Vehicle curve rollover prevention early warning method and system

Abstract

The invention relates to a vehicle curve rollover prevention early warning method and system, and the method comprises the steps: obtaining the latitude and longitude information of a road in front of a vehicle through an electronic map, and estimating the curvature radius of a road segment through a three-point method; and in combination with the road adhesion coefficient and a critical safe vehicle speed formula obtained through simulation, calculating the safe vehicle speed of the road section ahead in real time, and comparing the safe vehicle speed with the actual vehicle speed of the vehicle. When the speed of the vehicle is close to or exceeds the critical safe speed, graded early warning is conducted on a driver through the voice and interface warning module, and therefore the curve rollover risk is effectively reduced. Meanwhile, the vehicle-mounted early warning unit can also send a local early warning log to a cloud data center for storage and statistical processing, and decision data support is provided for traffic management departments, vehicle operation companies and other units. Compared with the prior art, the method does not need to depend on additional sensors, can achieve early warning only through existing navigation software and meteorological data, and has high practicability and popularization value.

Description

Technical Field

[0001] The present invention relates to the technical field of driving safety warning, and in particular to a method and system for preventing rollover on a curve for a vehicle with a high center of mass. Background Art

[0002] There are many sharp bends on low-grade roads in mountainous and rural areas of my country. If the driver lacks understanding of the road conditions ahead and turns sharply at a high speed, it is very easy to cause the vehicle, especially a high-center-of-mass vehicle (such as a commercial vehicle or truck), to roll over. Early warning of rollover risks can effectively reduce the incidence of such accidents. However, current early warnings mainly use sensors to collect vehicle load, acceleration and other data (such as patent number CN118343141A), which can only provide real-time assessment of the vehicle's current driving status, but cannot provide a forecast of risks on the road ahead. Summary of the invention

[0003] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a method and system for early warning of the rollover risk ahead.

[0004] The purpose of the present invention can be achieved by the following technical solutions:

[0005] As a first aspect of the present invention, a vehicle curve anti-rollover warning method is provided, the steps comprising:

[0006] Obtain the latitude and longitude information of the road ahead of the vehicle;

[0007] Real-time determination of the road section where the vehicle is currently located;

[0008] Combine the curvature radius of the road section and the road adhesion coefficient simulation to obtain the critical safe speed formula, and calculate the safe speed of the road section ahead in real time;

[0009] The safe speed of the road ahead is compared with the actual speed of the vehicle, and the driver is given a graded warning when the vehicle approaches or exceeds the critical safe speed.

[0010] As a preferred technical solution, the road section where the vehicle is currently located is determined using a vector dot product method:

[0011] A road segment is composed of two adjacent points. Based on the coordinates of the two points on the road segment and the longitude and latitude coordinates of the vehicle, the dot product of the current longitude and latitude coordinates of the vehicle and the coordinates of the two endpoints of the road segment is calculated to determine whether the vehicle is on the road segment:

[0012] When the dot product of the vector from one end of the road segment to the vehicle and the vector from one end of the road segment to the other end is negative, the vehicle is judged to be on the AB road segment;

[0013] When the dot product of the vector from one end of the road section to the vehicle and the vector from one end of the road section to the other end is positive, the vehicle is judged to be outside the AB section.

[0014] As a preferred technical solution, the early warning method performs the following judgment when the vehicle position is updated:

[0015] When the dot product of the vector from one end of the road section to the vehicle and the vector from one end of the road section to the other end is negative, it is considered that the road section has not changed;

[0016] On the contrary, if the dot product of the vector from one end of the road segment to the vehicle and the vector from one end of the road segment to the other end is positive, the vehicle is considered to enter the next road segment.

[0017] As a preferred technical solution, the method

[0018] Based on the estimated values ​​of the curvature radius of each road section and the adhesion coefficient of the road, and taking into account the influence of weather, the critical safety speed of each road section is calculated using the safety speed formula obtained by simulation and fitting:

[0019]

[0020] Where R is the curvature radius of the road section; is the adhesion coefficient; k is the correction coefficient of the adhesion coefficient; α, β, γ, δ, ε are the fitting coefficients of each item respectively, and C is the fitting constant item.

