A vehicle collision safety redundancy design method

Abstract

The application provides a vehicle collision safety redundancy design method, comprising the following steps: extracting simulation acceleration a21 of ACU position in a target vehicle simulation model from a whole vehicle simulation analysis model; selecting a reference vehicle type with high similarity to the target vehicle type and extracting acceleration of ACU position in a plurality of existing real vehicle collision data, and finding the closest acceleration to a21, which is named as a31; comparing a21 and a31, if a31<=a21, a31 is used as calibration acceleration, otherwise, a31 is scaled to a21 as calibration acceleration, and ACU program calibration is performed; determining a theoretical collision time, and selecting a time for sending a dangerous source signal cut-off according to the theoretical collision time. The application realizes the dangerous source cut-off function without real vehicle collision data, and provides an implementation method of ACU full function in the collection stage, so that the safety redundancy of the system can be improved, and the safety of the driver and passengers can be fully ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of automobiles, in particular to a vehicle collision safety redundancy design method. BACKGROUND

[0002] The current automobile design field has higher and higher requirements for test efficiency and accuracy in the research and development stage. In the development of whole vehicle collision safety, for a brand new platform vehicle, the relevant design performance is mainly collected and verified through real vehicle tests. The first round of test collection mainly investigates the structure design and the ACU non-collision ignition function, but the function of cutting off high-voltage electricity and other dangerous sources cannot be verified by the ACU in the first round of tests. Due to the single data collection method, the dangerous source cutting function test only has the second verification stage test, and the verification times are unique. If the requirements are not met, additional sample vehicles for this function need to be added, resulting in a large number of sample vehicles, time and repeated test costs in the design process. SUMMARY

[0003] In view of the defects in the prior art, the purpose of the present application is to provide a vehicle collision safety redundancy design method, which aims to fuse simulation data and existing collision vehicle data, redundantly design the dangerous source cutoff time, and provide a test process for redundancy design.

[0004] To achieve the above-mentioned application purpose, the present application adopts the following technical solution, including the following steps:

[0005] S1, ACU acceleration parameter calibration is performed;

[0006] S101, the simulation acceleration a21 of the ACU position is extracted from the whole vehicle simulation analysis model;

[0007] S102, a reference vehicle type with high similarity to the target vehicle type is selected, and the accelerations of the ACU positions of a plurality of existing real vehicle collision data are extracted, and the acceleration closest to a21 is found out and named as a31;

[0008] S103, a21 and a31 are compared, if a31≤a21, a31 is used as the calibration acceleration, otherwise a31 is scaled to a21 as the calibration acceleration, and the corresponding ACU program calibration of the working condition is performed;

[0009] S104, the safety margin range of a31 is increased by a first percentage %, to obtain the acceleration a32, and it is judged whether the minimum acceleration based on the a32 curve is not less than the working condition set value, if yes, the working condition calibration is ended, if not, the safety margin is reduced until the set condition is reached;

[0010] S105, calibration of other working conditions of the whole vehicle, refer to the above steps S101-S104, complete calibration of other working conditions, and then complete ACU calibration of the whole vehicle;

[0011] S2, calibration of redundancy design when cutting off the dangerous source moment:

[0012] S201, determine the theoretical collision moment: according to theoretical calculation, the ignition moment of the airbag is t11, the ignition moment of the pre-tightening safety belt is t12, the moment of colliding with the dangerous source in the collision working condition is t21, and the length of time required to execute the demand of cutting off the dangerous source is t22;

[0013] S202, take the minimum value of t11 and t12 as the minimum ignition moment t13, take the minimum value of t13 and |t21-t22| as the moment t23 of sending the collision signal to cut off the dangerous source, and the duration of t23 is determined according to the shortest time required by the program;

[0014] S203, calibrate the ACU program corresponding to different working conditions with t23, and select different ACU according to different working conditions required by the collision test.

[0015] Preferably, in the S1 step, if there is no real vehicle test data as a reference, the ACU acceleration a21 in the whole vehicle simulation can be directly used as the calibration curve a31: and in verification, the original safety margin range of a31 is increased by a second proportion to obtain a32, and it is judged whether the minimum ignition acceleration of a32 curve is not less than the working condition setting value, if yes, the calibration is ended, if not, the safety margin is reduced until the set condition is reached.

[0016] Preferably, in the S104 step, it also includes limiting the range after reducing the safety margin to be not less than 1 times the original safety margin range; if the set condition cannot be reached by adjusting the safety margin, modify the calibration program so that the minimum acceleration limit value of the calibration acceleration of the corresponding working condition sending the collision signal is not less than the working condition setting value.

