajectory measurement request sent by terminal 10, server 20 will obtain a series of head motion trajectory measurement instructions and transmit the head motion trajectory measurement instructions to other terminals 10 through network 30. Specifically, server 20 can be an independent physical server, 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 communication, middleware services, domain name services, security services, CDN (Content Delivery Network), and big data and artificial intelligence platforms.

[0033] Network 30 is a medium used to provide a communication link between terminal 10 and server 20. Network 30 may include various connection types, such as wired, wireless communication links, or fiber optic cables, etc.

[0034] In addition, it should be noted that, Figure 1 The system shown is merely one example of the system provided in this disclosure. In practical applications, other systems may also be included, such as more terminals.

[0035] In the embodiments described in this specification, the terminal 10 and the server 20 can be directly or indirectly connected through wired or wireless communication, and this disclosure does not impose any restrictions.

[0036] Please refer to the following. Figure 2 , Figure 2 This specification provides an overall flowchart of a method for measuring the head motion trajectory of a test subject while the vehicle is in motion, which can be used in server 20.

[0037] like Figure 2 As shown, the method for measuring the head movement trajectory of a test subject while the vehicle is in motion may include at least the following steps:

[0038] Step 201: Obtain the head test data of the target test object, and determine the rotation matrix corresponding to each moment of the angular velocity data based on the angle change method.

[0039] The head test data includes angular velocity data and relative acceleration data.

[0040] In the embodiments of this specification, when conducting vehicle driving target testing, head test data of the target test object can be collected by using data acquisition devices such as an inertial measurement unit (IMU) worn by the target test object. The head test data may include angular velocity data and relative acceleration data. Optionally, to reduce the impact of noise on the collected data, a low-pass filter can be used to filter the collected angular velocity and relative acceleration data. Next, the initial rotation matrix in the initial state is determined first using the angle change method. Then, the angle change is obtained from the angular velocity data, and the corresponding rotation matrix is ​​constructed based on the angle change. Further, starting from the initial test moment, for each time interval, the rotation matrix of the target at the next moment is obtained by cross-product of the rotation matrix of the previous moment and the angle change at the current moment. Through the above transformation steps, the rotation matrix corresponding to the angular velocity data at each moment can be obtained.

[0041] In one possible implementation, before determining the rotation matrix corresponding to each moment of the angular velocity data based on the angle change method, the method further includes:

[0042] Determine the first sampling frequency corresponding to the angular velocity data and the second sampling frequency corresponding to the relative acceleration data in the head test data;

[0043] The co-occurrence of the first sampling frequency and the second sampling frequency is determined, and the validity of the head test data is determined based on the determination result.

[0044] In the embodiments of this specification, after acquiring the angular velocity and relative acceleration data of the target test object, since the angular velocity and relative acceleration are not acquired simultaneously, the first sampling frequency corresponding to the angular velocity data and the second sampling frequency corresponding to the relative acceleration data in the header test data are first determined by reading the data file time. Optionally, it is first checked whether the first sampling frequency and the second sampling frequency meet the minimum sampling frequency requirement. Next, it is determined whether the first sampling frequency and the second sampling frequency are in sync, that is, whether the sampling frequency and the duration of the data file are consistent. When the determination result indicates that the in sync of the first sampling frequency and the second sampling frequency meets the requirement, the acquired header test data is determined to be valid, and subsequent data processing steps can be performed. When the determination result indicates that the in sync of the first sampling frequency and the second sampling frequency does not meet the requirement, the acquired header test data is determined to be invalid, the data is resampled and re-evaluated, and subsequent data processing steps are not performed.

[0045] In one possible implementation, determining the rotation matrix corresponding to each moment of angular velocity data based on the angle change method includes:

[0046] Integrate the angular velocity data of the target test object at each time step to obtain the change in angle at each time step;

[0047] The angle change at each time moment is transformed using the angle matrix cross product method to obtain the rotation matrix at each time moment.