[0021] As a preferred technical solution, the estimated curvature radius of the road section is as follows:

[0022] A road segment is formed by two adjacent points, and each road segment and the two points before and after the road segment respectively form two triangles;

[0023] The Haversine formula is used to calculate the straight-line distance of each point in the road section based on the longitude and latitude coordinates of each point, and the length of each side of the two triangles is obtained;

[0024] Based on the side lengths of the two triangles, calculate the circumscribed circle radius of the two triangles using the sine theorem;

[0025] Take the average of the circumscribed circle radii of the two triangles to get the estimated curvature radius of the road section.

[0026] As a preferred technical solution, for the first and last road sections, the radius of the circumscribed circle of the triangle formed by the first and last road sections and the next / previous point is directly used as the radius of curvature.

[0027] As a preferred technical solution, the present invention uses the lateral load transfer rate LTR close to 1 as an indicator for determining the rollover / slip criticality when calculating the critical safety speed, wherein the lateral load transfer rate LTR is defined by the formula:

[0028]

[0029] In the formula, F l 、F r are the loads on the wheels on the left and right sides of the vehicle respectively.

[0030] As a preferred technical solution, the hierarchical alarm is specifically:

[0031] If the vehicle speed is below the first critical safety speed, no alarm will be given;

[0032] Between the first and second critical safety speeds, the driver is reminded with a first-frequency alarm and flashing warning triangles, and a voice announcement: There is a risk of rollover ahead, please slow down! A weak first positive torque is applied to the steering wheel to remind the driver;

[0033] When the vehicle speed is above the second safe speed, the second frequency alarm sound and warning triangle flash to remind the driver, and the voice broadcast: "It is about to roll over, slow down immediately!" and a strong second self-aligning torque is applied to the steering wheel to remind the driver.

[0034] As a preferred technical solution, the method determines the road section where the vehicle is located in real time each time the vehicle position is updated, and calculates the safety based on the curvature radius of several sections ahead of the road section and the current vehicle speed to provide warning information.

[0035] As a second aspect of the present invention, a vehicle curve rollover prevention warning system is provided, the system implements the vehicle curve rollover prevention warning method as described above, and the system comprises:

[0036] Electronic map service providers, providing geographic information services;

[0037] The vehicle-mounted unit is responsible for sending warning information to the driver and recording and uploading it; the vehicle-mounted unit includes: a power module, a vehicle-mounted unit processor, a geographic information receiving and processing module, an alarm execution module and an alarm log recording and receiving module;

[0038] The alarm execution module includes a voice warning submodule, an interface warning submodule and a steering wheel torque feedback submodule:

[0039] The data center collects and utilizes vehicle-mounted warning information to provide data support to traffic management departments, operating companies and other units.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] The electronic map-based anti-rollover warning method proposed in the present invention obtains road and vehicle information through the electronic map GIS, calculates the road curvature radius and determines the current section of the vehicle in real time, and calculates the safe speed of the section ahead of the vehicle in combination with the curvature radius of the section and the road adhesion coefficient. When the vehicle is about to enter a sharp curve section, it can be judged in advance whether there is a risk of rollover or skidding if it continues to drive at the current speed, and when the risk is detected, an alarm is issued to the driver through text, voice, and force feedback of different sizes, thereby improving driving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 The figure is a flow chart of the method for preventing rollover on a curved road based on an electronic map of the present invention;

[0043] Figure 2 A schematic diagram of an algorithm for estimating road section curvature according to the present invention;

[0044] Figure 3 It is a schematic diagram of the dot product criterion of the present invention;

[0045] Figure 4 The hardware composition diagram of the curve anti-rollover warning system based on the electronic map of the present invention;

[0046] Figure 5 This is the software architecture diagram of the curve rollover warning system based on electronic maps. DETAILED DESCRIPTION

[0047] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0048] Example 1

[0049] As one implementation of the present invention, this embodiment provides a curve anti-rollover warning method based on an electronic map, such as Figure 1 As shown, the specific steps of the method are as follows: first, the latitude and longitude coordinates of each point on the path ahead (especially the sharp bend point) are obtained through an electronic map; then, in combination with a certain estimation method, the estimated curvature value of each road section is calculated, and through a certain criterion, it is determined which road section the vehicle is currently traveling on; then, the estimated curvature radius of the road section that the vehicle is about to enter (the advance amount of several road sections can be set according to the speed) is substituted into the critical safety speed formula to calculate the critical safety speed; finally, the speed is compared with the current actual speed. If it is below 80% of the critical speed, it is determined to be safe, 80% to 100% of the critical speed is determined to be critical, and above 100% is determined to be dangerous, and corresponding alarms are issued for each speed section.

