A vehicle early warning method based on vehicle-road cooperation in mountainous curved road

Abstract

The application discloses a kind of mountainous area curve vehicle early warning method based on vehicle-road cooperation, the real-time information of vehicle is obtained first, and BSM is broadcasted in real time, then the MAP map information of road side terminal RSU is obtained, the vehicle is matched according to MAP map information, and the curve is subdivided into two independent early warning areas, when the vehicle is located in one of early warning areas, if there is vehicle in another early warning area, early warning mechanism will be triggered, the vehicle on the other side will also trigger early warning mechanism simultaneously, this two-way early warning design can early warn the existence of curve opposite vehicle to driver, effectively reduce the driving risk caused by factors such as inattention, illegal lane occupation driving, curve sight blind area etc., this design not only fits the driving habit and cognitive logic of driver, but also significantly reduces the strict requirement for mountainous area vehicle positioning accuracy, more in line with the actual road and natural environment of complex and changeable mountainous area.

Description

Technical Field

[0001] This invention belongs to the field of road traffic system technology, specifically relating to a vehicle early warning method for mountain curves based on vehicle-road cooperation. Background Technology

[0002] Driving on curves, an indispensable part of the road traffic system, has always been a high-risk area for traffic accidents due to inherent obstructed vision, difficulty in speed control, and the complexity of road structures. According to authoritative statistics, globally, traffic accidents caused by improper driving on curves account for as much as 20% to 30%, especially in mountainous and hilly areas and on highway curves, where this percentage is alarming. In China, with the rapid expansion of the highway network and the continuous increase in vehicle ownership, the problem of traffic safety on curves has become increasingly prominent, becoming one of the major bottlenecks restricting the improvement of road traffic safety levels.

[0003] In recent years, the rapid development of vehicle-road cooperative technology has injected strong vitality into the research and development of vehicle warning systems for mountain curves. Information exchange between vehicles and between vehicles and roads has become increasingly convenient and efficient due to the continuous maturation of the technology. This technological innovation not only greatly enhances the vehicle's environmental perception capabilities during driving but also provides a solid technical guarantee for the accurate warning of vehicles on curves.

[0004] However, existing mountain curve warning technologies mainly rely on hardware devices such as cameras, millimeter waves, geomagnetic coils, and reflectors, which have certain limitations. Their effectiveness is significantly reduced, especially when encountering obstructions, adverse weather conditions, or poor positioning in mountainous areas. The complex terrain and vegetation cover in mountainous areas often lead to unstable satellite signals, affecting the accuracy of vehicle positioning. Therefore, we need to propose a vehicle curve warning method based on vehicle-road cooperation to address these problems. This method should be able to flexibly adapt to the complex and ever-changing mountain curve environment, unaffected by obstructions, weather conditions, and poor positioning, thereby improving the accuracy of vehicle positioning. Summary of the Invention

[0005] The purpose of this invention is to provide a vehicle early warning method for mountain curves based on vehicle-road cooperation, which can flexibly adapt to the complex and ever-changing mountain curve environment, and is not affected by obstructions, weather factors, and poor positioning effects, thereby improving the accuracy of vehicle positioning and solving the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A vehicle warning method for mountain curves based on vehicle-road cooperation includes the following steps:

[0008] S1. By integrating the on-board unit (OBU) into the vehicle, the vehicle's real-time information is fully acquired and the BSM is broadcast in real time.

[0009] S2. Obtain the MAP map information from the roadside unit (RSU) and broadcast the MAP map information to surrounding vehicles through the wireless communication module built into the RSU to ensure that vehicles can obtain road conditions in real time.

[0010] S3. Perform vehicle HV map matching based on MAP map information. The vehicle HV map matching includes vehicle phase position judgment and precise matching of vehicle heading and road heading. If the matching fails, return to S2. If the matching succeeds, obtain the matching warning area based on the current curve position on the map and proceed to S4.

[0011] S4. The on-board unit (OBU) determines the corresponding warning area information on the opposite side of the curve where the vehicle's HV is located through a detailed screening process based on the warning area matched to the vehicle.

[0012] S5. The on-board unit (OBU) obtains the BSM data broadcast by the remote vehicle (RV).

