A road rear-end collision prevention early warning system and method in foggy weather

Abstract

This invention discloses a road rear-end collision prevention warning system in foggy weather, including an environmental data acquisition module, an on-board control module, and a warning information processing module. The environmental data acquisition module is used to collect real-time weather data and data from the vehicle ahead; the on-board control module is used to collect real-time data from the vehicle itself; the warning information processing module is used to determine whether to send a warning message based on the real-time weather data, data from the vehicle ahead, and data from the vehicle itself; the on-board control module is also used to receive the warning message sent by the warning information processing module and issue a warning. This invention also discloses a road rear-end collision prevention warning method in foggy weather. By real-time monitoring and tracking of the traffic status of the vehicle ahead and the current status of the vehicle itself, this invention guides the driver to execute driving strategies under different traffic conditions, effectively improving following safety, reducing rear-end collisions caused by the braking of the vehicle ahead, and improving traffic efficiency and urban road traffic safety.

Description

Technical Field

[0001] This invention belongs to the field of traffic safety control technology, specifically relating to a road rear-end collision prevention warning system and method in foggy weather conditions. Background Technology

[0002] With the rapid development of road transportation and the automotive industry, the number of motor vehicles and drivers in my country has been increasing year by year. However, rear-end collisions are still common. Adverse weather conditions such as rain and fog greatly reduce road capacity. As the most active yet uncontrollable factor in the traffic system, drivers' behavior is prone to significant fluctuations in such complex driving environments. If they fail to take timely driving measures, serious traffic accidents are highly likely. Therefore, reducing the adverse effects of adverse weather on drivers and improving vehicle operating efficiency has become one of the urgent problems to be solved.

[0003] Currently, drivers are typically alerted to adverse weather conditions by setting up static roadside signs, supplemented by flashing signs and variable message signs. However, drivers' following behavior varies under different traffic conditions. When traffic flow is low, drivers have more freedom of action, and ensuring drivers maintain their current speed safely is the primary concern for traffic management departments. Conversely, when traffic flow is high, drivers may slow down or even stop prematurely to find a suitable following distance, leading to wasted road resources and traffic delays. In such cases, guiding drivers to slow down at appropriate locations is a crucial task that needs to be addressed with existing technology. Summary of the Invention

[0004] To address the shortcomings of the existing technology, this invention discloses a road rear-end collision prevention and warning system for foggy weather conditions, employing the following technical solution:

[0005] A rear-end collision prevention warning system for foggy weather includes an environmental data acquisition module, a vehicle control module, and a warning information processing module. The environmental data acquisition module is used to collect real-time weather data and data from vehicles ahead. The vehicle control module is used to collect real-time data from the vehicle itself. The warning information processing module is used to determine whether a warning is needed based on the real-time weather data, data from vehicles ahead, and the vehicle's own data. If so, a warning message is sent; otherwise, no warning message is sent. The vehicle control module is also used to receive the warning message sent by the warning information processing module and issue a warning.

[0006] Furthermore, the environmental data acquisition module includes a weather data acquisition unit and a vehicle-to-cause data acquisition unit. The weather data acquisition unit is used to collect real-time weather data and send the weather data to the early warning information processing module. The weather data includes visibility, humidity, atmospheric temperature, wind speed, rainfall, and air pressure. The vehicle-to-cause data acquisition unit is used to collect real-time vehicle-to-cause data and send the vehicle-to-cause data to the early warning information processing module. The vehicle-to-cause data includes the vehicle type, speed, acceleration, and distance between the vehicle and the vehicle.

[0007] Furthermore, the vehicle control module includes a vehicle data acquisition unit and a voice warning unit. The vehicle data acquisition unit is used to collect real-time vehicle data and send the vehicle data to the warning information processing module. The vehicle data includes vehicle speed and vehicle acceleration. The voice warning unit is used to receive the warning information sent by the warning information processing module and issue a voice warning.

