ACC control warning method and device based on vehicle-road cooperative information risk coefficient

Abstract

The present invention discloses an ACC control and early warning method based on the risk coefficient of vehicle-road cooperative information, and the steps are as follows: S1, receiving cruising speed and time headway between vehicles; S2, cruising without receiving vehicle-road cooperative information; S3, calculating collision risk coefficient f1 after receiving information, and comparing f1 with threshold value θ; S4, if f1 is greater than or equal to θ, calculating the distance from the vehicle to the point where the event occurred and the risk coefficient F of vehicle-road cooperative information, and calculating safety distances D1 and D2; S5, detecting the vehicle in front; S6, if there is a vehicle, cruising at the cruising speed; S7, calculating the increase in time headway between vehicles; S8, calculating the decrease in cruising speed; S9, when the distance is less than or equal to D2, the vehicle stops. The present invention also discloses an ACC control and early warning device and computer system based on the risk coefficient of vehicle-road cooperative information. The present invention can improve the safety of the ACC system based on the control of the risk coefficient of vehicle-road cooperative information, and can be widely used in the field of intelligent assisted driving.

Description

Technical Field

[0001] The present invention relates to intelligent assisted driving (ADAS) technology, and in particular to an ACC control warning method and device based on a vehicle-road collaborative information risk coefficient. Background Art

[0002] With the rapid development of intelligent assisted driving ADAS technology, many mass-produced models are now equipped with adaptive cruise control (ACC system). The ACC system uses environmental perception sensors (millimeter-wave radar, camera, etc.) to detect the relative distance and relative speed between the vehicle in front and the vehicle itself, and controls the EMS controller and ESC controller to achieve adaptive control of the vehicle's speed. Since sensors such as millimeter-wave radar and cameras have certain limitations in identifying targets, in order to make the ACC system usable and not frequently "misrespond" to road infrastructure, all OEMs basically state in the ACC function manual that "the ACC system may not be able to recognize stationary targets." However, if the driver uses the ACC system without knowledge, distracted driving, or improper operation, the following problems may occur:

[0003] 1. It may cause the vehicle to collide with a stationary vehicle or a broken-down vehicle ahead;

[0004] 2. It may cause the vehicle to collide with road construction facilities, stationary vehicles in congested sections of road, or accident vehicles at the scene of a traffic accident.

[0005] Based on the above-mentioned problems, some inventors have tried to combine C-V2X technology with the V2I information provided by the road test unit RSU (Road Side Unit) and the V2V information of surrounding vehicles to detect the collision risk between the main vehicle and the remote vehicle; if it is detected that there is no collision risk between the main vehicle and the remote vehicle, and after the main vehicle driver's behavior is determined to be driving in a standardized manner based on the main vehicle driver's driving concentration, the main vehicle's adaptive cruise control system is turned on. This invention uses C-V2X technology to conduct real-time monitoring of target vehicles on any road to reduce the risk of collision, and can also improve driving safety and ride comfort. For example, CN 113682305 A can ensure that the ACC system can only be turned on after the driver's behavior is standardized, which can reduce the risk of abuse of the ACC system. However, this will also greatly limit the use scenarios of the ACC system, and it cannot deal with the sudden risks faced during the activation of the ACC system.

[0006] In light of this, some inventors have proposed a low-speed cruise control method that integrates multiple sensors with V2X. This method, when V2X deployment is low, can improve the perception and application scope of V2X-equipped vehicles by performing state inference, data filtering, and data fusion on data collected from traditional ADAS vehicles equipped with V2X equipment. This significantly promotes the application and promotion of V2X from a technical perspective. Furthermore, it can improve the vehicle's perception range, enabling early prediction of congested road conditions ahead, improving the stability of adaptive cruise control and fuel efficiency during low-speed cruise control, and reducing the dependence of V2X applications on deployment. For example, CN 110606083 A aims to obtain forward congestion information through vehicle-road cooperative technology, enabling the ACC system to make early predictions and improve the stability and fuel efficiency of adaptive cruise control during low-speed cruise control. However, this invention cannot address scenarios such as stationary or faulty vehicles ahead, road construction, and traffic accidents, and the safety of the ACC system needs further improvement.

[0007] Therefore, existing technical solutions are unable to cope with scenarios such as stationary or faulty vehicles ahead, road construction, traffic congestion, and traffic accidents during the use of the ACC system. Summary of the Invention

[0008] The purpose of the present invention is to overcome the shortcomings of the above-mentioned background technology and provide an ACC control and warning method and device based on the vehicle-road collaborative information risk coefficient, so that it can improve the safety of use of the ACC system based on the control and warning method of the vehicle-road collaborative information risk coefficient, and at the same time further expand the scope of application of the ACC system.