[0017] Preferably, it further includes the following steps:

[0018] S3 system test: assemble and test the real vehicle with the calibrated ACU, test whether the ACU can normally execute the dangerous source cutting-off program after receiving the collision signal with the simulation signal, start testing and record the sending moment of the collision data and the related time of the execution mechanism, and analyze whether the redundancy design goal is achieved.

[0019] Preferably, the S3 step further includes: preparing an ACU and a VCU with collision special functions, assembling and testing the real vehicle, testing whether the ACU and the VCU can normally execute the dangerous source cutting-off program after receiving the collision signal with the simulation signal, starting testing and recording the sending moment of the collision data and the related time of the execution mechanism, and analyzing whether the redundancy design goal is achieved.

[0020] Preferably, the VCU calibration method with collision special function is:

[0021] S401, non-destructive real vehicle test or obtaining the maximum braking force of the whole vehicle acceleration a41 under the condition of the reference vehicle model;

[0022] S402, read the whole vehicle acceleration a51 of the whole vehicle collision under different working conditions from the whole vehicle simulation model;

[0023] S403, VCU identifies different collision acceleration directions and positive and negative values according to different collision conditions; front collision mainly identifies X-direction acceleration, and is negative; left collision mainly identifies Y-direction acceleration, and is positive; rear collision mainly identifies X-direction acceleration, and is positive;

[0024] S404, set the acceleration a61 threshold value of VCU sending the dangerous source cut-off signal according to |a51|≥|a61|≥1.2*|a41|, and calibrate the VCU of different conditions.

[0025] Preferably, the VCU with collision special function includes a collision input signal control circuit at the front end of the VCU, and the VCU sends the dangerous source cut-off signal according to the collision signal.

[0026] Preferably, it also includes S3 system test:

[0027] S301, prepare ACU and VCU with collision special function and assemble test real vehicle;

[0028] S302, detect whether the function is normal, test ACU and VCU can receive collision signal after normal execution of cut-off dangerous source program;

[0029] S303, sample vehicle transportation, zero kilometer transportation is adopted;

[0030] S304, laboratory preparation, first disassemble the ACU and VCU with point explosion function execution mechanism, and restore the installation of the execution mechanism after the test preparation is completed;

[0031] S305, start testing and record the sending time of collision data and the related time of the execution mechanism, and analyze whether the redundancy design goal is achieved.

[0032] Preferably, the lower limit value of a61 in the S305 step is set to a value between 1.0*|a41| and 1.3*|a41|.

[0033] Preferably, the first ratio and / or the second ratio are preferably 10% or 20% or 30% or a ratio between 10-30%.

[0034] Compared with the prior art, the present application has the following beneficial effects:

[0035] 1、 The present application converts the simulation acceleration data of a new platform vehicle model into calibration acceleration data alone or in combination with other vehicle model data, so that the dangerous source disconnection / alarm function can be realized without real vehicle collision data;

[0036] 2、 The present application provides a fusion method of simulation data and existing collision vehicle model data, so that the calibration data is closer to the actual demand and can meet the safety requirement;

[0037] 3、 The present application provides a redundant design of the dangerous source disconnection time, provides the earliest theoretical time, achieves the fastest power-off design, and can guarantee the safety of subsequent passengers;

[0038] 4、 The present application provides a test process of collision safety redundant design, which can verify the dangerous source disconnection twice, improve the verification redundancy, and reduce the test and design cost. BRIEF DESCRIPTION OF DRAWINGS

[0039] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments with reference to the attached drawings:

[0040] Figure 1 Fig. 1 is a schematic diagram of the fusion method of test data and simulation data in the first embodiment;

[0041] Figure 2 Fig. 2 is a flow chart of the real vehicle test method after the redundant design is completed in the first embodiment;

[0042] Figure 3 Fig. 3 is a schematic diagram of the external circuit controlling the VCU collision function in the second embodiment. DETAILED DESCRIPTION

[0043] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0044] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without making creative efforts are within the scope of protection of the present application.

[0045] It should be noted that similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, all directional indications (such as up, down, left, right, front, back, bottom, etc.) in this application are only used to explain the relative positional relationships and movements between components in a specific orientation (as shown in the figures). If the specific orientation changes, the directional indication will also change accordingly.

[0046] Example 1

[0047] This embodiment provides a vehicle collision safety redundancy design method, which mainly includes the following steps:

[0048] S1: Calibrate ACU parameters by fusing experimental and simulation data.

