A vehicle collision assessment method based on vehicle-road collaborative model

Abstract

The present invention discloses a vehicle collision assessment method based on a vehicle-road collaborative model. Through survey and modeling, based on the motor vehicle access restriction rules around the protected object, the type of motor vehicle that can be used as a collision tool is evaluated and selected. The accessibility conditions of the roads around the protected object are analyzed, and all access path parameters (including the acceleration distance, slope, turning radius, collision angle, etc. of the motor vehicle road) to which the protected object is subject to vehicle collision threats are quantified. Then, the possible vehicle collision threat to the protected object is calculated and quantified using vehicle mass, maximum possible collision speed, and collision energy data. This provides quantitative data support for the construction, reconstruction, and reinforcement of perimeter protection facilities.

Description

Technical Field

[0001] The present invention relates to the field of security technology, and in particular to a vehicle collision assessment method based on a vehicle-road collaborative model. Background Art

[0002] To prevent the use of motor vehicles to crash into key departments or places where people gather, various industries have successively installed or upgraded perimeter walls, gates, vehicle barriers, and other protective facilities, investing significant financial and material resources. However, due to the lack of evaluation methods for such threats and the effectiveness of prevention measures, excessive, insufficient, or lack of targeted measures are common.

[0003] Currently, the common practice is to construct street-side perimeter protection facilities based on qualitative analysis results and in accordance with relevant standards. For example, walls, gates, and flower beds are constructed according to architectural standards, and a specific grade of lifting vehicle barriers is selected in accordance with the requirements of GA / T 1343-2016, "Violent Lifting Vehicle Barriers." Calculations and analysis of selected scenarios have revealed that previous methods and empirical data often provide over- or under-protection. Furthermore, the security industry lacks a quantitative evaluation method for protecting against vehicle impact threats tailored to the specific targets being protected.

[0004] From a security perspective, the physical perimeter of a protected object is the first and most important line of defense to ensure the safety of personnel, assets, and facilities within the protected object. Regarding preventing vehicle collisions, the shortcomings of existing technologies are as follows:

[0005] 1. The technical requirements for facilities such as walls, entrances and exits, crash columns, crash piers, and landscape flower beds in the national building standard design drawings are considered from the perspective of the construction industry and cannot determine their ability to resist vehicle collisions.

[0006] 2. While national standard GB 50688-2011 sets out relevant technical requirements for preventing vehicle collisions, it applies only to road traffic and lacks reference value for perimeter construction. Industry standard GA / T1343-2016, while specifically addressing pre-buried, liftable riot barriers, specifies the selection requirements for liftable bollards within perimeters. However, this standard lacks integration with the technical standards for other physical facilities, such as walls, gates, crash barriers, and landscaped flower beds. Consequently, in practice, perimeter protection facilities lack coherence.

[0007] 3. Different protected objects have different perimeter threats to them. Existing technologies cannot quantitatively evaluate the risk of vehicle collisions against protected objects. Adopting uniform technical standards for construction can easily lead to excessive or insufficient protection. Summary of the Invention

[0008] In view of the shortcomings of the existing technology, the present invention aims to provide a vehicle collision assessment method based on a vehicle-road cooperative model.

[0009] In order to achieve the above object, the present invention adopts the following technical solutions:

[0010] A vehicle collision assessment method based on a vehicle-road collaborative model, the specific process is as follows:

[0011] S1. Surrounding road analysis:

[0012] By analyzing the roads around the protected object, the total number N of all accessible paths to the protected object threatened by vehicle collision is determined;

[0013] S2. Determination of vehicle parameters:

[0014] The type of motor vehicle used as the collision tool is selected based on the traffic restrictions of motor vehicles in the vicinity of the protected object. The vehicle parameters are determined based on the public data of each type of motor vehicle and used as the calculation input of the collision algorithm. The vehicle parameters include: maximum gross mass m, acceleration time t0, wheelbase d, maximum speed V m ;

[0015] S3. Quantification of access path information:

[0016] The information of each accessible path is quantified separately, including the survey of straight sections, circular curve sections and collision angles; the survey data of straight sections include the length S z , the vertical height h of the path slope and the horizontal width l of the path slope; the survey data of the circular curve section include the curve length S y , curve radius r; determine the collision angle β of each access path colliding with the protected object based on the survey results;