[0013] S6. The on-board unit (OBU) performs map matching of the remote vehicle (RV) based on the BSM data of the remote vehicle (RV) and the corresponding warning area information on the opposite side of the curve where the vehicle's HV is located. If the matching fails, it returns to S4. If the matching succeeds, it proceeds to S7.

[0014] S7. Upon receiving the warning information, the terminal display module of this vehicle's HV responds quickly, accurately marking the vehicle's latitude and longitude location on the map, while simultaneously playing a clear voice prompt.

[0015] Preferably, the vehicle-mounted terminal (OBU) includes a vehicle information acquisition module, a vehicle-mounted terminal V2X wireless communication module, a curve warning processing module, and a terminal display module. The vehicle information acquisition module is used to capture and process the vehicle's key status information in real time, including latitude and longitude, driving speed, and heading angle data.

[0016] The vehicle-mounted terminal V2X wireless communication module efficiently transmits the collected vehicle status data to the roadside unit (RSU) and other vehicle-mounted units (OBU) using V2X communication technology, while also receiving data feedback from other vehicle-mounted units (OBU).

[0017] The curve warning processing module performs curve warning calculations on the vehicle based on the received multi-source information to accurately assess potential collision risks.

[0018] The terminal display module is used to present the warning data generated by the warning module to the driver in an intuitive and easy-to-understand way, ensuring that key information can be conveyed in a timely and effective manner.

[0019] Preferably, in step S2, the roadside terminal RSU includes a map information construction module and a roadside V2X wireless communication module. The map information construction module constructs MAP information that conforms to the application layer and application data interaction standards of the intelligent transportation system vehicle communication system based on the actual data of the current curve.

[0020] The roadside V2X wireless communication module broadcasts the map information of the curved intersection to nearby vehicles, providing them with detailed road guidance and warning information.

[0021] Preferably, when acquiring the MAP map information of the roadside unit (RSU), the RSU is configured with two approach roads, marked as warning area one and warning area two respectively. Warning area one and warning area two start from a point away from the turning point and gradually extend to the turning point as the end point. Based on this route, the RSU can generate a detailed MAP map of the current curve and broadcast the MAP map information to surrounding vehicles through its built-in roadside V2X wireless communication module.

[0022] Preferably, in step S3, the process for determining the vehicle phase position is as follows:

[0023] S31. Using the vehicle point as the starting point and the target point as the ending point, calculate the north and east distance differences d between the vehicle and the target point using latitude and longitude information. North and d East And based on this, the heading angle θ1 from the target point to the vehicle is calculated;

[0024]

[0025] Where, d North d represents the difference in distance between two points in the latitudinal direction. East This represents the distance difference between two points in the longitude direction. R is the Earth's radius, θ1 is the heading angle from the starting point to the ending point, θ2 is the vehicle heading angle, θ3 is the heading angle from the starting point to the ending point of the warning area, Δθ is the angle between the two heading angles, gps1(lon1,lat1) is the latitude and longitude position of the starting point, and gps2(lon2,lat2) is the latitude and longitude position of the ending point.

[0026] S32. By comparing the angle Δθ between the vehicle's heading angle θ2 and the vehicle's heading angle θ1 to the target point, the position of the target point relative to the vehicle can be accurately determined. There are three possible scenarios:

[0027] S321. When 0 ≤ Δθ < 90, the target point is in front of the vehicle.

[0028] S322. When 90 < Δθ ≤ 180, the target point is behind the vehicle.

[0029] S323. When Δθ = 90°, the target point is either directly to the right or to the left of the vehicle.

[0030] The preferred process for precisely matching the vehicle's heading with the road's heading is as follows:

[0031] S33. Using the starting point of the warning area as the starting point and the ending point of the warning area as the ending point, calculate the angle Δθ between the heading angle θ1 of the warning area and the heading angle θ2 of the vehicle. When Δθ < 90, the current vehicle's driving direction is consistent with the path direction of the warning area.