[0048] In the embodiments of this specification, after obtaining the angular velocity data of the target test object, the angular velocity data of the target test object at each time step can be integrated to obtain the angle change at each time step. Then, the angle change at each time step is transformed using the angle matrix cross product method. The format of the rotation matrix can be set as follows:

[0049]

[0050] Where α, β, and γ represent the yaw, pitch, and roll angles of the target test object at the corresponding time points, respectively. When calculating the rotation matrix for the next time point, the rotation matrix of the previous time point can be cross-multiplied by the corresponding change in angle. Through these transformation steps, the rotation matrices for each time point can be obtained.

[0051] Step 202: Based on the point overlap, translate the angular velocity data and relative acceleration data to obtain the head center of mass acceleration of the target test object.

[0052] The point overlap degree refers to the degree of overlap between the measurement points of the head test data and the centroid of the head of the target test object.

[0053] In the embodiments of this specification, the installation position of the acquisition sensor on the head of the target test object, i.e., the measurement point position, can be determined first. Then, the position of the centroid of the target test object's head can be determined through a geometric model or biometric data. Next, the distance between the measurement point and the centroid of the head can be calculated to obtain the degree of overlap between the two. If the point overlap indicates that the two points are exactly aligned, no translation processing is required. If the obtained degree of overlap indicates that the two points are not aligned, it is necessary to first calculate the difference in coordinates between the two points, and then combine the relative acceleration corresponding to the measurement point with the angular velocity data and the coordinate difference to perform a translation in the global coordinate system to obtain the centroid acceleration of the target test object's head.

[0054] In one possible implementation, the step of translating the angular velocity data and relative acceleration data based on the point overlap to obtain the head center of mass acceleration of the target test object includes:

[0055] The degree of overlap between the measurement points of the head test data and the centroid of the head of the target test object is determined based on the coordinate calculation method.

[0056] Based on the degree of overlap, the angular velocity data and relative acceleration data are processed by relative point translation to obtain the head center of mass acceleration of the target test object.

[0057] In the embodiments of this specification, the installation position coordinates of the acquisition sensor on the head of the target test object are first determined, i.e., the measurement point position coordinates. Then, the center of mass position coordinates of the target test object's head are determined through a geometric model or biometric data. Based on the coordinate calculation method, the degree of coincidence between the measurement point and the head's center of mass is determined using the measurement point position coordinates and the center of mass position coordinates. Furthermore, the head center of mass acceleration of the target test object = relative acceleration at the measurement point + ω 2 R, where ω is the angular velocity, and R is the vector from the measurement point to the center of mass. The specific calculation method is as follows:

[0058]

[0059] Where a COG_x a COG_y a COG_z These are the accelerations in the X, Y, and Z directions at the center of mass, respectively; a x a y a z These represent the accelerations in the X, Y, and Z directions measured at the measurement point, respectively; ω x ω y ω z Δx, Δy, and Δz are the angular velocities of rotation about the X, Y, and Z axes, respectively; Δx, Δy, and Δz are the differences in the X, Y, and Z coordinates between the point where the acceleration is measured and the center of mass, respectively.

[0060] Step 203: Correct the acceleration of the head's center of mass based on the gravity factor and the rotation matrix at each time point to obtain the absolute acceleration.

[0061] In the embodiments described in this specification, in order to eliminate the influence of gravitational acceleration, it is necessary to ensure that the acceleration measurement does not include a component caused by Earth's gravity. Optionally, the gravitational acceleration component is first separated from the center-of-mass acceleration using a gravity factor, and the head's center-of-mass acceleration is corrected for gravity separation. Then, the corrected acceleration is subjected to coordinate transformation using the obtained rotation matrices at each time point to obtain the absolute acceleration.

[0062] In one possible implementation, the step of correcting the acceleration of the head's center of mass based on the gravity factor and the rotation matrix at each of the stated times to obtain the absolute acceleration includes:

[0063] The head's center of mass acceleration is corrected based on the gravity factor to obtain the corrected acceleration;

[0064] Based on the rotation matrix at each time point, the corrected acceleration is transformed to obtain the absolute acceleration in the global coordinate system.