[0017] S4. Calculate the maximum possible collision speed and collision energy that can be reached by the vehicle collision threat on each accessible path using the collision algorithm: The collision algorithm calculation process for each accessible path is as follows:

[0018] (1) Calculate the speed of a straight section: When the acceleration time of the vehicle is available, calculate the vehicle's acceleration a0 based on the acceleration time:

[0019] Calculate the slope i of the path:

[0020]

[0021] Where h is the vertical height of the path slope. When there is no uphill or downhill slope, h is 0. l is the horizontal width of the path slope.

[0022] Calculate the slope angle α of the path:

[0023] α=arctan(i)

[0024] According to the distance S z Calculate the speed v of a straight section:

[0025]

[0026] v=v0+a z ·t

[0027] And from this we can get:

[0028]

[0029] Among them, v0 is determined according to the actual situation. If there is no initial speed, then v0 = 0. If it is a straight section after a circular curve section, then v0 = V y ;a z Determine according to actual situation. When going uphill, a z =a0·cos(α), when going downhill,

[0030] Determine the final speed V on the straight section z , when v<V m When V z =v, otherwise V z =V m ;

[0031] (2) Calculate the speed of circular curve sections

[0032] Calculate the critical speed V at which the vehicle rolls over when turning c :

[0033]

[0034] Where r is the radius of the circular curve section, d is the wheelbase of the vehicle; j is the height of the vehicle's center of mass; g is the acceleration due to gravity;

[0035] Calculate the acceleration a of the vehicle on the circular curve y :

[0036]

[0037] According to the length S y Calculate the speed v' of a straight section:

[0038]

[0039] Where v0 = V z ;

[0040] Determine the final velocity V of the circular curve segment y , when v'<Vc When V y =v', otherwise V y =V c ;

[0041] (3) Determine the maximum possible collision velocity V for each path based on the calculation results of steps (1) and (2), and calculate the collision energy E accordingly;

[0042] S5. Evaluation results display:

[0043] The maximum collision speed and collision energy of all paths calculated in step S4 are used as the evaluation results of the threat of vehicle collision to the protected object, and are used to guide the construction, reconstruction and reinforcement of the perimeter protection facilities of the protected object.

[0044]

[0045] Furthermore, in step (1), when the acceleration time of the vehicle is the 100 km / h acceleration time, the acceleration calculation formula is as follows:

[0046]

[0047] When the vehicle's acceleration time is 50 kilometers per hour, the acceleration calculation formula is as follows:

[0048]

[0049] Where t0 is the vehicle's nominal acceleration time from 0 to 100 km / h or from 0 to 50 km / h.

[0050]

[0051] Furthermore, the specific process of step (3) is:

[0052] When the path has only straight sections, according to V z The result of this is the value of V:

[0053] V=V z ·sinβ;

[0054] When the path consists of a straight line and a circular curve, first calculate the speed V of the straight line segment. z , and then calculate the speed V of the circular curve section based on this y , and the collision velocity V is obtained:

[0055] V=V y sinβ

[0056] When the path consists of a straight line, a circular curve, and a straight line, first calculate the speed V of the first straight line segment. z, and then calculate the speed V of the circular curve section based on this y , and then proceed to the next straight section at a speed of V z , and the collision velocity V is obtained:

[0057] V=V z sinβ

[0058] After calculating the collision velocity V, calculate the collision energy E generated at the moment of collision according to the following formula:

[0059]

[0060] Furthermore, in step (1), when the acceleration time parameter of the vehicle cannot be obtained, the acceleration of the vehicle is calculated according to the following process:

[0061] Step 1: Calculate the maximum speed that can be achieved when the vehicle is driving in each gear:

[0062]

[0063] Where R is the rolling radius of the vehicle tire; n is the engine output speed; i g is the gear ratio of the transmission; i0 is the total reduction ratio of the rear axle;

[0064] Step 2: Calculate the maximum acceleration that the vehicle can achieve when driving in each gear:

[0065]

[0066] Among them, F t is the driving force of the car, F f is the rolling resistance, F w is the air resistance, δ is the conversion coefficient of the vehicle's rotational mass; m is the total mass of the vehicle; to simplify the calculation complexity, the rolling resistance and air resistance are ignored, and the vehicle's driving force is T tq is the maximum torque, η T is the mechanical efficiency of the transmission system, which is a constant;

[0067] The third step is to take the average value of the maximum acceleration of each gear as the acceleration a0 of the vehicle on the straight section.

