Method for evaluating running risk of vehicle on slope road section

Abstract

The invention discloses a slope road section vehicle operation risk evaluation method. The method comprises the following steps: S1, calculating the lateral acceleration a side of a vehicle when the vehicle runs on a slope road section; s2, calculating a friction coefficient mu lane changing required by lane changing and provided for the vehicle by the slope road section road; s3, from the angle of the friction circle, calculating a road surplus attachment coefficient # imgabs0 # of the road on the curve slope section except for the friction coefficient required for meeting lane change provided for the vehicle; and S4, evaluating the vehicle operation risk based on the road surplus attachment coefficient # imgabs1 #. According to the method, the combination of multiple factors such as the vehicle speed, the road adhesion coefficient, the road longitudinal slope and the superelevation condition is comprehensively considered, traditional road geometric parameters are included, and the lateral acceleration factor during lane changing of the vehicle is introduced, so that the method better fits the actual vehicle-road interaction scene, and vehicle operation risk assessment is more scientific and accurate.

Description

Technical Field

[0001] The invention relates to the field of road safety, and in particular to a method for evaluating vehicle operation risks on curved and sloping roads. Background Art

[0002] In the actual operation of current highway projects, curved and sloping sections have always been a high-incidence area for traffic accidents due to their complex geometric characteristics and driving conditions. Especially on mountain roads, multiple factors such as vehicle speed, road adhesion coefficient, road longitudinal slope and superelevation conditions are intertwined, forming a complex vehicle-road interaction scenario that is prone to cause serious traffic accidents. However, the existing highway project safety evaluation and route design-related specifications have not yet provided a special evaluation method for vehicle operation risks on curved and sloping sections, and lack effective risk quantification methods.

[0003] For example, the Highway Project Safety Evaluation Specification only evaluates vehicle operation safety from aspects such as road geometry parameters and vehicle speed coordination, but does not involve special risk assessment of curved and sloping sections, nor does it consider the impact of lateral acceleration such as vehicle lane changes on driving safety. Similarly, although the Highway Route Design Specification stipulates the combination of horizontal curves and longitudinal curves on curved and sloping sections, it does not fully consider the impact of the road adhesion coefficient on vehicle operation safety.

[0004] Since the relevant specifications do not take into account the impact of lateral acceleration such as vehicle lane changes on driving safety, they are not sufficient to analyze and evaluate the operating risks of vehicles under normal conditions, and are difficult to meet actual needs, and need to be optimized and improved. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the present invention is to provide a method for evaluating the risk of vehicle operation on a curved and sloping road section, which aims to evaluate the risk of vehicle operation on a curved and sloping road section during the road design or operation stage, so as to optimize and adjust the road longitudinal slope and superelevation design parameters during the design stage, or provide a basis for taking measures such as road section speed limit during road operation management.

[0006] The technical solution of the present invention is as follows: A method for evaluating the risk of vehicle operation on a curved and sloping section of a highway, characterized in that it comprises the following steps:

[0007] S1. Calculate the lateral acceleration a of the vehicle when it is traveling on a curved road section 侧 ;

[0008] S2. Calculate the friction coefficient μ provided by the curved and sloping road for the vehicle to meet the requirements of lane change. 变道 ;

[0009] S3. Calculate the excess adhesion coefficient of the curved road section in addition to the friction coefficient required for the vehicle to change lanes from the perspective of the friction circle.

[0010] S4, based on road surplus adhesion coefficient Assess vehicle operation risks.

[0011] Furthermore, in step S1, a is calculated 侧 The formula is:

[0012]

[0013] In the formula, v 运 Indicates the vehicle running speed (unit: m / s), which is calculated according to JTG B05-2015 Highway Project Safety Evaluation Specification or selected according to the measured value;

[0014] Indicates the curvature of the road flat curve (unit: m -1 ), R is the horizontal curve radius of the road (unit: m);

[0015] ρ represents the maximum curvature of the vehicle’s trajectory during lane change when driving on a straight road (unit: m -1 ).

[0016] Further, in step S2, μ is calculated 变道 The formula is:

[0017]

[0018] In the formula, i 超 Indicates the superelevation value of the curved and sloping section of the road (unit: rad).

[0019] Further, in step S3, calculate The formula is:

[0020]

[0021] In the formula, Indicates the road adhesion coefficient in wet conditions, generally taken as 0.4;

[0022] i 纵 Indicates the longitudinal slope of the road, with uphill being positive and downhill being negative (unit: rad).