[0065] In the embodiments of this specification, the tilt angle of the target test object's head center of mass can first be determined based on the gravity factor, which may include the pitch angle and roll angle of the head center of mass. Then, the head center of mass acceleration is corrected using this tilt angle to obtain the corrected acceleration. Furthermore, by calling Python's scipy library functions and inputting the corrected acceleration and the corresponding rotation matrix at each moment, the coordinate transformation of the corrected acceleration can be directly performed to obtain the absolute acceleration in the global coordinate system.

[0066] In one possible implementation, the step of correcting the acceleration of the head's center of mass based on the gravity factor to obtain the corrected acceleration includes:

[0067] The tilt angle of the head center of mass of the target test object relative to the direction of gravity is obtained, and the gravitational acceleration component corresponding to the tilt angle is determined based on the gravity factor.

[0068] The acceleration of the head's center of mass is corrected by gravity separation based on the gravitational acceleration component to obtain the corrected acceleration.

[0069] In the embodiments of this specification, when correcting the head center-of-gravity acceleration using a gravity factor, the tilt angles, such as pitch and roll angles, of the target test subject's head center-of-gravity relative to the direction of gravity can be determined first. Then, the gravity acceleration component corresponding to the tilt angle is determined using the gravity factor g. Next, the head center-of-gravity acceleration is corrected by gravity separation using the gravity acceleration component to obtain the corrected acceleration.

[0070] The specific formula for calculating the corrected acceleration is as follows:

[0071]

[0072] Where a ′ x a ′ y a ′ z This is the corrected acceleration after acceleration correction. These are the three elements of the third row of the rotation matrix at the current moment; These are the three elements of the third row of the rotation matrix at the initial moment. It describes the z-axis component in the x-axis direction after rotation; It describes the z-axis component in the y-axis direction after rotation; This describes the component of the z-axis in the z-axis direction after rotation, because when the z-axis itself rotates, its component remains unchanged in the z-axis direction, usually close to 1.

[0073] Step 204: Perform integral calculation on the absolute acceleration based on the integral algorithm, and integrate the integral calculation results to obtain the head motion trajectory of the target test object.

[0074] In the embodiments of this specification, after obtaining the absolute acceleration of the target object to be measured, the absolute acceleration can be integrated twice using an integration algorithm. The specific calculation method is as follows:

[0075] v1 = v0 + dv

[0076] s1 = s0 + (v + 0.5dv)dt

[0077] Where v0 is the velocity at the previous moment, v1 is the velocity at the next moment, and dv is the change in velocity; s0 is the displacement at the previous moment, s1 is the displacement at the next moment, and ds is the change in displacement. By integrating twice, a list of absolute displacements in the X, Y, and Z directions can be obtained. Furthermore, by marking the coordinate system points on the absolute displacements at all moments, the head movement trajectory of the target test object can be obtained.

[0078] In one possible implementation, the step of integrating the absolute acceleration using an integral algorithm and integrating the integration results to obtain the head motion trajectory of the target test object includes:

[0079] The absolute acceleration is integrally calculated using the trapezoidal integral algorithm to obtain velocity data.

[0080] The velocity data is integrated to obtain displacement data at each moment in the global coordinate system;

[0081] The displacement coordinates of the displacement data at each time point are integrated to obtain the head movement trajectory of the target test object.

[0082] In the embodiments of this specification, absolute acceleration data can first be converted into velocity data using a trapezoidal integral algorithm. An integration time interval, the same as the sampling interval for the acceleration data, can be set. Then, trapezoidal integral operations are performed on the acceleration data at each time interval to obtain velocity data. Next, velocity integration is performed on the velocity data to obtain the displacement data of the target test object's head in the global coordinate system. Finally, the displacement data obtained at each moment are integrated according to the time sequence to obtain the head motion trajectory of the target test object.

[0083] The foregoing has described specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired result. In some embodiments, multitasking and parallel processing are possible or may be advantageous.

