WO2022040872A1

WO2022040872A1 - Radar and imu-based accident data storage method and device for event data recorder

Info

Publication number: WO2022040872A1
Application number: PCT/CN2020/110856
Authority: WO
Inventors: 朱帆; 尚明生; 陈琳
Original assignee: 中国科学院重庆绿色智能技术研究院
Priority date: 2020-08-24
Filing date: 2020-08-24
Publication date: 2022-03-03
Also published as: CN114402220A

Abstract

A Radar and IMU-based accident data storage method and device for an event data recorder. Said method comprises the following steps: acquiring Radar data and speed data of a vehicle; calculating, according to the Radar data, a collision time of the vehicle with respect to each obstacle; selecting the minimum collision time as a first collision time of the vehicle at the current moment; calculating first collision times at all moments from the current moment to a preset moment, and analyzing whether the current moment is a Radar dangerous moment; at the same time, receiving an IMU triaxial acceleration of the vehicle at the current moment, and determining whether the current moment is a recorder dangerous moment; and if the current moment is the Radar dangerous moment and the recorder dangerous moment, marking the current moment as a real dangerous moment, and storing driving data before and after the real dangerous moment. Radar data and triaxial acceleration are obtained from a vehicle chassis and analyzed to obtain accident data, so that the accuracy of accident data storage is improved, and the event data recorder and a black box are prevented from being affected by a memory so that the accident data is circularly covered.

Description

A method and device for saving accident data of driving recorder based on Radar and IMU

technical field

The invention belongs to the technical field of vehicle data information storage, and in particular relates to a Radar and IMU-based driving recorder accident data storage method and device.

Background technique

At present, the traffic safety situation is becoming more and more severe, traffic accidents occur frequently, and casualties and property losses are heavy; and in the process of traffic accident handling and analysis, accidents caused by vehicle failures often have difficulties in technical analysis and responsibility definition. The reason is that the key vehicle status data cannot be effectively saved, and the driving conditions of the vehicle at the time of the accident cannot be reproduced, and the driving recorder and the black box will cyclically overwrite the saved data due to memory reasons, making it difficult to save the accident data. In the future, with the acceleration of the intelligent process of automobiles, the problem of defining and distinguishing the responsibilities of people and vehicles in traffic accidents will become increasingly prominent. How to correctly divide the responsibilities depends on the in-depth analysis of the vehicle status in the event of the accident, the preservation and Records also appear more necessary.

The current data storage methods include: using on-board instruments. The on-board instrument system is a device in the automotive electronic system that reflects the working conditions of various systems of the vehicle, and is mainly used to indicate the operating conditions of the vehicle. In the existing on-board instrument system architecture, the system passes The status data obtained by the bus will be discarded after being output and displayed by the liquid crystal instrument. The system does not have the function of data recording and storage, and cannot provide data playback, and cannot provide decision-making reference for the analysis of vehicle driving status. The data is not fully utilized, resulting in a huge waste of resources; and in the existing technology, some use the traditional driving recorder to save accident data, in the traditional driving recorder accident judgment and recording method, for storage after the vehicle stops The speed and vehicle signal data 20 seconds before reaching a standstill can only be confirmed by the formal state of the vehicle, that is, the change from driving to stopping to confirm the accident data. The data is stored as accident data. Moreover, the data storage space of the driving recorder is limited, and cyclic coverage is generally used. However, there are too many accident data and it is easy to cover the real data, which will affect the analysis and utilization of the data in the later period of the driving accident.

Another data storage method is to analyze the running state of the vehicle through the data of the vehicle chassis, and save the driving data in the accident state. The driving data of the vehicle chassis is obtained. After the data is obtained, there is no way to judge the emergency state of the vehicle through the driving data, so as to save the driving data in the emergency state.

SUMMARY OF THE INVENTION

In view of this, one of the objects of the present invention is to provide a method for saving accident data of a driving recorder based on Radar and IMU, which can save the accident data in driving for a long time.

