A dynamic displacement measurement system based on inertial navigation technology in vehicle crash test

Abstract

The application relates to the technical field of vehicle collision test, and discloses a dynamic displacement measurement system based on inertial navigation technology in vehicle collision test, which comprises an inertial measurement unit, a vehicle-mounted recording unit and a ground control unit; the inertial measurement unit comprises a plurality of sub-inertial navigation units; the sub-inertial navigation units are used for collecting basic operation information of to-be-measured points; the vehicle-mounted recording unit comprises a main inertial navigation unit and a collection and storage module; the main inertial navigation unit is used for collecting main body operation information of a vehicle; the collection and storage module is used for storing information data collected by the main inertial navigation unit and the sub-inertial navigation units; the ground control unit comprises a data processing module; the data processing module is used for processing information data of the main inertial navigation unit and the sub-inertial navigation units, calculating dynamic displacement data of the to-be-measured points, and generating corresponding displacement pictures and reports; when processing the information data of the main inertial navigation unit and the sub-inertial navigation units, the data processing module adopts an inertial navigation algorithm to calculate the dynamic displacement data. The application has a simple structure and can accurately and efficiently complete dynamic displacement measurement of the to-be-measured points.

Description

Technical Field

[0001] This invention relates to the field of vehicle crash testing technology, and more specifically to a dynamic displacement measurement system based on inertial navigation technology for vehicle crash testing. Background Technology

[0002] To improve vehicle operational safety, conducting crash simulation tests is essential. By analyzing the obtained test data, improvements can be made to the vehicle structure and restraint systems, thereby enhancing vehicle safety.

[0003] In vehicle crash testing, it is necessary to simulate the collision impact process of the vehicle and the test dummy on the vehicle, and to evaluate the degree of deformation of the test sample during and after the collision. It is also necessary to analyze the measurement aspects such as the amount of movement of characteristic parts of the dummy, dynamic crushing of the steering column, dynamic intrusion of the pedal, and dynamic deformation of key structural components, and then improve the vehicle structure based on the analysis data.

[0004] In the aforementioned measurement aspects, accurate measurement of the dynamic displacement of the target point is crucial. Currently known measurement methods for measuring the dynamic displacement of target points in vehicle crash tests mainly include high-speed photography (image processing) and wire displacement sensors. However, high-speed photography-based image processing methods are often hampered by target point occlusion and the inability to set reference points, making them ineffective in acquiring the target point's dynamic displacement. Furthermore, acquiring three-dimensional dynamic displacement requires deploying multiple calibrated high-speed cameras, and the 3D image processing algorithm is complex, resulting in relatively poor accuracy. Wire displacement sensor-based methods, due to the wire's inherent resistance to external interference, are relatively difficult to implement. Moreover, due to the limitations of the wire measurement principle and mechanical structure, they typically only measure unidirectional displacement, making them suitable only for scenarios where the wire's movement is unaffected and only unidirectional dynamic displacement is a concern. None of these measurement methods can efficiently and conveniently acquire the three-dimensional dynamic displacement of the target point in a crash test, and therefore cannot accurately and efficiently determine the target point's dynamic displacement. Summary of the Invention

[0005] The present invention aims to provide a dynamic displacement measurement system based on inertial navigation technology for vehicle collision testing. The system has a simple structure and can accurately and efficiently complete the dynamic displacement measurement of the test point.

[0006] The basic solution provided by this invention is: a dynamic displacement measurement system based on inertial navigation technology for vehicle collision testing, comprising an inertial measurement unit, an on-board recording unit, and a ground control unit; the inertial measurement unit includes several sub-inertial navigation systems; the sub-inertial navigation systems are used to collect basic operational information of the test point; the on-board recording unit includes a main inertial navigation system and an acquisition and storage module; the main inertial navigation system establishes a communication connection with the sub-inertial navigation systems, and the main inertial navigation system is used to collect the main operational information of the vehicle; the acquisition and storage module is used to store the information data collected by the main inertial navigation system and the sub-inertial navigation systems; the ground control unit includes a data processing module; the data processing module is used to process the information data of the main inertial navigation system and the sub-inertial navigation systems, calculate the dynamic displacement data of the test point, and generate corresponding displacement images and reports; when processing the information data of the main inertial navigation system and the sub-inertial navigation systems, the data processing module uses a series of inertial navigation algorithms to calculate the dynamic displacement data.

