阅读说明：本技术 基于后车驾驶模式的防追尾制动系统和方法 (Rear-end collision prevention braking system and method based on rear vehicle driving mode ) 是由 王畅 苏彦奇 许清津 胡亚辉 付锐 郭应时 袁伟 于 2019-10-29 设计创作，主要内容包括：本发明公开了一种基于后车驾驶模式的防追尾制动系统和方法,属于交通安全技术领域；本发明是通过安装在车辆前端的毫米波雷达来判断前车是否紧急制动,通过车辆后端的毫米波雷达和摄像头采集到的后车运动状态数据来分析后车的驾驶行为：车道保持、换道、跟车和制动响应时,后车的响应速度和响应方式,来判断后车的驾驶模式；再根据后车的驾驶模式选择与之对应的制动策略。在保证自车安全的前提下,适当降低制动强度,降低后车的追尾几率。(The invention discloses a rear-end collision prevention braking system and method based on a rear vehicle driving mode, belonging to the technical field of traffic safety; the invention judges whether the front vehicle brakes emergently through the millimeter wave radar arranged at the front end of the vehicle, analyzes the driving behavior of the rear vehicle through the millimeter wave radar at the rear end of the vehicle and the motion state data of the rear vehicle collected by the camera: judging the driving mode of the rear vehicle by the response speed and the response mode of the rear vehicle when the lane keeping, lane changing, vehicle following and braking responses are carried out; and then the corresponding brake strategy is selected according to the driving mode of the rear vehicle. On the premise of ensuring the safety of the bicycle, the brake strength is properly reduced, and the rear-end collision probability of the rear bicycle is reduced.)

1. Rear-end collision prevention braking system based on rear vehicle driving mode, comprising: the system comprises a front millimeter wave radar arranged at the front end of the vehicle, a rear millimeter wave radar and a camera arranged at the rear end of the vehicle, a microprocessor and a brake module; the microprocessor is integrated in a control center of the vehicle;

the signal output end of the front millimeter wave radar is electrically connected with the first signal input end of the microprocessor, the signal output end of the rear millimeter wave radar is electrically connected with the second signal input end of the microprocessor, the signal output end of the camera is electrically connected with the third signal input end of the microprocessor, and the signal output end of the microprocessor is connected with the signal input end of the brake module;

the front millimeter wave radar is used for acquiring the motion state information of the front vehicle: real-time relative distance and relative speed between the front vehicle and the self vehicle;

the rear millimeter wave radar is used for acquiring the motion state information of the rear vehicle: real-time relative distance and relative speed between the rear vehicle and the self vehicle;

the camera is used for acquiring the relative position of the rear vehicle relative to the lane line and the turn-on condition of a steering lamp of the rear vehicle;

the microprocessor is used for judging the driving mode of the rear vehicle according to the input motion state information of the front vehicle and the rear vehicle and the relative position of the rear vehicle relative to the lane line, determining a braking strategy according to the driving mode of the rear vehicle and transmitting the braking strategy to the braking module;

the brake module is used for receiving the brake strategy of the microprocessor and implementing corresponding braking.

2. The rear-end collision prevention braking method based on the driving mode of the rear vehicle is characterized by comprising the following steps of:

step 1, the self-vehicle collects the motion state information of the front vehicle, the motion state information of the rear vehicle and the relative position of the rear vehicle relative to a lane line in real time;

the motion state information of the front vehicle is the real-time relative distance and the relative speed between the front vehicle and the self vehicle, and the motion state information of the rear vehicle is the real-time relative distance and the relative speed between the rear vehicle and the self vehicle;

step 2, judging whether the front vehicle has emergency braking according to the motion state information of the front vehicle, if so, turning to step 3, otherwise, keeping the driving speed;

step 3, judging the driving mode of the rear vehicle according to the motion state information of the rear vehicle and the relative position of the rear vehicle relative to the lane line, and further determining a corresponding braking strategy;

and 4, calculating the braking distance required by the rear vehicle according to the braking strategy, further determining the braking distance required by the self vehicle, determining the braking time and acceleration of the self vehicle according to the braking distance, and finishing the rear-end collision prevention braking of the self vehicle.

3. The rear-end collision prevention braking method based on the driving mode of the rear vehicle as claimed in claim 2, wherein the judging whether the front vehicle is emergently braked is specifically as follows:

firstly, calculating the real-time acceleration a of a front vehicle;

then, whether the acceleration of the preceding vehicle satisfies: a is less than or equal to-2 m/s ²And the continuous duration time t is more than or equal to 0.5s, if yes, the front vehicle is judged to be emergently braked.

