Vehicle rear collision early warning and active prevention and control system and method in network connection environment

Abstract

The invention discloses a vehicle rear collision early warning and active prevention and control system and method in a network connection environment, and belongs to the technical field of traffic safety. The invention aims to improve the driving safety, the rear-end collision prevention early warning system can monitor the surrounding road environment and the traffic condition behind the vehicle in real time, and when potential rear-end collision risks are found, early warning is given out in time to remind a driver to take measures to avoid collision. And the active prevention and control system can automatically perform emergency braking and other operations when necessary, so that the driving safety is greatly improved, and the possibility of traffic congestion and accidents is further reduced. When a driver drives for a long time or in a complex traffic environment, the driver may feel tired or inattention, through real-time monitoring and early warning, the system can help the driver better grasp the traffic condition around the vehicle, operation such as emergency braking in an emergency situation is reduced, additional safety guarantee is provided for the driver, and the safety of the driver is improved. The driving pressure is relieved, and the driving comfort is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of traffic safety, and particularly relates to a vehicle rear collision warning and active prevention and control system and method in a connected environment. Background Art

[0002] In China, according to the "Annual Report on Road Traffic Accident Statistics of the People's Republic of China", rear-end collisions account for about 10% - 20% of all accidents, second only to side collisions and frontal collisions, and have always been a frequent type of accident.

[0003] In the research on preventing collisions and rear-end collisions in the prior art, all are aimed at controlling the following vehicle not to rear-end the preceding vehicle. There is no report on the method of the preceding vehicle to be rear-ended taking active speed change or lane change and other avoidance measures after warning and active prevention and control during the avoidance.

[0004] Therefore, there is an urgent need for a new technical solution in the prior art to solve this problem. Summary of the Invention

[0005] The technical problem to be solved by the present invention is: to provide a vehicle rear collision warning and active prevention and control system and method in a connected environment to solve the technical problem that in the research on preventing collisions and rear-end collisions in the prior art, all are aimed at controlling the following vehicle not to rear-end the preceding vehicle, and there is no report on the method of the preceding vehicle to be rear-ended taking active avoidance and active prevention and control during the avoidance.

[0006] The vehicle rear collision warning and active prevention and control system in a connected environment includes a vehicle information acquisition module, a data processing module, a safety judgment module, a warning module, and an execution module. The input end of the vehicle information acquisition module is connected to the vehicle networking platform, and the output end of the vehicle information acquisition module is connected to the data processing module. The vehicle information acquisition module is used to obtain information on the road traffic flow, the driving status of adjacent vehicles, the driving situation of the vehicle itself, and the status of pedestrians and non-motor vehicles from the vehicle networking platform, and send the obtained information to the data processing module;

[0007] The data processing module calculates the minimum safe distance between the two vehicles through the speeds of the vehicle itself and the following vehicle obtained from the vehicle information acquisition module, and then determines the safety braking distance threshold for each section in each case according to the set speed limit; and then determines the collision risk probability by combining the information on the road traffic flow and the real-time difference change between the distance between the front and rear vehicles and the minimum safe distance.

[0008] The safety judgment module has a risk assessment function module and a risk classification function module. Among them, the risk assessment function module evaluates whether there is a risk of being rear-ended for the vehicle itself based on the safety distance threshold calculated by the data processing module and the dangerous state factor measuring the collision risk. The risk classification function module, after the assessment result shows that there is a risk of being rear-ended, classifies the rear-end risk into multiple levels according to the risk degree value, including the first warning level, the second warning level, and the third warning level. Among them, the higher the risk level, the more serious the rear-end risk is.

[0009] The warning module gives corresponding safety warnings to the driver of the vehicle itself and the following vehicle according to the risk level obtained by the safety judgment module. The warning module includes an acoustic and optical warning function and an information interaction warning function.

[0010] The execution module controls the vehicle to take proactive avoidance measures in advance when the driver does not respond to the warning signal in time, reducing the occurrence of traffic rear-end accidents. The execution module executes different proactive avoidance measures according to the warning information of the warning module.

[0011] The information of the road surface traffic flow includes traffic flow density, the number of lanes and driving conditions, and road information. The road information includes road surface adhesion coefficient information, road section form information, and road channelization state information. The driving states of adjacent vehicles include the speed, acceleration / deceleration, and distance from the vehicle itself. The driving conditions of the vehicle itself include the driving speed and acceleration / deceleration of the vehicle itself. The states of pedestrians and non-motor vehicles include the speed and distance from the vehicle itself of pedestrians and non-motor vehicles.

[0012] The proactive avoidance measures include:

[0013] Acceleration execution function: When there is no vehicle in front and no collision risk on the side and rear, automatically accelerate to widen the distance from the following vehicle.

[0014] Lane change execution function: When there is a vehicle in front and no vehicle on the side, automatically plan a lane change route and execute a lane change operation.

[0015] Vehicle speed maintenance execution function: When there is a vehicle in front and there is a collision risk on the side and rear, maintain the vehicle speed and activate the protection device installed on the vehicle to reduce collision injuries.

[0016] A method for rear-end collision warning and active prevention and control of a vehicle in a connected environment, using the rear-end collision warning and active prevention and control system in the connected environment, includes the following steps, and the following steps are carried out sequentially:

[0017] Step 1: The vehicle information collection module obtains the information of the road surface traffic flow, the driving states of adjacent vehicles, the driving conditions of the vehicle itself, and the states of pedestrians and non-motor vehicles from the vehicle networking platform, and sends the obtained information to the data processing module.