[0008] Furthermore, based on real-time weather data, data from vehicles ahead, and data from the vehicle itself, the determination of whether a warning is needed includes the following steps:

[0009] Step 1: Determine if the weather is foggy based on weather data. If yes, proceed to Step 2; otherwise, no warning is needed. Step 2: Determine if the vehicle ahead is decelerating based on data from the vehicle ahead. If yes, proceed to Step 3; otherwise, no warning is needed. Step 3: Calculate the vehicle's warning parameters based on real-time data from the vehicle ahead and the vehicle's own data. Step 4: Determine the vehicle's status based on the warning parameters and the theoretical emergency state range. If the vehicle is in a safe state, no warning is needed; if the vehicle is not in a safe state, send a warning message based on the vehicle's status. Step 5: After the onboard control module issues a warning, determine whether the vehicle takes countermeasures based on real-time data from the vehicle ahead and the vehicle's own data. If yes, stop sending warning messages; otherwise, return to Step 3.

[0010] Furthermore, the calculation formula for the vehicle's warning parameters is as follows:

[0011]

[0012] In the formula, τ -1 Let t be the ratio of the rate of change of the imaging angle of the vehicle in front to the size of the imaging image in the eyes of the driver of the vehicle ahead, i.e., the warning parameter of the vehicle ahead; W is the width of the vehicle in front; v L The speed at which the vehicle in front begins to decelerate; a L v is the acceleration of the vehicle in front; F Δt is the speed of the vehicle when the vehicle in front begins to decelerate; Δt is the time interval from when the vehicle in front begins to decelerate to time t; d is the distance between the front and rear vehicles at time t.

[0013] Furthermore, the theoretical emergency state interval is: when τ -1 The safe interval is when I1 ≤ I1, and when I1 < τ -1 When I ≤ I2, it is a general emergency interval; when I2 < τ -1 When ≤I3, it is an emergency interval; when τ -1 >I3 is the emergency braking range; where I1 is the 95th percentile of the warning parameters of the vehicle at the moment the preceding vehicle begins to decelerate in the "driver warning parameter database"; I3 is the 95th percentile of the warning parameters of the vehicle at the moment the vehicle begins to decelerate in the "driver warning parameter database"; and I2 is the median value of I1 and I3.

[0014] Furthermore, step four specifically involves: determining the vehicle's status based on its warning parameters and the theoretical emergency state range. If the vehicle's warning parameters fall within the safe range, the vehicle is in a safe state and no warning is needed. If the vehicle's warning parameters fall within the general emergency range, the vehicle is in a general emergency state and a "general emergency" warning message is sent. If the vehicle's warning parameters fall within the emergency range, the vehicle is in an emergency state and an "emergency" warning message is sent. If the vehicle's warning parameters fall within the emergency braking range, the vehicle is in an emergency braking state and an "emergency braking" warning message is sent.

[0015] Furthermore, when the voice warning unit receives a "general emergency" warning message, it broadcasts a "maintain a safe distance" voice warning message; when the voice warning unit receives an "emergency" warning message, it broadcasts a "rear-end collision risk, slow down" voice warning message; when the voice warning unit receives an "emergency braking" warning message, it broadcasts an "emergency rear-end collision warning" voice warning message. The vehicle control module also includes an emergency braking unit, which is used to control the vehicle to perform emergency braking after receiving an "emergency braking" warning message.

[0016] Furthermore, in step five, determining whether the vehicle has taken countermeasures based on real-time data from the preceding vehicle and the vehicle itself is as follows: Calculate the vehicle's safe acceleration based on real-time data from the preceding vehicle and the vehicle itself, and determine whether the absolute value of the vehicle's actual acceleration is greater than the absolute value of the vehicle's safe acceleration. If so, it is determined that the vehicle has taken countermeasures; otherwise, it is determined that the vehicle has not taken countermeasures.

[0017] The formula for calculating the safe acceleration of the vehicle is as follows:

[0018]

[0019] In the formula, a min L is the safe acceleration of the vehicle; L is the minimum safe distance after both vehicles have come to a stop, and L ranges from 0 to 5m.