[0084] Please refer to the following. Figure 3 , Figure 3 This diagram illustrates the structure of a device for measuring the head movement trajectory of a test subject during vehicle movement, as provided in an embodiment of this specification. It should be noted that... Figure 3 The head motion trajectory measuring device of the test object during vehicle movement shown is used to perform the functions described in this application. Figure 2 The methods shown in the embodiments are for illustrative purposes only, illustrating the parts relevant to the embodiments of this application. For specific technical details not disclosed, please refer to this application. Figure 2 The example shown.

[0085] like Figure 3 As shown, the device for measuring the head movement trajectory of the test subject during vehicle movement may include at least:

[0086] The acquisition module 301 is used to acquire the head test data of the target test object and determine the rotation matrix corresponding to each moment of the angular velocity data based on the angle change method. The head test data includes angular velocity data and relative acceleration data.

[0087] Translation module 302 is used to translate the angular velocity data and relative acceleration data based on the point coincidence degree to obtain the head center of mass acceleration of the target test object. The point coincidence degree is the degree of coincidence between the measurement point of the head test data and the head center of mass of the target test object.

[0088] Correction module 303 is used to correct the acceleration of the head's center of mass based on the gravity factor and the rotation matrix at each time moment to obtain the absolute acceleration;

[0089] The integration module 304 is used to perform integration calculation on the absolute acceleration based on the integration algorithm, and integrate the integration calculation results to obtain the head motion trajectory of the target test object.

[0090] In one possible implementation, the acquisition module 301 is specifically used for:

[0091] Determine the first sampling frequency corresponding to the angular velocity data and the second sampling frequency corresponding to the relative acceleration data in the head test data;

[0092] The co-occurrence of the first sampling frequency and the second sampling frequency is determined, and the validity of the head test data is determined based on the determination result.

[0093] In one possible implementation, the acquisition module 301 is further configured to:

[0094] Integrate the angular velocity data of the target test object at each time step to obtain the change in angle at each time step;

[0095] The angle change at each time moment is transformed using the angle matrix cross product method to obtain the rotation matrix at each time moment.

[0096] In one possible implementation, the translation module 302 is specifically used for:

[0097] The degree of overlap between the measurement points of the head test data and the centroid of the head of the target test object is determined based on the coordinate calculation method.

[0098] Based on the degree of overlap, the angular velocity data and relative acceleration data are processed by relative point translation to obtain the head center of mass acceleration of the target test object.

[0099] In one possible implementation, the correction module 303 is specifically used for:

[0100] The head's center of mass acceleration is corrected based on the gravity factor to obtain the corrected acceleration;

[0101] Based on the rotation matrix at each time point, the corrected acceleration is transformed to obtain the absolute acceleration in the global coordinate system.

[0102] In one possible implementation, the correction module 303 is further configured to:

[0103] The tilt angle of the head center of mass of the target test object relative to the direction of gravity is obtained, and the gravitational acceleration component corresponding to the tilt angle is determined based on the gravity factor.

[0104] The acceleration of the head's center of mass is corrected by gravity separation based on the gravitational acceleration component to obtain the corrected acceleration.

[0105] In one possible implementation, the integration module 304 is specifically used for:

[0106] The absolute acceleration is integrally calculated using the trapezoidal integral algorithm to obtain velocity data.

[0107] The velocity data is integrated to obtain displacement data at each moment in the global coordinate system;

[0108] The displacement coordinates of the displacement data at each time point are integrated to obtain the head movement trajectory of the target test object.

[0109] Those skilled in the art will clearly understand that the technical solutions of the embodiments of this application can be implemented by means of software and / or hardware. In this specification, "unit" and "module" refer to software and / or hardware capable of independently completing or cooperating with other components to complete a specific function, wherein the hardware may be, for example, a Field-Programmable Gate Array (FPGA), an Integrated Circuit (IC), etc.

[0110] Each processing unit and / or module in the embodiments of this application can be implemented by an analog circuit that implements the functions described in the embodiments of this application, or by software that executes the functions described in the embodiments of this application.

[0111] Please refer to the following. Figure 4 , Figure 4 A schematic diagram of the structure of an electronic device provided in an embodiment of this specification is shown.