[0032] S34. Perform map matching for this vehicle. Specifically, with the center point of the intersection as the target point and the current position of the vehicle as the starting point, calculate whether the center point of the intersection is in front of the vehicle. If the center point of the intersection is not in front of the vehicle, the matching fails and other maps need to be calculated. If the center point of the intersection is in front of the vehicle, the current intersection map is valid.

[0033] S35. Perform warning area filtering, specifically: Take a warning area data from the intersection map, using the current position as the starting point, and calculate the relative positions Δθ1 and Δθ2 using the starting and ending points of the warning area as the ending points. When Δθ1>90 and Δθ2<90 (e.g., ... Figure 6 (as shown) or Δθ1<90 and Δθ2>90 (as shown) Figure 7 If the vehicle is within the warning area (as shown in the image), it means that the current warning area has been successfully matched between the start and end points of the warning area. Otherwise, it is determined that the current warning area has failed to match, and another warning area is selected for matching, and the above matching process is repeated.

[0034] S36. Calculate the heading angle θ1 from the start point to the end point of the current warning area and the vehicle heading angle θ2. Calculate the angle Δθ between the two heading angles. If Δθ>60, it is determined that the vehicle heading angle and the warning area do not match, and the matching is considered to be a failure. If Δθ<60, it is determined that the current vehicle heading angle and the warning area match the warning area.

[0035] S37. Calculate the vertical region between the current vehicle and the start and end points of the warning area, and determine whether it exceeds the road width configured on the map. If it is greater than half the road width, it is assumed to be outside the road, and the match fails. If it is less than half the road width, the current warning area is successfully matched. Figure 8 As shown.

[0036] Preferably, in step S5, when the on-board unit (OBU) acquires the remotely broadcast BSM data, it uses V2X wireless communication technology and follows the CSAE 157-2020 Cooperative Intelligent Transportation Systems Vehicle Communication System Application Layer and Application Data Interaction Standard to successfully receive the BSM message sent by the remote vehicle (RV). The BSM message contains detailed key vehicle status data such as the RV's latitude and longitude location, driving speed, and heading angle.

[0037] Preferably, in step S6, when the vehicle-mounted terminal (OBU) performs map matching for the remote vehicle (RV), if the vehicle is stationary, it is not necessary to verify whether the heading angle of the remote vehicle (RV) is consistent with the heading angle of the warning area 2. In this scenario, it is only necessary to confirm that the remote vehicle (RV) is located within the warning area 2 to determine that the map matching is successful. If the remote vehicle (RV) is in motion, the map matching process will follow the method in step S3 to perform comprehensive verification and matching.

[0038] Preferably, the on-board unit (OBU) performs map matching with a remote RV to accurately determine whether the remote RV poses a potential risk to the vehicle. If map matching fails, it indicates that there is no direct collision risk between the remote RV and the vehicle's HV. In this case, the system will restart the data collection and calculation process to continuously monitor environmental changes. Conversely, if map matching is successful, the system will immediately determine that there is a risk between the remote RV and the vehicle's HV and automatically generate a warning message, which will be quickly transmitted to the terminal display module.

[0039] Preferably, both the remote vehicle (RV) and the local vehicle (HV) are equipped with an on-board unit (OBU) with V2X wireless communication capabilities.

[0040] The present invention proposes a vehicle warning method for mountain curves based on vehicle-road cooperation, which has the following advantages compared with the prior art:

[0041] 1. This invention performs vehicle HV map matching based on MAP map information. The vehicle HV map matching includes vehicle phase position judgment and precise matching of vehicle heading and road heading. If the matching is successful, the matching warning area is obtained based on the current position of the curve on the map. The on-board unit (OBU) determines the corresponding warning area information on the opposite side of the curve where the vehicle HV is located through a detailed screening process based on the warning area matched by the vehicle, so as to subdivide the curve into two independent warning areas. When the vehicle is located in one warning area, if there is a vehicle in the other warning area, the warning mechanism will be triggered. The vehicle on the other side will also trigger the warning mechanism at the same time. This two-way warning design can warn the driver in advance of the presence of oncoming vehicles on the curve, effectively reducing the driving risks caused by factors such as inattention, illegal lane occupation, and blind spots on curves. This design not only conforms to the driver's driving habits and cognitive logic, but also significantly reduces the strict requirements for vehicle positioning accuracy in mountainous areas through the scientific setting of warning areas, making it more suitable for the complex and ever-changing actual roads and natural environment in mountainous areas.