[0050] In the section curvature estimation part, the present invention selects a method for calculating the road curvature radius based on the three-point method. This method calculates the radius of the circumscribed circle of a triangle formed by three consecutive points on the road to obtain the curvature radius of the road. The principle and calculation process of this method will be described in detail below.

[0051] First, if Figure 2 As shown, a series of ordered points on a given road and their corresponding longitude and latitude coordinate pairs:

[0052] x1=(lat1,lon1)

[0053] x2=(lat2,lon2)

[0054] …

[0055] x n =(lat n ,lon n )

[0056] Where every two points x i With x i+1 (2≤i≤n-2) constitutes a "road segment". Each "road segment" and the two points x before and after it i-1 , x i+2 Then, use Haversin's formula:

[0057]

[0058] Calculate the lengths of each side a, b, and c from the longitude and latitude coordinates of each point.

[0059] Then use Heron's formula to calculate the radii ρ1 and ρ2 of the circumscribed circles of the front and back triangles:

[0060]

[0061] in,

[0062] The curvature radius of the road section is For the first and last road sections, the radius of the subsequent / previous triangle is directly used as the curvature radius.

[0063] In determining the current road section of the vehicle, the system uses the coordinate dot product criterion. Specifically, Figure 3 As shown in the figure, let the coordinates of two points on a road section be A and B, and the longitude and latitude coordinates of the vehicle be C. It is easy to know that when When , point C should be between points AB and can be considered to be on the AB section; otherwise, when According to this criterion, the present invention writes a criterion judgment into the callback method of vehicle position update: when the dot product is negative, it is considered that the road section has not changed; on the contrary, if the dot product is positive, it is considered that the vehicle has entered the next road section, and so on.

[0064] In the critical safety speed calculation part, the present invention uses the lateral load transfer rate (LTR) close to 1 as an indicator for determining "rollover / slip criticality". The LTR definition formula is:

[0065]

[0066] In the formula, F l 、F r are the loads on the wheels on the left and right sides of the vehicle respectively.

[0067] The present invention uses Trucksim simulation + MATLAB surface fitting to obtain the following curve radius: Adhesion coefficient Calculate the critical safety speed V as the independent variable s The calculation formula is:

[0068]

[0069] Among them, k is the correction coefficient of the adhesion coefficient, which is used to correct the adhesion coefficient value under different weather conditions.

[0070] The present invention uses electronic maps to detect and warn of high-risk rollover points on the path ahead in advance, so that the driver can perceive the risks of the road ahead in advance and reduce the speed, thereby reducing the probability of accidents and improving driving safety. At the same time, through platform data sharing, road sections that often trigger critical alarms can be reported to traffic management departments, vehicle operating companies and other units, providing decision-making basis for matters such as road design, vehicle and driver management.

[0071] In the alarm part, if the vehicle speed is below 80% of the critical safety speed, no alarm will be issued; if the vehicle speed is between 80% and 100% of the critical safety speed, an alarm with a frequency of 1Hz and a flashing warning triangle will be used to remind the driver, and a voice broadcast will be given at the same time, "There is a risk of rollover ahead, please slow down!", and a weaker return torque will be applied to the steering wheel to remind the driver; if the vehicle speed is above 100% of the critical speed, an alarm with a frequency of 2Hz and a flashing warning triangle will be used to remind the driver, and a voice broadcast will be given at the same time, "It is about to roll over, slow down immediately!", and a stronger return torque will be applied to the steering wheel to remind the driver. Example 2

[0072] As another embodiment of the present invention, this embodiment also provides a curve anti-rollover warning system using the curve anti-rollover warning method based on the electronic map as described in the above embodiment. The hardware components of this system are as follows: Figure 4As shown, the vehicle-mounted end obtains the vehicle and road geographic information required for early warning through the electronic map service provider, and determines the early warning method through a series of algorithms; the results of the early warning are recorded locally and backed up, shared, and processed in the cloud through log recording and transceiver modules, providing decision-making data support for traffic management and vehicle operating companies and other units.