[0020] This invention also discloses a method for preventing rear-end collisions in foggy weather, comprising the following steps:

[0021] S1. Obtain real-time weather data, data from the vehicle ahead, and data from your own vehicle. S2. Determine if it is foggy based on the weather data. If yes, proceed to step S3; otherwise, skip the next step. S3. Determine if the vehicle ahead is decelerating based on the data from the vehicle ahead. If yes, proceed to step S4; otherwise, skip the next step. S4. Calculate the warning parameters for your own vehicle based on the real-time data from the vehicle ahead and your own vehicle. Determine the vehicle's status based on the warning parameters and the theoretical emergency state range. If the vehicle's status is safe, skip the next step; if the vehicle's status is not safe, issue a warning based on the vehicle's status. S5. After issuing a warning, calculate the vehicle's safe acceleration based on the real-time data from the vehicle ahead and your own vehicle. Determine if the absolute value of the vehicle's actual acceleration is greater than the absolute value of the vehicle's safe acceleration. If yes, stop issuing the warning; otherwise, proceed to step S4.

[0022] By adopting the above technical solution, the beneficial effects of the present invention are as follows: The present invention monitors and tracks the weather conditions, the real-time status of the vehicle in front and the vehicle itself by setting up an environmental data acquisition module and an on-board control module, and feeds back the weather conditions, the real-time status of the vehicle in front and the vehicle itself to the early warning information processing module. When the driver's driving behavior is risky under adverse weather conditions, the early warning information processing module sends the early warning information to the on-board control module to issue an early warning, thereby guiding the driver to take the correct driving strategy, slow down at the appropriate time, avoid the risk of rear-end collision, and at the same time avoid the waste of road resources and traffic delays caused by the driver slowing down too early. Attached Figure Description

[0023] Figure 1 This invention provides an embodiment of a road rear-end collision prevention and warning system for foggy weather conditions.

[0024] Figure 2 This is a schematic diagram of the warning process of a road rear-end collision prevention warning system in foggy weather according to an embodiment of the present invention. Detailed Implementation

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1

[0027] like Figure 1-2As shown in the figure, this embodiment discloses a road rear-end collision prevention warning system in foggy weather, including an environmental data acquisition module, a vehicle control module, and a warning information processing module. The environmental data acquisition module is used to collect real-time weather data and data of the vehicle ahead; the vehicle control module is used to collect real-time data of the vehicle itself; the warning information processing module is used to determine whether a warning is needed based on the real-time weather data, data of the vehicle ahead, and data of the vehicle itself. If so, a warning information is sent, and the vehicle should slow down. If not, no warning information is sent, and the vehicle is in a safe state and can drive normally without slowing down. The vehicle control module is also used to receive the warning information sent by the warning information processing module and issue a warning. The warning method can be voice warning, text warning, etc., preferably voice warning.

[0028] This invention monitors and tracks weather conditions and the real-time status of the vehicle in front and the vehicle itself by setting up an environmental data acquisition module and an on-board control module. It then feeds back the real-time status of these data to a warning information processing module. When the driver's driving behavior is at risk under adverse weather conditions, the warning information processing module sends a warning to the on-board control module to guide the driver to execute the correct driving strategy under different traffic conditions. This effectively improves the safety of following other vehicles, allows for timely deceleration to avoid the risk of rear-end collisions, and also prevents the waste of road resources and traffic delays caused by premature deceleration.

[0029] In a preferred embodiment, the environmental data acquisition module includes a weather data acquisition unit and a preceding vehicle data acquisition unit. Further, the weather data acquisition unit includes a particulate matter sensor, a meteorological parameter detection transmitter, and a network data transmitter. The weather data acquisition unit is used to collect real-time weather data and send the weather data to the early warning information processing module. The weather data includes visibility, humidity, atmospheric temperature, wind speed, rainfall, and air pressure. Further, the preceding vehicle data acquisition unit includes a sensor. The preceding vehicle data acquisition unit is used to collect real-time preceding vehicle data and send the preceding vehicle data to the early warning information processing module. The preceding vehicle data includes the preceding vehicle type, preceding vehicle speed, preceding vehicle acceleration, and the distance between the preceding vehicle and the vehicle itself.