[0009] The present invention provides an ACC control warning method based on the vehicle-road cooperative information risk coefficient, comprising the following steps: S1, the ACC system receives the cruising speed and time interval between vehicles set by the driver in real time, and controls the vehicle speed by sending a deceleration request to the ESC controller and a positive and negative torque request to the EMS controller; S2, detecting whether the on-board unit OBU has received the vehicle-road cooperative information, and if not, performing the cruising speed and time interval control based on the ACC control mode of step S1; S3, if it is detected that the on-board unit OBU has received the vehicle-road cooperative information, calculating the collision risk coefficient f1 for the vehicle-road cooperative information, and judging whether the collision risk coefficient f1 is greater than or equal to the set threshold θ, if the collision risk coefficient f1 If the collision risk factor f1 is greater than or equal to the set threshold θ, the cruise speed and time distance between vehicles are controlled based on the ACC control mode of step S1; S4, if the collision risk factor f1 is greater than or equal to the set threshold θ, the real-time distance between the vehicle and the occurrence point of the vehicle-road cooperative event and the vehicle-road cooperative information risk factor F are calculated. At the same time, the nearest occurrence point among multiple vehicle-road cooperative events is used as the control benchmark, and the first safety distance D1 and the second safety distance D2 are calculated and used as the basis for the collaborative control of the ACC system; S5, check whether the on-board sensing device detects a target vehicle in front of the lane. If there is no target vehicle, calculate the cruise speed reduction value ΔV, and reset the original cruise speed V to V1=V-ΔV, and at the same time remind the driver of the road conditions ahead on the instrument panel; S6 , if the on-board sensing device detects that there is a target vehicle in front of the lane, and the speed of the target vehicle in front is greater than or equal to the reset cruising speed V1, then cruise at the cruising speed V1, and remind the driver of the road conditions ahead on the instrument panel; S7, if the speed of the target vehicle in front is less than the reset cruising speed V1, and the distance between the vehicle and the point where the vehicle-road cooperative event occurs in front is greater than the first safety distance D1, then cruise at the cruising speed V1, calculate the increased time distance ΔT between the vehicles, and reset the time distance between the vehicles to (T+ΔT), maintain a longer safe distance from the vehicle in front, and remind the driver of the road conditions ahead on the instrument panel; S8, if the distance between the vehicle and the point where the vehicle-road cooperative event occurs in front is greater than the second safety distance D2 and If the distance between the vehicle and the point where the vehicle-road cooperative event occurs is less than the first safe distance D1, the cruising speed reduction value ΔS is recalculated, and the cruising speed Vs=V1-ΔS is reset. A negative torque request is sent to the EMS controller to reduce the speed to the corresponding safe cruising speed. The driver is requested to take over immediately on the instrument panel and a level 1 alarm is issued, and the hazard warning lights are turned on. S9. If the distance between the vehicle and the point where the vehicle-road cooperative event occurs in front is less than or equal to the second safe distance D2, the vehicle is braked to a stop by sending a deceleration request to the ESC controller to avoid a collision between the vehicle and the dangerous obstacle in front. During the braking process, the driver is requested to take over immediately on the instrument panel and a level 2 alarm is issued, and the hazard warning lights are turned on. After the driver takes over, the ACC system exits and the alarm and hazard warning lights are deactivated.

[0010] In the above technical solution, the specific process of step S3 is as follows: S31. After the on-board unit OBU receives the vehicle-road cooperative information, it extracts the longitude and latitude information in the vehicle-road cooperative event information; S32. Converts the longitude and latitude coordinates into Gaussian projection coordinates; S33. Calculates the collision risk coefficient f1 according to the vehicle-road cooperative information risk calculation table; S34. Determine whether f1 is greater than or equal to the set threshold θ. If it is less than the threshold θ, directly filter the obtained vehicle-road cooperative information, and perform cruise speed and vehicle-to-vehicle time distance control based on the ACC control mode of step S1.

[0011] In the above technical solution, in step S33, the vehicle-road collaborative information risk calculation table.

[0012] In the above technical solution, in step S33, the collision risk coefficient f1 is calculated as follows: f1 = a 1j *k1+a 2j *k2+a 3j *k3+a 4j *k4; where a ij is a score determined according to the grade determination criteria, and a ij is an integer between 1 and 10; k i is the weight of a single indicator, satisfying f1 is the risk coefficient of a single influencing factor, and 0≤f1≤10.

[0013] In the above technical solution, the specific process of step S4 is as follows: S41, if the collision risk coefficient f1 is greater than or equal to the threshold θ, calculate the real-time distance between the vehicle and the point where the vehicle-road cooperative event occurs based on the converted Gaussian projection coordinates; S42, calculate the vehicle-road cooperative information risk coefficient F: f2 = b 1j *l1+b 2j *l2+b 3j *l3+b 4j *l4,f3=c 1j *m1+c 2j *m2+c 3j *m3+c 4j *m4, F=f1*q1+f2*q2+f3*q3, where b ij 、c ij is the score determined according to the grade judgment conditions, and b ij 、c ij are integers between 1 and 10; l i 、m i is the weight of a single indicator, satisfying fi is the risk coefficient of a single influencing factor, and 0≤fi≤10; q i is the weight of each influencing factor, satisfying F is the final calculated risk coefficient of vehicle-road collaboration information;

[0014] S43: Using the closest occurrence point among the multiple vehicle-road cooperative events as a control benchmark, simultaneously calculate a second safety distance D2 and the first safety distance D1 as a basis for cooperative control of the ACC system. The calculation process of the second safety distance D2 is as follows: Among them, V l is the maximum speed limit of the current road, t0 is the reaction time of the braking system, a max is the maximum deceleration that the braking system can provide in ACC control mode, d s The safety distance reserved for avoiding collision in extreme situations; the calculation process of the first safety distance D1 is: D1=D2+V*t1, where V is the current set cruising speed and t1 is the emergency response time reserved for the driver.