[0049] like Figure 1 As shown, extract the ACU acceleration curves a11, a12, and a13 from the frontal collision scenario. Select vehicle models c11, c12, and c13 from the existing real-vehicle collision database (more or fewer vehicle models can also be selected). Extract the ACU acceleration curve a21 from the frontal collision simulation model. Find the acceleration curve closest to a21 from a11, a12, and a13, and rename it a31. Compare the maximum eigenvalues ​​of the two curves. If a31 ≤ a21, directly use a31 as the calibration acceleration; if a31 > a21, scale a31 to a21 and use it as the new a31 calibration acceleration curve.

[0050] Based on the a31 acceleration curve, calibration is performed according to the relevant calibration procedures. Simultaneously, the safety margin range of a31 is increased by 20%, to 1.2 times the original safety margin (±50%), i.e., (±60%), resulting in curve a32. The minimum ignition acceleration of curve a32 is compared to whether it is greater than or equal to the preset value for a frontal collision condition. In this embodiment, the minimum acceleration is greater than or equal to the preset value of 5g, and the calibration for this condition is completed. Other vehicle conditions are then selected, and the data fusion steps described above are followed, taking the minimum acceleration limit for each condition to complete the calibration of other conditions, thereby completing the ACU calibration of the entire vehicle. In other embodiments, the increase in the safety margin range during the verification process (first proportion) can also be a proportion between 10%, 20%, 30%, or 10-30%. The increased margin is calculated by increasing the original safety margin range by the first proportion.

[0051] In other side and rear collision conditions, the preset value is 5g. In frontal, side and rear collision conditions, the preset value is 5g. Under different conditions, the original safety margin range of a31 is ±50%, preferably -30% to +50%.

[0052] In other embodiments not shown, if the minimum ignition acceleration of a32 is less than 5g, the calibration safety margin range of a32 is reduced (but the margin is limited to no less than the original 1 times (±50%)), until the minimum acceleration of a32 is greater than or equal to the working condition setting value 5g. If the minimum acceleration is still not greater than 5g after the safety margin is reduced, the calibration program is modified so that the minimum acceleration limit of the calibration acceleration curve of the working condition is no less than 5g. The calibration acceleration curve of the working condition is determined.

[0053] S2: Calibration of redundancy design of cutting off dangerous source time

[0054] According to theoretical calculation, the ignition time of the airbag in the frontal rigid impact working condition is t11=18ms, and the ignition time of the pre-tightening safety belt is t12=13ms. Analyzing the above frontal impact working conditions at the frontal impact speeds of 25km / h, 50km / h, 56km / h, the offset impact speed of 64km / h, and the MPDB impact speed of 50km / h, the minimum time of encountering the dangerous source is t21=40ms, and the length of time required for executing the cutting off process is t22=100ms. Taking the minimum value t13 of t11 and t12 as the minimum ignition time of the airbag and the safety belt, t11 is less than t12, so t13=t11=13ms. Taking the minimum value between t13 and (t22-t21) as the time t23 of sending the impact signal, since t13<(t22-t21), so t23=t13=13ms. That is, the time of sending the impact signal for cutting off the dangerous source is t23=13ms.

[0055] S3: Test of real vehicle dangerous source disconnection and alarm system

[0056] As shown in Figure 2 , first, the ACU (with ignition function) and VCU (with ignition function) dedicated to the impact sample vehicle are prepared and installed on the real vehicle. The ACU and VCU functions are tested with a simulation signal to see if they are normal, and high-voltage electricity and fuel cut-off can be received through the impact signal. Then, the sample vehicle is transported by zero-kilometer transportation method and prepared for testing. During the laboratory preparation, the ACU, VCU, and other execution components with ignition function are disassembled, and after the test preparation is completed, the ACU and VCU are restored. In the test, test equipment is added, and the sending time of the impact data and the execution time of the execution mechanism are recorded. The collected test data are analyzed, and the design goal of the previous stage is achieved.

[0057] In other embodiments, when the test vehicle is assembled, only the ACU with impact function and the VCU without impact function can be used.

[0058] In this embodiment, the implementation method of the VCU with the collision function is that the VCU uses an internal control program to control the functions of BMS power-off, other mechanism oil-off, and the warning system being turned on, and the related collision program calibration method is as follows:

[0059] S401, obtaining the vehicle acceleration a41 under the maximum braking force through non-destructive real vehicle testing; in other embodiments, the vehicle acceleration a41 can also be obtained by selecting the existing reference vehicle data with high similarity to the target vehicle model;

[0060] S402, reading the vehicle acceleration a51 under different working conditions from the CAE simulation, and the acceleration direction of a51 in a single collision working condition is certain. For example, it is set that the tail to the head is the positive direction of X, the left side to the right side is the positive direction of Y, and the bottom to the top is the positive direction of Z. In the frontal collision, the X-direction acceleration of the vehicle is negative; in the left side barrier collision working condition, the Y-direction acceleration of the vehicle is positive; and in the rear collision working condition, the X-direction acceleration of the vehicle is positive.