[0030] In a preferred embodiment, the vehicle control module includes a vehicle data acquisition unit and a voice warning unit. Further, the vehicle data acquisition unit includes a vehicle radar. The vehicle data acquisition unit is used to collect real-time vehicle data and send the vehicle data to the warning information processing module. The vehicle data includes vehicle speed and vehicle acceleration. The voice warning unit is used to receive the warning information sent by the warning information processing module and issue a voice warning.

[0031] In one embodiment, the early warning information processing module includes a computational processing unit, which is used to determine whether an early warning is needed based on real-time weather data, data from the vehicle ahead, and data from the vehicle itself.

[0032] In a preferred approach, the need for a warning is determined based on real-time weather data, data from vehicles ahead, and data from the vehicle itself. Specific steps include:

[0033] Step 1: Determine whether the weather is foggy based on weather data. If so, proceed to Step 2. If not, no warning is needed.

[0034] For specific methods to determine whether it is foggy weather based on weather data, please refer to the relevant provisions of the Chinese National Standard "Weather Forecast Terminology" (GB / T 19202-2011) and the "Road Traffic Safety Law". Fog weather is divided into the following levels according to different visibility:

[0035] (1) Haze: When visibility is less than 10 kilometers but greater than or equal to 1 kilometer, it is usually called haze. Haze is caused by reduced visibility due to suspended particulate matter, pollutants and other pollutants in the atmosphere.

[0036] (2) Light fog: When the visibility is less than 1 kilometer but greater than or equal to 500 meters, it is called light fog. The visibility is low on light fog days, but there is still a certain visual range.

[0037] (3) Moderate fog: When visibility is less than 500 meters but greater than or equal to 200 meters, it is called moderate fog. Visibility is very limited on moderate fog days, and the driving visibility range is severely restricted.

[0038] (4) Severe fog: When visibility is less than 200 meters but greater than or equal to 50 meters, it is called severe fog. In severe fog, visibility is extremely low and the field of vision is very blurry. Drivers need to turn on fog lights, low beam headlights, side marker lights and front and rear position lights. The speed must not exceed 60 kilometers per hour, and a distance of more than 100 meters must be maintained from the vehicle in front in the same lane.

[0039] (5) Extremely dense fog: When visibility is less than 50 meters, it is usually called extremely dense fog. Under extremely dense fog conditions, visibility is extremely limited, and it is almost impossible to distinguish the road and the surrounding environment. The vehicle speed must not exceed 20 kilometers per hour.

[0040] In actual use, the road rear-end collision prevention warning system of the present invention can determine the environment as foggy weather according to the driver's needs, such as haze or above, light fog or above, or moderate fog or above. Generally, moderate fog or above with visibility of less than 500 meters is more suitable as a foggy weather environment. Haze and light fog still have relatively long visibility and generally do not affect the driver's normal driving, so there is no need to issue a warning in the road rear-end collision prevention warning system.

[0041] Step 2: Determine whether the vehicle in front is decelerating based on the data from the vehicle in front. If yes, proceed to Step 3; otherwise, no warning is required.

[0042] Determining whether the vehicle ahead is decelerating can be based on whether its acceleration is less than zero in the collected data. If the vehicle ahead is not decelerating, the driver can follow normally without slowing down to avoid excessive following distance and traffic delays. If the vehicle ahead is decelerating, the following distance decreases, indicating that the driver may need to adjust their speed. In this case, the warning information processing module determines whether to send a warning message and what kind of warning message to send based on the collected data from the vehicle ahead and the driver's own vehicle, thus prompting the driver on how to proceed. See steps three to five for details.