[0018] Step 2: The data processing module calculates the minimum safe distance between the two vehicles based on the speeds of the vehicle itself and the following vehicle obtained from the vehicle information collection module, and then determines the safety braking distance thresholds for each section in various situations according to the set speed limit.

[0019] Step 3: Establish a dangerous state factor formula based on the minimum safe distance between the two vehicles and the safety braking distance threshold for this section. Determine the dangerous warning level through the interval where the obtained dangerous state factor value is located. The dangerous warning levels include: primary warning, secondary warning, and tertiary warning. The severity of the dangerous warning levels increases in order according to the level sequence.

[0020] Set the initial warning condition. Reaching the initial warning condition indicates a collision risk, and enter the warning mode. Obtain the driving state of the following vehicle through the vehicle information collection module, including the distance s from the vehicle itself, the speed v of the following vehicle, the relative speed v' between the following vehicle and the vehicle itself, and the acceleration / deceleration of the following vehicle. If the following vehicle has a deceleration a, it means the following vehicle has braking measures. Return to Step 2 and judge again whether there is a collision risk between the two vehicles when the vehicle itself continues to drive with the current motion state unchanged.

[0021] If there is no collision risk when driving at the current distance and speed, it is safe.

[0022] If there is a collision risk when driving at the current distance and speed, it is unsafe at this time. Issue an audible and visual warning, give a voice broadcast reminder to the following vehicle to decelerate, and at the same time give a light warning to the headlights of the preceding vehicle, and display the speed of the following vehicle, the distance from the vehicle itself, and the dynamic trend of the following vehicle on the display screen installed on the preceding vehicle.

[0023] If the following vehicle decelerates within the set time and returns to Step 2, and it is judged again that there is no collision risk between the two vehicles when the vehicle itself continues to drive with the current motion state unchanged, it is safe and the warning ends.

[0024] If the following vehicle still does not decelerate or decelerates but it is judged that there is still a collision risk between the two vehicles within the set time, a secondary alarm is issued to the vehicle itself and the following vehicle.

[0025] First, the driver makes an independent judgment. If the driver of the vehicle itself accelerates or changes lanes, the warning ends, return to Step 1, and the vehicle information collection module re-detects.

[0026] Step 4: After the vehicle information collection module re-detects, it is determined by the data processing module and the safety judgment module whether there is still a risk of collision or rear-end collision with the vehicle in front or the vehicle on the side or rear side after the driver of the vehicle itself accelerates or changes lanes.

[0027] If it is determined that there is a risk of collision or rear-end collision, a tertiary warning is taken.

[0028] If it is determined that there is no risk of collision or rear-end collision, then for the vehicle in front adjacent to the vehicle itself, the vehicle itself becomes the following vehicle, and the vehicle in front conducts cyclic monitoring and warning through steps 1 to 3. The vehicle in front uses the vehicle rear collision warning and active prevention and control system in the connected environment to conduct cyclic monitoring and warning on the vehicle itself after lane change by repeating steps 1 to 3, and reminds the following vehicle, that is, the driver of the vehicle itself, to control the speed after lane change and maintain a safe distance;

[0029] If the driver of the vehicle itself does not take effective actions to avoid collision or rear-end collision within the set time after receiving the warning, then the active prevention and control system is executed for assisted driving;

[0030] Step 5: When the vehicle in front detects a risk of collision or rear-end collision during cyclic monitoring and warning, and there is still a risk of collision or rear-end collision after audible and visual warnings, then the vehicle in front repeats step 4 and also takes measures such as accelerating or changing lanes to actively get out of danger;

[0031] Step 6: The vehicle in front of the vehicle in front is used as the monitoring vehicle again, repeating steps 4 and 5. Through cyclic monitoring and warning, the hidden danger of danger to the vehicle in front driving normally in the original lane after the vehicle itself changes lanes is solved, and the safety of the auxiliary function is improved.

[0032] When executing the active prevention and control system, different scenario models are distinguished according to the motion states of surrounding vehicles currently, and different decisions are made according to different scenario models to achieve assisted driving:

[0033] (1) The first scenario model is that there is no vehicle in front within the safe distance on this road, and there is a vehicle on the side rear;

[0034] At this time, the vehicle itself can accelerate, but it is divided into two situations:

[0035] One situation is that there is no vehicle within the safe distance after accelerating, which is not considered;

[0036] The other situation is that after accelerating, it enters the safe distance threshold from the vehicle in front. Then, a prompt is given to the vehicle itself. At the same time, relative to the vehicle in front, the vehicle itself is the following vehicle, and the vehicle in front conducts cyclic monitoring and warning, and there is no need to execute the active prevention and control system;

[0037] (2) The second scenario model is that there is a vehicle in front and no vehicle on the side;

[0038] At this time, lane change measures are taken, and it is also divided into two situations:

[0039] One situation is that the driver makes an effective judgment and operation to avoid collision, which is not considered;

[0040] Another situation is that under the condition of level-three early warning, the driver still fails to make an effective response to avoid collision within the set time. At this time, the active prevention and control system is executed, and at the same time, the distance from the vehicle ahead and surrounding obstacles is detected by radar, and the lane change is automatically planned.