For achieving the above object, the technical scheme of the present invention is:

A method for saving accident data of a driving recorder based on Radar and IMU, comprising the following steps:

(1) Obtaining the Radar data of the vehicle and the speed data of the vehicle; the Radar data includes the distance, angle, and relative speed of the obstacle and the vehicle relative to the obstacle;

(2) Calculate the collision time of the vehicle relative to each obstacle according to the vehicle Radar data;

(3) Compare the collision time of all obstacles at the current moment of the vehicle, and select the minimum data as the first collision time at the current moment of the vehicle;

(4) Calculate the first collision time from the current time t0 to the preset time t1. If the first collision time at 90% or more of the time is less than 2 seconds, mark the current time as the Radar dangerous time; 5s≤t1 -t0≤10s;

(5) Simultaneously receive the IMU three-axis acceleration of the vehicle at the current moment, if the three-axis acceleration has an instantaneous acceleration greater than 3±m/s ² in any direction, the current moment is marked as the dangerous moment of the recorder; the three-axis acceleration includes left and right acceleration, Front and rear acceleration, up and down acceleration;

(6) When the current time is both the Radar dangerous time and the recorder dangerous time, mark the current time as the real dangerous time, and mark the driving data within 30 seconds before and after the real dangerous time as important data to save.

Further, the step (2) specifically includes the following steps:

Judging whether the obstacle is in front of the vehicle according to the vehicle Radar data, when the above formula is satisfied, the obstacle is not in front of the vehicle, and the collision time at the current moment is positive infinite:

d sin θ>2;

Among them, d is the distance of the vehicle relative to the obstacle, and θ is the angle of the vehicle relative to the obstacle;

Otherwise, the obstacle is in front of the vehicle and the collision time is:

v _r is the relative speed of the obstacle and the vehicle.

Further, the on-board Radar data and the three-axis acceleration data of the vehicle's built-in IMU are obtained from the chassis analysis.

Further, the driving recorder of the vehicle is connected to the black box on the canbus, communicates with the chassis, and analyzes the vehicle Radar data and the three-axis acceleration data of the vehicle's built-in IMU from the chassis.

Further, the important data is stored in the driving recorder or the black box, and will not be overwritten by circulation.

In view of this, the second purpose of the present invention is to provide a device for saving accident data of a driving recorder based on Radar and IMU, which can save the accident data in driving for a long time.

In order to achieve the above object, the technical scheme of the present invention is: a driving recorder accident data storage device based on Radar and IMU, comprising:

a data receiving module, used to obtain the three-axis acceleration data of the vehicle, the Radar data of the vehicle, and the vehicle speed data of the vehicle; the three-axis acceleration data includes the left and right acceleration, the front and rear acceleration, and the up and down acceleration of the vehicle;

The Radar module is connected to the data receiving module, and is used to calculate the collision time of the vehicle relative to each obstacle at the current moment according to the Radar data of the vehicle, select the minimum data as the first collision time of the vehicle at the current moment, and calculate the collision time of the vehicle at the current moment according to the current moment t0. Whether there is 90% or more of the first collision time within the preset time t1 and the first collision time is less than 2 seconds, mark whether the current time is a Radar dangerous time; 5s≤t1-t0≤10s;

The recorder module, connected with the data receiving module, is used to judge whether the current moment is the recorder dangerous moment according to the three-axis acceleration data of the vehicle at the current moment; when the three-axis acceleration has an instantaneous acceleration greater than 3m/s ² in any direction, Then mark the current moment as the dangerous moment of the recorder;

The data preservation module is connected with the data receiving module, the Radar module and the recorder module, and is used to mark the current moment as the real dangerous moment when the current moment is both the Radar dangerous moment and the recorder dangerous moment, And the driving data within 30 seconds before and after the real dangerous moment is marked as important data for preservation.

Further, the Radar module comprises a judgment unit, a collision time unit, and a Radar marking unit;

Wherein, the judging unit judges whether the obstacle is in front of the vehicle according to the vehicle Radar data, and when the following formula is satisfied, the obstacle is not in front of the vehicle:

d sin θ>2;

The collision time unit is connected with the judgment unit, and is used to calculate the collision time of the vehicle relative to each obstacle, and select the first collision time;

The Radar marking unit is connected to the collision time unit, and is used for recording whether the current moment is a Radar dangerous moment.

Further, the data receiving module includes a driving recorder and a black box; the driving recorder and the black box are connected to the canbus and communicate with the vehicle chassis.

Further, the data receiving module obtains three-axis acceleration data and on-board Radar data of the vehicle's built-in IMU by analyzing the chassis.