4. The rear-end collision prevention braking method based on the driving mode of the rear vehicle according to claim 2, wherein the driving mode of the rear vehicle is judged according to the motion state information of the rear vehicle and the relative position of the rear vehicle with respect to the lane line, and specifically comprises the following steps: judging the driving mode under the corresponding behavior according to the lane keeping behavior, the following behavior, the lane changing behavior and the braking behavior of the rear vehicle respectively; when the driving mode under 2 behaviors is unmanned, judging that the rear vehicle is in the unmanned mode; otherwise, judging that the rear vehicle is in the driver driving mode.

5. The rear-end collision prevention braking method based on the driving mode of the rear vehicle as claimed in claim 4, wherein the driving mode under the behavior is judged according to the lane keeping behavior of the rear vehicle, which is specifically as follows:

firstly, setting a sampling interval, and sampling the acquired distance data between the self-vehicle and the left lane line and the acquired distance data between the self-vehicle and the right lane line;

secondly, calculating lane keeping parameters, namely the difference value between the distance from the rear vehicle to the left lane line and the distance from the rear vehicle to the right lane line at each sampling moment;

thirdly, calculating an average lane keeping parameter, namely an average value of the lane keeping parameters within the lane keeping judging distance;

and finally, comparing the average lane keeping parameter with a set lane keeping threshold value, if the average lane keeping parameter is not greater than the lane keeping threshold value, judging that the rear vehicle is in an unmanned driving mode, and otherwise, judging that the rear vehicle is in a driver driving mode.

6. The rear-end collision prevention braking method based on the driving mode of the rear vehicle according to claim 4, wherein the driving mode under the behavior is judged according to the following behavior of the rear vehicle, which is specifically as follows: determining the driving mode of the rear vehicle according to the unmanned driving mode judgment condition corresponding to the following vehicle behavior;

wherein the unmanned driving mode judgment condition corresponding to the following behavior is as follows: within 10s, when the following distance of the following vehicle does not change more than 5m or the following distance of the following vehicle does not change more than 0.1 s; namely, it is

S _{Following vehicle}-5m≤S _{Following vehicle}≤S _{Following vehicle}+5m or

In the formula, S _{Following vehicle}Is the relative distance between the rear vehicle and the self vehicle and has the unit of m, v _{Rear vehicle}The real-time running speed of the rear vehicle is in the unit of m/s.

7. The rear-end collision prevention braking method based on the driving mode of the rear vehicle as claimed in claim 4, wherein the driving mode under the behavior is judged according to the lane change behavior of the rear vehicle, which is specifically as follows: judging whether the lane changing behavior of the rear vehicle meets the following conditions, and if the lane changing behavior of the rear vehicle meets more than 2 items, judging that the rear vehicle is in an unmanned driving mode;

(1) the turn-on time of a turn light of the rear vehicle is more than 3s, and the lane changing frequency of the rear vehicle is not more than a set lane changing threshold value;

(2) within the set lane changing time, the transverse speed of the rear vehicle conforms to a specific rule;

(3) within the set lane changing time, the longitudinal speed of the rear vehicle conforms to a specific rule;

(4) in the set track-changing time, the track-changing time,the deceleration of the rear vehicle on the target lane is not more than 0.5m/s ²；

Wherein, the specific rule is to keep constant or conform to a sine function; the frequency of lane changing is the number of times of lane changing within a unit distance.

8. The rear-end-collision-prevention braking method based on the driving mode of the rear vehicle according to claim 4, characterized in that the driving mode under the behavior is judged according to the braking response behavior of the rear vehicle, which is specifically as follows: when the self-vehicle brakes, if the response time of the rear vehicle is less than 0.5s, namely t _{Response to}The time is less than or equal to 0.5s, and the rear vehicle is judged to be in an unmanned mode preliminarily;

and the response time of the rear vehicle is the time difference between the time when the self vehicle starts to brake and the time when the rear vehicle starts to brake.