[0007] The working principle and advantages of this invention are as follows: By utilizing inertial navigation technology and related algorithms, it solves the problem of being unable to measure the dynamic displacement of the test point in vehicle collision testing due to factors such as obstructed target points, inability to select reference points, and limitations on the placement of wire displacement sensors. The invention, consisting of a main inertial navigation system and a sub-inertial navigation system, has a simple structure and convenient connection. By calculating and analyzing the difference in displacement increments generated by the two systems after a collision, the dynamic displacement of the test point can be accurately analyzed.

[0008] Furthermore, this measurement system uses a series of inertial navigation algorithms to calculate the dynamic displacement of the test point, enabling the calculation of three-dimensional dynamic displacement measurement information. This provides richer, multi-dimensional displacement information, offering better dynamic displacement measurement results compared to existing solutions such as high-speed photography and wire displacement sensors. It is less affected by the collision action itself and high-speed collision scenarios, resulting in more valuable data. It also has fewer requirements for test scenarios and greater system adaptability. In addition, the data collected by the main and sub-inertial navigation systems can communicate via cables, eliminating the need for mechanical connections and enabling electrified measurement. One main inertial navigation system can serve as a reference, connecting to multiple sub-inertial navigation systems, allowing a single device to simultaneously measure the dynamic displacement of multiple test points. This significantly improves the efficiency of dynamic displacement measurement in collision testing, ensuring accurate and efficient measurements. Attached Figure Description

[0009] Figure 1 This is a schematic diagram of a first embodiment of a dynamic displacement measurement system based on inertial navigation technology for vehicle collision testing according to the present invention;

[0010] Figure 2 This is a schematic diagram of the inertial navigation measurement principle of a dynamic displacement measurement system based on inertial navigation technology in vehicle collision testing according to an embodiment of the present invention.

[0011] Figure 3 This is a hardware system block diagram of a dynamic displacement measurement system based on inertial navigation technology for vehicle collision testing according to a first embodiment of the present invention;

[0012] Figure 4 This is a schematic diagram of the right-hand rule for the body coordinate system in a first embodiment of a dynamic displacement measurement system based on inertial navigation technology for vehicle collision testing according to the present invention.

[0013] Figure 5 This is a schematic diagram of the right-hand rule of the world coordinate system in an embodiment of a dynamic displacement measurement system based on inertial navigation technology for vehicle collision testing according to the present invention.

[0014] Figure 6 This is the software interface of the ground control unit in Embodiment 1 of the dynamic displacement measurement system based on inertial navigation technology in vehicle collision testing according to the present invention. Detailed Implementation

[0015] The following detailed explanation illustrates the specific implementation methods:

[0016] Example 1

[0017] The basic implementation examples are as follows: Figure 1 As shown: A dynamic displacement measurement system based on inertial navigation technology for vehicle collision testing includes an inertial measurement unit, an on-board recording unit, a collision T0 sensor, and a ground control unit.

[0018] The inertial measurement unit includes several sub-inertial navigation systems (INS). These sub-INS are used to collect basic operational information of the points to be measured. In this embodiment, four sub-INS are provided, allowing simultaneous measurement of the dynamic displacement of four points. The vehicle-mounted recording unit includes a main INS and a data acquisition and storage module. The main INS establishes a communication connection with the sub-INS, and is used to collect the vehicle's main operational information. The data acquisition and storage module stores the information data collected by the main and sub-INS. The collision T0 sensor is used to detect the zero point of a vehicle collision.