[0073] The system consists of three parts: an on-board unit responsible for sending warning information to drivers, an electronic map service provider that provides geographic information services, and a data center that collects and utilizes on-board warning information to provide data support to traffic management departments, operating companies and other units.

[0074] Among them, the on-board unit includes a power module, an on-board unit processor, a geographic information receiving and processing module, an alarm execution module, and an alarm log recording, receiving and sending module, etc.

[0075] The vehicle-mounted unit uses the geographic information receiving and processing module to obtain a coordinate set on the best path, wherein the coordinate set includes the latitude and longitude information of each sample point on the path;

[0076] The on-board unit uses the Haversine formula to calculate the longitude and latitude distance of each point in the road section using the coordinate set, and calculates the circumscribed circle radius of the triangle using the Heron formula. The starting and ending points of the road section and the two points before and after the road section are selected to form two triangles respectively, and the estimated curvature radius of the road section is obtained by calculating the average of the circumscribed circle radii of the two triangles;

[0077] The on-board unit calculates the critical safety speed for each road section based on the estimated value of the curvature radius of each road section and the adhesion coefficient of the road, taking into account the influence of weather, using the safety speed formula obtained through simulation and fitting. The formula takes into account the possibility of vehicle rollover when the lateral load transfer rate (LTR) is close to 1;

[0078] The on-board unit uses a vector dot product method to determine the road section where the vehicle is currently located, the method comprising: performing a dot product calculation on the current latitude and longitude coordinates of the vehicle and the coordinates of two endpoints of the road section to determine whether the vehicle is on the road section;

[0079] The on-board unit compares the critical safety speed with the current actual speed of the vehicle to determine whether the vehicle is in a safe state, and issues a real-time warning to the driver based on the comparison result;

[0080] The vector dot product method includes the following steps: assuming that the coordinates of the two end points of a road section are point A and point B, and the coordinates of the current position of the vehicle are point C, the vector product is calculated. If it is a negative value, the vehicle is located on the road section, otherwise the vehicle is not on the road section; at each position update, the road section where the vehicle is located is determined in real time, and the safety is calculated based on the curvature radius of 2-3 sections ahead of the road section and the current vehicle speed, thereby providing accurate warning information.

[0081] Among them, the alarm execution module includes a voice warning submodule, an interface warning submodule and a steering wheel torque feedback submodule: when the vehicle speed is below 80% of the critical safety speed, no alarm is issued; at 80%-100% of the critical safety speed, an alarm with a frequency of 1Hz and a flashing warning triangle are used to remind the driver, and at the same time, a voice broadcast of "There is a risk of rollover ahead, please slow down!" is broadcast, and a weak return torque is applied to the steering wheel to remind the driver; above 100% of the critical speed, an alarm with a frequency of 2Hz and a flashing warning triangle are used to remind the driver, and at the same time, a voice broadcast of "It is about to roll over, slow down immediately!" is broadcast, and a strong return torque is applied to the steering wheel to remind the driver.

[0082] The data center uses the log transceiver module of the vehicle-mounted unit to obtain the warning triggering situation of each vehicle and perform certain statistical processing. The statistical results can be used for various purposes, such as combining the location to indicate the road sections where the warning is frequently triggered to the traffic control department; combining the driver information to provide the driver's aggressive driving record to the operating company, etc.

[0083] The software architecture of this system is as follows Figure 5 As shown in the figure, with the support of the application layer and the business layer, this system can provide driving safety warning services to drivers at the user layer, and can provide drivers' high-risk behavior information and road rollover high-risk point information to traffic management departments and companies that own operating vehicles.

[0084] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A vehicle curve anti-rollover warning method, characterized in that the steps include: Obtain the latitude and longitude information of the road ahead of the vehicle; Real-time determination of the road section where the vehicle is currently located; Combine the curvature radius of the road section and the road adhesion coefficient simulation to obtain the critical safe speed formula, and calculate the safe speed of the road section ahead in real time; The safe speed of the road ahead is compared with the actual speed of the vehicle, and the driver is given a graded warning when the vehicle approaches or exceeds the critical safe speed.

