Traffic safety evaluation method and equipment in crosswind environment

Abstract

The invention discloses a traffic safety evaluation method and device in a crosswind environment, and relates to the technical field of traffic safety in the crosswind environment, and the method comprises the steps: building a geometric model and an aerodynamic-system dynamics coupling model of a to-be-evaluated vehicle according to the type of the vehicle; according to the to-be-evaluated crosswind environment, determining the driving state of the to-be-evaluated vehicle in the to-be-evaluated crosswind environment and the lateral displacement of each boundary point by using the aerodynamic-system dynamics coupling model and the geometric model; and determining a driving safety state of the to-be-evaluated vehicle in the to-be-evaluated crosswind environment based on the driving state and the lateral displacements of the plurality of boundary points. According to the method, the driving safety evaluation in the crosswind environment is carried out by determining the vehicle driving state in the crosswind environment and the lateral displacement of each boundary point, so that the efficiency, safety and rationality of the driving safety evaluation in the crosswind environment can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of driving safety in a crosswind environment, and in particular to a driving safety evaluation method and device in a crosswind environment. Background Art

[0002] Current wind-induced driving safety researchers often focus on whether a vehicle will deflect, slide, or roll over in a crosswind environment. When evaluating deflection, the main reference is the deflection displacement of the center of mass. However, during normal driving, due to the vehicle's own motion characteristics, geometric shape, and the influence of crosswind during driving, deflection and yaw motions will occur. Under the coupling of deflection and yaw motions, the maximum lateral displacement of the vehicle's body contour boundary will be much greater than the lateral displacement of the center of mass. When the wind speed reaches a certain level, it will have a certain impact on the normal driving of the vehicle and even pose a certain threat to driving safety.

[0003] The problem of vehicle handling stability in a crosswind environment involves the coupling of vehicle aerodynamics and vehicle system dynamics. There are currently three main research methods for this problem: wind tunnel test method, real vehicle road test and coupled simulation. The wind tunnel test method not only requires the manufacture of a prototype vehicle, but also has a long R&D cycle and high costs. Carrying out real vehicle experiments will produce great instability factors and is highly dangerous, which is not conducive to research under extreme working conditions. Therefore, the coupled simulation evaluation method proposed in this application has a good application prospect. Summary of the invention

[0004] The purpose of this application is to provide a method and device for evaluating driving safety in a crosswind environment, which can improve the efficiency, safety and rationality of driving safety evaluation in a crosswind environment.

[0005] To achieve the above objectives, this application provides the following solutions:

[0006] In a first aspect, the present application provides a method for evaluating driving safety in a crosswind environment, comprising:

[0007] Get the vehicle type of the vehicle to be evaluated;

[0008] According to the vehicle type, build a geometric model and an aerodynamic-system dynamics coupling model of the vehicle to be evaluated;

[0009] Obtain the crosswind condition to be evaluated;

[0010] According to the side wind working condition to be evaluated, the driving state of the vehicle to be evaluated and the lateral displacement of each boundary point under the side wind working condition to be evaluated are determined by using the aerodynamics-system dynamics coupling model and the geometric model;

[0011] Based on the driving state and the lateral displacements of the plurality of boundary points, a driving safety state of the vehicle to be evaluated under the crosswind condition to be evaluated is determined.

[0012] Optionally, the vehicle type includes a passenger car, a van or a container truck.

[0013] Optionally, the sidewind conditions to be evaluated include vehicle speed, sidewind speed, wind direction, vehicle frontal area and vehicle characteristic length.

[0014] Optionally, according to the vehicle type, a geometric model and an aerodynamic-system dynamics coupling model of the vehicle to be evaluated are constructed, including:

[0015] According to the vehicle type, the vehicle to be evaluated is divided into modeling areas; the modeling areas are one or two;

[0016] Based on the geometric information of the modeling area, construct a geometric model of the modeling area;

[0017] Using computational fluid dynamics software, an aerodynamic model of the modeling area was constructed;

[0018] Use multi-body dynamics software to build a system dynamics model of the modeling area;

[0019] The aerodynamic model and the system dynamics model corresponding to the same modeling area are coupled to obtain an aerodynamic-system dynamics coupling model of the modeling area;

[0020] Determine the geometric model of all modeling areas of the vehicle to be evaluated as the geometric model of the vehicle to be evaluated;

[0021] The aerodynamics-system dynamics coupling model of all modeling areas of the vehicle to be evaluated is determined as the aerodynamics-system dynamics coupling model of the vehicle to be evaluated.

[0022] Optionally, according to the vehicle type, the vehicle to be evaluated is divided into modeling areas, including:

[0023] When the vehicle type is a passenger car or a van, the entire vehicle to be evaluated is determined as the modeling area;

[0024] When the vehicle type is a container truck, the tractor area and the trailer area in the vehicle to be evaluated are respectively used as a modeling area.