[0015] In the above technical solution, in step S5, the calculation formula for the cruising speed reduction value ΔV is as follows: ΔV=A1*V+B1*F, where A1 and B1 are coefficients determined by calibration, V is the currently set cruising speed, and F is the calculated vehicle-road collaborative information risk coefficient.

[0016] In the above technical solution, in step S7, the calculation formula of the increase in headway time ΔT is as follows: Among them, C1 and N1 are coefficients determined by calibration, D S is the real-time distance between the ego vehicle and the point where the vehicle-road cooperative event occurs, D ２ is the safe distance, V h is the vehicle speed, V f is the speed of the preceding vehicle, and F is the calculated vehicle-road collaborative information risk coefficient.

[0017] In the above technical solution, in step S8, the cruising speed reduction value ΔS is calculated based on the calibrated MAP curve; in step S41, the point where the vehicle-to-road cooperative event occurs is the point where the collision risk coefficient f1 is greater than or equal to the set threshold θ; and step S1 also includes step S0, activating the ACC system.

[0018] The present invention also provides an ACC control warning device based on the vehicle-road collaborative information risk coefficient, which can execute an ACC control warning method based on the vehicle-road collaborative information risk coefficient.

[0019] The present invention further provides a computer system, which includes an ACC control warning device based on the vehicle-road cooperative information risk coefficient.

[0020] The principle of the present invention is to filter and screen the vehicle-road cooperative information based on the collision risk coefficient, calculate the vehicle-road cooperative information risk coefficient F and the safety distances D2 and D1, and use them as the basis for the collaborative control of the ACC system. In combination with the target vehicle information detected by the on-board sensing equipment, the cruise setting speed and vehicle-to-vehicle time distance are adjusted according to different safety distances, as well as the driver's safety warning, thereby improving the safety of the ACC system and further expanding the scope of application of the ACC system.

[0021] The ACC control warning method and device based on the vehicle-road cooperative information risk coefficient of the present invention has the following beneficial effects:

[0022] The present invention proposes an ACC control warning method and device based on the vehicle-road collaborative information risk coefficient. The method filters and selects the vehicle-road collaborative information based on the collision risk coefficient, and simultaneously calculates the vehicle-road collaborative information risk coefficient F and the safety distances D2 and D1 as the basis for the collaborative control of the ACC system. Combined with the target vehicle information detected by the on-board sensing device, the cruise control speed and vehicle-to-vehicle time interval are adjusted for different safety distances, as well as the driver's safety warning. This method can predict and warn of road emergencies such as stationary or faulty vehicles ahead, road construction, traffic congestion, and traffic accidents in advance, reduce the occurrence of collision accidents caused by the limitations of on-board sensors during the use of the ACC system, improve the safety of the ACC system during use, and increase the applicable scenarios of the ACC system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the overall process of the ACC control warning method based on the vehicle-road cooperative information risk coefficient of the present invention;

[0024] Figure 2 This is a structural diagram of the ACC control and warning device based on the vehicle-road cooperative information risk coefficient of the present invention;

[0025] Figure 3 A structural diagram of the computer system of the present invention;

[0026] Figure 4 This is a diagram of the ACC system vehicle-road cooperative information architecture for obtaining the ACC control warning method based on the vehicle-road cooperative information risk coefficient of the present invention;

[0027] Figure 5 This is an architectural diagram of the ACC control and warning components of the ACC control and warning method based on the vehicle-road cooperative information risk coefficient of the present invention;

[0028] Figure 6 This is a diagram illustrating the calculation of the real-time distance between the vehicle and the occurrence point of the vehicle-infrastructure cooperation event in step 501 in an embodiment of the ACC control warning method based on the vehicle-infrastructure cooperation information risk coefficient of the present invention;

[0029] Figure 7 This is a calibration MAP diagram of the cruising speed reduction value in step 9 in the embodiment of the ACC control warning method based on the vehicle-road cooperative information risk coefficient of the present invention. DETAILED DESCRIPTION

[0030] The present invention will be further described in detail below with reference to the accompanying drawings and examples, but the examples should not be construed as limiting the present invention.

[0031] See also Figure 1 The ACC control warning method based on the vehicle-road cooperative information risk coefficient of the present invention has the following specific process:

[0032] 1. The driver activates the ACC system;

[0033] 2. The ACC system receives the driver's set cruising speed and time headway in real time, and controls the vehicle's speed by sending deceleration requests to the ESC controller and positive and negative torque requests to the EMS controller.

[0034] 3. Detect whether the on-board unit (OBU) has received vehicle-road collaboration information from the third-party information service platform, the roadside unit (RSU), and the on-board unit (OBU). If no vehicle-road collaboration information is received, cruise speed and time-to-headness control are performed based on the traditional ACC control mode;

[0035] 4. If the on-board detection unit (OBU) has received V2I information, it calculates a collision risk factor f1 based on the V2I information (such as information about stationary or faulty vehicles, road construction, traffic congestion, and traffic accidents) and determines whether f1 is greater than or equal to a set threshold θ. If the collision risk factor f1 is less than the set threshold θ, it is considered that there is no collision risk ahead and the V2I information can be directly filtered. Cruise speed and time-to-headness control will continue based on the traditional ACC control mode.

[0036] 5. If the collision risk factor f1 is greater than or equal to the set threshold θ, the real-time distance between the ego vehicle and the point where the V2I event occurred (i.e., the point where f1 is greater than or equal to the set threshold θ) and the V2I information risk factor F are calculated. Simultaneously, using the closest point of multiple V2I events as the control benchmark, the first safety distance D1 and the second safety distance D2 are calculated as the basis for ACC system collaborative control.