[0023] Furthermore, based on the road surplus adhesion coefficient The vehicle operation risk is evaluated as follows:

[0024] when When the vehicle is running, the risk is very high; when When it is 0.15-0.25, the vehicle operation risk is high; when When it is 0.25-0.35, the vehicle operation risk is average; when When the vehicle is running, the risk is low.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] This method comprehensively considers multiple factors such as vehicle speed, road adhesion coefficient, road longitudinal slope and superelevation conditions. It not only includes traditional road geometry parameters, but also introduces the lateral acceleration factor when the vehicle changes lanes, so as to be more in line with the actual vehicle-road interaction scenario, making the vehicle operation risk assessment more scientific and accurate. This is not only suitable for the safety assessment of vehicle operation on existing roads, providing a basis for highway operation control, but also providing an important reference for the linear optimization design in the road design stage, thereby improving the safety level of highway operation.

[0027] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work:

[0029] Figure 1 is a schematic diagram of the method of the present invention;

[0030] Figure 2 It is a schematic diagram of a situation in which a vehicle travels along the center of a lane on a curved and sloping section of a highway according to the present invention;

[0031] Figure 3 It is a schematic diagram of a driving situation of a vehicle changing lanes on a curved and sloping section of a highway according to the present invention;

[0032] Figure 4 It is a schematic diagram of a case study of risk assessment of vehicle operation on a curved and sloping section of a highway according to the present invention. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] like Figure 1-Figure 3 A method for evaluating the risk of vehicle operation on a curved and sloping section of a highway is shown, comprising the following steps:

[0035] S1. Calculate the lateral acceleration a of the vehicle when it is traveling on a curved road section 侧 , calculate a 侧 The formula is:

[0036]

[0037] In the formula, v 运 Indicates the vehicle running speed (unit: m / s), which is calculated according to JTG B05-2015 Highway Project Safety Evaluation Specification or selected according to the measured value;

[0038] Indicates the curvature of the road flat curve (unit: m -1 ), R is the horizontal curve radius of the road (unit: m);

[0039] ρ represents the maximum curvature of the vehicle’s trajectory during lane change when driving on a straight road (unit: m -1 ), this value varies with the vehicle running speed, and the specific value can be found in Table 1.

[0040] Table 1 Reference values ​​of ρ at different vehicle running speeds

[0041] Vehicle speed (km / h) 80 100 120 ρ 0.0050 0.0035 0.0024

[0042] S2. Calculate the friction coefficient μ provided by the curved and sloping road for the vehicle to meet the requirements of lane change. 变道 , calculate μ 变道 The formula is:

[0043]

[0044] In the formula, i 超 Indicates the superelevation value of the curved and sloping section of the road (unit: rad).

[0045] S3. Calculate the excess adhesion coefficient of the curved road section in addition to the friction coefficient required for the vehicle to change lanes from the perspective of the friction circle.

[0046] Specifically, the friction circle is a visual tool used to describe the maximum G-force (grip) that a vehicle can generate in different directions (acceleration, braking, cornering). It represents the dynamic limit of the tire when handling and describes how the grip is distributed between the longitudinal and lateral directions. When the vehicle is at the boundary of the friction circle, the performance limit of the tire has been reached.

[0047] In step S3, the maximum friction coefficient μ that the curved road section can provide to the vehicle in addition to the friction coefficient required for the vehicle to change lanes is calculated from the friction circle angle. max , then based on μ max Calculate the excess road adhesion coefficient

[0048] Calculate μ max The formula is:

[0049]

[0050] In the formula, It indicates the road adhesion coefficient when the road is wet, and is generally taken as 0.4.

[0051] calculate The formula is:

[0052]

[0053] i 纵 Indicates the longitudinal slope of the road, with uphill being positive and downhill being negative (unit: rad).

[0054] S4, based on road surplus adhesion coefficient Evaluate the vehicle operation risk, and the evaluation threshold is shown in Table 2

[0055] Table 2 Road surface excess adhesion coefficient and vehicle operation risk value

[0056]

[0057] like Figure 4 The figure shows a specific implementation of the present invention, with the vehicle running speed v 运 100km / h, road adhesion coefficient is 0.4, the radius R is 800m, and the longitudinal slope i 纵 -1.5%, ultra high 超 Take the risk assessment of vehicle operation on a 3% curved slope as an example. In this case, a high-risk situation occurs. For the highway design or operation stage, the following measures should be considered to improve driving safety.

[0058] Design stage: If the assessment results show a high risk, the terrain and geological conditions can be comprehensively considered during the design stage to optimize the road's curve curvature, longitudinal slope and superelevation design to reduce vehicle operation risks.