[0112] like Figure 4 As shown, the electronic device 400 may include: at least one device processor 401, at least one network interface 404, user interface 403, memory 405, and at least one communication bus 402.

[0113] The communication bus 402 can be used to realize the connection and communication of the above components.

[0114] The user interface 403 may include buttons, and the optional user interface may also include a standard wired interface or a wireless interface.

[0115] Among them, network interface 404 may include, but is not limited to, Bluetooth module, NFC module, Wi-Fi module, etc.

[0116] The device processor 401 may include one or more processing cores. The device processor 401 connects to various parts within the electronic device 400 using various interfaces and lines. It 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 by calling data stored in the memory 405. Optionally, the device processor 401 may be implemented using at least one hardware form of DSP, FPGA, or PLA. The device processor 401 may integrate one or more of the following: CPU, GPU, and modem. The CPU primarily handles the operating system, user interface, and applications; the GPU is responsible for rendering and drawing the content required for display; and the modem handles wireless communication. It is understood that the modem may also not be integrated into the device processor 401 and may be implemented as a separate chip.

[0117] The memory 405 may include RAM or ROM. Optionally, the memory 405 may include a non-transitory computer-readable medium. The memory 405 may be used to store instructions, programs, code, 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 touch function, sound playback function, image playback function, etc.), instructions for implementing the above-described method embodiments, etc.; the data storage area may store data involved in the above-described method embodiments, etc. Optionally, the memory 405 may also be at least one storage device located remotely from the aforementioned device processor 401. Figure 4 As shown, the memory 405, which serves as a computer storage medium, may include an operating system, a network communication module, a user interface module, and program instructions.

[0118] Specifically, the device processor 401 can be used to call the application for measuring the head motion trajectory of a test object while the vehicle is in motion, stored in the memory 405, and specifically perform the following operations:

[0119] The head test data of the target test object is obtained, and the rotation matrix corresponding to each moment of the angular velocity data is determined based on the angle change method. The head test data includes angular velocity data and relative acceleration data.

[0120] The angular velocity data and relative acceleration data are translated based on the point overlap to obtain the head center of mass acceleration of the target test object. The point overlap is the degree of overlap between the measurement point of the head test data and the head center of mass of the target test object.

[0121] The acceleration of the head's center of mass is corrected based on the gravity factor and the rotation matrix at each time point to obtain the absolute acceleration.

[0122] The absolute acceleration is integrated using an integral algorithm, and the integration results are combined to obtain the head motion trajectory of the target test object.

[0123] As an optional embodiment of this specification, before determining the rotation matrix corresponding to each moment of the angular velocity data based on the angle change method, the method further includes:

[0124] Determine the first sampling frequency corresponding to the angular velocity data and the second sampling frequency corresponding to the relative acceleration data in the head test data;

[0125] The co-occurrence of the first sampling frequency and the second sampling frequency is determined, and the validity of the head test data is determined based on the determination result.

[0126] As an optional embodiment of this specification, the step of determining the rotation matrix corresponding to each moment of angular velocity data based on the angle change method includes:

[0127] Integrate the angular velocity data of the target test object at each time step to obtain the change in angle at each time step;

[0128] The angle change at each time moment is transformed using the angle matrix cross product method to obtain the rotation matrix at each time moment.

[0129] As an optional embodiment of this specification, the step of translating the angular velocity data and relative acceleration data based on the point overlap to obtain the head center of mass acceleration of the target test object includes:

[0130] The degree of overlap between the measurement points of the head test data and the centroid of the head of the target test object is determined based on the coordinate calculation method.

[0131] Based on the degree of overlap, the angular velocity data and relative acceleration data are processed by relative point translation to obtain the head center of mass acceleration of the target test object.

[0132] As an optional embodiment of this specification, the step of correcting the acceleration of the head's center of mass based on the gravity factor and the rotation matrix at each time moment to obtain the absolute acceleration includes:

[0133] The head's center of mass acceleration is corrected based on the gravity factor to obtain the corrected acceleration;

[0134] Based on the rotation matrix at each time point, the corrected acceleration is transformed to obtain the absolute acceleration in the global coordinate system.