[0068] The beneficial effects of the present invention are as follows: the method of the present invention is based on the road accessibility conditions and the parameters of the vehicles allowed to pass around the protected object, assuming that the road environment and the driver can satisfy the vehicle to achieve its maximum dynamic performance, and calculates the minimum energy that the protected object should be able to withstand vehicle collisions, thereby achieving a quantitative evaluation of the threat of vehicle collisions to the protected object from different access paths, and based on the results of the quantitative evaluation, proposes specific protection requirements for the construction of protective facilities such as walls, gates, anti-collision columns, anti-collision piers, and landscape flower beds. The method has the characteristics of strong operability and wide applicability, and can solve the difficult problem that the construction of protective facilities to prevent the threat of vehicle collisions to the protected object cannot be quantitatively evaluated. BRIEF DESCRIPTION OF THE DRAWINGS

[0069] Figure 1 is a flow chart of a method according to an embodiment of the present invention;

[0070] Figure 2 A schematic diagram of a vehicle collision path in an embodiment of the present invention;

[0071] Figure 3 Schematic diagram of slope and slope angle in an embodiment of the present invention. DETAILED DESCRIPTION

[0072] The present invention will be further described below in conjunction with the accompanying drawings. It should be noted that this embodiment is based on the technical solution and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to this embodiment.

[0073] This embodiment provides a vehicle collision assessment method based on a vehicle-road collaboration model. This method focuses on the road accessibility conditions and vehicle parameters surrounding the protected object. It constructs a vehicle-road collaboration model that assumes the road environment and driver conditions meet the vehicle's maximum dynamic performance. It quantifies all accessible paths for vehicle collision threats to the protected object, selects the type of vehicle that can serve as a collision tool, and estimates the vehicle collision threat faced by the protected object through a collision assessment algorithm. This is quantified using vehicle mass, maximum possible collision velocity, and collision energy data, ultimately drawing an assessment conclusion.

[0074] The vehicle-road collaboration model described in this embodiment is based on evaluating the vehicle collision threat to the protected object. It uses all accessible paths to the protected object and the types of vehicles that could act as collision vehicles as model variables. The maximum possible collision speed and collision energy data are calculated using a collision assessment algorithm. The vehicle-road collaboration model covers the following:

[0075] i. Assume that the road environment of all accessible paths to the protected object can meet the requirements for the vehicle to achieve its maximum power performance, and ignore the impact of possible obstacles on each accessible path;

[0076] ii. It is assumed that the driver's driving skills are capable of achieving the vehicle's maximum power;

[0077] iii. Ignoring traffic regulations, i.e., the impacting vehicle does not comply with traffic regulations and uses the vehicle's maximum power performance to carry out the impact;

[0078] iv. According to highway design specifications, each motor vehicle lane is composed of straight lines and flat curves, which can be further divided into circular curves and transition curves. The purpose of the method in this embodiment is to calculate the maximum possible collision speed that can be achieved by a vehicle collision. The vehicle-road collaborative model simplifies the accessible path to consist of straight lines or straight lines and circular curves. The processing rules for transition curves are determined based on on-site survey results. Transition curves that do not affect the vehicle's motion are treated as straight lines; transition curves that affect the vehicle's motion are treated as circular curves.

[0079] v. Access paths to protected objects include three types, such as Figure 2 As shown, they are: an accessible path consisting of only straight sections, an accessible path with a straight section first and then a circular curve section or a circular curve section first and then a straight section, and an accessible path with a straight section first, then a circular curve section, and then a straight section.

[0080] vi. The impact of superelevation on lane turning sections is not considered.