9. The rear-end collision prevention braking method based on the driving mode of the rear vehicle as claimed in claim 2, wherein the required braking distance of the rear vehicle is calculated according to the braking strategy, and then the required braking distance of the self vehicle is determined, which specifically comprises the following steps:

firstly, if the braking strategy corresponds to the unmanned driving mode, the braking distance required by the rear vehicle is as follows:

where a is the maximum limited deceleration of the rear vehicle, v _{Rear vehicle}The running speed of the rear vehicle;

if the braking strategy corresponds to the driving mode of the driver, the braking distance required by the rear vehicle is as follows:

in the formula, t _{Reaction of}Average human response time;

then, it is determined that the required braking distance of the own vehicle satisfies the following relationship: s _{Bicycle brake}≥S _{Rear vehicle requirements}-ΔS

In the formula, S _{Rear vehicle requirements}The braking distance required by the rear vehicle in different modes, and when the rear vehicle is judged to be in the unmanned driving mode S _{Rear vehicle requirements}＝S _NobodyWhen the driver driving mode is judged, S _{Rear vehicle requirements}＝S _{Driver's seat}(ii) a And Delta S is the relative distance between the self-vehicle and the rear vehicle when the self-vehicle brakes.

10. The rear-end-collision-prevention braking method based on the driving mode of the rear vehicle according to claim 9, wherein the time and the acceleration of the braking of the self vehicle are determined by: at the minimum braking distance S required by braking of the bicycle _minBased on this, the braking time t of the bicycle is calculated _{Braking device}And acceleration a _{Bicycle brake}：

Wherein v is _{Braking device}The running speed of the vehicle when the vehicle starts to brake.

Technical Field

The invention belongs to the technical field of traffic safety, and particularly relates to a rear-end collision prevention braking system and method based on a rear vehicle driving mode.

Background

The main reason for the occurrence of rear-end collision is that in the following process, when the front vehicle brakes emergently, the rear vehicle does not have enough braking distance, thereby causing the occurrence of rear-end collision. For example, when a front vehicle is emergently braked during the running of a fleet, an adjacent following vehicle may take effective braking measures to prevent a rear-end collision of the front vehicle, but the braking intensity is too large, so that the braking distance of the rear vehicle of the front vehicle is insufficient, and a rear-end collision accident occurs.

In the current automatic braking system, only the correlation between the vehicle and the front obstacle is considered, but whether the rear vehicle has enough braking distance after the vehicle takes emergency braking is not considered. If the safety of the rear vehicle is considered in the braking strategy, the rear-end collision accident in the driving of the motorcade can be effectively prevented.

Meanwhile, the rear vehicle may be in a manned driving mode or in an unmanned driving mode in which the vehicle is automatically driven. In both manned and unmanned modes of the rear vehicle, the braking reaction time and distance of the rear vehicle to the front vehicle are different, and therefore, the braking strategy is different, for example, the reflection and operation characteristics of the driver are poorer than those of a computer system, but the flexibility is higher. Therefore, the rear vehicle driving mode is critical to the accuracy and safety of braking.

Disclosure of Invention

In order to solve the above problems, the present invention provides a rear-end collision prevention braking system and method based on a rear vehicle driving mode, wherein the rear vehicle safety is considered in a braking strategy of a self vehicle, and different braking strategies are adopted by identifying the driving mode of the rear vehicle; when the emergency braking of the front vehicle is performed, the braking strength of the front vehicle is properly reduced on the premise of ensuring the safety of the front vehicle, the rear-end collision of the rear vehicle is prevented, the safety is high, the braking efficiency is high, and the occurrence of the rear-end collision can be effectively reduced.

The principle of the invention is that whether the front vehicle brakes emergently is judged by a millimeter wave radar arranged at the front end of the vehicle, and the driving behavior of the rear vehicle is analyzed by the millimeter wave radar at the rear end of the vehicle and the motion state data of the rear vehicle collected by a camera: judging the driving mode of the rear vehicle according to the response speed and the response mode of the rear vehicle when lane keeping, lane changing, vehicle following and braking; and then the corresponding brake strategy is selected according to the driving mode of the rear vehicle. On the premise of ensuring the safety of the bicycle, the brake strength is properly reduced, and the rear-end collision probability of the rear bicycle is reduced.

In order to achieve the above object, the present invention adopts the following technical solutions.