[0025] Optionally, constructing a geometric model of the modeling area based on the geometric information of the modeling area includes:

[0026] Determine the circumscribed rectangle of the modeling area as the initial model;

[0027] Determine the two endpoints corresponding to the cut length of the front of the vehicle in the modeling area in the initial model as the critical points of the front end of the vehicle body;

[0028] Determine the two endpoints corresponding to the cut length of the rear end of the modeling area in the initial model as the critical points of the rear end of the vehicle body;

[0029] The centroid position of the modeling area in the initial model is determined to obtain a geometric model of the modeling area.

[0030] Optionally, according to the side wind condition to be evaluated, the aerodynamics-system dynamics coupling model and the geometric model are used to determine the lateral displacement of each boundary point of the vehicle to be evaluated under the side wind condition to be evaluated, including:

[0031] The motion state and dynamic response of the vehicle are calculated according to the aerodynamic-system dynamics coupling model of the side wind condition to be evaluated, and the lateral displacement of the center of mass and the yaw angle of all modeling areas in the vehicle to be evaluated under the side wind condition to be evaluated are obtained;

[0032] When the vehicle to be evaluated slides or rolls over under the crosswind condition to be evaluated, the driving safety state of the vehicle to be evaluated is determined to be dangerous;

[0033] When the vehicle to be evaluated deviates sideways under the sidewind condition to be evaluated, when the modeling area is the full vehicle area of ​​a passenger car and a van or the tractor area of ​​a container truck, the first boundary point lateral displacement formula group is used to determine the lateral displacement of each boundary point of the modeling area under the sidewind condition to be evaluated; when the modeling area is the trailer area of ​​a container truck, the second boundary point lateral displacement formula group is used to determine the lateral displacement of each boundary point of the modeling area under the sidewind condition to be evaluated, and the lateral displacement of all boundary points of each modeling area in the vehicle to be evaluated under the sidewind condition to be evaluated is obtained.

[0034] Optionally,

[0035] The first boundary point lateral displacement formula group is:

[0036]

[0037] in,

[0038]

[0039] The second boundary point lateral displacement formula group is:

[0040]

[0041] In the formula, ey a is the lateral displacement of the critical point a at the left front end of the vehicle body; ey is the lateral displacement of the center of mass of the modeling area; dl fis the distance from the critical point of the front end of the vehicle body to the center of mass in the modeling area; W is the width of the vehicle body in the modeling area; θ a is the angle between the critical point a at the left front end of the vehicle body and the center line of the modeling area; is the body yaw angle in the modeling area; ey b is the lateral displacement of the critical point b at the right front end of the vehicle body; θ b is the angle between the critical point b at the right front end of the vehicle body and the center line of the modeling area; ey c is the lateral displacement of the critical point c at the rear end of the left vehicle body; dl r is the distance from the critical point of the rear end of the vehicle body to the center of mass in the modeling area; θ c is the angle between the critical point c at the rear end of the left vehicle body and the center line of the modeling area; ey d is the lateral displacement of the critical point d at the rear end of the right vehicle body; θ d L is the angle between the critical point d at the rear end of the right vehicle body and the center line of the modeling area; f L is the distance from the center of mass to the front end of the vehicle body in the modeling area; r is the distance from the center of mass to the front end of the vehicle body in the modeling area.

[0042] Optionally, determining the driving safety state of the vehicle to be evaluated under the crosswind condition to be evaluated based on the lateral displacements of the plurality of boundary points includes:

[0043] Determine any modeling area as the current modeling area;

[0044] Determine the difference between the lane width and the vehicle body width in the modeling area as the intermediate value;

[0045] Determine half of the middle value as the lane critical value corresponding to the current modeling area;

[0046] When the lateral displacement of any boundary point of the vehicle to be evaluated under the crosswind condition to be evaluated reaches the lane critical value of the corresponding modeling area, the driving safety state of the vehicle to be evaluated is determined to be dangerous.

[0047] In a second aspect, the present application provides a computer device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the above-mentioned driving safety evaluation method in a crosswind environment.

[0048] According to the specific embodiments provided in this application, this application discloses the following technical effects:

[0049] The present application provides a method and device for evaluating driving safety in a crosswind environment, which utilizes the vehicle shape and the vehicle motion response parameters in a crosswind environment, including the lateral displacement of the center of mass and the yaw angle, and obtains the lateral displacement of the vehicle boundary points through geometric conversion, and judges driving safety in combination with the actual lane conditions, which can have better reliability and rationality. In a crosswind environment, aerodynamics and system dynamics are coupled to determine whether the vehicle has side deviation, side slip, and rollover. When side deviation occurs, driving safety is determined by comparing the lateral displacement of the vehicle boundary points with the maximum allowable lateral displacement. This can be used to better regulate driving safety management standards in strong wind environments, as well as auxiliary control of the vehicle during lane keeping driving, complete vehicle handling stability analysis in a crosswind environment, and provide technical support for driving safety evaluation. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0051] Figure 1 The figure is a flow chart of a driving safety evaluation method in a crosswind environment.