[0037] 6. Check whether the vehicle's sensing device detects a target vehicle ahead in the lane. If not, calculate the cruising speed reduction value ΔV and reset the original cruising speed V to V1 = V-ΔV. At the same time, the driver is reminded of the road conditions ahead on the instrument panel.

[0038] 7. If the vehicle's onboard sensing device detects a target vehicle ahead in the lane, and the target vehicle's speed is greater than or equal to the reset cruising speed V1, the vehicle will cruise at the cruising speed V1, and the driver will be reminded of the road conditions ahead on the instrument panel.

[0039] 8. If the target vehicle ahead is traveling at a speed lower than the reset cruising speed V1, and the distance between the vehicle and the point where the vehicle-road cooperative event occurs is greater than the first safety distance D1, the vehicle will cruise at the cruising speed V1, calculate the increased headway value ΔT, and reset the headway value to (T + ΔT), maintaining a longer safety distance from the vehicle ahead. Meanwhile, the driver will be notified of the road conditions ahead on the instrument panel.

[0040] 9. If the distance between the ego vehicle and the point where the vehicle-road cooperative event occurred is greater than the second safety distance D2 and less than the first safety distance D1, the cruising speed reduction value ΔS is recalculated and the cruising speed Vs is reset to V1 - ΔS. A negative torque request is sent to the EMS controller to reduce the speed to the corresponding safe cruising speed. The instrument panel requests the driver to take immediate control and issues a level 1 alarm, while illuminating the hazard warning lights.

[0041] 10. If the distance between the vehicle and the point where the vehicle-road cooperative event occurs is less than or equal to the second safety distance D2, a deceleration request (no more than -3m / s) is sent to the ESC controller. 2 ) Brake the vehicle to avoid collision with dangerous obstacles ahead. During the braking process, the instrument panel will request the driver to take over immediately and issue a secondary alarm, while illuminating the hazard warning lights. The ACC system will exit and deactivate the alarm and hazard warning lights until the driver takes over.

[0042] See also Figure 2 The present invention provides an ACC control and warning device based on the vehicle-road cooperative information risk coefficient, including the following parts:

[0043] Start module: activate ACC system;

[0044] Control module: The ACC system receives the driver's set cruising speed and inter-vehicle time interval in real time, and controls the vehicle's speed by sending deceleration requests to the ESC controller and positive and negative torque requests to the EMS controller.

[0045] Communication coordination module: detects whether the on-board unit (OBU) has received vehicle-road coordination information. If not, it controls the cruise speed and time distance between vehicles based on the ACC control mode of the control module.

[0046] Collision risk coefficient calculation module: If the on-board unit (OBU) detects that it has received vehicle-road cooperative information, it calculates the collision risk coefficient f1 for the vehicle-road cooperative information and determines whether the collision risk coefficient f1 is greater than or equal to the set threshold θ. If the collision risk coefficient f1 is less than the set threshold θ, the cruise speed and inter-vehicle time distance control are performed based on the ACC control mode of the control module;

[0047] Safety distance calculation module: If the collision risk factor f1 is greater than or equal to the set threshold θ, the real-time distance between the ego-vehicle and the point where the VIS event occurred and the VIS information risk factor F are calculated. Simultaneously, using the closest point of occurrence among multiple VIS events as the control benchmark, the first safety distance D1 and the second safety distance D2 are calculated and used as the basis for the ACC system's collaborative control.

[0048] Target vehicle detection module: Detects whether the on-board sensing device detects a target vehicle ahead in the lane. If not, it calculates the cruising speed reduction value ΔV and resets the original cruising speed V to V1 = V-ΔV. At the same time, it reminds the driver of the road conditions ahead on the instrument panel.

[0049] Cruise speed setting module: If the on-board sensing device detects a target vehicle ahead in the lane, and the speed of the target vehicle ahead is greater than or equal to the reset cruise speed V1, the vehicle will cruise at the cruise speed V1, and the driver will be reminded of the road conditions ahead on the instrument panel;

[0050] Inter-vehicle time distance setting module: If the speed of the target vehicle ahead is less than the reset cruising speed V1, and the distance between the ego vehicle and the point where the vehicle-road cooperative event occurs ahead is greater than the first safety distance D1, the ego vehicle cruises at the cruising speed V1, calculates the inter-vehicle time distance increase value ΔT, and resets the inter-vehicle time distance to (T+ΔT), maintaining a longer safety distance from the vehicle ahead. Meanwhile, the driver is reminded of the road conditions ahead on the instrument panel.

[0051] Level 1 Alarm Module: If the distance between the ego vehicle and the point where the vehicle-road cooperative event occurs is greater than the second safety distance D2 and less than the first safety distance D1, the cruise speed reduction value ΔS is recalculated and the cruise speed Vs is reset to V1-ΔS. A negative torque request is sent to the EMS controller to reduce the speed to the corresponding safe cruise speed. The instrument panel requests the driver to take over immediately and issues a level 1 alarm, while illuminating the hazard warning lights.