[0043] Step 3: Calculate the warning parameters for the vehicle based on real-time data from the vehicle in front and the vehicle itself;

[0044]

[0045] In the formula, τ -1 Let t be the ratio of the rate of change of the imaging angle of the vehicle in front to the size of the imaging image in the eyes of the driver of the vehicle ahead, i.e., the warning parameter of the vehicle ahead; W is the width of the vehicle in front; v L The speed at which the vehicle in front begins to decelerate; a L v is the acceleration of the vehicle in front; F Δt is the speed of the vehicle when the vehicle in front begins to decelerate; Δt is the time interval from when the vehicle in front begins to decelerate to time t; d is the distance between the front and rear vehicles at time t.

[0046] Among them, the width W of the preceding vehicle can be obtained based on the vehicle model (the warning information processing module stores vehicle information for various models, which can be matched during actual use), v L a L Both d and Δt can be derived from the data of the vehicle in front. Δt can be derived from the time when the vehicle in front begins to decelerate and time t, or from a. L v L v is calculated from the detected speed of the vehicle ahead at time t. F This was derived from vehicle data.

[0047] Step 4: Determine the vehicle's status based on the vehicle's warning parameters and theoretical emergency state range. If the vehicle is in a safe state, no warning is needed. If the vehicle is not in a safe state (i.e., the vehicle is in a general emergency state, an emergency state, or an emergency braking state), then send a warning message based on the vehicle's status.

[0048] Wherein, the theoretical emergency state interval is: when τ -1 The safe interval is when I1 ≤ I1, and when I1 < τ -1When I ≤ I2, it is a general emergency interval; when I2 < τ -1 When ≤I3, it is an emergency interval; when τ -1 >I3 is the emergency braking zone;

[0049] Wherein, I1 is the 95th percentile of the warning parameters of the vehicle at the moment the preceding vehicle begins to decelerate in the "Driver Warning Parameter Database"; I3 is the 95th percentile of the warning parameters of the vehicle at the moment the preceding vehicle begins to decelerate in the "Driver Warning Parameter Database"; and I2 is the median value of I1 and I3. The "Driver Warning Parameter Database" is a database generated by collecting driving data from a batch of drivers, and this database is stored as theoretical data in the warning information processing module.

[0050] The warning parameter τ calculated in step three -1 Compared with I1, I2, and I3, if the vehicle's warning parameters fall within the safe range, the vehicle is in a safe state and no warning is needed; the driver does not need to adjust their driving behavior. If the vehicle's warning parameters fall within the general emergency range, the vehicle is in a general emergency state, and a "general emergency" warning message is sent. Upon receiving the "general emergency" warning message, the voice warning unit will broadcast a "maintain a safe distance" voice warning message to remind the driver. If the vehicle's warning parameters fall within the emergency range, the vehicle is in an emergency state, and an "emergency" warning message is sent. Upon receiving the "emergency" warning message, the voice warning unit will broadcast a "rear-end collision risk, slow down" voice warning message to remind the driver. If the vehicle's warning parameters fall within the emergency braking range, the vehicle is in an emergency braking state, and an "emergency braking" warning message is sent. Upon receiving the "emergency braking" warning message, the voice warning unit will broadcast an "emergency rear-end collision warning" voice warning message to remind the driver. In a preferred embodiment, the vehicle control module further includes an emergency braking unit, which is used to control the vehicle to perform emergency braking after receiving an "emergency braking" warning message, thereby further ensuring driving safety.

[0051] Step 5: When the vehicle control module issues a warning, it determines whether the vehicle should take countermeasures based on real-time data from the vehicle in front and the vehicle itself. If yes, it stops sending warning information; otherwise, it returns to Step 3.