Further, the important data saved in the data saving module will not be cyclically overwritten.

The beneficial effects are as follows: the present invention provides a method and device for saving accident data of a driving recorder based on Radar and IMU. It can improve the accuracy of accident data storage selection by analyzing and selecting accurate accident data, which can improve the accuracy of accident data storage selection by driving recorder and black box in actual situations, and reduce accident data storage due to inaccurate accident data judgment. Ordinary driving data is regarded as excessive storage of accident data, which leads to memory loss and complicated query; parallel driving recorder and black box store the analyzed accident data for a long time, so as to avoid driving recorder and black box from being affected by memory, and the saved data is covered by loop , resulting in a situation where accident data is overwritten and cannot be queried.

Description of drawings

In order to illustrate the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that are required to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

1 is a schematic structural diagram of a Radar and IMU-based driving recorder accident data storage device of the present invention;

FIG. 2 is a flowchart of a method for saving accident data of a driving recorder based on Radar and IMU according to the present invention.

detailed description

In order to make the purposes, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The examples are given to better illustrate the present invention, but the content of the present invention is not limited to the examples. Therefore, those skilled in the art make non-essential improvements and adjustments to the embodiments according to the above-mentioned contents of the invention, which still belong to the protection scope of the present invention.

Example 1

Referring to Fig. 1, it is a schematic structural diagram of a Radar and IMU-based driving recorder accident data storage device of the present invention. Specifically, a Radar and IMU-based driving recorder accident data storage device includes:

The data receiving module 1 is used to obtain the three-axis acceleration data of the vehicle, the speed data of the vehicle, and the Radar data of the vehicle;

In this embodiment, the data receiving module 1 includes a driving recorder and a black box; the driving recorder and the black box are connected to CANBUS (controller area network bus technology) and communicate with the vehicle chassis, and the data receiving module 1 analyzes the chassis to obtain the vehicle's built-in IMU (Inertial sensor) three-axis acceleration data, on-board Radar data and vehicle speed data, the three-axis acceleration data includes the vehicle's left and right acceleration, front and rear acceleration, and up and down acceleration;

Radar module 2, connected with data receiving module 1, is used to calculate the collision time of the vehicle relative to each obstacle at the current moment according to the Radar data of the vehicle, select the minimum data as the first collision time of the vehicle at the current moment, and calculate the collision time of the vehicle at the current moment according to the current moment t0. Whether there is more than 90% of the first collision time within the preset time t1 when the first collision time is less than 2 seconds, mark whether the current time is a Radar dangerous time;

Specifically, the Radar module in this embodiment includes a judgment unit 21, a collision time unit 22, and a Radar marking unit 23;

Wherein, the judgment unit 21 judges whether the obstacle is in front of the vehicle according to the vehicle Radar data, and the specific judgment method is as follows:

d sin θ>2;

When the above formula is satisfied, the obstacle is not in front of the vehicle;

The collision time unit 22 is connected to the judgment unit 21, and is used for calculating the collision time of the vehicle relative to each obstacle, and selecting the first collision time;

In this embodiment, when the collision time unit 22 receives that the judgment unit determines that the obstacle is not in front of the vehicle, the collision time between the vehicle and the obstacle is positive infinite; otherwise, the collision time unit 22 calculates the collision time of the vehicle equivalent to the obstacle :

v _r is the relative speed between the obstacle and the vehicle, and TTC is the collision time; when the collision time of the vehicle equivalent to each obstacle is obtained, the collision time unit will select the minimum data among all the collision times as the first collision of the vehicle at the current moment time; then, calculate the first collision time after the current time to the preset time, if the first collision time at 90% or more of the time is less than 2 seconds, then mark the current time as the Radar dangerous time; this embodiment The preset time in can be 5 seconds after the current time, or considering the speed of the vehicle, when the speed is slow, it can also be set to 7 seconds or 10 seconds from the current time;

The Radar marking unit 23 is connected with the collision time unit, and is also connected with the judgment unit 21 for recording whether the current moment is a Radar dangerous moment;

In this embodiment, the Radar marking unit 23 receives all the first collision times from the current time of the vehicle to the preset time in the collision time unit 22, and then interacts with the judging unit 21 to calculate the first collision time in this time period. The total proportion of less than 2 seconds, if the first collision time of 90% and above moments is less than 2 seconds, the Radar marking unit 23 will mark the current moment as the Radar marking unit 23;

