A method for frontal 25% offset collision slide test based on dummy displacement

Abstract

This invention relates to the field of simulated collision testing technology, specifically to a method for a 25% offset frontal collision sliding table test based on dummy displacement. The method includes: S1, acquiring acceleration change data of the entire vehicle body and the dummy during a 25% offset frontal collision test; S2, determining the acceleration waveform of the sliding table test based on the X-axis acceleration change data acquired in S1; and S3, determining the body-in-white deflection angle of the sliding table test based on the dummy acceleration change data acquired in S1. This invention provides a standardized sliding table test parameter setting process for sliding table collision tests. The set sliding table test parameters are closer to those of a real vehicle collision test, and there is no need for video analysis of the real vehicle collision process. This reduces computational load and ensures high data repeatability.

Description

Technical Field

[0001] This invention relates to the field of simulated collision testing technology, specifically to a frontal 25% offset collision slide test method based on dummy displacement. Background Technology

[0002] In traffic accidents, frontal collisions account for approximately 40% of all accidents, with offset collisions (small overlap) accounting for up to 25% of these and causing significant injuries to occupants, making them high-incidence and high-risk accidents. Research on this type of accident can effectively improve occupant safety and reduce automakers' R&D costs and shorten development cycles. Therefore, the 25% offset frontal collision test has become a focus of attention for the industry and consumers. During a collision, the seat belts, car seats, airbags, and other components of the vehicle's restraint system have a significant impact on occupant movement and injury. However, real-vehicle crash tests are costly and time-consuming, causing many inconveniences for system optimization. Automakers increasingly use sliding platform simulated crash tests to achieve low-cost and short-time crash test results.

[0003] However, existing slide-table simulated crash tests still have shortcomings: in real vehicle crash tests, the vehicle body will deflect at a large angle around the Z-axis, while the slide can only achieve single-degree-of-freedom motion. Therefore, traditional slide-table simulation test schemes cannot accurately reproduce the real vehicle crash situation. It is necessary to input acceleration waveforms into the slide to simulate the actual acceleration process of the vehicle, and simultaneously set corresponding deflection angles between the body-in-white and the collision direction of the slide to simulate the lateral impact effect experienced by the dummy during the actual collision. Currently, there is no unified and effective implementation plan for adjusting the acceleration waveforms and the body-in-white deflection angles. If the adjustment method is inappropriate, it will lead to a significant difference between the injury results of the simulated crash test and the occupant injury results in the real vehicle crash test. Summary of the Invention

[0004] This invention provides a frontal 25% offset collision slide test method based on dummy displacement, which can provide a standardized slide test parameter setting process for slide collision tests. The set slide test parameters are closer to those of real vehicle collision tests. At the same time, there is no need to perform video analysis of the real vehicle collision process, the amount of calculation is small, and the data repeatability is high.

[0005] This application provides the following technical solution:

[0006] A method for a frontal 25% offset collision slide test based on dummy displacement includes the following steps:

[0007] S1. Collect acceleration change data of the vehicle body and dummy in a 25% offset frontal collision test of a real vehicle;

[0008] S2. Determine the acceleration waveform of the slide test based on the X-axis acceleration change data obtained in S1;

[0009] S3. Determine the body-in-white deflection angle for the slide test based on the dummy acceleration change data obtained in S1.

[0010] Technical principle: Based on the actual vehicle's acceleration curve and the acceleration data of the dummy's chest in the driver's position, the acceleration change curve of the dummy's chest is obtained by double integration. The part from zero displacement to maximum displacement in the displacement trajectory curve is extracted and linear regression fitting is performed. The vehicle's deflection angle is solved by the coefficients of the obtained linear regression function. The X-axis acceleration curve of the vehicle body corresponding to the dummy's chest position is used as the acceleration waveform of the slide test, and the solved offset angle is used as the deflection angle of the white body in the slide test.