[0052] If the voice warning unit of the vehicle control module broadcasts "Keep a safe distance," "Rear-end collision risk, slow down," or "Emergency rear-end collision warning," the warning information processing module determines whether the vehicle has taken countermeasures based on real-time data from the vehicle in front and the vehicle itself. Here, countermeasures refer to whether the vehicle has taken safe acceleration (at this time, the acceleration is a negative value, that is, the vehicle is decelerating). Specifically, the warning information processing module calculates the vehicle's safe acceleration based on real-time data from the vehicle in front and the vehicle itself, and determines whether the absolute value of the vehicle's actual acceleration is greater than the absolute value of the vehicle's safe acceleration. If so, it is determined that the vehicle has taken countermeasures; if not, it is determined that the vehicle has not taken countermeasures.

[0053] The formula for calculating the safe acceleration of the vehicle is as follows:

[0054]

[0055] In the formula, a min L is the safe acceleration of the vehicle; L is the minimum safe distance after both vehicles have come to a stop. The value of L ranges from 0 to 5 meters, and the specific value can be set according to the actual needs of the driver.

[0056] The specific derivation process of the vehicle's safe acceleration is as follows:

[0057] For the vehicle at time t, d+d L =d F +L, where d L This is the distance the vehicle in front travels from braking to a complete stop; d F This is the distance the driver travels from braking the vehicle to a complete stop.

[0058] For the vehicle in front, (v L -a L Δt) 2 -0 = 2a L d L ;

[0059] For bicycles,

[0060] Therefore, it can be deduced that:

[0061]

[0062] The real-time acceleration of the vehicle is compared with the safe acceleration. At this point, the vehicle should be decelerating, and both the vehicle's actual acceleration and the safe acceleration are negative. When the absolute value of the vehicle's actual acceleration is greater than the absolute value of the vehicle's safe acceleration (for example, the vehicle's actual acceleration is -7 m / s²), the vehicle is considered to be decelerating. 2 The safe acceleration of the vehicle is -6 m / s². 2If the vehicle accelerates to a sufficiently safe speed, it indicates that the driver has taken effective countermeasures, and the warning can be discontinued. However, if the actual absolute value of the vehicle's acceleration is less than the vehicle's safe absolute value (e.g., the vehicle's actual acceleration is -6 m / s²), the warning will be discontinued. 2 The safe acceleration of the vehicle is -7 m / s². 2 If the warning signal is not received, it indicates that the vehicle has not taken effective countermeasures. At this point, return to step three. The warning information processing module will continue to calculate the vehicle status in real time and send warning signals until the vehicle is in a safe state, or the vehicle has taken effective countermeasures, or the vehicle is braked urgently.

[0063] Previous research on drivers' assessment of the urgency of a vehicle decelerating in front has largely focused on information such as the speed, deceleration, and headway of the vehicle ahead. However, the extent to which drivers can receive information about the speed and deceleration of the vehicle ahead, or make reasonable judgments about the distance between the two vehicles, remains unclear. Studies show that drivers' distance judgments are highly inaccurate. Even in good lighting conditions with unobstructed vision, drivers often misjudge the distance between two vehicles due to variations in driving speed. As the vehicle ahead continues to decelerate, the image of its rear end on the driver's retina increases in size; this phenomenon is called visual change stimulus. Based on this visual change stimulus, i.e., setting warning parameters according to the driver's visual perception, can more closely reflect the driver's actual situation and avoid warnings that are too early or too late.

[0064] As can be seen from the above description of the embodiments, those skilled in the art can clearly understand that the present invention can be implemented by means of software plus necessary general-purpose hardware. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the embodiments of the present invention or some parts thereof.

[0065] Example 2

[0066] This embodiment discloses a method for preventing rear-end collisions in foggy weather, including the following steps:

[0067] S1. Obtain real-time weather data, data from the vehicle ahead, and data from your own vehicle. S2. Determine if it is foggy based on the weather data. If yes, proceed to step S3; otherwise, skip the next step. S3. Determine if the vehicle ahead is decelerating based on the data from the vehicle ahead. If yes, proceed to step S4; otherwise, skip the next step. S4. Calculate the warning parameters for your own vehicle based on the real-time data from the vehicle ahead and your own vehicle. Determine the vehicle's status based on the warning parameters and the theoretical emergency state range. If the vehicle's status is safe, skip the next step; if the vehicle's status is not safe, issue a warning based on the vehicle's status. S5. After issuing a warning, calculate the vehicle's safe acceleration based on the real-time data from the vehicle ahead and your own vehicle. Determine if the absolute value of the vehicle's actual acceleration is greater than the absolute value of the vehicle's safe acceleration. If yes, stop issuing the warning; otherwise, proceed to step S4.