The recorder module 3 is connected to the data receiving module 1, and receives the three-axis acceleration data of the vehicle at the current moment in the data receiving module 1. When the three-axis acceleration has an instantaneous acceleration greater than 3m/s ² in any direction, the current moment is marked as a record time of danger;

The data saving module 4 is connected with the recorder module 3, the data receiving module 1 and the Radar module 2. The data saving module 4 first receives the mark of the current moment from the recorder module 3. If the current moment is both a Radar dangerous moment and a recorder At the time of danger, mark the current moment as the real danger moment, and interact with the data receiving module to mark the driving data at the current moment and the driving data within 30 seconds before and after the real danger moment as important data for preservation;

Preferably, in this embodiment, when it is important data, the important data is stored in the data storage module, and in this embodiment, the important data is marked so that the important data is not affected by the driving recorder. , Black box memory impact, important data will not be overwritten by loop.

Example 2

With reference to Fig. 2, it is the flow chart of a kind of driving recorder accident data preservation method based on Radar and IMU of the present invention, specifically, a kind of driving recorder accident data preservation method based on Radar and IMU comprises the following steps:

S100: Obtain the vehicle speed data of the vehicle and the IMU three-axis acceleration of the vehicle at the current moment of the vehicle Radar data; then perform step S210;

In this embodiment, the driving recorder and the black box of the vehicle are connected to the CANBUS, communicate with the chassis, and obtain the three-axis acceleration data of the built-in IMU of the vehicle, the vehicle-mounted Radar data, and the vehicle speed data from the chassis analysis; the three-axis acceleration data includes: Vehicle's left and right, front and rear, up and down acceleration data;

In practice, when the vehicle chassis information is communicated through CANBUS, different models will have different information formats, and the CANBUS message is in the format of 8 bytes=64bit, because the format is different, when receiving the information of the vehicle chassis, it needs Adaptation, but when the vehicle is a commercial truck, since the chassis information of the commercial truck is in a standard format, it only needs to be adapted to CANBUS once, and it can be applied to all commercial trucks. If the vehicle is an ordinary passenger car, the chassis information is a hard model. However, when communicating through CANBUS, it needs to be adapted one by one; after adaptation, the three-axis acceleration data of the IMU can be obtained from the chassis through CANBUS analysis;

Similarly, the information format of vehicle radar (radar) will not be exactly the same depending on the type of radar, but it will include the following key information (for each obstacle): obstacle distance d, obstacle angle θ (relative to the forward direction of the main vehicle), the relative speed v _r of the obstacle and the vehicle;

S210: Calculate the collision time of the vehicle relative to each obstacle according to the vehicle Radar data; then execute step S220;

In this step, the collision time of the vehicle relative to each obstacle near the vehicle needs to be calculated according to the Radar data of the vehicle. The specific steps are:

First determine whether the obstacle is in front of the vehicle. The specific determination method is as follows:

d sin θ>2;

When the above formula is satisfied, the obstacle is not in front of the vehicle; but when the obstacle is not in front of the vehicle, the collision time of the obstacle relative to the vehicle is positive infinite; if the obstacle is in front of the vehicle, the vehicle relative to the obstacle is calculated by the following formula Collision time of objects:

v _r is the relative speed of the obstacle and the vehicle, TTC is the collision time;

S220: Select the minimum collision time at the current moment of the vehicle relative to all obstacles as the first collision time TTC1 at the current moment of the vehicle; then execute step S230;

After obtaining the collision time of the vehicle corresponding to each obstacle in step S210, the method also selects the minimum data among all the collision times as the first collision time TTC1 at the current moment of the vehicle;

S230: Calculate the first collision time TTC1 at all times from the current time to the preset time; then perform step S240;

After calculating the first collision time at the current moment in step S230, we then calculate the first collision time after the current time t0 to the preset time t1, where 5s≤t1-t0≤10s, and the preset time in this embodiment The time can be set to 5 seconds after the current time, or considering the speed of the vehicle, when the speed is slow, it can also be set to 7 seconds or 10 seconds from the current time;

S240: judging whether TTC1 is less than 2 seconds at the time of 90% and above;