The rear-end collision prevention braking system based on the driving mode of the rear vehicle comprises: the system comprises a front millimeter wave radar arranged at the front end of the vehicle, a rear millimeter wave radar and a camera arranged at the rear end of the vehicle, a microprocessor and a brake module; the microprocessor is integrated in a control center of the vehicle;

the signal output end of the front millimeter wave radar is electrically connected with the first signal input end of the microprocessor, the signal output end of the rear millimeter wave radar is electrically connected with the second signal input end of the microprocessor, the signal output end of the camera is electrically connected with the third signal input end of the microprocessor, and the signal output end of the microprocessor is connected with the signal input end of the brake module;

the front millimeter wave radar is used for acquiring the motion state information of the front vehicle: real-time relative distance and relative speed between the front vehicle and the self vehicle;

the rear millimeter wave radar is used for acquiring the motion state information of the rear vehicle: real-time relative distance and relative speed between the rear vehicle and the self vehicle;

the camera is used for acquiring the relative position of the rear vehicle relative to the lane line and the turn-on condition of a steering lamp of the rear vehicle;

the microprocessor is used for judging the driving mode of the rear vehicle according to the input motion state information of the front vehicle and the rear vehicle and the relative position of the rear vehicle relative to the lane line, determining a braking strategy according to the driving mode of the rear vehicle and transmitting the braking strategy to the braking module;

the brake module is used for receiving the brake strategy of the microprocessor and implementing corresponding braking.

Further, the front millimeter wave radar and the rear millimeter wave radar are respectively delford ESR millimeter wave radars.

Further, the camera is a 3D high definition video camera.

Further, the microprocessor is an ARM9 processor.

Further, the brake module is the brake module of the vehicle itself.

(II) the rear-end collision prevention braking method based on the driving mode of the rear vehicle comprises the following steps based on the braking system:

step 1, the self-vehicle collects the motion state information of the front vehicle, the motion state information of the rear vehicle and the relative position of the rear vehicle relative to a lane line in real time;

the motion state information of the front vehicle is the real-time relative distance and the relative speed between the front vehicle and the self vehicle, and the motion state information of the rear vehicle is the real-time relative distance and the relative speed between the rear vehicle and the self vehicle;

step 2, judging whether the front vehicle has emergency braking according to the motion state information of the front vehicle, if so, turning to step 3, otherwise, keeping the driving speed;

step 3, judging the driving mode of the rear vehicle according to the motion state information of the rear vehicle and the relative position of the rear vehicle relative to the lane line, and further determining a corresponding braking strategy;

and 4, calculating the braking distance required by the rear vehicle according to the braking strategy, further determining the braking distance required by the self vehicle, determining the braking time and acceleration of the self vehicle according to the braking distance, and finishing the rear-end collision prevention braking of the self vehicle.

Further, the judging whether the front vehicle has emergency braking specifically includes:

firstly, calculating the real-time acceleration a of a front vehicle;

then, whether the acceleration of the preceding vehicle satisfies: a is less than or equal to-2 m/s ²And the continuous duration time t is more than or equal to 0.5s, if yes, the front vehicle is judged to be emergently braked.

Further, according to the motion state information of the rear vehicle and the relative position of the rear vehicle with respect to the lane line, the driving mode of the rear vehicle is judged, which specifically comprises: judging the driving mode under the corresponding behavior according to the lane keeping behavior, the following behavior, the lane changing behavior and the braking response behavior of the rear vehicle; when the driving mode under 2 behaviors is unmanned, judging that the rear vehicle is in the unmanned mode; otherwise, the rear vehicle is judged to be in a manual driving mode.

Furthermore, according to the lane keeping behavior of the following vehicle, the driving mode under the behavior is judged, which specifically comprises the following steps:

firstly, setting a sampling interval, and sampling the acquired distance data between the self-vehicle and the left lane line and the acquired distance data between the self-vehicle and the right lane line;

secondly, calculating lane keeping parameters, namely the difference value between the distance from the rear vehicle to the left lane line and the distance from the rear vehicle to the right lane line at each sampling moment;

thirdly, calculating an average lane keeping parameter, namely an average value of the lane keeping parameters within the lane keeping judging distance;

and finally, comparing the average lane keeping parameter with a set lane keeping threshold value, if the average lane keeping parameter is not greater than the lane keeping threshold value, judging that the rear vehicle is in an unmanned driving mode, and otherwise, judging that the rear vehicle is in an artificial driving mode.