[0068] For detailed road rear-end collision prevention and warning methods, please refer to Example 1, which will not be repeated in this example.

[0069] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention.

Claims

1. A road rear-end collision prevention and early warning system for foggy weather conditions, characterized in that: It includes an environmental data acquisition module, an onboard control module, and an early warning information processing module. The environmental data acquisition module is used to collect real-time weather data and data of vehicles ahead; The vehicle control module is used to collect real-time vehicle data; The warning information processing module is used to determine whether a warning is needed based on real-time weather data, data of the vehicle ahead, and data of the vehicle itself. If so, a warning information is sent; otherwise, no warning information is sent. The vehicle control module is also used to receive and issue warnings from the warning information processing module. Determining whether a warning is needed based on real-time weather data, data from vehicles ahead, and data from the vehicle itself involves the following steps: Step 1: Determine whether the weather is foggy based on weather data. If so, proceed to Step 2. If not, no warning is needed. Step 2: Determine whether the vehicle in front is decelerating based on the data from the vehicle in front. If yes, proceed to Step 3; otherwise, no warning is required. Step 3: Calculate the warning parameters for the vehicle based on real-time data from the vehicle in front and the vehicle itself; Step 4: Determine the vehicle's status based on the vehicle's warning parameters and theoretical emergency state range. If the vehicle's status is safe, no warning is needed. If the vehicle's status is not safe, send a warning message based on the vehicle's status. Step 5: After the warning, calculate the vehicle's safe acceleration based on real-time data from the vehicle in front and the vehicle's own data. Determine whether the absolute value of the vehicle's actual acceleration is greater than the absolute value of the vehicle's safe acceleration. If yes, stop the warning; otherwise, proceed to step 4. The formula for calculating the warning parameters of the vehicle is as follows: In the formula, Let t be the ratio of the rate of change of the imaging angle of the vehicle in front to the size of the imaging in the eyes of the driver of the vehicle in front, which is the warning parameter of the vehicle in front. The width of the vehicle in front; The speed at which the vehicle in front begins to decelerate; The acceleration of the vehicle in front; The speed of the vehicle when the vehicle in front begins to decelerate; The time interval from when the vehicle in front begins to decelerate to time t; Let t be the distance between the front and rear of the vehicle.

2. The road rear-end collision prevention and early warning system according to claim 1, characterized in that: The environmental data acquisition module includes a weather data acquisition unit and a vehicle-to-the-front data acquisition unit. The weather data acquisition unit is used to collect real-time weather data and send the weather data to the early warning information processing module. The weather data includes visibility, humidity, atmospheric temperature, wind speed, rainfall, and air pressure. The preceding vehicle data acquisition unit is used to collect real-time preceding vehicle data and send the preceding vehicle data to the early warning information processing module. The preceding vehicle data includes the preceding vehicle model, preceding vehicle speed, preceding vehicle acceleration, and the distance between the preceding vehicle and the vehicle itself.

3. The road rear-end collision prevention and warning system according to claim 1, characterized in that: The vehicle control module includes a vehicle data acquisition unit and a voice warning unit. The vehicle data acquisition unit is used to collect real-time vehicle data and send the vehicle data to the early warning information processing module. The vehicle data includes vehicle speed and vehicle acceleration. The voice warning unit is used to receive warning information sent by the warning information processing module and issue voice warnings.