[0019] In this embodiment, as shown in the appendix Figure 3 As shown (attached) Figure 3The symbols and functions in the system are defined in Appendix 1. The vehicle-mounted recording unit also includes a power module, a housing, and connecting cables. The power module, main inertial navigation system, and data acquisition and storage module are all housed inside the housing. The inner wall of the housing is lined with cushioning material to provide support and protection for the internal components. Interfaces and switches are arranged on the surface of the housing. The power module is controlled by the switches, which in turn controls the power supply to the vehicle-mounted recording unit. The interfaces, along with corresponding connecting cables, allow the vehicle-mounted recording unit to connect to the sub-inertial navigation system, ground control unit, and collision T0 sensor. These interfaces include USB and serial communication interfaces. Furthermore, there are two data acquisition and storage modules: a primary module and a secondary module, each with independent USB and serial communication interfaces. These modules serve as backups for each other, ensuring higher data storage security. After the collision test, the data stored in the vehicle-mounted recording unit can be uploaded to a computer via the USB and serial communication interfaces of the primary and secondary modules for backup and analysis.

[0020] Appendix 1 Hardware System Block Diagram Symbol Definitions and Functions

[0021]

[0022]

[0023] The ground control unit includes a data processing module, a test control module, and a user login module. In this embodiment, the ground control unit is located in a host computer, and the ground control unit has a corresponding visual software operation interface. The host computer has operation indicator lights corresponding to the software operation. The data processing module is used to process the information data of the main inertial navigation system and the sub-inertial navigation system, calculate the dynamic displacement data of the test point, and generate corresponding displacement images and reports. When processing the information data of the main inertial navigation system and the sub-inertial navigation system, the data processing module uses a series of inertial navigation algorithms to calculate the dynamic displacement data.

[0024] The series of inertial navigation algorithms includes initial alignment algorithm, navigation integration algorithm, and inertial navigation pre-integration algorithm.

[0025] Specifically, the initial alignment algorithm used in this embodiment is used to determine S. b With S w The initial relative relationship.

[0026] Among them, S b This is the body coordinate system; for any inertial navigation system, its center of mass is the origin; the X-axis moves forward along its longitudinal axis; the Y-axis is perpendicular to its reference plane and upwards; the Z-axis is determined by the right-hand rule, as shown in the appendix. Figure 4 As shown. The body coordinate system corresponding to the main inertial navigation system is denoted as S.b0 The body coordinate system corresponding to the sub-inertial navigation system is denoted as S. b1 ~S b4 The body coordinate system changes accordingly with the motion of the inertial navigation system. w The coordinate system is the world coordinate system; it is determined by the initial state of the vehicle being positioned at the starting point and the main inertial navigation system (INS) being installed; the origin is the center of mass of the INS; the vertical plane containing the parallel lines of the vehicle's longitudinal axis intersects the local horizontal plane of the INS' center of mass, with the X-axis pointing towards the front of the vehicle along this intersection line; the Y-axis is perpendicular to the local horizontal plane and points upwards; the Z-axis is determined by the right-hand rule, as shown in the appendix. Figure 5 As shown. The world coordinate system serves as the absolute reference for the master inertial navigation motion.

[0027] In the initial alignment algorithm, considering the characteristics of the inertial measurement device, accuracy requirements, and estimation time, a gravity-direction-based initial alignment algorithm is adopted. Specifically, the attitude estimation algorithm in the initial alignment algorithm is as follows:

[0028] in,

[0029] Preferably, since the single-point error is relatively large in actual calculations, multiple frames of data can be selected, the average value can be calculated, and then the calculation can be performed.