Furthermore, according to the following behavior of the following vehicle, the driving mode under the behavior is judged, which specifically comprises: determining the driving mode of the rear vehicle according to the unmanned driving mode judgment condition corresponding to the following vehicle behavior;

wherein the unmanned driving mode judgment condition corresponding to the following behavior is as follows: within 10s, when the following distance of the following vehicle does not change more than 5m or the following distance of the following vehicle does not change more than 0.1 s; namely, it is

S _{Following vehicle}-5m≤S _{Following vehicle}≤S _{Following vehicle}+5m or

In the formula, S _{Following vehicle}Is the relative distance between the rear vehicle and the self vehicle and has the unit of m, v _{Rear vehicle}The real-time running speed of the rear vehicle is in the unit of m/s.

Furthermore, according to the lane change behavior of the following vehicle, the driving mode under the behavior is judged, which specifically comprises the following steps: judging whether the lane changing behavior of the rear vehicle meets the following conditions, and if the lane changing behavior of the rear vehicle meets more than 2 items, judging that the rear vehicle is in an unmanned driving mode;

(1) the turn-on time of a turn light of the rear vehicle is more than 3s, and the lane changing frequency of the rear vehicle is not more than a set lane changing threshold value;

(2) within the set lane changing time, the transverse speed of the rear vehicle conforms to a specific rule;

(3) within the set lane changing time, the longitudinal speed of the rear vehicle conforms to a specific rule;

(4) within the set lane change time, the deceleration of the rear vehicle on the target lane is not more than 0.5m/s ²；

Wherein, the specific rule is to keep constant or conform to a sine function; the frequency of lane changing is the number of times of lane changing within a unit distance.

Furthermore, according to the braking response behavior of the following vehicle, the driving mode under the behavior is judged, which specifically comprises the following steps: when the self-vehicle brakes, if the response time of the rear vehicle is less than 0.5s, namely t _{Response to}The time is less than or equal to 0.5s, and the rear vehicle is judged to be in an unmanned mode preliminarily;

and the response time of the rear vehicle is the time difference between the time when the self vehicle starts to brake and the time when the rear vehicle starts to brake.

Further, the required braking distance of the rear vehicle is calculated according to the braking strategy, and the required braking distance of the self vehicle is further determined, which specifically comprises the following steps:

firstly, if the braking strategy corresponds to the unmanned driving mode, the braking distance required by the rear vehicle is as follows:

where a is the maximum limited deceleration of the rear vehicle, v _{Rear vehicle}The running speed of the rear vehicle.

If the braking strategy corresponds to the manual driving mode, the braking distance required by the rear vehicle is as follows:

in the formula, t _{Reaction of}Average human reaction time, which is generally 1 s;

then, it is determined that the required braking distance of the own vehicle satisfies the following relationship: s _{Bicycle brake}≥S _{Rear vehicle requirements}-ΔS

In the formula, S _{Rear vehicle requirements}The braking distance required by the rear vehicle in different modes, and when the rear vehicle is judged to be in the unmanned driving mode S _{Rear vehicle requirements}＝S _NobodyWhen the manual driving mode is judged, S _{Rear vehicle requirements}＝S _{Driver's seat}(ii) a And Delta S is the relative distance between the self-vehicle and the rear vehicle when the self-vehicle brakes.

Further, the determining the time and the acceleration of the braking of the self-vehicle is specifically as follows: at the minimum braking distance S required by braking of the bicycle _minBased on this, the braking time t of the bicycle is calculated _{Braking device}And acceleration a _{Bicycle brake}：

Wherein v is _{Braking device}The running speed of the vehicle when the vehicle starts to brake.

Compared with the prior art, the invention has the beneficial effects that:

the invention determines the braking strategy of the self vehicle by judging the braking intention of the front vehicle and the driving mode of the rear vehicle, greatly reduces the braking safety of the vehicles next to the rear vehicle and the rear vehicle on the premise of ensuring the safety, thereby effectively preventing rear-end accidents when the vehicles are queued to run and reducing the accident rate of rear-end collisions of other vehicles caused by the emergency braking of a certain vehicle.

Drawings

The invention is described in further detail below with reference to the figures and specific embodiments.

FIG. 1 is a schematic illustration of a rear-end-collision-prevention braking system based on a rear-vehicle driving mode in accordance with the present invention;

FIG. 2 is a schematic view of the working flow of the rear-end collision prevention braking method based on the driving mode of the rear vehicle according to the present invention;

in the figure: 1. front vehicle; 2. self-turning; 3. carrying out rear vehicle; 4. a front millimeter wave radar; 5. a microprocessor; 6. a camera; 7. a rear millimeter wave radar; 8. and a brake module.