[0061] S403, the VCU identifies different collision acceleration directions and positive and negative values according to different collision working conditions. For example, the X-direction acceleration is mainly identified in the frontal collision, and the value is negative; the Y-direction acceleration is mainly identified in the left side collision, and the value is positive; and the X-direction acceleration is mainly identified in the rear collision, and the value is positive.

[0062] S404, the VCU sets the acceleration a61 threshold value of the signal of power-off, oil-off, etc. In order to ensure that the vehicle collision working condition is identified according to the vehicle acceleration during the collision, and the signal of power-off, oil-off, etc. is sent, the acceleration a61 threshold value is as small as possible. The positive and negative of a61 are set according to S403, the size is set according to the method of |a51|≥|a61|≥1.2*|a41|, and the duration is determined according to the shortest time required by the program. In other embodiments, the lower limit of the a61 value range can be 1*|a41|, 1.3*|a41| or 1.4*|a41|, or any number between 1 and 1.4 times |a41|.

[0063] S405, calibrate the acceleration program of different working conditions, determine the size, direction and duration of the acceleration a61, and write it into the VCU program of different working conditions.

[0064] S406, select different VCU for related collision test under different collision working conditions.

[0065] Embodiment 2

[0066] The redundancy design method of this embodiment is basically the same as that of the first embodiment, one of the differences is that another method is provided for the ACU parameter calibration of S1 step:

[0067] In the absence of real vehicle test data as a reference, the calibration step can be shortened. The ACU numerical value a21 in the target vehicle simulation model is directly used as the acceleration calibration curve a31. Based on the a31 curve, the calibration-related program is followed, and the safety margin is increased by a second proportion of 20%, to 1.2 times (±60%) of the original safety margin required by conventional technology. The calibrated curve is a32. The minimum firing acceleration of the curve a32 is compared. If the minimum acceleration is greater than or equal to 5g, the calibration is complete. Otherwise, the safety margin of a32 is reduced (the safety margin is not less than 1 times (±50%) of the original safety margin), until the minimum acceleration is greater than or equal to 5g. If the minimum acceleration is still not greater than 5g after the margin is reduced, the calibration program is modified so that the minimum acceleration limit of the calibration acceleration of the working condition that sends the crash signal is not less than 5g. The calibration of the acceleration curve of the working condition is completed. The calibration of other working conditions is also referred to the above calibration steps, and the minimum acceleration limit of each working condition is taken to complete the calibration of other working conditions, and thus the ACU calibration of the whole vehicle is completed.

[0068] In other embodiments, the second proportion can also be 10% or 30% or a proportion between 10-30%, and the increased safety margin is calculated as an increase of the original safety margin range by the second proportion.

[0069] The difference between this embodiment and the first embodiment is that the implementation method of the VCU with the crash function in this embodiment is that the VCU uses external circuit control to send power-off, fuel-off and other required signals. As shown in Figure 3 The specific process is as follows:

[0070] S501, the signal of the external control circuit is sent by a specific device during the crash;

[0071] S502, after the external control circuit receives the whole vehicle crash signal, a state signal is provided to the VCU;

[0072] S503, the VCU judges the real vehicle to send the crash according to the state signal, and outputs the power-off, fuel-off and alarm signals;

[0073] S504, the BMS and other actuators execute the predetermined program action to complete the related functions.

[0074] The above describes the specific embodiments of the present application. Through the above description, relevant personnel can make various changes and modifications without deviating from the technical idea of the present application.