[0081] The vehicle collision assessment method based on the vehicle-road cooperative model proposed in this embodiment is based on the actual situation of the protected object. It calculates the maximum possible collision speed and collision energy of the accessible path subjected to vehicle collision behavior through surrounding road analysis, vehicle parameters, access path information quantification, collision algorithm, and evaluation result display. Finally, it estimates the protection requirements of each accessible path of the protected object to resist the threat of vehicle collision. Figure 1 As shown, the specific process is as follows:

[0082] S1. Surrounding road analysis:

[0083] Through on-site surveys of roads surrounding the protected object, the number N of all accessible paths to the protected object that are threatened by vehicle collisions is determined.

[0084] S2. Determination of vehicle parameters:

[0085] Based on the traffic restrictions around the protected area, the type of vehicle to be used as the collision tool (e.g., sedan, SUV, bus, truck) is selected. Based on the public data (factory data) of each vehicle type, the vehicle parameters are determined as the calculation input of the collision algorithm. Vehicle parameters include: maximum gross vehicle mass m, acceleration time to 100 kilometers per hour t0, wheelbase d, maximum speed V m .

[0086] S3. Quantification of access path information:

[0087] Through on-site survey, the information of each accessible path is quantified, including the survey of straight sections, circular curve sections and collision angles. Among them, the survey data of straight sections include length S z , the vertical height h of the path slope and the horizontal width l of the path slope. The survey data of the circular curve section include the curve length S y , curve radius r. Then, based on the survey results, determine the collision angle β of each access path that collides with the protected object.

[0088] S4. Calculate the maximum possible collision speed and collision energy that can be reached by the vehicle collision threat on each accessible path using a collision algorithm.

[0089] The collision algorithm calculation steps for each accessible path are as follows:

[0090] (1) Calculate the speed of a straight section:

[0091] Calculate the vehicle's acceleration a0:

[0092]

[0093] Where t0 is the vehicle’s nominal acceleration time from 0 to 100 km / h.

[0094] Calculate the slope i of the path:

[0095]

[0096] Among them, h is the vertical height of the path slope (when there is no uphill or downhill slope, h is 0), l is the horizontal width of the path slope, such as Figure 3 shown.

[0097] Calculate the slope angle α of the path:

[0098] α=arctan(i)

[0099] According to the distance S z Calculate the speed v of a straight section:

[0100]

[0101] v=v0+a z ·t

[0102] And from this we can get:

[0103]

[0104] Among them, v0 is determined according to the actual situation. If there is no initial speed, then v0 = 0. If it is a straight section after a circular curve section, then v0 = Vy . a z Determine according to actual situation. When going uphill, a z =a0·cos(α), when going downhill,

[0105] Determine the final speed V on the straight section z When v<V m When V z =v. Otherwise V z =V m .

[0106] (2) Calculate the speed of circular curve sections

[0107] Calculate the critical speed V at which the vehicle rolls over when turning c :

[0108]

[0109] Where r is the turning radius (approximately equal to the curve radius of a circular curve section), d is the vehicle wheelbase, j is the vehicle center of mass height (estimated value: 0.5-0.6 m for sedans, 0.65 m-0.75 m for SUVs, and 0.8 m-1.2 m for trucks), and g is the acceleration due to gravity.

[0110] Calculate the acceleration a of the vehicle on the circular curve y :

[0111]

[0112] According to the length S y Calculate the speed v' of a straight section:

[0113]

[0114] Where v0 = V z .

[0115] Determine the final velocity V of the circular curve segment y When v'<V c When V y = v'; otherwise V y =V c .

[0116] (3) Determine the maximum possible collision speed V for this path

[0117] When the path has only straight sections, according to V z The result of this is the value of V:

[0118] V=V z sinβ(0<β≤90°);

[0119] When the path consists of a straight line and a circular curve, first calculate the speed V of the straight line segment. z , and then calculate the speed V of the circular curve section based on this y , and the collision velocity V is obtained:

[0120] V=V y sinβ(0<β≤90°)

[0121] When the path consists of a straight line, a circular curve, and a straight line, first calculate the speed V of the first straight line segment. z , and then calculate the speed V of the circular curve section based on this y , and then proceed to the next straight section at a speed of V z , and the collision velocity V is obtained:

[0122] V=V z sinβ(0<β≤90°)

[0123] Calculate the collision energy E generated at the moment of collision:

[0124]

[0125] S5. Evaluation results display

[0126] All accessible paths are calculated using a collision algorithm to obtain the maximum collision speed and collision energy of all paths. This is used as an evaluation result of the threat of vehicle collision to the protected object and is used to guide the construction, reconstruction and reinforcement of perimeter protection facilities for the protected object.