[0030]

[0031] To reduce the computational cost of summing across multiple frames, a recursive method is used to calculate the mean of each term, i.e.:

[0032]

[0033] While the vehicle is in traction, the data processing module updates the attitude of the main inertial navigation system and the sub-inertial navigation system in real time based on the information data of the main inertial navigation system and the sub-inertial navigation system through the initial alignment algorithm.

[0034] In the navigation integration algorithm used in this embodiment, the discretized form of the inertial navigation motion equation is as follows:

[0035]

[0036] If the sampling frequency remains unchanged, the above equation simplifies to the following equation, and the coordinate representation is omitted:

[0037]

[0038] in, The transformation of the rotation matrix from time t+Δt to time t can be considered as follows:

[0039]

[0040] For rotation matrices, according to the matrix chain multiplication rule, we have:

[0041] Exp(·) is the exponential mapping from the rotation vector to the rotation matrix, i.e., the transformation function from ξ = σa (where a is a unit vector) to C; and C = (cosσ)I + (1 - cosσ)aa T +(sinσ)[a] × ;

[0042] For from S b To S w The rotation matrix, and They are transposes of each other; v w For the inertial navigation center of mass velocity vector in S w The projection; p w The position vector of the inertial navigation centroid in S w The projection; For S b Compared to S w The angular velocity vector in S b The projection is measured by the inertial navigation gyroscope component; f b For the inertial navigation center of mass specific force vector in S b The projection is measured by the inertial accelerometer component.

[0043] Given initial states C0, v0, and p0, the above equation can be used for numerical integration to recursively obtain the motion state C at each time step. k v k p k Rotational attitude angle ψ, γ is obtained by solving some elements of the rotation matrix C using the following inverse equation:

[0044]

[0045] Before the collision, only the attitude matrix (and attitude angle calculation) of the first line of the discrete equations is updated; the velocity and position updates of the second and third lines are not performed. The velocity and position update equations are used in the subsequent inertial navigation pre-integration algorithm.

[0046] The data processing module calculates the displacement increment of the main inertial navigation system after the collision and the displacement increment of the sub-inertial navigation system after the collision using the inertial navigation pre-integration algorithm. The difference between the two yields the relative displacement data. The dynamic displacement data consists of the relative displacement data at each moment after the vehicle collision.

[0047] In this embodiment, the inertial navigation pre-integration algorithm uses the following dynamic displacement calculation formula based on inertial navigation pre-integration:

[0048]

[0049] Where k = i is the instant of collision, and k = j is any instant after the collision;

[0050] Furthermore, in this embodiment, it is assumed that at the moment of collision, the point to be measured does not move relative to the vehicle, then:

[0051] Then we have:

[0052] Among them, according to the discretized navigation update formula (corresponding to equations a and b), C at time k = i i v i p i C at time k=j can be obtained by updating item by item. j v j p j ;

[0053] in,

[0054] The test control module is used for debugging and controlling the main inertial navigation system and the sub-inertial navigation system. Specifically, in this embodiment, the test control module is also used for performing system self-test operations and data operations.

[0055] The system self-test operation includes: sending a self-test command to the onboard recording unit; after receiving the self-test command, the onboard recording unit sends multi-channel MIMU data (the MIMU data here refers to the information data acquired by the inertial navigation system) and power status information to the test control module; and displays the data in the corresponding software interface of the ground control unit in the form of curves and digital quantities, as shown in the attached figure. Figure 6 As shown; if the self-test is successful, the self-test indicator light will be green; if the self-test fails, the self-test indicator light will be red, and a message dialog box will pop up in the software interface, displaying "Self-test failed" and the fault code.

[0056] The data operations include: data erasure, recording start, recording stop, and data reading. Specifically, the data erasure operation involves sending a FLASH erase command to the vehicle-mounted recording unit. After receiving the erase command, the vehicle-mounted recording unit completes FLASH self-test, erasure, and reconstruction operations, and returns the erasure result to the test control module. If erasure is successful, the erase indicator light displays green; if erasure fails, the erase indicator light displays red and a message dialog box pops up, displaying "Erasing failed" and a fault code.