[0041] (3) The third model is that there is a vehicle ahead and a vehicle on the side and rear.

[0042] In this case, accelerating will cause a collision or rear-end collision between this vehicle and the vehicle ahead. If the driver of this vehicle makes an operation error, a level-three early warning is given and the active prevention and control system is executed to actively prevent and control the vehicle speed to avoid rear-ending the vehicle ahead. At the same time, when the vehicle behind is in an out-of-control state and the speed is too fast, the active prevention and control system is executed to control the vehicle to pop out the driver's neck protection layer to reduce the injury in case of an accident.

[0043] The specific method of the lane change is as follows:

[0044] First, judge whether there will be a collision with the vehicle on the side and rear during the lane change. If there is a collision, a level-three early warning is issued. If the driver still continues to execute the lane change at this time, the active prevention and control system is executed;

[0045] Then, judge whether there will be a rear-end collision with the vehicle behind after the lane change. If not, the lane change is carried out. If there is, analyze the danger of the two lanes at the same time to obtain whether to change lanes or stop changing lanes;

[0046] Finally, after the lane change, repeat the hierarchical early warning for the vehicles in the front and rear of the section, and select the lane with the smaller maximum speed limit and the smallest safety braking distance threshold for the lane change operation.

[0047] When the lane to be changed is a multi-lane and there are vehicles in front of both the left and right lanes of this vehicle, first judge which lane has a safer vehicle condition. According to the speed, acceleration, adhesion coefficient between the vehicle and the ground of the vehicle ahead on the two lanes obtained from the vehicle networking platform, and the relative distance d between this vehicle and the vehicle ahead, and then combine the speed, acceleration, and adhesion coefficient between the vehicle and the ground of this vehicle, select the lane that meets the non-collision condition shown in the following formula for lane change:

[0048]

[0049] In the formula, v 1 is the speed of this vehicle, a 1 is the acceleration of this vehicle, v 2 is the speed of the vehicle ahead, a 2 is the acceleration of the vehicle ahead;

[0050] If both the left and right lanes meet the above formula, select the lane with a smaller value for lane change, which has a greater safety distance and less potential safety hazard.

[0051] The initial early warning conditions are divided into two situations:

[0052] The first case is that vehicle A is d meters in front of vehicle B, the speed of vehicle B is v B , and the deceleration of vehicle B is a BB , the speed of vehicle A is v A , and the acceleration of vehicle A is a A , and its initial warning condition is:

[0053]

[0054] The second case is that vehicle A is d meters in front of vehicle B, vehicle A is moving at a constant speed of v A , the speed of vehicle B is v B , and the acceleration of vehicle B is a B , and its initial warning condition is:

[0055]

[0056] The formula for the safe braking distance threshold is:

[0057]

[0058] where D b is the safe braking distance threshold; V max is the maximum speed limit of the current lane; G is the load; b is the distance from the center of mass of the motor vehicle to the center line of the rear axle; m is the mass of the motor vehicle; h g is the height of the center of mass of the vehicle; is the road surface adhesion coefficient, taking 0.8 for dry road surface and 0.4 for wet and slippery road; α is the slope angle, taking the plus sign for the denominator formula when going uphill and the minus sign when going downhill;

[0059] The formula for the minimum safe distance between the two vehicles is:

[0060]

[0061] Whether there is a risk of collision, or whether there is a risk of collision or rear-end collision, both are determined by the risk state factor. The solution formula for the risk state factor is as follows:

[0062]

[0063] where f d is the risk state factor, D w is the minimum safe distance, D b is the safe braking distance threshold, and D is the actual distance between the front and rear vehicles.

[0064] Through the above design scheme, the present invention can bring the following beneficial effects:

[0065] The present invention aims to improve driving safety. First of all, the rear-end collision warning system can monitor the surrounding road environment and the traffic conditions behind the vehicle in real time. When a potential rear-end collision risk is detected, it will issue a warning in time to remind the driver to take measures to avoid collision. The active prevention and control system can automatically perform emergency braking and other operations when necessary, thus greatly improving driving safety and further reducing the possibility of traffic congestion and accidents. Secondly, it promotes the development of intelligent transportation and automotive technology, which is in line with the future trend of traffic development. The research on the rear-end collision warning and active prevention and control system for sedans based on rear detection involves multiple fields such as sensor technology, data processing, and artificial intelligence, which has a positive effect on promoting the progress and innovation of automotive technology, further developing intelligent transportation, and improving road traffic efficiency. At the same time, it has a beneficial effect on reducing the driver's psychological pressure. During long-term driving or in a complex traffic environment, the driver may feel fatigued or inattentive. At this time, the rear-end collision warning and active prevention and control system can intervene in time to provide additional safety protection for the driver and reduce their driving pressure. Through real-time monitoring and warning, the system can help the driver better master the traffic conditions around the vehicle, reduce operations such as emergency braking in case of emergency, and thus improve driving comfort. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] The present invention will be further described below in conjunction with the drawings and specific embodiments:

[0067] Figure 1 It is a flowchart of the method in the vehicle rear-end collision warning and active prevention and control system and method under the networked environment of the present invention;

[0068] Figure 2 It is a flowchart of the first scenario model in the vehicle rear-end collision warning and active prevention and control system and method under the networked environment of the present invention;

[0069] Figure 3 It is a flowchart of the second scenario model in the vehicle rear-end collision warning and active prevention and control system and method under the networked environment of the present invention;