[0042] 2. This invention, through the cooperation of the vehicle-mounted unit (OBU) and the roadside unit (RSU), adopts advanced V2X communication technology. It not only has strong environmental adaptability and can easily cope with the complex and ever-changing road environment and weather conditions in mountainous areas, but also greatly simplifies the complexity of system deployment and improves the flexibility and reliability of the overall solution, making it more adaptable and practical in the intelligent traffic early warning system for mountainous areas. Attached Figure Description

[0043] Figure 1 This is a flowchart of the present invention;

[0044] Figure 2 This is a schematic diagram of the connection frame between the roadside unit (RSU) and the vehicle-mounted unit (OBU) of the present invention.

[0045] Figure 3 This is a schematic diagram of the roadside unit (RSU) and warning area of ​​the present invention;

[0046] Figure 4 This is a schematic diagram of the vehicle phase position determination method according to the present invention;

[0047] Figure 5 This is a schematic diagram illustrating the matching of vehicle heading and road heading according to the present invention;

[0048] Figure 6 This is a schematic diagram of the early warning area matching in this invention when Δθ1>90 and Δθ2<90;

[0049] Figure 7 This is a schematic diagram of the early warning area matching according to the present invention when Δθ1<90 and Δθ2>90;

[0050] Figure 8 This is a schematic diagram illustrating a successful map matching warning area match according to the present invention. Detailed Implementation

[0051] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention. 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.

[0052] This invention provides, for example Figure 1-8 The method for vehicle early warning on mountain curves based on vehicle-road cooperation, as shown, includes the following steps:

[0053] S1. By integrating the on-board unit (OBU) into the vehicle, the vehicle's real-time information is fully acquired and the BSM is broadcast in real time, including but not limited to key data such as precise latitude and longitude position, current heading angle and driving speed. This data provides a solid foundation for subsequent vehicle positioning, navigation and safety warning.

[0054] The vehicle-mounted unit (OBU) includes a vehicle information acquisition module, a vehicle-mounted terminal V2X wireless communication module, a curve warning processing module, and a terminal display module. The vehicle information acquisition module is used to capture and process the vehicle's key status information in real time. The key status information includes latitude and longitude, driving speed, and heading angle data to provide the system with accurate vehicle dynamic information.

[0055] The vehicle-mounted terminal V2X wireless communication module efficiently transmits the collected vehicle status data to the roadside unit (RSU) and other vehicle-mounted units (OBU) using V2X communication technology, while simultaneously receiving data feedback from other vehicle-mounted units (OBU), thus enabling bidirectional information flow.

[0056] The curve warning processing module performs curve warning calculations on the vehicle based on the received multi-source information to accurately assess potential collision risks.

[0057] The terminal display module is used to present the warning data generated by the warning module to the driver in an intuitive and easy-to-understand way, ensuring that key information can be conveyed in a timely and effective manner.

[0058] S2. Obtain the MAP map information from the roadside unit (RSU) and broadcast the MAP map information to surrounding vehicles through the wireless communication module built into the RSU to ensure that vehicles can obtain road conditions in real time.

[0059] The roadside unit (RSU) includes a map information construction module and a roadside V2X wireless communication module. The map information construction module constructs MAP information that conforms to the application layer and application data interaction standards of the intelligent transportation system vehicle communication system based on the actual data of the current curve, ensuring the accuracy and standardization of the map information.

[0060] The roadside V2X wireless communication module broadcasts map information of the curved intersection to nearby vehicles, providing them with detailed road guidance and warning information, thereby enhancing driving safety.

[0061] When obtaining the MAP map information of the roadside unit (RSU), such as Figure 3As shown, the roadside unit (RSU) is configured with two approach roads, marked as Warning Zone 1 and Warning Zone 2 respectively. Warning Zone 1 and Warning Zone 2 start from a point away from the turning point and gradually extend to the turning point as the end point. Based on this route, the roadside unit (RSU) can generate a detailed MAP map of the current curve and broadcast the MAP map information to surrounding vehicles through its built-in roadside V2X wireless communication module to ensure that vehicles can obtain road conditions in real time.