[0011] Beneficial effects: In the experimental waveform selection method, this scheme directly collects the acceleration at the base plate corresponding to the chest position of the dummy in the real vehicle, and obtains the real acceleration experienced by the dummy in the vehicle coordinate system; In the deflection angle selection method, this scheme obtains the deflection angle based on the dummy's displacement data, pays more attention to the dummy's movement relative to the vehicle body, and can better simulate the real vehicle collision situation.

[0012] This solution requires no video analysis, is simple to calculate, and has good repeatability.

[0013] Furthermore, S1 includes:

[0014] S11. Attach the first set of acceleration sensors to the lower edge of the B-pillars on both sides of the vehicle body:

[0015] S12. Attach a second set of acceleration sensors to the chest area of ​​the dummy; attach a third set of acceleration sensors to the vertical projection of the base plate at the chest area of ​​the dummy.

[0016] S13. Conduct a 25% offset frontal crash test on a real vehicle and collect data.

[0017] Furthermore, in step S2, the X-axis acceleration curve collected by the third set of acceleration sensors in step S13 is used as the acceleration waveform of the slide test.

[0018] Furthermore, S3 includes:

[0019] S31. Calculate the displacement of the dummy's chest in the X and Y directions;

[0020] S32. Draw the motion trajectory curve of the dummy's chest relative to the vehicle body;

[0021] S33. Perform linear regression fitting based on the motion trajectory curve;

[0022] S34. Solve for the initial deflection angle of the slide test based on the linear regression function determined in S33.

[0023] Furthermore, in step S31, the X-axis acceleration curves collected by the third set of acceleration sensors are integrated twice over time to obtain the X-axis displacement S of the front test seat reference point. xref The X-axis acceleration curves acquired by the second set of accelerometers are integrated twice over time to obtain the X-axis displacement S of the dummy's chest. xchest Calculate S xchest and S xref The difference was used to obtain the X-direction displacement ΔS of the dummy's chest. x ;

[0024] The Y-axis acceleration curves collected by the third set of acceleration sensors are integrated twice over time to obtain the Y-axis displacement S of the front test seat reference point. yref The Y-axis acceleration curves collected by the second set of accelerometers are integrated twice over time to obtain the Y-axis displacement S of the dummy's chest. ychest Calculate S ychest and S yref The difference was used to obtain the Y-direction displacement ΔS of the dummy's chest. y .

[0025] Furthermore, step S33 extracts the motion trajectory curve of the dummy in the X direction from the start of displacement to the maximum displacement, and constructs a linear regression function reflecting the dummy's collision motion response from the extracted portion of the curve. The expression is as follows:

[0026] Y chest =a*x chest +b chest

[0027] Among them, Y chest Let x be the displacement of the dummy in the Y direction, a be the coefficient of the regression function, and x be the displacement of the dummy in the Y direction. chest Let b be the displacement of the dummy in the X direction. chest The intercept of the regression function is denoted as .

[0028] Further: In step S34, the initial deflection angle θ for the frontal 25% offset collision slide test is obtained using inverse trigonometric functions, as shown in the following formula:

[0029] θ = arctan(a)

[0030] Where θ is the initial deflection angle of the collision slide test section, and a is the slope of the regression function constructed by S33. Attached Figure Description

[0031] Figure 1 This is a schematic diagram showing the location of the sensor on the dummy's chest corresponding to the chassis position during a crash test.

[0032] Figure 2 This is a schematic diagram of the trajectory of the dummy's chest relative to the vehicle body. Detailed Implementation

[0033] The following detailed description illustrates the specific implementation method:

[0034] Example 1

[0035] A method for a frontal 25% offset collision slide test based on dummy displacement includes the following steps:

[0036] S1. Collect acceleration change data of the entire vehicle body and the dummy during a 25% offset frontal crash test, including:

[0037] S11. Attach the first set of acceleration sensors to the lower edge of the B-pillars on both sides of the vehicle body:

[0038] The data collected by the first set of acceleration sensors reflects the overall acceleration changes of the vehicle body during the test. The acceleration sensors simultaneously collect acceleration data in three directions.