In this embodiment, if the first collision time is calculated to be less than 2 seconds when 90% or more of the time exists, if so, step S250 is performed; otherwise, step S100 is continued;

S250: mark the current moment as the Radar dangerous moment; then execute step S320;

In step S240, it is determined that 90% and above of the first collision time is less than 2 seconds, that is to say, within this time period, the collision time of the vehicle relative to the obstacle is too small, and there is a possibility of an accident , at this time, the accident data storage device of the driving recorder based on Radar and IMU marks the current moment as the Radar dangerous moment;

S310: Determine whether the three-axis acceleration has an instantaneous acceleration greater than 3 in any direction; if so, execute step S320; otherwise, continue to execute step S100;

In this method, step S310 is performed simultaneously from steps S210 to S250, and the three-axis acceleration of the IMU in step S100 is received. According to the magnitude of the three-axis acceleration, if the current moment instantaneous acceleration in any direction in the three-axis acceleration is greater than 3±0.5 If the m/s is ² , step S20 is performed; otherwise, step S100 is performed to continue to receive relevant data from the vehicle;

S320: mark the current time as the dangerous time of the recorder; then execute step S400;

However, in the three-axis acceleration in step S310, the absolute value of the instantaneous acceleration at the current moment in any direction is greater than the range of 3±0.5m/s ² , which proves that the vehicle state is changing rapidly at the current moment. If the absolute value of the front and rear acceleration is 3.5m/s ² , then the vehicle is braking suddenly or the speed increases abnormally in a short period of time, then it can be considered that this moment is an emergency moment, and it is marked as a dangerous moment of the recorder; or in one embodiment , the absolute value of the vehicle's vertical acceleration is 2.5m/s ² , then the vehicle is running, and the fluctuations and shakes are obvious, so it can be considered that this moment is an emergency moment, which is marked as a recorder dangerous moment; or in one embodiment, If the instantaneous absolute value of the left and right acceleration of the vehicle is 3m/s ² , then the vehicle is making a sharp turn, then it can be considered that this moment is an emergency moment, and it is marked as a dangerous moment of the recorder;

S400: Determine whether the current time is the Radar time and the recorder dangerous time at the same time, if so, go to step S500, otherwise go to step S100;

After step S250 Radar dangerous time and step S320 recorder dangerous time, in order to improve the accuracy of the vehicle's judgment on the occurrence of the accident, in this step, it is also necessary to judge whether it is marked as the Radar dangerous time and the recorder dangerous time at the same time at the same time. , if it is marked at the same time, go to step S500, if not, go to step S100 to re-receive vehicle-related Radar data and three-axis acceleration data;

S500: Mark the current moment as the real dangerous moment, and mark the driving data within 30 seconds before and after the real dangerous moment as important data to save.

In this step, after step S400 it is judged that the current time is marked as the Radar dangerous time and the recorder dangerous time at the same time, the current time is marked as the real dangerous time, and the driving data within 30 seconds before and after the real dangerous time is marked as important data for preservation ;

Preferably, in this embodiment, when the important data is marked as important data, the important data is saved in the driving recorder and the black box, and the important data is set not to be affected by the memory of the driving recorder and the black box, and the data recorded in the future will not circulate. Overwrite the important data, which can be stored for a long time, and can be read and viewed later.

Further, in this embodiment, after the important data is marked, the driving recorder and the black box can send the important data to the traffic bureau, the terminal of the vehicle owner, etc., so as to avoid damage to the black box and the driving recorder in an accident. Important data cannot be inquired, and accident analysis is difficult.

The embodiments of the present invention have been described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific embodiments, which are merely illustrative rather than restrictive. Under the inspiration of the present invention, without departing from the scope of protection of the present invention and the claims, many forms can be made, which all belong to the protection of the present invention.