[0057] The recording start operation includes: when the system self-test and data erasure are both successful, the "recording start" operation can be executed; after receiving the corresponding command of the "recording start" operation, the vehicle recording unit sends a handshake command to the ground control unit (specifically the test control module) and writes the MIMU data into the FLASH according to a certain period.

[0058] The recording stop operation includes: after the vehicle collision test is completed, the "recording stop" operation can be executed; the test control module sends a stop recording command to the vehicle recording unit, and after receiving the command, the vehicle recording unit sends a handshake instruction to the test control module and stops writing MIMU data.

[0059] The data reading operation includes: the test control module sending a data reading command to the vehicle-mounted recording unit; upon receiving the command, the vehicle-mounted recording unit sending a handshake instruction to the test control module and transmitting data from its FLASH memory to the test control module at a certain rate. After the data transmission is complete, the test control module displays a message dialog box prompting the user to turn off the power to the vehicle-mounted recording unit.

[0060] The test control module allows for precise control of the data acquisition process, making it convenient and providing a better testing experience.

[0061] The user login module provides a user registration interface and a user login interface. The settings here are basically the same as usual, so they will not be explained in detail.

[0062] In practical applications, the various structural components of the system are first installed as required, and the electrical connections between the components are completed and powered on. Specifically, the main inertial navigation system (INS) and the data acquisition and storage module are both located in vehicle parts that do not participate in collision deformation. In this embodiment, both the main INS and the data acquisition and storage module are rigidly installed at the rear of the vehicle. The sub-INS is located at the test point. In this embodiment, a test dummy is placed in the test vehicle, and the dummy's neck is used as the test point. In this case, the displacement of the sub-INS relative to the main INS represents the displacement of the test point relative to the undeformed position of the vehicle. That is, during a vehicle collision, the test dummy will move relative to the vehicle body due to inertia. The sub-INS will move along with the test dummy's neck, while the main INS moves with the vehicle body, representing the motion of the undeformed parts of the vehicle. At this time, the displacement of the sub-INS relative to the main INS is the dynamic displacement of the dummy's neck relative to the vehicle body coordinate system, as shown in the attached figure. Figure 2 As shown.

[0063] Next, the test control module was used to test whether the inertial navigation measurement functions of the main and sub-inertial navigation systems were normal. The test control module was also used to test the system's power supply function and the data acquisition and storage function of the data acquisition and storage module. After confirming that the system was working properly, the test data generated in the previous tests was cleared from the data acquisition and storage module, and data acquisition and recording began again.

[0064] At the start of the crash test, both the vehicle and the test dummy are stationary relative to the ground. At this point, the initial attitude of the main and sub-inertial navigation systems (INS) is determined using an initial alignment algorithm. The vehicle's movement is then controlled, and it is brought back to a stationary state after the crash test. During this process, while the vehicle is in traction, the data processing module updates the attitude of the main and sub-INS in real time based on the information from the main and sub-INS and using a navigation integration algorithm.

[0065] The moment of impact can be determined based on the external T0 signal from the collision T0 sensor. At the instant of impact, the test dummy, restrained by the seat and seatbelt, has no relative movement to the vehicle; however, relative movement gradually occurs during the collision. After the vehicle returns to a stationary state, data recording stops, and data measured by the main inertial navigation system (INS) and sub-INS are collected and read. The data processing module then analyzes and processes the data, generating corresponding displacement images and reports. The ground control unit is then shut down, thus completing the test. Specifically, during the analysis and processing, the angular velocity and acceleration information measured by the main INS and sub-INS during the collision are collected, and the displacement increments after the collision are calculated using the INS pre-integration algorithm. The difference between the two values ​​yields the required relative displacement, thus obtaining the dynamic displacement of the dummy's neck movement.