[0062] S3. Perform vehicle HV map matching based on MAP map information. The vehicle HV map matching includes vehicle phase position judgment and precise matching of vehicle heading and road heading. If the matching fails, return to S2. If the matching succeeds, obtain the matching warning area based on the current curve position on the map and proceed to S4.

[0063] The process for determining the vehicle's phase position is as follows:

[0064] S31. Starting from the vehicle point and ending at the target point (e.g., ...). Figure 4 As shown in the figure, the distance difference d between the vehicle and the target point in the north and east directions is calculated using latitude and longitude information. North and d East And based on this, the heading angle θ1 from the target point to the vehicle is calculated;

[0065]

[0066]

[0067] Where, d North This represents the difference in latitude between two points, which is obtained by multiplying the latitude difference between the two points by the Earth's radius (and converting it to radians); d East This represents the difference in longitude between two points, but it needs to consider the curvature of the Earth at different latitudes. Therefore, it needs to first calculate the circumference of the Earth's radius corresponding to the latitude of the first point (i.e., the radius of that latitude circle), and then multiply it by the difference in longitude between the two points (and convert it to radians); R is the Earth's radius (6,371,000 meters), θ1 is the heading angle from the starting point to the ending point, θ2 is the vehicle heading angle (0 degrees with true north as 0 degrees, clockwise 0-360 degrees), θ3 is the heading angle from the starting point to the ending point of the warning area, Δθ is the angle between the two heading angles, gps1(lon1,lat1) is the latitude and longitude position of the starting point, and gps2(lon2,lat2) is the latitude and longitude position of the ending point;

[0068] S32. By comparing the angle Δθ between the vehicle's heading angle θ2 and the vehicle's heading angle θ1 to the target point, the position of the target point relative to the vehicle can be accurately determined. There are three possible scenarios:

[0069] S321. When 0 ≤ Δθ < 90, the target point is in front of the vehicle.

[0070] S322. When 90 < Δθ ≤ 180, the target point is behind the vehicle.

[0071] S323. When Δθ = 90°, the target point is either directly to the right or to the left of the vehicle.

[0072] The process for precisely matching the vehicle's heading with the road's heading is as follows:

[0073] S33. Using the starting point of the warning area as the starting point and the ending point of the warning area as the ending point, calculate the angle Δθ between the heading angle θ1 of the warning area and the heading angle θ2 of the vehicle. When Δθ < 90, the current vehicle's driving direction is consistent with the path direction of the warning area.

[0074] S34. Perform map matching for this vehicle. Specifically, with the center point of the intersection as the target point and the current position of the vehicle as the starting point, calculate whether the center point of the intersection is in front of the vehicle. If the center point of the intersection is not in front of the vehicle, the matching fails and other maps need to be calculated. If the center point of the intersection is in front of the vehicle, the current intersection map is valid.

[0075] S35. Perform warning area filtering, specifically: take a warning area data from the intersection map, with the current position as the starting point, and calculate the relative positions Δθ1 and Δθ2 with the starting point and ending point of the warning area as the ending points respectively. If Δθ1>90 and Δθ2<90 or Δθ1<90 and Δθ2>90, it means that the vehicle is between the starting point and ending point of the warning area, and the current warning area is successfully matched. Otherwise, it is determined that the current warning area is not matched, another warning area is selected for matching, and the above matching process is repeated.

[0076] S36. Calculate the heading angle θ1 from the start point to the end point of the current warning area and the vehicle heading angle θ2. Calculate the angle Δθ between the two heading angles. If Δθ>60, it is determined that the vehicle heading angle and the warning area do not match, and the matching is considered to be a failure. If Δθ<60, it is determined that the current vehicle heading angle and the warning area match the warning area.

[0077] S37. Calculate the vertical area between the current vehicle and the start and end points of the warning area, and determine whether it exceeds the road width configured on the map. If it is greater than half the road width, it is not on the road by default and the matching fails. If it is less than half the road width, the current warning area is matched successfully.