[0127] It should be noted that the slope i can be determined based on either on-site survey data or relevant standards. For example, CJJ 193-2012, "Urban Road Alignment Design Specifications," specifies the relationship between the maximum longitudinal slope of motor vehicle lanes and the road design speed as shown in the following table. If the roads surrounding the protected area are standard design roads, the data in Table 1 can be directly used as the route data.

[0128] Table 1

[0129]

[0130] Similarly, CJJ 193-2012 "Urban Road Route Design Specifications" also stipulates the design standards for circular curve radii for different design speeds. If the roads around the protected object are standard design roads, the data in the table can be directly adopted as path data.

[0131] It should be noted that the vehicle's acceleration a0 can be calculated using either the vehicle's nominal 100km / h acceleration time or the vehicle's nominal 50km / h acceleration time. For example, if the 50km / h acceleration time is used, When the vehicle does not give the acceleration time, its acceleration a0 can also be determined by using the vehicle driving equation. The specific calculation method is as follows:

[0132] The first step is to calculate the maximum speed that can be achieved when the vehicle is driving in each gear (the maximum speed limit is used as the standard if a speed limiter is installed):

[0133]

[0134] Where R is the rolling radius of the vehicle tire; n is the engine output speed; i g is the gear ratio of the transmission; i0 is the total reduction ratio of the rear axle.

[0135] The second step is to calculate the maximum acceleration that the vehicle can achieve when driving in each gear:

[0136]

[0137] Among them, F t is the driving force of the car, F f is the rolling resistance, F w is the air resistance, δ is the vehicle rotation mass conversion coefficient, which is between 1.1 and 1.4 (the mass conversion coefficient has a standard calculation method. For the convenience of calculation, the value here is an approximate estimate); m is the total mass of the vehicle. To simplify the calculation complexity, rolling resistance and air resistance can be ignored. The driving force of the vehicle T tq is the maximum torque, η T is the mechanical efficiency of the transmission system, η T It can be regarded as a constant (0.9~0.92 for sedans; 0.8~0.85 for SUVs; 0.82~0.85 for trucks and buses. Similarly, there is a standard calculation method for the mechanical efficiency of the transmission system. For the convenience of calculation, the value here is an approximate estimate).

[0138] The third step is to take the average value of the maximum acceleration of each gear as the acceleration a0 of the vehicle on the straight section.

[0139] It should be noted that in the above process, the critical speed V of the vehicle turning due to the superelevation of the road is ignored. c When considering superelevation, the critical speed V at which a vehicle rolls over when turning is c The calculation formula is as follows:

[0140]

[0141] Among them, r is the turning radius (approximately equal to the circular curve radius), d is the vehicle wheelbase; j is the height of the vehicle's center of mass; g is the acceleration of gravity; and k is the road surface superelevation.

[0142] Those skilled in the art can make various corresponding changes and modifications based on the above technical solutions and concepts, and all of these changes and modifications should be included in the scope of protection of the claims of the present invention.