[0070] Figure 4 It is a flowchart of the third scenario model in the vehicle rear-end collision warning and active prevention and control system and method under the networked environment of the present invention. SPECIFIC EMBODIMENTS

[0071] Vehicle Rear Collision Warning and Active Prevention and Control System in the Internet of Vehicles Environment, including a vehicle information collection module, a data processing module, a safety judgment module, a warning module, and an execution module. The input end of the vehicle information collection module is connected to the vehicle networking platform, and the output end is connected to the data processing module. The function of the vehicle information collection module is to obtain information on road traffic flow from the vehicle networking platform, including traffic flow density, the number of lanes and driving conditions, road information including road adhesion coefficient information, road section form information, and road channelization status information, the driving status of adjacent vehicles including the speed, acceleration and deceleration, distance from the vehicle itself, the driving conditions of the vehicle itself including speed, acceleration and deceleration, and the status of pedestrians and non-motor vehicles. And send the obtained information to the data processing module.

[0072] The data processing module is used to calculate the risk level according to the information received from the vehicle networking platform according to the set program steps. Calculate the minimum safe distance to ensure safety through the speed of the vehicle itself and the following vehicle obtained from the vehicle information collection module. Assuming that the road speed limit is the speed of the following vehicle and the preceding vehicle, based on the minimum safe vehicle distance calculation formula, determine the safety braking distance threshold for each section in each case. Then, in combination with the road traffic flow situation and the comparison of the distance between the front and rear vehicles and the minimum safe distance, calculate the risk level at this time, predict whether there is a risk of collision between the vehicle itself and the surrounding vehicles, and if there is a risk of collision, determine the risk warning level, and send a corresponding warning signal to the risk warning module according to the risk warning level.

[0073] The safety judgment module judges whether the vehicle itself has the risk of being rear-ended based on the calculation result of the data processing module and obtains the risk level at this time if there is a safety risk. The safety judgment module has a risk assessment function and a risk classification function. Among them, the risk assessment function can evaluate whether the vehicle itself is at risk of being rear-ended according to the safety distance threshold and collision risk probability calculated by the data processing module; the risk classification function, when the assessment result shows that there is a risk of being rear-ended, classifies the rear-end risk into multiple levels according to the risk degree, including the first warning level, the second warning level, and the third warning level. Among them, the higher the risk level, the more serious the rear-end risk.

[0074] The warning module gives safety warnings to the driver of the vehicle itself and the following vehicle according to the result of the safety judgment module. The warning module includes an acoustic and optical warning function and an information interaction warning function. The acoustic and optical warning function sends a warning signal to the driver through voice broadcast and light flashing; the information interaction warning sends a warning message to the following vehicle through vehicle networking technology to remind the driver of the following vehicle to decelerate or take evasive measures. At the same time, the warning module gives warnings of different levels according to different safety levels of the safety judgment module. The risk warning levels include: the first warning level, the second warning level, and the third warning level. The severity of the risk warning levels increases in order according to the level;

[0075] When the danger warning level is the first warning level, the information processing and judgment module is configured to send a first warning signal to the danger warning module, so that the danger warning module performs a first warning action; when the danger warning level is the second warning level, the information processing and judgment module is configured to send a second warning signal to the danger warning module, so that the danger warning module performs a second warning action; when the danger warning level is the third warning level, the information processing and judgment module is configured to send a third warning signal to the danger warning module, so that the danger warning module performs a third warning action.

[0076] When the driver fails to respond to the warning signal in time, the execution module controls the vehicle to take active avoidance measures to reduce the occurrence of traffic rear-end accidents. The execution module executes different anti-rear-end implementation methods according to the warning information of the warning module. Acceleration execution function: When there is no vehicle in front and no collision risk on the side and rear, automatically accelerate to increase the distance from the vehicle behind; Lane-changing execution function: When there is a vehicle in front and no vehicle on the side, automatically plan the lane-changing route and execute the lane-changing operation; Vehicle speed maintenance execution function: When there is a vehicle in front and there is a collision risk on the side and rear, maintain the vehicle speed and activate the protection device to reduce collision injuries.

[0077] As the hardware device of the vehicle rear-end collision warning and active prevention and control system in the networked environment, it includes:

[0078] Positioning module: Adopt the MC20 module, which has the advantages of small volume, low power consumption, single SIM card standby, etc., and can provide wireless mobile communication and accurate navigation and positioning functions;

[0079] Information acquisition module: Adopt the CC1101 module, which is a micro-power UHF wireless transceiver;

[0080] Data processing module: Adopt the STC15W4K32S4 single-chip microcomputer;

[0081] STC15W4K32S4 is a high-performance 8-bit single-chip microcomputer produced by STC Company. It is based on the classic 8051 core, but has been significantly enhanced in performance and functions. STC15W4K32S4 provides rich peripheral interfaces, including an 8-channel 10-bit AD converter, a 6-channel 15-bit PWM output, and up to 9 groups of serial communication ports. These functions make it very suitable for applications that require complex control and communication tasks. The working voltage range is from 2.5V to 5.5V, which enables it to adapt to various different power supply environments, including battery-powered portable devices. It has 32KB of Flash program memory, which can store a large amount of program code and data, and is equipped with 4KB of RAM to ensure sufficient operating memory.