[0078] S4. The on-board unit (OBU) determines the corresponding warning area information on the opposite side of the curve where the vehicle's HV is located through a detailed filtering process based on the warning area matched to the vehicle. Specifically, based on the successful map matching in step S3, the vehicle can accurately obtain the location of the current curve on the map. Then, based on the warning area matched to the vehicle (tentatively named warning area 1), the corresponding warning area information on the opposite side of the curve (tentatively named warning area 2) can be determined through a detailed filtering process.

[0079] S5. The on-board unit (OBU) obtains the BSM data broadcast by the remote vehicle (RV).

[0080] When the on-board unit (OBU) acquires remotely broadcast BSM data, it utilizes V2X wireless communication technology and follows the CSAE157-2020 Cooperative Intelligent Transportation System Vehicle Communication System Application Layer and Application Data Interaction Standard to successfully receive the BSM message sent by the remote vehicle (RV). This BSM message contains detailed key vehicle status data such as the RV's latitude and longitude location, speed, and heading angle.

[0081] S6. The on-board unit (OBU) performs map matching of the remote vehicle (RV) based on the BSM data of the remote vehicle (RV) and the corresponding warning area information on the opposite side of the curve where the vehicle's HV is located. If the matching fails, it returns to S4. If the matching succeeds, it proceeds to S7.

[0082] When the on-board unit (OBU) performs map matching for the remote vehicle (RV), the map matching for the RV is performed when the vehicle is stationary (generally, a vehicle speed below 1 km / h is considered stationary). In this case, it is not necessary to verify whether the heading angle of the RV is consistent with the heading angle of the warning area 2. In this scenario, it is only necessary to confirm that the RV is located within the warning area 2 to determine that the map matching is successful. This method can effectively avoid the risks that may be caused by parking in the blind spot of a curve. If the RV is in motion, the map matching process will follow the method in step S3 to perform comprehensive verification and matching.

[0083] The on-board unit (OBU) can accurately determine whether a remote RV poses a potential risk to the vehicle by performing map matching. If map matching fails, it indicates that there is no direct collision risk between the remote RV and the vehicle's HV. In this case, the system will restart the data collection and calculation process to continuously monitor environmental changes. Conversely, if map matching is successful, the system will immediately determine that there is a risk between the remote RV and the vehicle's HV and automatically generate a warning message. This warning message will be quickly transmitted to the terminal display module so that the driver or relevant systems can take timely countermeasures.

[0084] S7. Upon receiving the warning information, the terminal display module of this vehicle's HV responds quickly and accurately marks the vehicle's latitude and longitude position on the map for the driver to observe intuitively. At the same time, it plays clear voice prompts, such as "Beware of vehicles on the curve ahead," to remind the driver to pay attention and slow down in time to ensure driving safety.

[0085] Both the remote RV and the local HV are equipped with on-board units (OBUs) with V2X wireless communication capabilities. Employing advanced V2X communication technology, they not only have strong environmental adaptability, easily coping with the complex and ever-changing road environment and weather conditions in mountainous areas, but also greatly simplify the complexity of system deployment, improve the flexibility and reliability of the overall solution, and demonstrate stronger adaptability and practicality in mountainous intelligent traffic early warning systems.

[0086] This invention divides the curve into two independent warning zones. When the vehicle is in one warning zone, if a vehicle is present in the other warning zone, the warning mechanism will be triggered. At the same time, the warning mechanism of the vehicle on the other side will also be triggered. This two-way warning design can warn the driver in advance of the presence of oncoming vehicles on the curve, effectively reducing driving risks caused by factors such as inattention, illegal lane occupation, and blind spots on curves. This design not only conforms to the driver's driving habits and cognitive logic, but also significantly reduces the strict requirements for vehicle positioning accuracy in mountainous areas through the scientific setting of warning zones, making it more suitable for the complex and ever-changing actual roads and natural environment in mountainous areas.