[0059] Operation stage: If high-risk sections are found during actual operation, speed limit control measures can be taken or warning signs can be added at appropriate locations before dangerous sections to alert drivers, thereby improving the safety level of vehicle driving.

[0060] In summary, compared with the prior art, the present invention has the following characteristics:

[0061] (1) Proposed an evaluation method for vehicle operation risk on curved and sloping sections: The method of the present invention comprehensively considers multiple factors such as vehicle speed, road adhesion coefficient, road longitudinal slope and superelevation conditions, and is aimed at a more realistic vehicle-road interaction scenario. Compared with the prior art, the present invention fills the gap in the evaluation method of vehicle operation risk on curved and sloping sections in the field of highway engineering safety evaluation, making the vehicle operation risk assessment more scientific and accurate.

[0062] (2) The influencing factor of vehicle lateral acceleration is introduced: The method of the present invention not only considers the traditional road geometry parameters, but also introduces the lateral acceleration factor of the vehicle when changing lanes. This innovation makes the vehicle operation risk assessment more comprehensive. Compared with the existing technology, the method of the present invention has significant advantages in assessing the operation risk of the vehicle during the lane change process.

[0063] (3) Quantitative assessment method for vehicle operation risk based on friction circle theory: The present invention provides a new quantitative assessment method for vehicle operation risk based on the excess adhesion coefficient on curved and sloping roads from the perspective of friction circle. This method not only provides a scientific basis for road design and traffic safety management, but also helps to reduce the occurrence of traffic accidents and improve the operational safety level of mountain roads. Through this assessment method, it is possible to evaluate the operation risk of key curved and sloping sections, which has a strong engineering application value.

[0064] (4) Improving the rationality and safety of road geometry design: The systematic risk assessment method provided by the present invention can effectively guide actual road design and reconstruction. By comprehensively considering various influencing factors, the rationality of road geometry design is improved, thereby ensuring the driving safety of drivers on curved and sloping roads. The present invention not only enriches the content of road safety evaluation in theory, but also has important guiding significance in practice.

[0065] (5) Enhance the scientificity and effectiveness of traffic safety management: Through the risk assessment method proposed in this invention, highway operating units and traffic safety management departments can more scientifically and conveniently identify high-risk curved and sloping sections, thereby formulating more targeted safety management measures. This will greatly enhance the effectiveness of traffic safety management and further ensure safe passage on mountain roads.

[0066] Although a portion of the embodiments of the present invention have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations to these embodiments are within the scope of protection of the claims of the present invention without departing from the principles and purpose of the present invention.

Claims

1. A method for evaluating the risk of vehicle operation on a curved and sloping road section, characterized in that: The following steps are involved: S1. Calculate the lateral acceleration a of the vehicle when it is traveling on a curved road section 侧 ; S2. Calculate the friction coefficient μ provided by the curved and sloping road for the vehicle to meet the requirements of lane change. 变道 ; S3. Calculate the excess adhesion coefficient of the curved road section in addition to the friction coefficient required for the vehicle to change lanes from the perspective of the friction circle. S4, based on road surplus adhesion coefficient Assess vehicle operation risks.

2. The method for evaluating vehicle operation risk on a curved and sloping road section according to claim 1, characterized in that: In step S1, calculate a 侧 The formula is: In the formula, v 运 Indicates the vehicle running speed (unit: m / s), which is calculated according to JTG B05-2015 Highway Project Safety Evaluation Specification or selected according to the measured value; Indicates the curvature of the road flat curve (unit: m -1 ), R is the horizontal curve radius of the road (unit: m); ρ represents the maximum curvature of the vehicle’s trajectory during lane change when driving on a straight road (unit: m -1 ).

3. The method for evaluating vehicle operation risk on curved and sloping road sections according to claim 1, characterized in that: In step S2, calculate μ 变道 The formula is: In the formula, i 超 Indicates the superelevation value of the curved and sloping section of the road (unit: rad).

4. The method for evaluating vehicle operation risk on curved and sloping road sections according to claim 1, characterized in that: In step S3, calculate The formula is: In the formula, Indicates the road adhesion coefficient in wet conditions, generally taken as 0.4; i 纵 Indicates the longitudinal slope of the road, with uphill being positive and downhill being negative (unit: rad).

5. The method for evaluating vehicle operation risk on curved and sloping road sections according to claim 4 is characterized in that: Based on the road surplus adhesion coefficient The vehicle operation risk is evaluated as follows: when When the vehicle is running, the risk is very high; when When it is 0.15-0.25, the vehicle operation risk is high; when When it is 0.25-0.35, the vehicle operation risk is average; when When the vehicle is running, the risk is low.

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