[0052] Figure 2 Schematic diagram of the body geometry.

[0053] Figure 3 This is a schematic diagram of a driving safety evaluation method in a crosswind environment.

[0054] Figure 4 This is the lateral displacement diagram of the center of mass of the van.

[0055] Figure 5 This is the yaw angle diagram of a van.

[0056] Figure 6 is the lateral displacement diagram of the center of mass of the tractor.

[0057] Figure 7 is the yaw angle diagram of the tractor.

[0058] Figure 8 is the lateral displacement diagram of the trailer's center of mass.

[0059] Fig. 9 is the trailer yaw angle diagram.

[0060] Fig.10 Define schematic diagram for maximum safe lateral displacement.

[0061] Fig.11This is the simulation result diagram of the lateral displacement of the boundary points of the van.

[0062] Fig.12 This is the simulation result diagram of the lateral displacement of the tractor boundary point.

[0063] Fig.13 This is the simulation result diagram of the lateral displacement of the trailer boundary point.

[0064] Fig.14 A schematic diagram of the structure of a computer device. DETAILED DESCRIPTION

[0065] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0066] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0067] In an exemplary embodiment, Figure 1 As shown, a driving safety evaluation method in a crosswind environment is provided, comprising:

[0068] Step 101: Obtain the vehicle type of the vehicle to be evaluated. The vehicle type is a passenger car, a van, or a container truck.

[0069] Step 102: According to the vehicle type, a geometric model and an aerodynamic-system dynamics coupling model of the vehicle to be evaluated are constructed; the geometric model is as follows: Figure 2 shown.

[0070] Step 103: Obtain the crosswind conditions to be evaluated. The crosswind conditions to be evaluated include vehicle speed, crosswind speed, wind direction, vehicle frontal area, and vehicle characteristic length.

[0071] Step 104: According to the side wind condition to be evaluated, the lateral displacement of each boundary point of the vehicle to be evaluated under the side wind condition to be evaluated is determined by using the aerodynamics-system dynamics coupling model and the geometric model.

[0072] Step 105: Determine the driving safety status of the vehicle to be evaluated under the crosswind condition to be evaluated based on the lateral displacements of the multiple boundary points.

[0073] Step 102 includes: dividing the vehicle to be evaluated into modeling areas according to the vehicle type. There are one or two modeling areas. Constructing a geometric model of the modeling area based on the geometric information of the modeling area. Constructing a fluid dynamics model of the modeling area using computational fluid dynamics software. Constructing a system dynamics model of the modeling area using multi-body dynamics software. Coupling the system dynamics model and the aerodynamic model corresponding to the same modeling area to obtain an aerodynamic-system dynamics coupling model of the modeling area. Determining the geometric model of all modeling areas of the vehicle to be evaluated as the geometric model of the vehicle to be evaluated. Determining the aerodynamic-system dynamics coupling model of all modeling areas of the vehicle to be evaluated as the aerodynamic-system dynamics coupling model of the vehicle to be evaluated.

[0074] The modeling area of ​​the vehicle to be evaluated is divided according to the vehicle type, including: when the vehicle type is a passenger car or a van, the entire vehicle to be evaluated is determined as the modeling area. When the vehicle type is a container truck, the tractor area and trailer area of ​​the vehicle to be evaluated are each used as a modeling area.

[0075] Based on the geometric information of the modeling area, a geometric model of the modeling area is constructed, including: determining the circumscribed rectangle of the modeling area as the initial model. Determining the two endpoints corresponding to the length of the side cut by the front of the modeling area in the initial model as the critical points of the front end of the vehicle body. Determining the two endpoints corresponding to the length of the side cut by the rear of the modeling area in the initial model as the critical points of the rear end of the vehicle body. Determining the centroid position of the modeling area in the initial model to obtain the geometric model of the modeling area.