[0039] S12. Attach a second set of acceleration sensors to the chest area of ​​the dummy; attach a third set of acceleration sensors to the vertical projection of the base plate at the chest area of ​​the dummy.

[0040] In the 25% offset frontal crash test, the dummy's chest is significantly affected by the restraint system during the impact and, being located in the center of the dummy's body, its trajectory better represents the dummy's motion trend. To obtain the dummy's actual acceleration in the vehicle coordinate system, a second set of acceleration sensors was attached to the dummy's chest, serving as the basis for calculating the dummy's chest trajectory. Figure 1 As shown.

[0041] When a collision occurs, the dummy's chest displaces relative to the seat. Therefore, a third set of acceleration sensors is attached to the vertical projection of the dummy's chest onto the floor to collect acceleration data at the vehicle's floor, serving as the basis for calculating the vehicle seat's trajectory. The acceleration sensors can simultaneously collect acceleration change data in three directions.

[0042] S13. Conduct a 25% offset frontal crash test on a real vehicle and collect data.

[0043] S2. Determine the acceleration waveform of the slide test based on the dummy's X-axis acceleration change data obtained in S1.

[0044] The X-axis acceleration curve collected by the third set of acceleration sensors in S13 is used as the acceleration waveform for the slide test. Compared with the traditional method, this method directly obtains the real acceleration experienced by the dummy in the vehicle coordinate system and selects it as the test waveform, which is closer to the test data of real vehicle collision.

[0045] S3. Determine the body-in-white deflection angle for the slide test based on the dummy acceleration change data obtained in S1.

[0046] The chest, located in the center of the human body, is significantly restrained during a collision, and its motion trend can be representative of the overall motion trend of the human body. Therefore, a motion trajectory curve of the dummy's chest relative to the vehicle body is constructed. This trajectory curve can intuitively reflect the dummy's motion trend relative to the vehicle body in a 25% offset frontal collision. Furthermore, based on this trajectory curve, a suitable vehicle body deflection angle can be sought.

[0047] Specifically, S3 includes the following steps:

[0048] S31. Calculate the displacement of the dummy's chest in the X and Y directions:

[0049] According to the above scheme, the X-axis acceleration curve collected by the third set of acceleration sensors is the X-axis acceleration curve a at the chassis corresponding to the driver's chest. xref The X-direction displacement S of the front test seat reference point is obtained by performing a second integration over time. xref The X-axis acceleration curve collected by the second set of accelerometers is the X-axis acceleration signal a of the dummy's chest. xchest Similarly, by performing a second integral over time, the X-direction displacement S of the dummy's chest is obtained. xchest As shown below:

[0050]

[0051]

[0052] The difference between the two values ​​is calculated to obtain the X-direction displacement ΔS of the dummy's chest. x As shown below:

[0053] ΔS x =S xchest -S xref

[0054] Similarly, the Y-direction displacement ΔS of the dummy's chest is obtained. y As shown below:

[0055]

[0056] ΔS y =S ychest -S yref

[0057] S32. Draw the motion trajectory curve of the dummy's chest relative to the vehicle body:

[0058] Based on the X-direction displacement ΔS of the dummy's chest x Y-direction displacement ΔS of the dummy's chest y Draw the trajectory of the dummy's chest relative to the vehicle body, such as Figure 2 As shown by the blue curve.

[0059] S33. Perform linear regression fitting based on the motion trajectory curve:

[0060] During the dummy's motion response to a collision, the vehicle's speed rapidly decreases upon impact, and the dummy, under inertia, displaces, resulting in a gradually increasing displacement. Once the dummy is restrained by the restraint system, it reaches its maximum displacement, meaning the displacement stops increasing. Therefore, the data segment that truly reflects the dummy's displacement during the collision is the segment from zero displacement to maximum displacement in the X direction. Thus, the motion trajectory curve of the dummy in the X direction from the start of displacement to the maximum displacement is extracted, as shown below. Figure 2 The portion within the blue box is shown.