[0066] This embodiment provides a dynamic displacement measurement system based on inertial navigation technology for vehicle crash testing. Through inertial navigation technology and related algorithms, it solves the problems encountered in vehicle crash testing where dynamic displacement measurement of the test point is impossible due to target point obstruction, inability to select reference points, and interference from wire displacement sensors, preventing their placement. This measurement system employs a series of inertial navigation algorithms to calculate the three-dimensional dynamic displacement measurement information of the test point. The data measurement is accurate and reliable. Even in crash test scenarios where accurate measurement is impossible using high-speed photography or wire displacement sensors, this system can still provide accurate measurements. It has fewer restrictions on test scenario setup and is convenient for testing. Furthermore, the data collected by the main and sub-inertial navigation systems are communicated via cables, eliminating the need for mechanical connections and achieving electrification of the measurement. One main inertial navigation system can serve as a reference, connecting to multiple sub-inertial navigation systems, allowing a single device to simultaneously measure the dynamic displacement of multiple test points (the system is set to a maximum of four), significantly improving the testing efficiency of dynamic displacement measurement in crash tests.

[0067] Example 2

[0068] A dynamic displacement measurement system based on inertial navigation technology for vehicle collision testing, based on Embodiment 1, further includes a preprocessing module in the ground control unit; the preprocessing module is used to preprocess the information data of the main inertial navigation and sub-inertial navigation acquired; the information data processed by the data processing module is the information data preprocessed by the preprocessing module.

[0069] Specifically, the preprocessing strategy includes the following sub-steps:

[0070] S1: Based on the information data of the main inertial navigation system and the sub-inertial navigation system, determine whether the main inertial navigation system or the sub-inertial navigation system has information data with excessive random fluctuations caused by factors such as environmental noise and the accuracy of inertial devices (i.e., inertial navigation), or information data with initial values ​​exceeding the threshold affecting the solution, and mark the information data that meets the above conditions as abnormal data; when determining whether the main inertial navigation system or the sub-inertial navigation system has information data with excessive random fluctuations, the determination is made by comparing the actual collected data at the same time with the five-point quadratic polynomial smoothed data.

[0071] S2: Handling outlier data in the information data. For outlier data, time series analysis is used to analyze its random errors. First, offsets are removed and mean filtering is performed. Then, the angular velocity data in the information data is filtered using a UKF filter, and the acceleration data is preprocessed using a Kalman filter.

[0072] This embodiment provides a dynamic displacement measurement system based on inertial navigation technology for vehicle collision testing. Compared to Embodiment 1, it specifically preprocesses the information data acquired by the main and sub-inertial navigation systems, effectively eliminating error information and improving the accuracy of subsequent dynamic displacement calculations. It is important to note that this solution specifically considers the states of the main and sub-inertial navigation systems during and after the collision. In actual collision tests, the inertial navigation systems installed at the collision test points may be damaged by the collision and are affected by signal noise generated by the collision, limiting the accuracy of the inertial navigation system's own acquisition. If all data acquired by the inertial navigation system is used as displacement analysis data, it will significantly affect the accuracy of dynamic displacement calculations. This solution, through preprocessing, optimizes the acquired information data, contributing to higher accuracy in subsequent dynamic displacement calculations.

[0073] Example 3

[0074] A dynamic displacement measurement system based on inertial navigation technology for vehicle collision testing, based on Embodiment 1, further includes an optimization module in the ground control unit; the optimization module is used to optimize the sub-inertial navigation system that participates in dynamic displacement calculation when multiple sub-inertial navigation systems are set.

[0075] Specifically, the optimization module performs sub-inertial navigation selection according to an optimization strategy. This strategy includes: confirming whether there is a signal transmission delay in the sub-inertial navigation after a collision, and assigning priorities to the sub-inertial navigation based on the magnitude of the signal transmission delay; the larger the signal transmission delay, the lower the priority of the sub-inertial navigation. The module then selects the displacement data from the top 50% of the sub-inertial navigation with the highest priority for dynamic displacement calculation.