2. A vehicle curve rollover prevention warning method according to claim 1, characterized in that: The road section where the vehicle is currently located is determined using the vector dot product method: A road segment is composed of two adjacent points. Based on the coordinates of the two points on the road segment and the longitude and latitude coordinates of the vehicle, the dot product of the current longitude and latitude coordinates of the vehicle and the coordinates of the two endpoints of the road segment is calculated to determine whether the vehicle is on the road segment: When the dot product of the vector from one end of the road segment to the vehicle and the vector from one end of the road segment to the other end is negative, the vehicle is judged to be on the AB road segment; When the dot product of the vector from one end of the road section to the vehicle and the vector from one end of the road section to the other end is positive, the vehicle is judged to be outside the AB section.

3. A vehicle curve rollover prevention warning method according to claim 2, characterized in that: The early warning method makes the following judgment when the vehicle position is updated: When the dot product of the vector from one end of the road section to the vehicle and the vector from one end of the road section to the other end is negative, it is considered that the road section has not changed; On the contrary, if the dot product of the vector from one end of the road segment to the vehicle and the vector from one end of the road segment to the other end is positive, the vehicle is considered to enter the next road segment.

4. A vehicle curve rollover prevention warning method according to claim 1, characterized in that: The method is based on the estimated value of the curvature radius of each road section and the adhesion coefficient of the road, and takes into account the influence of weather, and uses the safe speed formula obtained by simulation and fitting to calculate the critical safe speed of each road section: Where R is the curvature radius of the road section; is the adhesion coefficient; k is the correction coefficient of the adhesion coefficient; α, β, γ, δ, ε are the fitting coefficients of each item respectively, and C is the fitting constant item.

5. A vehicle curve rollover prevention warning method according to claim 4, characterized in that: Estimate the radius of curvature of the road segment as follows: A road segment is formed by two adjacent points, and each road segment and the two points before and after the road segment respectively form two triangles; Based on the longitude and latitude coordinates of each point, the straight-line distance between two points in the road section is calculated according to the Haversine formula to obtain the length of each side of the two triangles; Based on the side lengths of the two triangles, calculate the circumscribed circle radius of the two triangles using the sine theorem; Take the average of the circumscribed circle radii of the two triangles to get the estimated curvature radius of the road section.

6. A vehicle curve anti-rollover warning method according to claim 5, characterized in that: For the first and last road sections, the radius of the circumscribed circle of the triangle formed by the first and last point is directly used as the radius of curvature.

7. A vehicle curve anti-rollover warning method according to claim 4, characterized in that: When calculating the critical safety speed, the present invention uses the lateral load transfer rate LTR close to 1 as an indicator for determining the rollover / slip criticality, wherein the lateral load transfer rate LTR is defined by the formula: In the formula, F l 、F r are the loads on the wheels on the left and right sides of the vehicle respectively.

8. The vehicle curve rollover prevention warning method according to claim 1, characterized in that: The hierarchical alarms are specifically: If the vehicle speed is below the first critical safety speed, no alarm will be given; Between the first and second critical safety speeds, the driver is reminded with a first-frequency alarm and flashing warning triangles, and a voice announcement: There is a risk of rollover ahead, please slow down! A weak first positive torque is applied to the steering wheel to remind the driver; When the vehicle speed is above the second safe speed, the second frequency alarm sound and warning triangle flash to remind the driver, and the voice broadcast: "It is about to roll over, slow down immediately!" and a stronger second self-aligning torque is applied to the steering wheel to remind the driver.

9. A vehicle curve anti-rollover warning method according to any one of claims 1 to 8, characterized in that: The method determines the road section where the vehicle is located in real time each time the vehicle position is updated, and calculates the safety according to the curvature radius of several sections ahead of the road section and the current vehicle speed, so as to provide early warning information.

10. A vehicle curve anti-rollover warning system, characterized in that: The system implements the vehicle curve anti-rollover warning method according to any one of claims 1 to 9, and the system includes: Electronic map service providers, providing geographic information services; The vehicle-mounted unit is responsible for sending warning information to the driver and recording and uploading it; the vehicle-mounted unit includes: a power module, a vehicle-mounted unit processor, a geographic information receiving and processing module, an alarm execution module and an alarm log recording and receiving module; The alarm execution module includes a voice warning submodule, an interface warning submodule and a steering wheel torque feedback submodule: The data center collects and utilizes vehicle-mounted warning information to provide data support to traffic management departments, operating companies and other units.

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