Claims

1. A vehicle collision safety redundancy design method, characterized by, Comprising the following steps: S1, ACU acceleration parameter calibration is carried out; S101, the simulation acceleration a21 of the ACU position is extracted from the whole vehicle simulation analysis model; S102, the reference vehicle type of the existing calibration data with high similarity to the target vehicle type is selected, the acceleration of the ACU position of several existing real vehicle crash data is extracted, and the acceleration closest to a21 is found out and named as a31; S103, a21 and a31 are compared, if a31≤a21, a31 is used as the calibration acceleration, otherwise a31 is scaled to a21 as the calibration acceleration, and the ACU program calibration of the corresponding working condition is carried out; S104, the safety margin range of a31 is increased by a first proportion to obtain the acceleration a32, it is judged whether the minimum acceleration based on the a32 curve is not less than the working condition setting value, if yes, the working condition calibration is ended, if not, the safety margin is reduced until the set condition is reached; S105, the calibration of other working conditions of the whole vehicle is carried out, the above steps S101-S104 are referred to, the calibration of other working conditions is completed, and then the ACU calibration of the whole vehicle is completed; S2, calibration of redundant design when cutting off the dangerous source time: S201, the theoretical collision time is determined: according to the theoretical calculation, the ignition time of the airbag is t11, the ignition time of the pre-tightening safety belt is t12, the time of hitting the dangerous source in the collision working condition is t21, and the length of time required for cutting off the dangerous source is t22; S202, the minimum value of t11 and t12 is taken as the minimum ignition time t13, the minimum value of t13 and |t21-t22| is taken as the time t23 of sending the collision signal to cut off the dangerous source, and the duration of t23 is determined according to the shortest time required by the program; S203, the ACU program corresponding to different working conditions is calibrated by t23, and different ACUs are selected according to different working conditions required by the collision test; S3, system test: the calibrated ACU is assembled and tested in the real vehicle, the ACU can receive the collision signal after the test, the cutting off of the dangerous source program is normally executed, the sending time of the collision data and the related time of the execution mechanism are recorded, and whether the redundant design goal is achieved is analyzed.

2. The vehicle crash safety redundancy design method of claim 1, wherein In the S1 step, if there is no real vehicle test data as a reference, the ACU acceleration a21 in the whole vehicle simulation is directly used as the calibration curve a31: and in the verification, the original safety margin range of a31 is increased by a second proportion to obtain a32, and it is judged whether the minimum ignition acceleration of the a32 curve is not less than the working condition setting value, if yes, the calibration is ended, if not, the safety margin is reduced until the set condition is reached.

3. The vehicle crash safety redundancy design method according to claim 1 or 2, characterized by, In the S104 step, it also includes limiting the range after reducing the safety margin to not less than 1 times the original safety margin range; if the set condition cannot be reached by adjusting the safety margin, the calibration program is modified, so that the minimum acceleration limit value of the calibration acceleration of the corresponding working condition for sending the collision signal is not less than the working condition setting value.

4. The vehicle crash safety redundancy design method of claim 1, wherein The S3 step further comprises: preparing the ACU and VCU with collision special function, and assembling the test vehicle, testing the ACU and VCU with simulation signals to see whether they can accept the collision signal and normally execute the dangerous source cutting-off program, starting the test and recording the sending time of the collision data and the related time of the actuator, and analyzing whether the redundancy design goal is achieved.

5. The vehicle crash safety redundancy design method of claim 4, wherein The VCU calibration method with collision special function is: S401, non-destructive vehicle test or obtaining the maximum braking force of the vehicle under the condition of acceleration a41; S402, reading the vehicle acceleration a51 of the vehicle collision under different working conditions from the vehicle simulation model; S403, the VCU identifies different collision acceleration directions and positive and negative values according to different collision conditions; the front collision mainly identifies the X-direction acceleration, which is negative; the left collision mainly identifies the Y-direction acceleration, which is positive; and the rear collision mainly identifies the X-direction acceleration, which is positive; S404, setting the acceleration a61 threshold value of the VCU sending the dangerous source cutting-off signal according to |a51|≥|a61|≥1.2*|a41|, and calibrating the VCU under different conditions.

6. The vehicle crash safety redundancy design method of claim 4, wherein The VCU with collision special function comprises a collision input signal control circuit added in the front end of the VCU, and the VCU sends the dangerous source cutting-off signal according to the collision signal.

7. The vehicle collision safety redundancy design method of claim 1, wherein The S3 system test specifically comprises the following steps: S301, preparing the ACU and VCU with collision special function and assembling the test vehicle; S302, testing whether the function is normal, testing the ACU and VCU with simulation signals to see whether they can accept the collision signal and normally execute the dangerous source cutting-off program; S303, sample vehicle transportation, using zero kilometer transportation; S304, laboratory preparation, first disassembling the ACU and VCU with the point explosion function of the actuator, and restoring the installation of the actuator after the test preparation is completed; S305, starting the test and recording the sending time of the collision data and the related time of the actuator, and analyzing whether the redundancy design goal is achieved.

8. The vehicle crash safety redundancy design method of claim 5, wherein, The lower limit value of a61 in the S404 step is set to a value between 1.0*|a41| and 1.3*|a41|.

9. The vehicle crash safety redundancy design method according to claim 1 or 2, characterized by, The first ratio and / or the second ratio is a ratio between 10% and 30%.

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