Detailed Description

The embodiments and effects of the present invention will be described in further detail below with reference to the accompanying drawings.

Referring to fig. 1, a rear-end collision prevention brake system based on a driving mode of a rear vehicle 3 of the present invention includes: the system comprises a front millimeter wave radar 4 arranged at the front end of the vehicle, a rear millimeter wave radar 7 and a camera 6 arranged at the rear end of the vehicle, a microprocessor 5 and a brake module; the microprocessor 5 is integrated in the control center of the vehicle;

the signal output end of the front millimeter wave radar 4 is electrically connected with the first signal input end of the microprocessor 5, the signal output end of the rear millimeter wave radar 7 is electrically connected with the second signal input end of the microprocessor 5, the signal output end of the camera 6 is electrically connected with the third signal input end of the microprocessor 5, and the signal output end of the microprocessor 5 is connected with the signal input end of the brake module;

the front millimeter wave radar 4 is used for acquiring the motion state information of the front vehicle 1: real-time relative distance and relative speed between the front vehicle 1 and the self vehicle 2;

the rear millimeter wave radar 7 is used for acquiring the motion state information of the rear vehicle 3: the real-time relative distance and the relative speed between the rear vehicle 3 and the self vehicle 2;

the camera 6 is used for acquiring the relative distance between the rear vehicle 3 and the lane line and the turn-on condition of a steering lamp of the rear vehicle 3;

the microprocessor 5 is used for judging the driving mode of the rear vehicle 3 according to the input motion state information of the front vehicle 1 and the rear vehicle 3 and the relative position of the rear vehicle 3 relative to the lane line, determining a braking strategy according to the driving mode of the rear vehicle 3 and transmitting the braking strategy to the braking module;

the braking module is used for receiving the braking strategy of the microprocessor 5 and implementing corresponding braking.

Illustratively, the front millimeter wave radar 4 and the rear millimeter wave radar 7 are respectively Delford ESR millimeter wave radars, the camera 6 is a 3D high-definition camera 6, and the microprocessor 5 is an ARM9 processor with the specific model of S3C 2410; the brake module is the vehicle's own brake module.

Referring to fig. 2, the rear-end collision prevention braking method based on the driving mode of the rear vehicle according to the present invention is implemented according to the following steps:

step 1, the self-vehicle collects the motion state information of the front vehicle, the motion state information of the rear vehicle and the relative position of the rear vehicle relative to a lane line in real time;

the motion state information of the front vehicle is the real-time relative distance and the relative speed between the front vehicle and the self vehicle, and the motion state information of the rear vehicle is the real-time relative distance and the relative speed between the rear vehicle and the self vehicle;

step 2, judging whether the front vehicle has emergency braking according to the motion state information of the front vehicle, if so, turning to step 3, otherwise, keeping the driving speed;

illustratively, calculating the real-time acceleration a of the front vehicle according to the relative speed and the relative distance of the front vehicle and the self vehicle; then, whether the acceleration of the preceding vehicle satisfies: a is less than or equal to-2 m/s ²And the duration time t is more than or equal to 0.5s, if yes, the front vehicle is judged to have emergency braking.

Step 3, judging the driving mode of the rear vehicle according to the motion state information of the rear vehicle and the relative position of the rear vehicle relative to the lane line, and further determining a corresponding braking strategy;

specifically, a lane keeping behavior, a following behavior, a lane changing behavior and a braking response behavior of the following vehicle are taken as judgment bases, and a driving mode corresponding to each behavior of the following vehicle is judged respectively; when the driving mode under 2 behaviors is unmanned, judging that the rear vehicle is in the unmanned mode; otherwise, the rear vehicle is judged to be in a manual driving mode.

Wherein, a) the driving mode judgment under the lane keeping behavior specifically is:

firstly, setting a sampling interval, and sampling the acquired distance data between the self-vehicle and the left lane line and the acquired distance data between the self-vehicle and the right lane line;

secondly, calculating lane keeping parameters, namely the difference value between the distance from the rear vehicle to the left lane line and the distance from the rear vehicle to the right lane line at each sampling moment;

thirdly, calculating an average lane keeping parameter, namely an average value of the lane keeping parameters within the lane keeping judging distance;

and finally, comparing the average lane keeping parameter with a set lane keeping threshold value, if the average lane keeping parameter is not greater than the lane keeping threshold value, judging that the rear vehicle is in an unmanned driving mode, and otherwise, judging that the rear vehicle is in an artificial driving mode.