Claims

A method for saving accident data of driving recorder based on Radar and IMU, characterized in that it comprises the following steps:

(1) Obtaining the Radar data of the vehicle and the speed data of the vehicle; the Radar data includes the distance and angle of the vehicle relative to the obstacle, and the relative speed of the obstacle and the vehicle;

(2) Calculate the collision time of the vehicle relative to each obstacle according to the vehicle Radar data;

(3) Compare the collision time of all obstacles at the current moment of the vehicle, and select the minimum data as the first collision time at the current moment of the vehicle;

(4) calculate the first collision time of all the moments after the current time t0 to the preset time t1, if the first collision time of 90% or more of the time is less than 2 seconds, then mark the current time as the Radar dangerous moment; Among them, 5s≤t1-t0≤10s;

(5) Simultaneously receive the IMU three-axis acceleration of the vehicle at the current moment. If the instantaneous acceleration of the three-axis acceleration in any direction is greater than 3±0.5m/s 2 , the current moment is marked as the dangerous moment of the recorder; the three-axis acceleration includes left and right acceleration, Front and rear acceleration, up and down acceleration;

(6) When the current time is both the Radar dangerous time and the recorder dangerous time, mark the current time as the real dangerous time, and mark the driving data within 30 seconds before and after the real dangerous time as important data to save.
The method according to claim 1, wherein the step (2) specifically comprises the following steps:

Determine whether the obstacle is in front of the vehicle according to the vehicle Radar data; when the following formula is satisfied, the obstacle is not in front of the vehicle, and the collision time at the current moment is positive infinity:

d sinθ>2;

Among them, d is the distance of the vehicle relative to the obstacle, and θ is the angle of the vehicle relative to the obstacle;

Otherwise, the obstacle is in front of the vehicle and the collision time is:

vr is the relative speed between the obstacle and the vehicle.
The method according to claim 1, wherein the on-board Radar data and the three-axis acceleration data of the built-in IMU of the vehicle are obtained by analyzing the chassis.
The method according to claim 3, wherein the driving recorder of the vehicle and the black box are connected to the canbus, communicate with the chassis, and analyze the vehicle-mounted Radar data and the three-axis acceleration data of the vehicle's built-in IMU from the chassis.
The method according to any one of claims 1-4, wherein the important data is stored in a driving recorder or a black box, and will not be overwritten by a cycle.
A driving recorder accident data storage device based on Radar and IMU, characterized in that it includes:

The data receiving module is used to obtain the three-axis acceleration data of the vehicle, the Radar data of the vehicle, and the vehicle speed data of the vehicle; the three-axis acceleration data includes the left and right acceleration, the front and rear acceleration, and the up and down acceleration of the vehicle;

The Radar module is connected to the data receiving module, and is used to calculate the collision time of the vehicle relative to each obstacle at the current moment according to the Radar data of the vehicle, select the minimum data as the first collision time of the vehicle at the current moment, and calculate the collision time of the vehicle at the current moment according to the current moment t0. Whether there is more than 90% of the first collision time within the preset time t1, the first collision time is less than 2 seconds, marking whether the current time is a Radar dangerous time; wherein, 5s≤t1-t0≤10s;

The recorder module, connected with the data receiving module, is used to judge whether the current moment is the recorder dangerous moment according to the three-axis acceleration data of the vehicle at the current moment; when the three-axis acceleration has an instantaneous acceleration greater than 3m/s 2 in any direction, Then mark the current moment as the dangerous moment of the recorder;

The data saving module is connected with the data receiving module, the Radar module and the recorder module, and is used to mark the current moment as the real dangerous moment when the current moment is both the Radar dangerous moment and the recorder dangerous moment, And the driving data within 30 seconds before and after the real dangerous moment is marked as important data for preservation.
The device according to claim 6, wherein the Radar module comprises a judgment unit, a collision time unit, and a Radar marking unit;

Wherein, the judging unit judges whether the obstacle is in front of the vehicle according to the vehicle Radar data, and when the following formula is satisfied, the obstacle is not in front of the vehicle:

d sinθ>2;

The collision time unit is connected with the judgment unit, and is used to calculate the collision time of the vehicle relative to each obstacle, and select the first collision time;

The Radar marking unit is connected to the collision time unit, and is used for recording whether the current moment is a Radar dangerous moment.
The device according to claim 6, wherein the data receiving module comprises a driving recorder and a black box; the driving recorder and the black box are connected to the canbus and communicate with the vehicle chassis.
The device according to claim 8, wherein the data receiving module analyzes and obtains three-axis acceleration data and on-board Radar data of a built-in IMU of the vehicle from the chassis.
The device according to any one of claims 6 to 9, wherein the important data stored in the data storage module will not be overwritten cyclically.