[0082] Warning Module: The intelligent voice warning module uses a voice broadcaster to achieve the voice alarm function. The voice chip selects the ISD1820OTP voice chip, which can be externally connected to a single-chip microcomputer and a player. When the data signal formed inside the single-chip microcomputer is completely within the dangerous range, the voice broadcast switch is triggered, and this module quickly broadcasts to remind the driver of this vehicle that they are in danger, so as to reduce the occurrence of traffic accidents. The lighting warning module uses an Arduino single-chip microcomputer as the core of the control unit, responsible for reading sensor data and controlling warning lights.

[0083] A vehicle rear collision warning and active prevention and control method under the networked environment is as follows:

[0084] I. Preliminary risk judgment:

[0085] Vehicle A is in front of vehicle B at a distance of d, the speed of vehicle B is v B , the deceleration of vehicle B is a BB , the speed of vehicle A is v A , the acceleration of vehicle A is a A , when , start warning to remind the driver of vehicle A.

[0086] Vehicle A is in front of vehicle B at a distance of d, vehicle A is traveling at a constant speed with a speed of v A , the speed of vehicle B is v B , the acceleration of vehicle B is a B , when , start warning to remind the driver of vehicle A.

[0087] By introducing a danger state factor f d to evaluate the danger level of the vehicle's own state, making the collision avoidance system control more detailed and accurate.

[0088]

[0089] f d is the danger state factor, D w is the minimum safety distance, D b is the safety braking distance threshold, D is the actual distance between the front and rear vehicles. When f d <0, it means the vehicle distance is greater than the alarm distance and is in a safe state; when 0 ≤ f d <0.5, it is a first-level warning, indicating that the vehicle distance has just entered the alarm distance and is in the system warning and pre-acceleration state; when 0.5 ≤ f d <1, it is a second-level warning, indicating that the vehicle distance is approaching the emergency acceleration distance and entering the system-assisted acceleration stage. In this stage, if the driver does not take evasive measures, the system will take over the vehicle; when f d ≥1, it is a third-level warning, indicating that the vehicle distance has reached the emergency acceleration distance and entered the emergency acceleration and steering stage.

[0090] The formula for the safety braking distance threshold is as follows:

[0091]

[0092] where D b is the safety braking distance threshold; V max is the maximum speed limit of the current lane; G is the load; b is the distance from the center of mass of the motor vehicle to the center line of the rear axle; m is the mass of the motor vehicle; h g is the height of the center of mass of the vehicle; is the road surface adhesion coefficient, taking 0.8 for dry road surfaces and 0.4 for wet and slippery roads; α is the slope angle, with the plus sign taken for the expression in the denominator when going uphill and the minus sign when going downhill;

[0093] The formula for the minimum safe distance between two vehicles is as follows:

[0094]

[0095] II. Early warning levels and avoidance measures at all levels:

[0096] (1) When the minimum safe distance between two vehicles is less than the safety braking distance threshold of this section, the driving state of the following vehicle is obtained through rear detection. The main parameters include the distance s from the following vehicle to the own vehicle, the vehicle speed v, the relative vehicle speed v', and the deceleration a when the following vehicle has braking measures. Whether there is a collision risk between the two vehicles is calculated through an algorithm when continuing to drive with the current motion state unchanged. Two levels, safe and unsafe, are set. When it is found that there is no collision risk when driving at the current distance and vehicle speed, it is safe. When it is found that the conditions for a rear-end collision are met, it is unsafe at this time. Acoustic and optical warnings are issued, and a voice broadcast reminder is given to the following vehicle to decelerate. At the same time, a light warning is issued to the headlights of the leading vehicle to indicate the state and dynamic trend of the following vehicle.

[0097] (2) When the following vehicle does not make an effective response (no operation change or the change is not enough to avoid a rear-end collision), a secondary alarm is issued to the own vehicle and the following vehicle at this time, and the best solution is analyzed in a timely manner according to the perceived current road surface information, that is, the motion state of the surrounding vehicles. First, the driver makes an independent judgment. When the driver of the own vehicle makes a completely effective operation, the early warning ends. When the driver makes an effective judgment but at the same time it will cause a rear-end collision risk with the vehicle in front and on the side and rear, at this time, regarding the vehicle in front, the own vehicle is regarded as the following vehicle, and a cyclic early warning is carried out for the vehicle in front. The vehicle in front uses the early warning based on the rear detection of the vehicle networking to monitor the vehicle after lane change, and timely reminds the driver of the following vehicle to control the vehicle speed after lane change to keep a safe distance. If it is still within the dangerous distance range, the road conditions ahead are analyzed, and measures such as accelerating or changing lanes are taken to actively get out of danger. Through the cyclic early warning, the potential danger to the vehicle in front driving normally in the original lane after the own vehicle changes lanes can be effectively solved, and the safety of the auxiliary function is improved.

[0098] (3) For the vehicle behind and to the side, a warning is given to this vehicle to indicate the risk; when the driver of this vehicle fails to take any action or makes a wrong action (which greatly increases the risk of collision with other vehicles), a three-level warning is taken for this vehicle at this time.

[0099] III. Autonomous Decision-making:

[0100] After the acoustic and optical warning module issues an alarm, if the driver fails to react in time or the current reaction is insufficient to avoid danger, the vehicle will make an autonomous decision.