[0076] Step 104 includes: calculating the motion state and dynamic response of the vehicle according to the aerodynamic-system dynamics coupling model of the crosswind condition to be evaluated, and obtaining the lateral displacement of the center of mass and the yaw angle of all modeling areas in the vehicle to be evaluated under the crosswind condition to be evaluated. When the modeling area is a passenger car, a full vehicle area of ​​a van, or a tractor area of ​​a container truck, the lateral displacement of each boundary point of the modeling area under the crosswind condition to be evaluated is determined using the first boundary point lateral displacement formula group. When the modeling area is the trailer area of ​​a container truck, the lateral displacement of each boundary point of the modeling area under the crosswind condition to be evaluated is determined using the second boundary point lateral displacement formula group, and the lateral displacement of all boundary points of each modeling area in the vehicle to be evaluated under the crosswind condition to be evaluated is obtained.

[0077] Among them, the lateral displacement formula group of the first boundary point is:

[0078]

[0079] in,

[0080]

[0081] The lateral displacement formula of the second boundary point is:

[0082]

[0083] In the formula, ey a is the critical point a at the left front end of the vehicle body (i.e. Figure 2 ey is the lateral displacement of the center of mass of the modeling area; dl is the lateral displacement of the center of mass of the modeling area; f is the distance from the critical point of the front end of the vehicle body to the center of mass in the modeling area; W is the width of the vehicle body in the modeling area; θ a is the angle between the critical point a at the left front end of the vehicle body and the center line of the modeling area; is the body yaw angle in the modeling area; ey b is the critical point b at the right front end of the vehicle body (i.e. Figure 2 The lateral displacement of point B shown in the figure; θ b is the angle between the critical point b at the right front end of the vehicle body and the center line of the modeling area; ey c is the critical point c at the rear end of the left vehicle body (i.e. Figure 2 The lateral displacement of point C shown in the figure; dl r is the distance from the critical point of the rear end of the vehicle body to the center of mass in the modeling area; θ c is the angle between the critical point c at the rear end of the left vehicle body and the center line of the modeling area; ey d is the critical point d at the rear end of the right vehicle body (i.e. Figure 2 The lateral displacement of point D shown in the figure; θ d L is the angle between the critical point d at the rear end of the right vehicle body and the center line of the modeling area; f L is the distance from the center of mass to the front end of the vehicle body in the modeling area; r is the distance from the center of mass to the front end of the vehicle body in the modeling area.

[0084] Step 105 includes: determining any modeling area as the current modeling area. Determining the difference between the lane width and the vehicle body width in the modeling area as the intermediate value. Determining half of the intermediate value as the lane critical value corresponding to the current modeling area. When the lateral displacement of any boundary point of the vehicle to be evaluated under the crosswind condition to be evaluated reaches the lane critical value of the corresponding modeling area, the driving safety state of the vehicle to be evaluated is determined to be dangerous.

[0085] The traditional driving safety evaluation method in a crosswind environment only regards the vehicle as the center of mass and considers the side deviation of the center of mass, but does not take into account the characteristics of the vehicle's appearance and the influence of the vehicle's yaw motion. When a large yaw angle or a large articulated vehicle deviates sideways, it is impossible to accurately judge the driving safety of the vehicle, which may lead to a major accident. The driving safety evaluation method in a crosswind environment proposed in the present application uses the obtained aerodynamic load as an input condition and applies it to the system dynamics model to obtain the vehicle dynamics transient response parameters under different crosswind conditions. Based on this, the maximum lateral displacement of the vehicle body contour under the current condition is calculated, providing a reference basis for the driving safety evaluation method and equipment in a crosswind environment. The calculation method and analysis results can not only provide a scientific and reasonable reference for the driving safety evaluation method and equipment in a crosswind environment, but also provide more valuable reference data for the driving control of future smart cars, so as to better ensure the wind-induced driving safety of smart cars.