In the above process, the sampling interval is set to 1m, i.e. sampling is performed every 1m, exemplarily; the lane determination distance is set to 100m, and the lane keeping threshold is set to 5-6 cm.

b) The driving mode under the following behavior is judged, and the method specifically comprises the following steps: determining the driving mode of the rear vehicle according to the unmanned driving mode judgment condition corresponding to the following vehicle behavior;

wherein the unmanned driving mode judgment condition corresponding to the following behavior is as follows: within 10s, when the following distance of the following vehicle does not change more than 5m or the following distance of the following vehicle does not change more than 0.1 s; namely, it is

S _{Following vehicle}-5m≤S _{Following vehicle}≤S _{Following vehicle}+5m or

In the formula, S _{Following vehicle}Is the relative distance between the rear vehicle and the self vehicle and has the unit of m, v _{Rear vehicle}The real-time running speed of the rear vehicle is in the unit of m/s. 5m is taken as the floating range of the following distance, and 0.1s is taken as the floating range of the following time.

c) The driving mode judgment under the lane changing behavior specifically comprises the following steps:

judging whether the lane changing behavior of the rear vehicle meets the following conditions, and if the lane changing behavior of the rear vehicle meets more than 2 items, judging that the rear vehicle is in an unmanned driving mode;

(1) the turn-on time of a turn light of the rear vehicle is more than 3s, and the lane changing frequency of the rear vehicle is not more than a set lane changing threshold value;

(2) within the set lane changing time, the transverse speed of the rear vehicle conforms to a specific rule;

(3) within the set lane changing time, the longitudinal speed of the rear vehicle conforms to a specific rule;

(4) within the set lane change time, the deceleration of the rear vehicle on the target lane is not more than 0.5m/s ²；

Wherein, the specific rule is to keep constant or conform to a sine function; the frequency of lane changing is the number of times of lane changing within a unit distance.

Illustratively, the lane change threshold is set to 5 times/km and the lane change time is set to 12-15 s.

d) The driving mode judgment under the braking response behavior specifically comprises the following steps: when the self-vehicle brakes, if the response time of the rear vehicle is less than 0.5s, namely t _{Response to}The time is less than or equal to 0.5s, and the rear vehicle is judged to be in an unmanned mode preliminarily;

and the response time of the rear vehicle is the time difference between the time when the self vehicle starts to brake and the time when the rear vehicle starts to brake.

And according to the final judgment result of the driving mode, if the driving mode is unmanned, corresponding to an unmanned braking strategy, and if not, corresponding to a manual driving mode braking strategy.

And 4, calculating the braking distance required by the rear vehicle according to the braking strategy, further determining the braking distance required by the self vehicle, determining the braking time and acceleration of the self vehicle according to the braking distance, and finishing the rear-end collision prevention braking of the self vehicle.

Specifically, first, if the braking strategy corresponds to the unmanned driving mode, the braking distance required by the rear vehicle is:

wherein a is the maximum limited deceleration of the rear vehicle, namely the maximum deceleration within the braking capability range of the rear vehicle, v _{Rear vehicle}The running speed of the rear vehicle.

If the braking strategy corresponds to the manual driving mode, the braking distance required by the rear vehicle is as follows:

in the formula, t _{Reaction of}Average human reaction time, which is generally 1 s;

then, it is determined that the required braking distance of the own vehicle satisfies the following relationship: s _{Bicycle brake}≥S _{Rear vehicle requirements}-ΔS

In the formula, S _{Rear vehicle requirements}The braking distance required by the rear vehicle in different modes, and when the rear vehicle is judged to be in the unmanned driving mode S _{Rear vehicle requirements}＝S _NobodyWhen the manual driving mode is judged, S _{Rear vehicle requirements}＝S _{Driver's seat}(ii) a And Delta S is the relative distance between the self-vehicle and the rear vehicle when the self-vehicle brakes.

Finally, the minimum braking distance S required by the braking of the bicycle _minBased on this, the braking time t of the bicycle is calculated _{Braking device}And acceleration a _{Bicycle brake}：

Wherein v is _{Braking device}The running speed of the vehicle when the vehicle starts to brake.

Thus, the process of preventing rear-end collision of the bicycle is completed.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.