[0087] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. 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 of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for early warning of vehicles on curves in mountainous areas based on vehicle-road cooperation, characterized in that: Includes the following steps: S1. By integrating the on-board unit (OBU) into the vehicle, the vehicle's real-time information is fully acquired and the BSM is broadcast in real time. S2. Obtain the MAP map information from the roadside unit (RSU) and broadcast the MAP map information to surrounding vehicles through the wireless communication module built into the RSU to ensure that vehicles can obtain road conditions in real time. S3. Perform vehicle HV map matching based on MAP map information. The vehicle HV map matching includes vehicle phase position judgment and precise matching of vehicle heading and road heading. If the matching fails, return to S2. If the matching succeeds, obtain the matching warning area based on the current curve position on the map and proceed to S4. The process for precisely matching the vehicle's heading with the road's heading is as follows: S33. Using the starting point of the warning area as the starting point and the ending point of the warning area as the ending point, calculate the angle Δθ between the heading angle θ1 of the warning area and the heading angle θ2 of the vehicle. When Δθ < 90, the current vehicle's driving direction is consistent with the path direction of the warning area. S34. Perform map matching for this vehicle. Specifically, with the center point of the intersection as the target point and the current position of the vehicle as the starting point, calculate and determine whether the center point of the intersection is in front of the vehicle. If the center point of the intersection is not in front of the vehicle, the matching fails and other maps need to be calculated. If the center point of the intersection is in front of the vehicle, the current intersection map is valid; S35. Perform warning area filtering, specifically: take a warning area data from the intersection map, with the current position as the starting point, and calculate the relative positions Δθ1 and Δθ2 with the starting point and ending point of the warning area as the ending points respectively. If Δθ1>90 and Δθ2<90 or Δθ1<90 and Δθ2>90, it means that the vehicle is between the starting point and ending point of the warning area, and the current warning area is successfully matched. Otherwise, it is determined that the current warning area is not matched, another warning area is selected for matching, and the above matching process is repeated. S36. Calculate the heading angle θ1 from the start point to the end point of the current warning area and the vehicle heading angle θ2. Calculate the angle Δθ between the two heading angles. If Δθ>60, it is determined that the vehicle heading angle and the warning area do not match, and the matching is considered to be a failure. If Δθ<60, it is determined that the current vehicle heading angle and the warning area match the warning area. S37. Calculate the vertical area between the current vehicle and the start and end points of the warning area, and determine whether it exceeds the road width configured on the map. If it is greater than half the road width, it is not on the road by default and the matching fails. If it is less than half the road width, the current warning area is matched successfully. S4. The on-board unit (OBU) determines the corresponding warning area information on the opposite side of the curve where the vehicle's HV is located through a detailed screening process based on the warning area matched to the vehicle. S5. The on-board unit (OBU) obtains the BSM data broadcast by the remote vehicle (RV). S6. The on-board unit (OBU) performs map matching of the remote vehicle (RV) based on the BSM data of the remote vehicle (RV) and the corresponding warning area information on the opposite side of the curve where the vehicle's HV is located. If the matching fails, it returns to S4. If the matching succeeds, it proceeds to S7. S7. Upon receiving the warning information, the terminal display module of this vehicle's HV responds quickly, accurately marking the vehicle's latitude and longitude location on the map, while simultaneously playing a clear voice prompt.

2. The method for vehicle early warning on mountain curves based on vehicle-road cooperation according to claim 1, characterized in that: The vehicle-mounted unit (OBU) includes a vehicle information acquisition module, a vehicle-mounted terminal V2X wireless communication module, a curve warning processing module, and a terminal display module. The vehicle information acquisition module is used to capture and process the vehicle's key status information in real time, including latitude and longitude, driving speed, and heading angle data. The vehicle-mounted terminal V2X wireless communication module efficiently transmits the collected vehicle status data to the roadside unit (RSU) and other vehicle-mounted units (OBU) using V2X communication technology, while also receiving data feedback from other vehicle-mounted units (OBU). The curve warning processing module performs curve warning calculations on the vehicle based on the received multi-source information to accurately assess potential collision risks. The terminal display module is used to present the warning data generated by the warning module to the driver in an intuitive and easy-to-understand way, ensuring that key information can be conveyed in a timely and effective manner.