[0076] This embodiment provides a dynamic displacement measurement system based on inertial navigation technology for vehicle collision testing. It can optimize the selection of sub-inertial navigation systems (INS) for dynamic displacement calculation based on signal transmission delay, ensuring that the angular velocity and acceleration data provided by the sub-INS for displacement calculation are real-time and accurate. In actual collision tests, the collision action may cause significant displacement of the sub-INS. The displacement of the structure or the appearance of structural debris caused by the collision may affect the communication between the sub-INS and the main INS, leading to deviations or missing data measurements. In such cases, data measured by the less affected sub-INS is preferred for dynamic displacement calculation, resulting in higher accuracy and more effective calculation.

[0077] The above descriptions are merely embodiments of the present invention. Commonly known structures and characteristics of the solutions are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field prior to the application date or priority date, are aware of all existing technologies in that field, and have the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in combination with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of the present invention. These should also be considered within the scope of protection of the present invention, and will not affect the effectiveness of the implementation of the present invention or the practicality of the patent.

Claims

1. A system for measuring dynamic displacement in a vehicle crash test based on inertial navigation technology, characterized in that, It comprises an inertial measurement unit, a collision T0 sensor, a vehicle-mounted recording unit and a ground control unit; the inertial measurement unit comprises a plurality of sub-inertial navigation units; the sub-inertial navigation units are used to collect basic operation information of the to-be-measured point; the vehicle-mounted recording unit comprises a main inertial navigation unit and a collection and storage module; The main inertial navigation unit is in communication connection with the sub-inertial navigation units, and is used to collect main body operation information of the vehicle; The collection and storage module is used to store information data collected by the main inertial navigation unit and the sub-inertial navigation units; the ground control unit comprises a data processing module; the data processing module is used to process information data of the main inertial navigation unit and the sub-inertial navigation units, and calculate dynamic displacement data of the to-be-measured point, and generate corresponding displacement pictures and reports; when processing information data of the main inertial navigation unit and the sub-inertial navigation units, the data processing module adopts a series of inertial navigation algorithms to calculate the dynamic displacement data; The collision T0 sensor is used to sense a time zero point of vehicle collision; the main inertial navigation unit is arranged at a part of the vehicle which does not participate in collision deformation; the sub-inertial navigation units are arranged at the to-be-measured points; The series of inertial navigation algorithms further comprises an initial alignment algorithm; when the vehicle is in a process of traction travel, the data processing module updates the attitude of the main inertial navigation unit and the sub-inertial navigation units in real time based on information data of the main inertial navigation unit and the sub-inertial navigation units and through the initial alignment algorithm; the initial alignment algorithm is a gravity direction-based initial alignment algorithm; The series of inertial navigation algorithms further comprises an inertial navigation pre-integration algorithm; the data processing module calculates a displacement increment after collision of the main inertial navigation unit and a displacement increment after collision of the sub-inertial navigation units respectively through the inertial navigation pre-integration algorithm, and obtains relative displacement data by subtracting the two; the dynamic displacement data is composed of relative displacement data at each moment after the vehicle collision.

2. The system for measuring dynamic displacement in a vehicle crash test based on inertial navigation technology according to claim 1, wherein, The ground control unit further comprises a test control module; the test control module is used to debug the main inertial navigation unit and the sub-inertial navigation units.

3. A system for measuring dynamic displacement in a vehicle crash test based on inertial navigation technology according to claim 2, wherein, The ground control unit further comprises a user login module; the user login module is used to provide a user registration interface and a user login interface.

4. The system of claim 2, wherein the system further comprises a plurality of accelerometers and a plurality of gyroscopes. The ground control unit further comprises a preprocessing module; the preprocessing module is used to preprocess information data of the main inertial navigation unit and the sub-inertial navigation units collected.

Images