[0052] Secondary alarm module: If the distance between the vehicle and the point where the vehicle-road cooperative event occurs in front is less than or equal to the second safety distance D2, the vehicle will be braked to a stop by sending a deceleration request to the ESC controller to avoid collision with dangerous obstacles in front. During the braking process, the driver will be requested to take over immediately and a secondary alarm will be issued on the instrument panel, and the hazard warning lights will be turned on at the same time. After the driver takes over, the ACC system will exit and the alarm and hazard warning lights will be deactivated.

[0053] See also Figure 3 , the computer system of the present invention includes an ACC control warning device based on the vehicle-road collaborative information risk coefficient.

[0054] See also Figure 4 , and the parts related to the acquisition of vehicle-road cooperative information of the ACC system include:

[0055] Traffic management information service platforms manage and publish information on road construction, traffic congestion, traffic accidents, real-time traffic conditions, etc., and provide such information to third-party information service platforms (such as navigation service platforms) via dedicated data lines;

[0056] Third-party information service platforms can publish information on traffic events such as road construction, traffic congestion, traffic accidents, and real-time traffic conditions through 4G / 5G networks. This information should at least include the event type, occurrence time, expected end time, and event latitude and longitude.

[0057] Roadside sensing equipment, such as millimeter-wave radar, smart cameras, and lidar, installed on the roadside, can transmit information about road traffic events (congestion, construction, accidents, etc.) and road traffic participants (pedestrians, non-motorized vehicles, motor vehicles, etc.) to the V2X cloud platform;

[0058] The V2X cloud platform automatically encapsulates traffic events and traffic participant information transmitted by roadside sensing devices, and transmits the encapsulated RSI, RSM, and MAP messages to the roadside unit (RSU) at the designated intersection at a fixed frequency.

[0059] The CA platform can provide security certificate services for V2X communication equipment (such as roadside units (RSUs) and on-board units (OBUs), ensuring secure communication and preventing forgery attacks.

[0060] The roadside unit (RSU) receives RSI, RSM, and MAP messages sent by the V2X platform and broadcasts these messages to the onboard unit (OBU) at a fixed frequency.

[0061] The on-board unit (OBU) can be detected and broadcast the vehicle's own status information (vehicle speed, fault status, longitude and latitude information, etc.) through PC5 direct communication. At the same time, it can also receive vehicle-road cooperative information transmitted by third-party information service platforms (via 4G / 5G networks), roadside units (RSU) (via PC5 direct communication), and other on-board units (OBU) (via PC5 direct communication) and provide it to the vehicle for control and information display;

[0062] Vehicles equipped with ACC systems achieve cruise control by combining the vehicle-road cooperative information obtained by the on-board detection unit OBU and the target object information obtained by the on-board sensing equipment (millimeter wave radar, camera, etc.).

[0063] See also Figure 5 The hardware modules related to the ACC system control and warning include:

[0064] The ACC controller combines vehicle-road cooperative information with target information obtained by on-board sensing devices (millimeter-wave radar, cameras, etc.), the driver's set cruise speed, and inter-vehicle time interval information to perform calculations. It then sends relevant control commands to the EMS controller and ESC controller to implement the vehicle's adaptive cruise control. It also interacts with the instrument panel to display ACC system icons, text, and alarm information.

[0065] The ESC (Electronic Stability Control) controller is widely equipped on modern vehicles. It can achieve functions such as vehicle deceleration and stability. It can achieve vehicle deceleration by receiving the deceleration request from the ACC controller;

[0066] The EMS controller controls the vehicle's powertrain, including the internal combustion engine and electric motor, and executes the positive and negative torque information sent by the ACC controller;

[0067] Detect vehicle-mounted sensing devices, including but not limited to vehicle-mounted millimeter-wave radars and cameras, which can sense the target information in front of the vehicle and provide it to the ACC controller for control;

[0068] Detecting the on-board unit (OBU) can obtain vehicle-road cooperative information in real time and calculate distance, and then provide the above information to the ACC controller for control;

[0069] The cruising speed setting module is used to provide the driver's desired cruising speed information to the ACC controller;

[0070] The vehicle headway setting module is used to provide the ACC controller with the vehicle headway information expected by the driver;

[0071] Instrument panel, used to display ACC system icons, text, driver reminders and warning information, etc.

[0072] The hazard warning lights receive activation requests from the ACC system and prompt vehicles behind to drive cautiously in an emergency.

[0073] The key technical points of the present invention are:

[0074] 1. Methods for calculating the risk factor of V2X information, and methods for filtering and screening V2X information;

[0075] 2. A method for extracting longitude and latitude information from vehicle-road cooperative information to calculate relative distance;

[0076] 3. Calculation method for cruising speed reduction ΔV, ΔS and headway increase ΔT based on the vehicle-road cooperative information risk factor, onboard sensor information, and vehicle information;

[0077] 4. Methods for controlling and warning the ACC system based on the vehicle-road collaborative information risk coefficient and on-board sensing device information.

[0078] The following is a detailed description of a specific embodiment:

[0079] After the vehicle ACC system is activated by the driver, ACC obtains the vehicle-road cooperative information obtained by the on-board unit OBU and the forward target information obtained by the on-board sensing device in real time. (This part corresponds to Figure 1 Steps 1 to 3)

[0080] Step 401: Once the on-board unit OBU receives the vehicle-road collaboration information, the longitude and latitude information in the vehicle-road collaboration event information is extracted.