4. The road rear-end collision prevention and warning system according to claim 1, characterized in that: The theoretical emergency state interval is: when When it is a safe zone, During the general emergency zone, when It was an emergency zone, when This is the emergency braking zone; in, The 95th percentile of the warning parameters of the vehicle at the moment when the vehicle in front begins to decelerate, as defined in the "Driver Warning Parameter Database"; The 95th percentile of the vehicle's warning parameters at the moment the vehicle begins to decelerate, as defined in the "driver warning parameter database". for and The median value.

5. The road rear-end collision prevention and warning system according to claim 4, characterized in that: Step four specifically involves determining the vehicle's status based on its warning parameters and the theoretical emergency state range. If the warning parameters of the vehicle fall within the safe range, the vehicle is in a safe state and no warning is needed. If the warning parameters of the vehicle fall within the general emergency range, the vehicle is in a general emergency state, and a "general emergency" warning message is sent. If the vehicle's warning parameters fall within the emergency zone, the vehicle is in an emergency state, and an "emergency" warning message is sent. If the warning parameters of the vehicle fall within the emergency braking range, the vehicle is in an emergency braking state, and an "emergency braking" warning message is sent.

6. The road rear-end collision prevention and early warning system according to claim 5, characterized in that: After receiving the "General Emergency" warning message, the voice warning unit will broadcast the "Maintain a safe distance" voice warning message. When the voice warning unit receives the "emergency" warning message, it will broadcast the voice warning message "risk of rear-end collision, slow down"; When the voice warning unit receives the "emergency braking" warning information, it broadcasts the voice warning information of "emergency rear-end collision warning". The vehicle control module also includes an emergency braking unit, which is used to control the vehicle to perform emergency braking after receiving the "emergency braking" warning information.

7. The road rear-end collision prevention and warning system according to claim 1, characterized in that: Step five, which determines whether the vehicle should take countermeasures based on real-time data from the vehicle ahead and its own vehicle, specifically involves: Based on real-time data from the vehicle ahead and the vehicle itself, the system calculates the vehicle's safe acceleration and determines whether the absolute value of the vehicle's actual acceleration is greater than the absolute value of the vehicle's safe acceleration. If so, the system determines that the vehicle has taken countermeasures; otherwise, the system determines that the vehicle has not taken countermeasures. The formula for calculating the safe acceleration of the vehicle is as follows: In the formula, Accelerate for the safety of your vehicle; This is the minimum safe distance after both vehicles have come to a stop. The value ranges from 0 to 5m.

8. A method for preventing rear-end collisions in foggy weather, characterized in that, Includes the following steps: S1. Obtain real-time weather data, data of the vehicle ahead, and data of your own vehicle; S2. Determine whether the weather is foggy based on the weather data. If yes, proceed to step S3; otherwise, do not proceed to the next step. S3. Determine whether the vehicle in front is decelerating based on the data of the vehicle in front. If yes, proceed to step S4; otherwise, do not proceed to the next step. S4. Calculate the warning parameters of the vehicle based on real-time data of the vehicle in front and the vehicle itself. Determine the status of the vehicle based on the warning parameters and the theoretical emergency state range. If the vehicle is in a safe state, do not proceed to the next step. If the vehicle is not in a safe state, issue a warning based on the vehicle's status. S5. After the warning, calculate the safe acceleration of the vehicle based on the real-time data of the vehicle in front and the vehicle's own data, and determine whether the absolute value of the actual acceleration of the vehicle is greater than the absolute value of the safe acceleration of the vehicle. If yes, stop the warning; otherwise, proceed to step S4. The formula for calculating the warning parameters of the vehicle is as follows: In the formula, Let t be the ratio of the rate of change of the imaging angle of the vehicle in front to the size of the imaging in the eyes of the driver of the vehicle in front, which is the warning parameter of the vehicle in front. The width of the vehicle in front; The speed at which the vehicle in front begins to decelerate; The acceleration of the vehicle in front; The speed of the vehicle when the vehicle in front begins to decelerate; The time interval from when the vehicle in front begins to decelerate to time t; Let t be the distance between the front and rear of the vehicle.

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