3. The method for vehicle early warning on mountain curves based on vehicle-road cooperation according to claim 2, characterized in that: In step S2, the roadside terminal RSU includes a map information construction module and a roadside V2X wireless communication module. The map information construction module constructs MAP information that conforms to the application layer and application data interaction standards of the intelligent transportation system vehicle communication system based on the actual data of the current curve. The roadside V2X wireless communication module broadcasts the map information of the curved intersection to nearby vehicles, providing them with detailed road guidance and warning information.

4. A method for early warning of vehicles on mountain curves based on vehicle-road cooperation according to claim 3, characterized in that: When acquiring MAP map information from the Roadside Unit (RSU), the RSU is configured with two approach roads, marked as Warning Zone 1 and Warning Zone 2 respectively. Warning Zone 1 and Warning Zone 2 start from a point away from the turning point and gradually extend to the turning point as the endpoint. Based on this route, the RSU can generate a detailed MAP map of the current curve and broadcast the MAP map information to surrounding vehicles through its built-in roadside V2X wireless communication module.

5. A method for early warning of vehicles on mountain curves based on vehicle-road cooperation according to claim 4, characterized in that: In step S3, the process for determining the vehicle's phase position is as follows: S31. Using the vehicle point as the starting point and the target point as the ending point, calculate the north and east distance differences d between the vehicle and the target point using latitude and longitude information. North and d East And based on this, the heading angle θ1 from the target point to the vehicle is calculated; Where, d North d represents the difference in distance between two points in the latitudinal direction. East This represents the distance difference between two points in the longitude direction. R is the Earth's radius, θ1 is the heading angle from the starting point to the ending point, θ2 is the vehicle heading angle, θ3 is the heading angle from the starting point to the ending point of the warning area, Δθ is the angle between the two heading angles, gps1(lon1,lat1) is the latitude and longitude position of the starting point, and gps2(lon2,lat2) is the latitude and longitude position of the ending point. S32. By comparing the angle Δθ between the vehicle's heading angle θ2 and the vehicle's heading angle θ1 to the target point, the position of the target point relative to the vehicle can be accurately determined. There are three possible scenarios: S321. When 0 ≤ Δθ < 90, the target point is in front of the vehicle. S322. When 90 < Δθ ≤ 180, the target point is behind the vehicle. S323. When Δθ = 90°, the target point is either directly to the right or to the left of the vehicle.

6. A method for early warning of vehicles on mountain curves based on vehicle-road cooperation according to claim 5, characterized in that: In step S5, when the on-board unit (OBU) acquires the remotely broadcast BSM data, it uses V2X wireless communication technology and follows the CSAE157-2020 Cooperative Intelligent Transportation System Vehicle Communication System Application Layer and Application Data Interaction Standard to successfully receive the BSM message sent by the remote vehicle (RV). The BSM message contains detailed key vehicle status data such as the latitude and longitude position, driving speed, and heading angle of the remote vehicle (RV).

7. A method for early warning of vehicles on mountain curves based on vehicle-road cooperation according to claim 6, characterized in that: In step S6, when the vehicle-mounted terminal (OBU) performs map matching for the remote vehicle (RV), if the vehicle is stationary, it is not necessary to verify whether the heading angle of the remote vehicle (RV) is consistent with the heading angle of the warning area 2. In this case, it is only necessary to confirm that the remote vehicle (RV) is within the warning area 2 to determine that the map matching is successful. If the remote vehicle (RV) is in motion, the map matching process will follow the method in step S3 to perform comprehensive verification and matching.

8. A method for early warning of vehicles on mountain curves based on vehicle-road cooperation according to claim 7, characterized in that: The on-board unit (OBU) can accurately determine whether a remote RV poses a potential risk to the vehicle by performing map matching. If map matching fails, it indicates that there is no direct collision risk between the remote RV and the vehicle's HV. In this case, the system will restart the data collection and calculation process to continuously monitor environmental changes. Conversely, if map matching is successful, the system will immediately determine that there is a risk between the remote RV and the vehicle's HV and automatically generate a warning message, which will be quickly transmitted to the terminal display module.

9. A method for early warning of vehicles on mountain curves based on vehicle-road cooperation according to claim 8, characterized in that: Both the remote RV and the local HV are equipped with an on-board unit (OBU) with V2X wireless communication capabilities.

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