[0086] like Figure 3The driving safety evaluation method under the crosswind environment provided by this application has the following principle: firstly, a vehicle geometric model is established in a three-dimensional software, and the calculation domain and the encryption area are set by using the pre-processing software, and the corresponding grid division is performed. The calculation model and boundary conditions are set in the computational fluid dynamics software for solving the calculation. The input variables are the current vehicle yaw angle, longitudinal velocity, lateral velocity, etc., and the output variables are the six aerodynamic forces. A vehicle dynamics model is built in the multi-body dynamics software, and reasonable driving feedback control is added. The road surface conditions and aerodynamic effects are added to the dynamics model to simulate the dynamic response of the car under the crosswind condition during driving. The output variables are the lateral displacement of the center of mass, the yaw angle, etc. This application mainly uses the dynamic coupling simulation method, and uses the computational fluid dynamics software to study the changing process of the transient flow field and aerodynamic load around the vehicle body. The vehicle multi-body dynamics software is used to calculate the vehicle dynamic response under the crosswind condition. The aerodynamic and system dynamics coupling model is built on the simulation platform to complete the interaction between the six aerodynamic forces and the dynamic response, and the dynamic response variables are output. The calculation results are closer to the actual situation. The dynamic response variables and the test results of the multi-body dynamics software are used to determine whether the vehicle has any dangerous behavior when driving under crosswind conditions. If the simulation results of the system dynamics software show that the vehicle has skidded or rolled over, that is, the vehicle is in a dangerous state, the driving safety evaluation is completed. If the vehicle deviates sideways when driving under crosswind conditions, simulation is performed based on the coupling model, and the lateral displacement of the center of mass and yaw angle of the vehicle when it deviates sideways under crosswind conditions are output through the dynamics software simulation. In the vehicle geometry model, the four extreme boundary corner points A, B, C, and D of the vehicle body are selected to expand the body geometry and simplify it into a collision rectangle. The lateral displacement of the center of mass and the yaw angle of the vehicle calculated in step 104 are combined with different types of vehicle shapes. In the simulation software, the lateral displacement of the center of mass and the yaw angle of the vehicle are converted into vehicle boundary points (taking a van as an example) through a geometric conversion relationship in combination with the above-mentioned vehicle collision rectangle. Figure 2 The present application mainly uses a dynamic coupling simulation method, uses computational fluid dynamics software to study the changing process of the transient flow field and aerodynamic load around the vehicle body, uses vehicle multi-body dynamics software to establish the vehicle dynamic response under crosswind conditions, builds an aerodynamic and system dynamics coupling model on the simulation platform, completes the interaction between the six aerodynamic components and the dynamic response, uses the vehicle geometry model to obtain the lateral displacement of the vehicle boundary points, and based on the vehicle driving road settings and the vehicle's geometric parameters, specifies the maximum safe lateral displacement definition of each boundary point of the vehicle, calculates the threshold value allowed for each boundary point, compares the lateral displacement of the vehicle boundary point with the maximum safe lateral displacement, and determines whether the vehicle deviates from the original lane and drives into other lanes, resulting in dangerous driving behavior, to conduct driving safety evaluation.

[0087] The present embodiment is described in detail below by taking an integral van and an articulated container truck as examples. The vehicle parameters are shown in Table 1.

[0088] Table 1 Parameters of van trucks and container trucks

[0089]

[0090] Step 1: First, establish the geometric models of vans and container trucks in the 3D software, use the pre-processing software to set the calculation domain and encryption area, and perform the corresponding mesh division. By introducing the slave domain to control the mesh quality around the car, and simulating the movement of the car, the slave domain and the car are given the same driving speed, so that the mesh reconstruction and deformation occur at a larger size outside the slave domain. Set the calculation model and boundary conditions in the computational fluid dynamics software for solution calculation. The input variables are the current vehicle yaw angle, longitudinal velocity, lateral velocity, etc., and the output variables are the six-component aerodynamic force.

[0091] Step 2: Select the corresponding vehicle model in the multi-body dynamics software, build a vehicle dynamics model and driving feedback control method based on the vehicle parameters, and simulate the dynamic response of the car encountering crosswind conditions during driving by setting the aerodynamic module data. The output variables are lateral displacement of the center of mass, yaw angle, etc.

[0092] A two-way four-lane road is selected as the scenario of the embodiment. The vehicle is located in the right lane, and a preview driver model is set. The preview time is 1.4s, the preview distance is 10m, the road adhesion coefficient is 0.85, the side wind starts from 2s of driving, the action time is 3s, the total driving time is 10s, and the vehicle mass is considered to be a dangerous working condition with only the driver under no-load conditions.

[0093] Step 3: Through dynamic coupling simulation method, computational fluid dynamics software is used to study the changing process of transient flow field and aerodynamic load around the vehicle body, and vehicle multi-body dynamics software is used to establish the vehicle dynamic response under crosswind conditions. An aerodynamic and system dynamics coupling model is built on the simulation platform to complete the interaction between the six aerodynamic forces and the dynamic response, and output the dynamic response variables.

[0094] Based on the established vehicle dynamics model, the van truck selected a vehicle speed of 40km / h, a crosswind speed of 32.7m / s, and a wind direction perpendicular to the direction of travel of the car, from the co-pilot side to the driver side. Then, in the multi-body dynamics software, the speed and angle of the crosswind encountered by the vehicle during driving and the corresponding vehicle speed are set, and the wind deflection angle is obtained through simulation. The aerodynamic coefficient of the side wind is input into the wind deflection angle corresponding to the aerodynamic module. Finally, the windward area and characteristic length are set to complete the construction of the van truck dynamics model under the crosswind environment.