[0135] As an optional embodiment of this specification, the step of correcting the acceleration of the head's center of mass based on the gravity factor to obtain the corrected acceleration includes:

[0136] The tilt angle of the head center of mass of the target test object relative to the direction of gravity is obtained, and the gravitational acceleration component corresponding to the tilt angle is determined based on the gravity factor.

[0137] The acceleration of the head's center of mass is corrected by gravity separation based on the gravitational acceleration component to obtain the corrected acceleration.

[0138] As an optional embodiment of this specification, the step of integrating the absolute acceleration based on an integral algorithm and integrating the integration results to obtain the head motion trajectory of the target test object includes:

[0139] The absolute acceleration is integrally calculated using the trapezoidal integral algorithm to obtain velocity data.

[0140] The velocity data is integrated to obtain displacement data at each moment in the global coordinate system;

[0141] The displacement coordinates of the displacement data at each time point are integrated to obtain the head movement trajectory of the target test object.

[0142] This specification also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described method. The computer-readable storage medium may include, but is not limited to, any type of disk, including floppy disks, optical disks, DVDs, CD-ROMs, microdrives, as well as magneto-optical disks, ROMs, RAMs, EPROMs, EEPROMs, DRAMs, VRAMs, flash memory devices, magnetic cards or optical cards, nanosystems (including molecular memory ICs), or any type of medium or device suitable for storing instructions and / or data.

[0143] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0144] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0145] In the several embodiments provided in this application, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some service interface; the indirect coupling or communication connection between devices or units may be electrical or other forms.

[0146] The units described as separate components may or may not be physically separate. 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 the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0147] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0148] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage device (CMD). Based on this understanding, the technical solution of this application, in essence, 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. This computer software product is stored in a memory and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned memory includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0149] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, which may include: a flash drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, etc.

[0150] The foregoing has described specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired result. In some embodiments, multitasking and parallel processing are possible or may be advantageous.

Claims

1. A method for measuring the head movement trajectory of a test subject while a vehicle is in motion, characterized in that, The method includes: The head test data of the target test object is obtained, and the rotation matrix corresponding to each moment of the angular velocity data is determined based on the angle change method. The head test data includes angular velocity data and relative acceleration data. The angular velocity data and relative acceleration data are translated based on the point overlap to obtain the head center of mass acceleration of the target test object. The point overlap is the degree of overlap between the measurement point of the head test data and the head center of mass of the target test object. The acceleration of the head's center of mass is corrected based on the gravity factor and the rotation matrix at each time point to obtain the absolute acceleration. The absolute acceleration is integrated using an integral algorithm, and the integration results are combined to obtain the head motion trajectory of the target test object. The method for determining the rotation matrix corresponding to each moment of angular velocity data based on the angle change method includes: Integrate the angular velocity data of the target test object at each time step to obtain the change in angle at each time step; The angle change at each time moment is transformed by the angle matrix cross product method to obtain the rotation matrix at each time moment. The angle matrix cross product method is used to represent the cross product of the rotation matrix at the previous time moment with the angle change at the next time moment to obtain the rotation matrix at the next time moment. The process of translating the angular velocity data and relative acceleration data based on the point overlap to obtain the head center of mass acceleration of the target test object includes: The degree of overlap between the measurement points of the head test data and the centroid of the head of the target test object is determined based on the coordinate calculation method. Based on the overlap ratio, the angular velocity data and relative acceleration data are processed by relative point translation to obtain the head center-of-mass acceleration of the target test object. The head center-of-mass acceleration of the target test object = relative acceleration at the measurement point + , where ω is the angular velocity and R is the vector from the measurement point to the center of mass; The process of correcting the acceleration of the head's center of mass based on the gravity factor and the rotation matrix at each moment to obtain the absolute acceleration includes: The tilt angle of the head center of mass of the target test object relative to the direction of gravity is obtained, and the gravitational acceleration component corresponding to the tilt angle is determined based on the gravity factor. The tilt angle is the attitude angle of the head center of mass of the target test object relative to the direction of gravity, including pitch angle and roll angle. The gravitational acceleration component is used to characterize the projection values ​​of gravitational acceleration in the X, Y and Z directions of the measurement coordinate system under the tilt angle state. Based on the gravitational acceleration components, the acceleration of the head's center of mass is corrected by gravity separation to obtain the corrected acceleration; Based on the rotation matrix at each time point, the corrected acceleration is transformed to obtain the absolute acceleration in the global coordinate system.