Claims

1. A vehicle collision assessment method based on a vehicle-road cooperative model, characterized in that: The specific process is: S1. Surrounding road analysis: By analyzing the roads around the protected object, the total number N of all accessible paths to the protected object threatened by vehicle collision is determined; S2. Determination of vehicle parameters: The type of motor vehicle used as the collision tool is selected based on the traffic restrictions of motor vehicles in the vicinity of the protected object; Determine vehicle parameters based on publicly available data on each vehicle type as input to the collision algorithm; Vehicle parameters include: maximum total mass m, acceleration time t0, wheelbase d, maximum speed V m ; S3. Quantification of access path information: The information of each accessible path is quantified separately, including the survey of straight sections, circular curve sections and collision angles; the survey data of straight sections include the length S z , the vertical height h of the path slope and the horizontal width l of the path slope; the survey data of the circular curve section include the curve length S y , curve radius r; determine the collision angle β of each access path colliding with the protected object based on the survey results; S4. Calculate the maximum possible collision speed and collision energy that can be reached by the vehicle collision threat on each accessible path using the collision algorithm: The collision algorithm calculation process for each accessible path is as follows: (1) Calculate the speed of a straight section: When the acceleration time of the vehicle is available, calculate the vehicle's acceleration a0 based on the acceleration time: Calculate the slope i of the path: Where h is the vertical height of the path slope. When there is no uphill or downhill slope, h is 0. l is the horizontal width of the path slope. Calculate the slope angle α of the path: α=arctan(i) According to the distance S z Calculate the speed v of a straight section: v=v0+a z ·t And from this we can get: Among them, v0 is determined according to the actual situation. If there is no initial speed, then v0 = 0. If it is a straight section after a circular curve section, then v0 = V y ;a z Determine according to the actual situation. When going uphill, a z =a0·cos(α), when going downhill, Determine the final speed V on the straight section z , when v<V m When V z =v, otherwise V z =V m ; (2) Calculate the speed of circular curve sections Calculate the critical speed V at which the vehicle rolls over when turning c : Where r is the radius of the circular curve section, d is the wheelbase of the vehicle; j is the height of the vehicle's center of mass; g is the acceleration due to gravity; Calculate the acceleration a of the vehicle on the circular curve y : According to the length S y Calculate the speed v' of a straight section: Where v0 = V z ; Determine the final velocity V of the circular curve segment y , when v'<V c When V y =v', otherwise V y =V c ; (3) Determine the maximum possible collision velocity V for each path based on the calculation results of steps (1) and (2), and calculate the collision energy E accordingly; S5. Evaluation results display: The maximum collision speed and collision energy of all paths calculated in step S4 are used as the evaluation results of the threat of vehicle collision to the protected object, and are used to guide the construction, reconstruction and reinforcement of the perimeter protection facilities of the protected object.

2. The method according to claim 1, characterized in that In step (1), when the vehicle's acceleration time is 100 kilometers per hour, the acceleration calculation formula is as follows: When the vehicle's acceleration time is 50 kilometers per hour, the acceleration calculation formula is as follows: Where t0 is the vehicle's nominal acceleration time from 0 to 100 km / h or from 0 to 50 km / h.

3. The method according to claim 1, characterized in that The specific process of step (3) is: When the path has only straight sections, according to V z The result of this is the value of V: V=V z ·sinβ; When the path consists of a straight line and a circular curve, first calculate the speed V of the straight line segment. z , and then calculate the speed V of the circular curve section based on this y , and the collision velocity V is obtained: V=V y ·sinβ When the path consists of a straight line, a circular curve, and a straight line, first calculate the speed V of the first straight line segment. z , and then calculate the speed V of the circular curve section based on this y , and then proceed to the next straight section at a speed of V z , and the collision velocity V is obtained: V=V z ·sinβ After calculating the collision velocity V, calculate the collision energy E generated at the moment of collision according to the following formula:

4. The method according to claim 1, wherein In step (1), when the acceleration time parameter of the vehicle cannot be obtained, the acceleration of the vehicle is calculated according to the following process: Step 1: Calculate the maximum speed that can be achieved when the vehicle is driving in each gear: Where R is the rolling radius of the vehicle tire; n is the engine output speed; i g is the gear ratio of the transmission; i0 is the total reduction ratio of the rear axle; Step 2: Calculate the maximum acceleration that the vehicle can achieve when driving in each gear: Among them, F t is the driving force of the car, F f is the rolling resistance, F w is the air resistance, δ is the conversion coefficient of the vehicle's rotational mass; m is the total mass of the vehicle; to simplify the calculation complexity, the rolling resistance and air resistance are ignored, and the vehicle's driving force is T tq is the maximum torque, η T is the mechanical efficiency of the transmission system, which is a constant; The third step is to take the average value of the maximum acceleration of each gear as the acceleration a0 of the vehicle on the straight section.

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