[0101] (1) As Figure 2 shown, the first scenario model is that there is no vehicle in front within the safe distance of this road, and there is a vehicle behind and to the side. At this time, this vehicle can accelerate. At this time, in one case, there is also no vehicle within the safe distance after accelerating, which is not considered. In another case, after accelerating, it enters the safe distance threshold from the vehicle in front, and a prompt can be given to this vehicle. At the same time, as a vehicle behind, this vehicle circularly warns the vehicle in front. Since the vehicle networking technology measures the speed in real time and shares information, the vehicle in front has already predicted the dynamics behind and shortened the reaction time, and the driver of this vehicle also has the ability to judge and operate. At this time, the possibility of risk is relatively small and the operation space is relatively large.

[0102] (2) As Figure 3 shown, the second scenario model is that there is a vehicle in front and no vehicle to the side. At this time, a lane change measure is taken, and a lane change measure can be taken at this time. It is not considered when the driver makes an effective judgment. When the driver still fails to make an effective reaction under the condition of a three-level alarm, the autonomous prevention and control system is started at this time, and at the same time, the distances from the vehicle in front and surrounding obstacles are detected by radar, and a reasonable lane change route can be planned.

[0103] (3) As Figure 4 shown, the third scenario model is that there is a vehicle in front and a vehicle behind and to the side. In this case, compared with model one, accelerating will cause a rear-end collision with the vehicle in front. When the driver of this vehicle operates wrongly, the early warning starts the assisted driving system and the protection system, maintains the original vehicle speed and actively prevents and controls the rear-end collision with the vehicle in front. At the same time, when the vehicle behind is out of control and has too high a speed, a protective layer pops out for the driver's neck to reduce the injury in case of an accident.

[0104] IV. Lane Change Operation:

[0105] When changing lanes, first analyze whether there will be a collision with the vehicle behind and to the side during the lane change process. If there is a collision, a three-level warning is issued. If the driver continues to execute the lane change, the active prevention and control is started; then analyze whether there is a rear-end collision after the lane change. If not, the lane change is carried out. If there is, analyze the danger of both lanes at the same time to obtain whether to change lanes or stop changing lanes. After changing lanes, repeat the hierarchical warning for the vehicles in front and behind the section, and repeat the alarm system of the original lane. Usually, the lane with the lowest maximum speed limit and the smallest safe braking distance threshold is preferably selected for lane change operation.

[0106] The specific logic control of the method proposed by the present invention is as follows:

[0107] 1. Data collection

[0108] In order to achieve the accuracy and precision of data collection and early warning judgment, local road network features of complex traffic roads are identified according to the existing electronic map, and the entire road network system is divided into intersection sections with intersections and straight sections. The electronic map is loaded in the vehicle networking service platform;

[0109] After real-time acquisition of vehicle position data and electronic map data, data parsing is performed to extract key data required for subsequent calculations and perform road matching. After data interaction, it can be known whether there are oncoming vehicles and their numbers in the section, as well as driving parameters such as the speed and acceleration of other vehicles.

[0110] 2. Data processing

[0111] First, set the safety distance threshold for the danger warning level. The alarm level is based on the pre-designed safety distance threshold and, in combination with the data such as the distance, speed, and acceleration between the vehicle itself and the following vehicle obtained, calculates the possibility of collision through data processing and issues corresponding alarms. And based on whether the subsequent driver operates or not and the movement status of the following vehicle, it is judged whether to further alarm. If the following vehicle does not take corresponding deceleration measures, a secondary warning is issued. If the driver of the vehicle itself does not take evasive measures or operates improperly, a tertiary warning is issued.

[0112] The logic flow of the present invention is as Figure 1 shown. The vehicle-road information obtained will be transmitted to the data processing module and the safety judgment module through the vehicle networking service platform; the current driving state of the driver is evaluated for safety, and the danger is classified and processed. Then, the execution command is transmitted to the alarm device, that is, the warning module. After the alarm is issued, according to the subsequent operations of the drivers of the front and rear vehicles, it is judged whether there is still a possibility of collision, and further warnings are given, and active decision-making and prevention and control are intervened. Through system integration, the integrated operation of the vehicle networking service platform, information collection device, data processing device, warning, and active prevention and control is realized. The vehicle-road information includes the driving vehicle of the current driver and the driving parameter information of the following vehicle and road information; the driving parameter information includes speed, acceleration, and distance; the road information includes road surface adhesion coefficient information, road section form information, and road channelization state information, and the road section form information includes urban roads and highways.

Claims

1. The vehicle rear collision warning and active prevention system in a connected environment is characterized by: It includes a vehicle information collection module, a data processing module, a safety judgment module, an early warning module and an execution module. The input end of the vehicle information collection module is connected to the vehicle networking platform, and the output end of the vehicle information collection module is connected to the data processing module. The vehicle information collection module is used to obtain road traffic flow information, the driving status of adjacent vehicles, the driving status of the vehicle, and the status of pedestrians and non-motor vehicles from the vehicle networking platform, and send the obtained information to the data processing module; The data processing module calculates the minimum safe distance between the two vehicles by using the speeds of the vehicle and the following vehicle obtained from the vehicle information collection module, and then determines the safe braking distance threshold for each road section under each situation according to the set speed limit; The collision risk probability is then determined by combining the road traffic flow information and the real-time difference between the distance between the front and rear vehicles and the minimum safe distance. The safety judgment module has a risk assessment function module and a risk classification function module; The risk assessment module evaluates whether the vehicle is at risk of being rear-ended based on the safety distance threshold calculated by the data processing module and the risk status factor for measuring the collision risk. The risk classification module classifies the rear-end collision risk into multiple levels according to the risk level value after the evaluation result shows that there is a risk of being rear-ended. The higher the risk level, the more serious the rear-end collision risk. The warning module provides corresponding safety warnings to the driver of the vehicle and the following vehicle according to the risk level obtained by the safety judgment module. The warning module includes an audio-visual warning function and an information interaction warning function. The execution module controls the vehicle to take proactive avoidance measures in advance when the driver fails to respond to the warning signal in time, thereby reducing the occurrence of rear-end collisions; the execution module executes different proactive avoidance measures according to the warning information of the warning module.