[0095] The container truck is composed of a tractor and a trailer, so the crosswind needs to be considered separately for the tractor and the trailer. The vehicle speed is 80km / h, the crosswind size is 24.5m / s, and the wind direction is perpendicular to the vehicle's driving direction, from the co-pilot side to the driver side. The wind deflection angles of the tractor and trailer are obtained in the multi-body dynamics software, and their respective aerodynamic coefficients are loaded into the aerodynamic module, and the windward area and characteristic length of the tractor and trailer are set respectively, thus completing the construction of the container truck dynamics model.

[0096] Step 4: Based on the coupling of aerodynamics and system dynamics in step 3, driving safety is judged. Under crosswind conditions, the vehicle may skid, roll over, or swerve while driving. By building an aerodynamic and system dynamics coupling model on the simulation platform, the dynamic response variables and simulation animation can be used to determine whether the vehicle has dangerous behaviors such as skidding or rolling over. However, if swerving occurs, it is necessary to consider whether the driving is safe in combination with the vehicle body.

[0097] Step 5: If the vehicle veers sideways under crosswind conditions, simulation is performed based on the coupling model in step 3. The lateral displacement of the center of mass and the yaw angle of the van are output through dynamics simulation software. Figure 4 and Figure 5 As shown, during the driving process of the van, the lateral displacement of the center of mass and the yaw angle of the vehicle reach peak values ​​at 3.6s and 3.66s respectively. Based on the established coordinate system, it can be seen that the vehicle has deviated to the left. Judging from the lateral displacement of the center of mass alone, the vehicle is in a safe driving state, but it is impossible to determine whether the vehicle body remains in the lane and drives safely.

[0098] In the dynamics software, the lateral displacement and yaw angle of the center of mass of the tractor and trailer are output respectively. Figures 6 to 9 As shown. The maximum lateral displacement and maximum yaw angle of the tractor and trailer of the container truck occur at different times. The maximum lateral displacement of the tractor occurs at 3.4s and the maximum yaw angle at 3.6s, and the maximum lateral displacement of the trailer occurs at 3.15s and the maximum yaw angle at 2.85s. Because the container truck is connected by a tractor and a trailer through an articulation, when affected by a crosswind, the tractor and the trailer will have different yaws when they deviate to the left. Based on the established coordinate system, it can be seen that the tractor yaws to the right and the trailer yaws to the left. The lateral displacement of the center of mass of the tractor and the trailer shows that under this condition, the vehicle has deviated from the lane and is in a dangerous state. However, the judgment based on other conditions may not be accurate. Therefore, it is necessary to judge whether the driving is safe by the lateral displacement of the boundary points of the vehicle body.

[0099] Step 6: Based on step 5, under the condition of no-load side wind, when adding the driver's preview control, the lateral displacement and yaw angle of the vehicle are obtained, and converted into the lateral displacement of the critical point of the vehicle by combining it with the vehicle's geometric parameters through geometric methods. The four front and rear boundary points are considered for van trucks (wherein the critical points of tractors and trailers are considered for container trucks respectively).

[0100] The critical point geometry for a box truck is calculated as follows:

[0101] Distance from center of mass to front end of vehicle body: L f =2.543m.

[0102] Distance from center of mass to rear end of vehicle body: L r =6.051m.

[0103] Body width: W=2.438m.

[0104] The lateral displacement of the four boundary points of the van is determined using the first boundary point lateral displacement formula group.

[0105] Container trucks are divided into tractors and trailers. Under the influence of crosswinds, they will skid at different yaw angles. Therefore, the lateral displacement of the boundary points of the tractor and trailer under the selected working conditions should be considered separately to determine whether the vehicle is driving off the lane. The calculation of the lateral displacement of the boundary points is affected by the lateral displacement and yaw angle of the tractor and trailer. The yaw directions of the tractor and trailer are different, so there are differences in the calculation. The yaw of the tractor is similar to that of the van, that is, the calculation of the boundary points of the tractor is the same as that of the van, while the lateral displacement of the boundary points of the trailer is calculated as follows:

[0106] Distance from center of mass to front end of vehicle body: L f =1.151m.

[0107] Distance from center of mass to rear end of vehicle body: L r =5.781m.

[0108] Body width: W = 2.4m

[0109] The lateral displacement of each boundary point of the trailer is determined using the second boundary point lateral displacement formula group.

[0110] Step 7: Based on the settings and calculations in step 6, the geometric relationship between the lateral displacement of the vehicle boundary point and the lane can be used to determine whether the vehicle has deviated from the lane at this moment. Maximum safe lateral displacement E ymax It is defined as the critical value of the vehicle body exceeding the lane where the vehicle is located, and its expression is:

[0111]

[0112] Where Wroad and W car are lane width and vehicle body width respectively. Fig.10 As shown (taking a van as an example).