[0081] Step 402: Convert the coordinate system: unify to the CGCS2000 coordinate system or the WGS84 coordinate system, and convert the longitude and latitude coordinates into Gaussian projection coordinates (xy). The calculation process is as follows:

[0082]

[0083]

[0084] Where: Angles are all in radians;

[0085] π=3.1415926535897932;

[0086] ρ°=180÷π=57.2957795130823210°;

[0087] ρ′=180×60÷π=3437.74677078493917′;

[0088] ρ"=180×60×60÷π=206264.806247096355";

[0089] (parameters / ellipsoid name) CGCS 2000 WGS 84 Semi-major axis a 6378137 6378137 minor axis b 6356752.3141403558 6356752.3142451795

[0090] η=e′cosB, e′ is the second eccentricity of the ellipse,

[0091] e is the first eccentricity of the ellipse

[0092] B is the latitude of the coordinate point, l″=L-L0, L is the longitude of the point, and L0 is the longitude of the central meridian;

[0093] N is the meridian curvature radius,

[0094] t = tan B;

[0095] in,

[0096] X is the meridian arc length,

[0097] M is the meridian curvature radius,

[0098] M expands the series according to Newton's binomial theorem and takes the 8th order term, then:

[0099] M=m0+m2 sin 2 B+m4 sin 4 B+m6 sin 6 B+m8 sin 8 B;

[0100]

[0101] Expand the power function of sine into multiple functions of cosine:

[0102] M=a0-a2 cos 2B+a4 cos 4B-a6 cos 6B+a8 cos 8B;

[0103]

[0104] Therefore, the above formula Integrate to get:

[0105]

[0106] Step 403: further calculate the collision risk coefficient f1 according to the vehicle-road cooperative information risk calculation table. The vehicle-road cooperative information risk calculation table is shown in the following table:

[0107] Table 1 Vehicle-road cooperative information risk calculation table

[0108]

[0109]

[0110] The calculation formula for the vehicle-road cooperative information risk coefficient is as follows:

[0111] f1=a 1j *k1+a 2j *k2+a 3j *k3+a 4j *k4;

[0112] Step 404: Determine whether f1 is greater than or equal to a set threshold value θ. If it is less than the threshold value θ, directly filter the acquired vehicle-infrastructure cooperative information and continue to perform cruise speed and time-to-headness control based on the traditional ACC control mode.

[0113] Step 501: If it is greater than or equal to the threshold value θ, refer to Figure 6 , calculate the real-time distance between the vehicle and the point where the vehicle-road cooperative event occurs based on the converted Gaussian projection coordinates:

[0114]

[0115] Continue to calculate the vehicle-road collaboration information risk coefficient F:

[0116] f2=b 1j *l1+b 2j *l2+b 3j *l3+b 4j *l4,

[0117] f3=c 1j *m1+c 2j *m2+c 3j *m3+c 4j *m4,

[0118] F=f1*q1+f2*q2+f3*q3,

[0119] in,

[0120] a ij 、b ij 、c ij is a score determined according to the grade determination criteria, and a ij 、b ij 、c ij All are integers between 1 and 10;

[0121] k i 、l i 、m iis the weight of a single indicator, satisfying

[0122] fi is the risk coefficient of a single influencing factor, and 0≤fi≤10;

[0123] qi is the weight of each influencing factor, satisfying F is the final calculated vehicle-road collaborative information risk coefficient.

[0124] Step 502: Using the closest occurrence point among multiple vehicle-infrastructure cooperative events as a control benchmark, a second safety distance D2 and a first safety distance D1 are calculated as a basis for cooperative control of the ACC system;

[0125] The calculation process of the second safety distance D2 is as follows:

[0126]

[0127] in,

[0128] V l is the maximum speed limit of the current road, t0 is the reaction time of the braking system, a max The maximum deceleration that the braking system can provide in ACC control mode, generally not exceeding 3m / s 2 , d s A safe distance reserved to avoid collision in extreme situations;

[0129] The calculation process of the first safety distance D1 is as follows:

[0130] D1=D2+V*t1,

[0131] in,

[0132] V is the current cruising speed, and t1 is the time reserved for the driver to respond to emergencies.

[0133] Step 6: When the on-board detection unit (OBU) obtains vehicle-road cooperative information indicating a collision risk and the on-board sensing device does not detect a target vehicle ahead in the lane, the ACC controller calculates the cruising speed reduction value ΔV and resets the cruising speed to V1 = V-ΔV. At the same time, the driver is reminded of the road conditions ahead on the instrument panel. The cruising speed reduction value is calculated as follows:

[0134] ΔV=A1*V+B1*F;

[0135] in,

[0136] A1 and B1 are coefficients determined through calibration, V is the currently set cruising speed, and F is the calculated vehicle-road collaborative information risk coefficient.

[0137] Step 7: If the onboard sensing device detects a target vehicle ahead in the lane, and the speed of the target vehicle ahead is greater than or equal to the reset cruising speed V1, the vehicle cruises at the cruising speed V1, and the driver is reminded of the road conditions ahead on the instrument panel.