2. The method according to claim 1, characterized in that, Before determining the rotation matrix at each moment corresponding to the angular velocity data based on the angle change method, the method further includes: Determine the first sampling frequency corresponding to the angular velocity data and the second sampling frequency corresponding to the relative acceleration data in the head test data; The co-occurrence of the first sampling frequency and the second sampling frequency is determined, and the validity of the head test data is determined based on the determination result.

3. The method according to claim 1, characterized in that, The step of integrating the absolute acceleration using an integral algorithm and integrating the results to obtain the head motion trajectory of the target test object includes: The absolute acceleration is integrally calculated using the trapezoidal integral algorithm to obtain velocity data. The velocity data is integrated to obtain displacement data at each moment in the global coordinate system; The displacement coordinates of the displacement data at each time point are integrated to obtain the head movement trajectory of the target test object.

4. A device for measuring the trajectory of a test subject's head movement during vehicle operation, characterized in that, The device includes: The acquisition module is used to acquire the head test data of the target test object and determine the rotation matrix corresponding to each moment of the angular velocity data based on the angle change method. The head test data includes angular velocity data and relative acceleration data. The translation module is used to translate the angular velocity data and relative acceleration data based on the point coincidence degree to obtain the head center of mass acceleration of the target test object. The point coincidence degree is the degree of coincidence between the measurement point of the head test data and the head center of mass of the target test object. The correction module is used to correct the acceleration of the head's center of mass based on the gravity factor and the rotation matrix at each time point to obtain the absolute acceleration. An integration module is used to perform integration calculations on the absolute acceleration based on an integration algorithm, and integrate the integration results to obtain the head motion trajectory of the target test object. The acquisition module is specifically used for: Integrate the angular velocity data of the target test object at each time step to obtain the change in angle at each time step; The angle change at each time moment is transformed by the angle matrix cross product method to obtain the rotation matrix at each time moment. The angle matrix cross product method is used to represent the cross product of the rotation matrix at the previous time moment with the angle change at the next time moment to obtain the rotation matrix at the next time moment. The translation module is specifically used for: The degree of overlap between the measurement points of the head test data and the centroid of the head of the target test object is determined based on the coordinate calculation method. Based on the overlap ratio, the angular velocity data and relative acceleration data are processed by relative point translation to obtain the head center-of-mass acceleration of the target test object. The head center-of-mass acceleration of the target test object = relative acceleration at the measurement point + , where ω is the angular velocity and R is the vector from the measurement point to the center of mass; The correction module is specifically used for: The tilt angle of the head center of mass of the target test object relative to the direction of gravity is obtained, and the gravitational acceleration component corresponding to the tilt angle is determined based on the gravity factor. The tilt angle is the attitude angle of the head center of mass of the target test object relative to the direction of gravity, including pitch angle and roll angle. The gravitational acceleration component is used to characterize the projection values ​​of gravitational acceleration in the X, Y and Z directions of the measurement coordinate system under the tilt angle state. Based on the gravitational acceleration components, the acceleration of the head's center of mass is corrected by gravity separation to obtain the corrected acceleration; Based on the rotation matrix at each time point, the corrected acceleration is transformed to obtain the absolute acceleration in the global coordinate system.

5. 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, it implements the steps of the method as described in any one of claims 1-3.

6. A computer-readable storage medium having a computer program stored thereon, the computer-readable storage medium storing instructions that, when executed on a computer or processor, cause the computer or processor to perform the steps of the method as claimed in any one of claims 1-3.

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