2. The vehicle rear collision warning and active prevention system in a networked environment according to claim 1, characterized in that: The information on road traffic flow includes traffic flow density, the number of lanes and driving conditions, and road information; the road information includes road adhesion coefficient information, road section morphology information, and road channelization status information; the driving status of adjacent vehicles includes the vehicle's speed, acceleration / deceleration, and distance from the vehicle; the driving condition of the vehicle includes the vehicle's driving speed and acceleration / deceleration; the status of pedestrians and non-motor vehicles includes the speed of pedestrians and non-motor vehicles, and the distance from the vehicle.

3. The vehicle rear collision warning and active prevention system in a networked environment according to claim 1, characterized in that: The active avoidance measures include: Acceleration execution function: When there is no car in front and no risk of collision on the side or rear, the car will automatically accelerate to increase the distance from the car behind. Lane change execution function: automatically plans the lane change route and executes the lane change operation when there is a car ahead and no car on the side; Vehicle speed maintenance execution function: When there is a car in front and there is a risk of collision from the side or rear, the vehicle speed is maintained and the protection device installed on the car is activated to reduce collision damage.

4. A vehicle rear collision warning and active prevention method in a networked environment, using the vehicle rear collision warning and active prevention system in a networked environment as described in claim 1, characterized in that: The process includes the following steps, which are performed in sequence: Step 1: The vehicle information collection module obtains information about road traffic flow, the driving status of adjacent vehicles, the driving status of the vehicle itself, the status of pedestrians and non-motorized vehicles from the Internet of Vehicles platform, and sends the obtained information to the data processing module; Step 2: The data processing module calculates the minimum safe distance between the two vehicles by using the speeds of the vehicle and the following vehicle obtained from the vehicle information collection module, and then determines the safe braking distance threshold for each road section under each situation according to the set speed limit; Step 3: Based on the minimum safe distance between the two vehicles and the threshold of the safe braking distance of the road section, a dangerous state factor formula is established, and the dangerous warning level is determined by the interval in which the obtained dangerous state factor value is located. The dangerous warning levels include: first-level warning, second-level warning and third-level warning, and the severity of the dangerous warning level increases in order of level; Set the initial warning conditions. When the initial warning conditions are met, it means there is a collision risk. Enter the warning mode and obtain the driving status of the rear vehicle through the vehicle information collection module, including the distance s from the vehicle, the speed v of the rear vehicle, the relative speed v' between the rear vehicle and the vehicle, and the acceleration / deceleration of the rear vehicle. If the rear vehicle has a deceleration a, it means that the rear vehicle has taken braking measures. Return to step 2 and judge again whether there is a collision risk between the two vehicles if the vehicle continues to drive with the current motion state unchanged; If there is no risk of collision at the current distance and speed, it is safe; If there is a risk of collision at the current distance and speed, it is unsafe and an audible and visual warning is issued. A voice message is broadcast to the vehicle behind to remind it to slow down. At the same time, a light warning is issued to the headlights of the vehicle in front. The speed of the vehicle behind, the distance to the vehicle, and the dynamic trend of the vehicle behind are displayed on the display screen installed in the vehicle in front. The following vehicle decelerates within the set time and returns to step 2. If it is determined that the vehicle continues to move in the current state of motion and there is no risk of collision between the two vehicles, it is safe and the warning ends. If the following vehicle does not slow down within the set time or slows down but it is judged that there is still a risk of collision between the two vehicles, a secondary alarm will be issued for the vehicle and the vehicle behind; First, the driver makes his own judgment. If the driver accelerates or changes lanes, the warning ends and the process returns to step 1. The vehicle information collection module re-detects. Step 4: After the vehicle information collection module re-detects, the data processing module and the safety judgment module determine whether the driver of the vehicle still has the risk of colliding or rear-ending the vehicle in front or behind after accelerating or changing lanes; If it is determined that there is a risk of collision or rear-end collision, a three-level warning will be adopted; If it is determined that there is no risk of collision or rear-end collision, then at this time, for the vehicle in front adjacent to the vehicle in front, the vehicle in front becomes the rear vehicle, and the vehicle in front performs cyclic monitoring and warning through steps 1 to 3. The vehicle in front uses the vehicle rear collision warning and active prevention and control system in the networked environment to perform cyclic monitoring and warning on the vehicle after changing lanes by repeating steps 1 to 3, and reminds the driver of the rear vehicle, i.e. the vehicle in front, to control the speed after changing lanes and maintain the distance between vehicles; If the driver of the vehicle fails to take effective actions to avoid a collision or rear-end collision within the set time after receiving the warning, the active prevention and control system will assist in driving; Step 5: If the vehicle ahead detects a risk of collision or rear-end collision during the cyclic monitoring and warning, and still shows a risk of collision or rear-end collision after the sound and light warning, the vehicle ahead repeats step 4 and also takes measures such as acceleration or lane change to actively escape from danger; Step 6: The vehicle in front of the vehicle in front is used as a monitoring vehicle again, and steps 4 and 5 are repeated. Through cyclic monitoring and early warning, the hidden danger of the vehicle in front that is normally driving in the original lane after the vehicle changes lanes is resolved, thereby improving the safety of the auxiliary function.