[0113] In this embodiment, the lane width is 3.5m, the body width of the van is 2.438m, the body width of the container truck is 2.4m, the crosswind direction is perpendicular to the driving direction of the car, from the co-driver side to the driver side, and the vehicle slides to the left. Substituting into the calculation, the maximum safe lateral displacement allowed for the left side of the van and container truck are 0.531m and 0.55m respectively. Therefore, the lateral displacement of the vehicle boundary point obtained in step six can be compared with the maximum safe lateral displacement.

[0114] This application mainly uses dynamic coupling simulation methods and computational fluid dynamics software to study the changing process of transient flow field and aerodynamic load around the vehicle body, adopts vehicle multi-body dynamics software to establish the vehicle dynamic response under crosswind conditions, builds an aerodynamic and system dynamics coupling model on the simulation platform, completes the interaction between the six aerodynamic components and the dynamic response, uses the vehicle geometry model to obtain the lateral displacement of the vehicle boundary points, and judges driving safety in combination with the definition of maximum safe lateral displacement.

[0115] The actual driving process of the van is simulated based on multi-body dynamics software, and the results are as follows Fig.11 As shown in the figure, the maximum lateral displacement of the boundary point of the van truck occurs at 3.6s, and its displacement is 0.85m, which has exceeded the maximum safe lateral displacement. The vehicle has deviated from the lane. Therefore, when the van truck is driving at a speed of 40km / h and a wind speed of 32.7m / s, the vehicle will deviate from the normal driving lane and cause a traffic safety accident.

[0116] The actual driving process of container trucks is simulated based on multi-body dynamics software, and the results are as follows Fig.12 and Fig.13 As shown in the figure, the maximum lateral displacement of the tractor boundary point occurs at 3.4s, and its displacement is 0.73m, which has exceeded the maximum safe lateral displacement, and the vehicle has deviated from the lane, while the maximum deviation of the trailer boundary point occurs at 3.15s, and its displacement is 0.88m, which far exceeds the maximum safe lateral displacement in this embodiment. Therefore, when the container truck is driving at a speed of 80km / h and a wind speed of 24.5m / s, the vehicle will deviate from the normal driving lane, causing a traffic safety accident.

[0117] The present application also provides an application scenario, which applies the above-mentioned driving safety evaluation method in a crosswind environment. Specifically: The driving safety evaluation method in a crosswind environment provided in this embodiment can be applied in truck design and assisted driving scenarios. The driving safety evaluation method in a crosswind environment provided in this embodiment belongs to the assisted driving design and testing link in the truck design link in this scenario.

[0118] In an exemplary embodiment, a computer device is provided. The computer device may be a server or a terminal. The internal structure diagram thereof may be as follows: Fig.14 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a driving safety evaluation method in a crosswind environment is implemented.

[0119] Those skilled in the art will understand that Fig.14 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components. In an exemplary embodiment, a computer device is provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above-mentioned method embodiments when executing the computer program.

[0120] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0121] In an exemplary embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0122] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0123] Those of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0124] The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on blockchain, etc., but is not limited thereto. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but is not limited thereto.

[0125] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0126] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A driving safety evaluation method in a crosswind environment, characterized in that: include: Get the vehicle type of the vehicle to be evaluated; According to the vehicle type, build a geometric model and an aerodynamic-system dynamics coupling model of the vehicle to be evaluated; Obtain the crosswind condition to be evaluated; According to the side wind working condition to be evaluated, the driving state of the vehicle to be evaluated and the lateral displacement of each boundary point under the side wind working condition to be evaluated are determined by using the aerodynamics-system dynamics coupling model and the geometric model; Based on the driving state and the lateral displacements of the plurality of boundary points, a driving safety state of the vehicle to be evaluated under the crosswind condition to be evaluated is determined.

2. The driving safety evaluation method in a crosswind environment according to claim 1, characterized in that: The vehicle types include passenger cars, vans or container trucks.

3. The driving safety evaluation method in a crosswind environment according to claim 1, characterized in that: The crosswind conditions to be evaluated include vehicle speed, crosswind speed, wind direction, vehicle frontal area and vehicle characteristic length.

4. The driving safety evaluation method in a crosswind environment according to claim 2, characterized in that: According to the vehicle type, build the geometric model and aerodynamic-system dynamics coupling model of the vehicle to be evaluated, including: According to the vehicle type, the vehicle to be evaluated is divided into modeling areas; the modeling areas are one or two; Based on the geometric information of the modeling area, construct a geometric model of the modeling area; Using computational fluid dynamics software, an aerodynamic model of the modeling area was constructed; Use multi-body dynamics software to build a system dynamics model of the modeling area; The aerodynamic model and the system dynamics model corresponding to the same modeling area are coupled to obtain an aerodynamic-system dynamics coupling model of the modeling area; Determine the geometric model of all modeling areas of the vehicle to be evaluated as the geometric model of the vehicle to be evaluated; The aerodynamics-system dynamics coupling model of all modeling areas of the vehicle to be evaluated is determined as the aerodynamics-system dynamics coupling model of the vehicle to be evaluated.