[0061] Based on the motion trajectory curve captured within the blue box, a linear regression function is constructed that can accurately reflect the motion response of the dummy during the collision process, such as... Figure 2 As shown by the red curve in the middle, its expression is as follows:

[0062] Y chest =a*x chest +b chest

[0063] Among them, Y chest Let x be the displacement of the dummy in the Y direction, a be the coefficient of the regression function, and x be the displacement of the dummy in the Y direction. chest Let b be the displacement of the dummy in the X direction. chest The intercept of the regression function is denoted as .

[0064] S34. Solve for the initial deflection angle of the slide test based on the linear regression function determined in S33:

[0065] Based on the slope 'a' of the established linear regression curve, the initial deflection angle θ for the 25% offset frontal collision slide test is obtained using inverse trigonometric functions, as shown in the following formula:

[0066] θ = arctan(a)

[0067] The above are merely embodiments of the present invention, and the invention is not limited to the fields covered by these embodiments. Commonly known structures and characteristics in the solutions are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A method for a frontal 25% offset collision slide test based on dummy displacement, characterized in that: Includes the following steps: S1. Collect acceleration change data of the vehicle body and dummy in a 25% offset frontal collision test of a real vehicle; S2. Determine the acceleration waveform of the slide test based on the X-axis acceleration change data obtained in S1; S3. Determine the body-in-white deflection angle for the slide test based on the dummy acceleration change data obtained in S1. S1 includes: S11. Attach the first set of acceleration sensors to the lower edge of the B-pillars on both sides of the vehicle body: S12. Attach a second set of acceleration sensors to the chest area of ​​the dummy; attach a third set of acceleration sensors to the vertical projection of the base plate at the chest area of ​​the dummy. S13. Conduct a 25% offset frontal crash test on a real vehicle and collect data; In S2, the X-axis acceleration curve collected by the third set of acceleration sensors in S13 is used as the acceleration waveform of the slide test; S3 includes: S31. Calculate the displacement of the dummy's chest in the X and Y directions; S32. Draw the motion trajectory curve of the dummy's chest relative to the vehicle body; S33. Perform linear regression fitting based on the motion trajectory curve; S34. Solve for the initial deflection angle of the slide test based on the linear regression function determined in S33.

2. The method for a frontal 25% offset collision slide test based on dummy displacement according to claim 1, characterized in that: In step S31, the X-axis acceleration curves collected by the third set of acceleration sensors are integrated twice over time to obtain the X-axis displacement of the test seat reference point. The X-axis displacement of the dummy's chest was obtained by integrating the X-axis acceleration curves collected by the second set of accelerometers over time. ,calculate and The difference was used to obtain the X-axis displacement of the dummy's chest. ; The Y-axis acceleration curves collected by the third set of acceleration sensors are integrated twice over time to obtain the Y-axis displacement of the test seat reference point. The Y-axis displacement of the dummy's chest is obtained by integrating the Y-axis acceleration curves collected by the second set of accelerometers over time. ,calculate and The difference was used to obtain the Y-direction displacement of the dummy's chest. .

3. The method for a frontal 25% offset collision slide test based on dummy displacement according to claim 2, characterized in that: S33 extracts the motion trajectory curve of the dummy in the X direction from the start of displacement to the maximum displacement, and constructs a linear regression function reflecting the dummy's collision motion response from the extracted portion of the curve. The expression is as follows: in ， Let be the displacement of the dummy in the Y direction. The coefficients of the regression function, Let X be the displacement of the dummy in the X direction. The intercept of the regression function is denoted as .

4. The method for a frontal 25% offset collision slide test based on dummy displacement according to claim 3, characterized in that: In step S34, the initial deflection angle of the frontal 25% offset collision slide test is obtained using inverse trigonometric functions. As shown in the following formula: in, The initial deflection angle of the collision slide test section. The slope of the regression function constructed for S33.

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