[0138] Step 8: If the speed of the target vehicle ahead is less than the reset cruising speed V1, and the distance between the ego vehicle and the point where the vehicle-road cooperative event occurs ahead is greater than the first safety distance D1, then cruise at the cruising speed V1, calculate the time headway increase ΔT, and reset the time headway to (T+ΔT), maintaining a longer safety distance from the vehicle ahead. At the same time, the driver is reminded of the road conditions ahead on the instrument panel. The calculation formula for the time headway increase ΔT is as follows:

[0139]

[0140] in,

[0141] C1 and N1 are coefficients determined by calibration, D S is the real-time distance between the ego vehicle and the point where the vehicle-road cooperative event occurs, D2 is the safety distance, and V h is the vehicle speed, V f is the speed of the preceding vehicle, F is the calculated risk coefficient of vehicle-road cooperative information, and the ΔT calculation formula shows that ΔT is related to the risk coefficient of vehicle-road cooperative information F and the real-time distance D from the point where the vehicle-road cooperative event occurs. S The time difference between the front and rear vehicles is proportional to the speed difference between the front and rear vehicles. When the real-time distance to the point where the vehicle-road cooperative event occurs is equal to D2, the increase in the time headway between the two vehicles will be at its maximum value ΔT. max =C1*F.

[0142] Step 9: If the distance between the ego vehicle and the point where the vehicle-road cooperative event occurs is greater than the second safety distance D2 and less than the first safety distance D1, recalculate the cruising speed reduction value ΔS and reset the cruising speed Vs = V1 - ΔS. Send a negative torque request to the EMS controller to reduce the speed to the new safe cruising speed. Request the driver to take over immediately and issue a level 1 alarm on the instrument panel. At the same time, illuminate the hazard warning lights. Figure 7 The cruising speed reduction value ΔS is calculated based on the calibrated MAP curve of the cruising speed reduction value calibration MAP diagram.

[0143] Step 10: If the distance between the vehicle and the point where the vehicle-road cooperative event occurs is less than or equal to the second safety distance D2, a deceleration request (no more than -3 m / s) is sent to the ESC controller. 2) Brake the vehicle to avoid collision with dangerous obstacles ahead. During the braking process, the instrument panel will request the driver to take over immediately and issue a secondary alarm, while illuminating the hazard warning lights. The ACC system will exit and deactivate the alarm and hazard warning lights until the driver takes over.

[0144] The abbreviations and key terms used in the present invention are defined as follows:

[0145] BSM (Basic Safety Message)——Basic Safety Message;

[0146] RSM (Road Side Message)——Roadside unit message;

[0147] RSI (Road Side Information) - traffic incident and traffic sign information;

[0148] OBU (On Board Unit) - detects the onboard unit;

[0149] RSU (Road Side Unit)——Roadside Unit.

[0150] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

[0151] The contents not described in detail in this specification belong to the prior art known to those skilled in the art.

Claims

1. An ACC control warning method based on vehicle-road cooperative information risk coefficient, characterized by: The steps include: S1. The ACC system receives the cruising speed and time interval set by the driver in real time, and controls the vehicle speed by sending a deceleration request to the ESC controller and a positive and negative torque request to the EMS controller; S2, detecting whether the on-board unit OBU has received vehicle-road cooperative information, wherein the vehicle-road cooperative information is information about stationary or faulty vehicles, road construction, traffic congestion, and traffic accidents. If the vehicle-road cooperative information is not received, the cruise speed and inter-vehicle time distance control are performed based on the ACC control mode of step S1; S3, if the detection vehicle-mounted unit OBU has received the vehicle-road cooperative information, calculate the collision risk coefficient f1 of the vehicle-road cooperative information, and determine whether the collision risk coefficient f1 is greater than or equal to the set threshold θ; if the collision risk coefficient f1 is less than the set threshold θ, perform the cruise speed and inter-vehicle time distance control based on the ACC control mode of step S1; S4. If the collision risk coefficient f1 is greater than or equal to the set threshold value θ, the real-time distance between the vehicle and the occurrence point of the vehicle-road cooperative event and the vehicle-road cooperative information risk coefficient F are calculated. At the same time, the closest occurrence point among multiple vehicle-road cooperative events is used as the control benchmark, and the first safety distance D1 and the second safety distance D2 are calculated and used as the basis for the cooperative control of the ACC system; S5. Check whether the vehicle-mounted sensing device detects a target vehicle ahead of the lane. If there is no target vehicle, calculate the cruising speed reduction value ΔV, and reset the original cruising speed V to V1=V-ΔV, while reminding the driver of the road conditions ahead on the instrument panel; S6. If the vehicle-mounted sensing device detects that there is a target vehicle ahead of the lane, and the speed of the target vehicle ahead is greater than or equal to the reset cruising speed V1, the vehicle cruises at the cruising speed V1, and the driver is reminded of the road conditions ahead on the instrument panel; S7. If the speed of the target vehicle ahead is less than the reset cruising speed V1, and the distance between the vehicle and the point where the vehicle-road cooperative event occurs ahead is greater than the first safety distance D1, the vehicle cruises at the cruising speed V1, calculates the increased time headway ΔT, and resets the time headway to (T+ΔT), maintaining a longer safety distance from the vehicle ahead, and reminds the driver of the road conditions ahead on the instrument panel; S8. If the distance between the vehicle and the point where the vehicle-road cooperative event occurs is greater than the second safety distance D2 and less than the first safety distance D1, recalculate the cruising speed reduction value ΔS, and reset the cruising speed Vs=V1-ΔS. Send a negative torque request to the EMS controller to reduce the speed to the corresponding safe cruising speed, request the driver to take over immediately and issue a level 1 alarm on the instrument panel, and light up the hazard warning lights at the same time. S9. If the distance between the vehicle and the point where the vehicle-road cooperative event occurs in front is less than or equal to the second safety distance D2, the vehicle will be braked to a stop by sending a deceleration request to the ESC controller to avoid a collision between the vehicle and a dangerous obstacle in front. During the braking process, the driver will be requested to take over immediately and a secondary alarm will be issued on the instrument panel, and the hazard warning lights will be turned on at the same time. The ACC system will not exit and remove the alarm and hazard warning lights until the driver takes over.