5. The driving safety evaluation method in a crosswind environment according to claim 4, characterized in that: According to the vehicle type, the modeling area of ​​the vehicle to be evaluated is divided, including: When the vehicle type is a passenger car or a van, the entire vehicle to be evaluated is determined as the modeling area; When the vehicle type is a container truck, the tractor area and the trailer area in the vehicle to be evaluated are respectively used as a modeling area.

6. The driving safety evaluation method in a crosswind environment according to claim 4, characterized in that: Based on the geometric information of the modeling area, a geometric model of the modeling area is constructed, including: Determine the circumscribed rectangle of the modeling area as the initial model; Determine the two endpoints corresponding to the cut length of the front of the vehicle in the modeling area in the initial model as the critical points of the front end of the vehicle body; Determine the two endpoints corresponding to the cut length of the rear end of the modeling area in the initial model as the critical points of the rear end of the vehicle body; The centroid position of the modeling area in the initial model is determined to obtain a geometric model of the modeling area.

7. The driving safety evaluation method in a crosswind environment according to claim 6, characterized in that: According to the side wind working condition to be evaluated, the lateral displacement of each boundary point of the vehicle to be evaluated under the side wind working condition to be evaluated is determined by using the aerodynamics-system dynamics coupling model and the geometric model, including: The motion state and dynamic response of the vehicle are calculated according to the aerodynamic-system dynamics coupling model of the crosswind condition to be evaluated, and the lateral displacement of the center of mass and the yaw angle of all modeling areas in the vehicle to be evaluated under the crosswind condition to be evaluated are obtained; When the vehicle to be evaluated slides or rolls over under the crosswind condition to be evaluated, the driving safety state of the vehicle to be evaluated is determined to be dangerous; When the vehicle to be evaluated deviates sideways under the sidewind condition to be evaluated, when the modeling area is the entire vehicle area of ​​a passenger car and a van or the tractor area of ​​a container truck, the first boundary point lateral displacement formula group is used to determine the lateral displacement of each boundary point of the modeling area under the sidewind condition to be evaluated; when the modeling area is the trailer area of ​​a container truck, the second boundary point lateral displacement formula group is used to determine the lateral displacement of each boundary point of the modeling area under the sidewind condition to be evaluated, and the lateral displacement of all boundary points of each modeling area in the vehicle to be evaluated under the sidewind condition to be evaluated is obtained.

8. The driving safety evaluation method in a crosswind environment according to claim 7, characterized in that: The first boundary point lateral displacement formula group is: in, The second boundary point lateral displacement formula group is: In the formula, ey a is the lateral displacement of the critical point a at the left front end of the vehicle body; ey is the lateral displacement of the center of mass of the modeling area; dl f is the distance from the critical point of the front end of the vehicle body to the center of mass in the modeling area; W is the width of the vehicle body in the modeling area; θ a is the angle between the critical point a at the left front end of the vehicle body and the center line of the modeling area; is the body yaw angle in the modeling area; ey b is the lateral displacement of the critical point b at the right front end of the vehicle body; θ b is the angle between the critical point b at the right front end of the vehicle body and the center line of the modeling area; ey c is the lateral displacement of the critical point c at the rear end of the left vehicle body; dl r is the distance from the critical point of the rear end of the vehicle body to the center of mass in the modeling area; θ c is the angle between the critical point c at the rear end of the left vehicle body and the center line of the modeling area; ey d is the lateral displacement of the critical point d at the rear end of the right vehicle body; θ d L is the angle between the critical point d at the rear end of the right vehicle body and the center line of the modeling area; f L is the distance from the center of mass to the front end of the vehicle body in the modeling area; r is the distance from the center of mass to the front end of the vehicle body in the modeling area.

9. The driving safety evaluation method in a crosswind environment according to claim 8, characterized in that: Determining the driving safety state of the vehicle to be evaluated under the crosswind condition to be evaluated based on the lateral displacements of the plurality of boundary points includes: Determine any modeling area as the current modeling area; Determine the difference between the lane width and the vehicle body width in the modeling area as the intermediate value; Determine half of the middle value as the lane critical value corresponding to the current modeling area; When the lateral displacement of any boundary point of the vehicle to be evaluated under the crosswind condition to be evaluated reaches the lane critical value of the corresponding modeling area, the driving safety state of the vehicle to be evaluated is determined to be dangerous.

10. A computer device comprising: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the driving safety evaluation method in a crosswind environment as described in any one of claims 1 to 9.

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