5. The vehicle rear collision warning and active prevention method in a networked environment according to claim 4 is characterized by: The active prevention and control system is implemented by distinguishing the following different scenario models according to the current motion status of surrounding vehicles, and making different decisions according to different scenario models to achieve assisted driving: (1) The first scenario model is that there is no car in front of the road within the safe distance, but there is a car on the side and rear; At this time, the car can accelerate, but there are two situations: One situation is that there is no vehicle within the safe distance after accelerating, so it is not considered; In another case, after accelerating, the vehicle enters the safety distance threshold with the vehicle in front, and then the vehicle is prompted. At the same time, the vehicle is the rear vehicle, and the vehicle in front performs cyclic monitoring and warning, and there is no need to implement the active prevention and control system. (2) The second scenario model is that there is a car in front and no car on the side; At this time, the lane change measures are also divided into two situations: In one case, the driver makes effective judgment and operation to avoid the collision, without any consideration; In another case, under the third-level warning condition, if the driver still fails to make an effective response to avoid collision within the set time, the active prevention and control system will be executed, and the distance to the vehicle in front and surrounding obstacles will be detected by radar, and lane change will be automatically planned; (3) The third model has a car in front and a car behind; Accelerating in this situation may cause a collision or rear-end collision with the vehicle ahead. If the driver of this vehicle makes an operational error, a level 3 warning will be issued and the active prevention and control system will be executed to actively control the vehicle speed to avoid a rear-end collision with the vehicle ahead. At the same time, if the rear vehicle is out of control and speeding too fast, the active prevention and control system will control the vehicle to pop out the driver's neck protection layer to reduce injuries in the event of an accident.

6. The vehicle rear collision warning and active prevention method in a networked environment according to claim 4 is characterized by: The specific method of changing lanes is as follows: First, it determines whether there will be a collision with the vehicle behind or on the side during the lane change process. If there is a collision, a level 3 warning will be issued. If the driver continues to change lanes, the active prevention and control system will be activated. Then, it is determined whether there is a rear-end collision with the rear vehicle after the lane change. If not, the lane is changed. If so, the danger of the two lanes is analyzed at the same time to decide whether to change lanes or stop changing lanes; Finally, after changing lanes, the system will repeat graded warnings for vehicles in front and behind the road section, and select the lane with a lower maximum speed limit and the smallest safe braking distance threshold for lane changing.

7. The vehicle rear collision warning and active prevention method in a networked environment according to claim 6 is characterized by: If the lane-changing road is multi-lane and there are vehicles in front of both the left and right lanes of the vehicle, first determine which lane is safer. According to the speed, acceleration, vehicle-ground adhesion coefficient, and relative distance d between the vehicle and the vehicle in front on the two lanes obtained from the Internet of Vehicles platform, and then combined with the speed, acceleration, and vehicle-ground adhesion coefficient of the vehicle, select the lane that meets the non-collision condition shown in the following formula for lane change: In the formula, v1 is the speed of the vehicle, a1 is the acceleration of the vehicle, v2 is the speed of the preceding vehicle, and a2 is the acceleration a2 of the preceding vehicle; If both the left and right lanes satisfy the above formula, then choose Changing lanes in a lane with a smaller value will have a greater safety distance and less potential safety hazards.

8. The vehicle rear collision warning and active prevention method in a networked environment according to claim 4 is characterized by: The initial warning conditions are divided into two situations: The first is that vehicle A is at a distance d in front of vehicle B, and the speed of vehicle B is v. B , the deceleration of the rear vehicle B is a BB , the speed of vehicle A is v A , the acceleration of vehicle A is a A , and its initial warning conditions are: The second is that vehicle A is at a distance d in front of vehicle B and is traveling at a constant speed of v. A , the speed of the following car B is v B , the acceleration of the following vehicle B is a B , and its initial warning conditions are:

9. The vehicle rear collision warning and active prevention method in a networked environment according to claim 4 is characterized by: The safe braking distance threshold formula is: Among them, D b is the safe braking distance threshold; V max is the maximum speed limit of the current lane; G is the load; b is the distance from the center of mass of the vehicle to the center line of the rear axle; m is the mass of the vehicle; h is the weight of the vehicle. g is the height of the center of mass of the car; is the road adhesion coefficient, which is 0.8 on dry roads and 0.4 on wet roads; α is the slope angle, which is positive when going uphill and negative when going downhill; The minimum safe distance formula between the two vehicles is:

10. The vehicle rear collision warning and active prevention method in a networked environment according to claim 4, characterized in that: Whether there is a risk of collision, or whether there is a risk of collision or rear-end collision, both are determined by the dangerous state factor, and the solution formula of the dangerous state factor is as follows: Among them, f d is the risk factor, D w is the minimum safety distance, D b is the safe braking distance threshold, and D is the actual distance between the front and rear vehicles.

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