2. The ACC control warning method based on vehicle-road cooperative information risk coefficient according to claim 1 is characterized by: The specific process of step S3 is as follows: S31, after receiving the vehicle-road collaboration information, the on-board unit OBU extracts the longitude and latitude information in the vehicle-road collaboration event information; S32, converting the longitude and latitude coordinates into Gaussian projection coordinates; S33, calculating the collision risk coefficient f1 according to the vehicle-road cooperative information risk calculation table; S34, determine whether f1 is greater than or equal to a set threshold value θ. If it is less than the threshold value θ, directly filter the acquired vehicle-road cooperative information, and perform cruising speed and vehicle-to-vehicle time distance control based on the ACC control mode of step S1.

3. The ACC control warning method based on vehicle-road cooperative information risk coefficient according to claim 2 is characterized by: In step S33, the vehicle-road cooperative information risk calculation table is as follows: 。 4. The ACC control warning method based on vehicle-road cooperative information risk coefficient according to claim 3 is characterized by: In step S33, the collision risk coefficient f1 is calculated as follows: f1= a 1j * k1 + a 2j * k2 + a 3j * k3 + a 4j * k4; Among them, a ij is a score determined according to the grade determination criteria, and a ij is an integer between 1 and 10; k i is the weight of a single indicator, satisfying ; f1 is the risk coefficient of a single influencing factor, and 0≤f1≤10.

5. The ACC control warning method based on vehicle-road cooperative information risk coefficient according to claim 4 is characterized by: The specific process of step S4 is as follows: S41, if the collision risk coefficient f1 is greater than or equal to the threshold θ, the real-time distance between the vehicle and the point where the vehicle-road cooperative event occurs is calculated according to the converted Gaussian projection coordinates; S42. Calculate the risk factor F of vehicle-road collaboration information: <h2 style=";text-align:left;direction:ltr">f2=b<h2 style=";text-align:left;direction:ltr"> 1j <h2 style=";text-align:left;direction:ltr"> * l1 + b<h2 style=";text-align:left;direction:ltr"> 2j <h2 style=";text-align:left;direction:ltr"> * l2 + b<h2 style=";text-align:left;direction:ltr"> 3j <h2 style=";text-align:left;direction:ltr"> * l3 + b<h2 style=";text-align:left;direction:ltr"> 4j <h2 style=";text-align:left;direction:ltr"> * l4, f3= c 1j * m1 + c 2j * m2 + c 3j * m3 + c 4j * m4, F= f1 * q1 + f2 * q2 + f3 * q3, Among them, b ij 、c ij is the score determined according to the grade determination criteria, and b ij 、c ij All are integers between 1 and 10; l i 、m i is the weight of a single indicator, satisfying , ; fi is the risk coefficient of a single influencing factor, and 0≤fi≤10; q i is the weight of each influencing factor, satisfying ; F is the final calculated risk coefficient of vehicle-road collaboration information; S43, taking the nearest occurrence point among the multiple vehicle-road cooperative events as the control benchmark, and calculating the second safety distance D2 and the first safety distance D1 as the basis for cooperative control of the ACC system, The calculation process of the second safety distance D2 is as follows: D2 = ， in, is the maximum speed limit of the current road. is the reaction time of the braking system, is the maximum deceleration that the braking system can provide in ACC control mode. A safe distance reserved to avoid collision in extreme situations; The calculation process of the first safety distance D1 is as follows: D1 = ， in, Set the current cruising speed. To reserve time for drivers to respond to emergencies.

6. The ACC control warning method based on vehicle-road cooperative information risk coefficient according to claim 5 is characterized by: In step S5, the cruising speed reduction value ΔV is calculated as follows: ΔV = , in, and is the coefficient determined by calibration, is the currently set cruising speed, is the calculated vehicle-road collaboration information risk coefficient.

7. The ACC control warning method based on vehicle-road cooperative information risk coefficient according to claim 6 is characterized by: In step S7, the calculation formula of the increase value ΔT of the headway time is as follows: ΔT = , in, and is the coefficient determined by calibration, is the real-time distance between the vehicle and the point where the vehicle-road cooperative event occurs, For a safe distance, is the vehicle speed, is the speed of the front vehicle, is the calculated vehicle-road collaboration information risk coefficient.

8. The ACC control warning method based on vehicle-road cooperative information risk coefficient according to claim 7 is characterized by: In step S8, the cruising speed reduction value ΔS is calculated by looking up the value of the calibrated MAP curve; In the step S41, the point where the self-vehicle-to-road cooperative event occurs is a point where the collision risk coefficient f1 is greater than or equal to a set threshold value θ; Before step S1, the method further includes step S0 of activating the ACC system.

9. An ACC control warning device based on vehicle-road collaborative information risk coefficient, capable of executing the ACC control warning method based on vehicle-road collaborative information risk coefficient as described in any one of claims 1 to 8.

10. A computer system comprising an ACC control warning device based on the vehicle-road cooperative information risk coefficient as described in claim 9.

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