A method for evaluating vehicle operation risk on a curved slope road section

Abstract

The application discloses a kind of bend slope section vehicle operation risk evaluation methods, comprising the following steps: S1, the lateral acceleration a of vehicle is calculated when driving in bend slope section 侧 ;S2, the friction coefficient μ that bend slope section road provides to vehicle satisfies the lateral acceleration a required for lane changing 变道 ;S3, from the angle of friction circle, the excess coefficient of adhesion S4 of bend slope section road is calculated in addition to the friction coefficient μ required for lane changing provided to vehicle;S4, vehicle operation risk is evaluated based on excess coefficient of adhesion of road.This method comprehensively considers multiple factor combinations such as vehicle speed, road adhesion coefficient, road longitudinal slope and superhigh conditions, not only includes traditional road geometric parameters, but also introduces lateral acceleration factor when vehicle changes lane, so as to be more close to actual vehicle-road interaction scene, so that vehicle operation risk assessment is more scientific and accurate.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of road safety, in particular to a method for evaluating vehicle running risk on a curved slope road section. BACKGROUND

[0002] In the actual operation of current highway projects, curved slope road sections have been high-accident areas due to complex geometric characteristics and driving conditions. In particular, in mountainous highways, multiple factors such as vehicle speed, road surface adhesion coefficient, road longitudinal slope, and super-elevation conditions are intertwined, forming a complex vehicle-road interaction scenario, which is prone to cause serious traffic accidents. However, the existing safety evaluation and route design specifications for highway projects have not provided a special evaluation method for vehicle running risk on curved slope road sections, and lack effective risk quantification means.

[0003] For example, the "Highway Project Safety Evaluation Specification" only evaluates vehicle running safety from the coordination of road geometric parameters and vehicle running speed, without involving special risk evaluation of curved slope road sections, and without considering the influence of lateral acceleration such as vehicle lane changing on driving safety. Similarly, the "Highway Route Design Specification" has made provisions for the combination of horizontal curve and longitudinal section curve on curved slope road sections, but has not fully considered the influence of road surface adhesion coefficient on vehicle running safety.

[0004] Since the relevant specifications do not consider the influence of lateral acceleration such as vehicle lane changing on driving safety, they are not sufficient for analyzing and evaluating the running risk of vehicles under normal working conditions, and it is difficult to meet the actual needs, and optimization and improvement are needed. SUMMARY

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

[0006] The technical solution of the present application is as follows: a method for evaluating vehicle running risk on a curved slope road section of a highway, characterized in that it comprises the following steps:

[0007] S1, calculating the lateral acceleration a of the vehicle when driving on the curved slope road section 侧 ;

[0008] S2, calculating the friction coefficient μ provided by the curved slope road section for the vehicle to meet the requirements of lane changing 变道 ;

[0009] S3. From the perspective of the friction circle, calculate the excess adhesion coefficient of the road on the curve slope section to the friction coefficient required by the vehicle to meet the lane change

[0010] S4. Based on the excess adhesion coefficient of the road Evaluate the vehicle operation risk.

[0011] Further, in step S1, calculate a 侧 The formula is:

[0012]

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

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

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

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

[0017]

[0018] In the formula, i 超 represents the superelevation value of the road curve slope section (unit: rad).

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

[0020]

[0021] In the formula, represents the road surface adhesion coefficient in the wet state, generally taking 0.4;

[0022] i 纵 represents the road longitudinal slope, positive for uphill and negative for downhill (unit: rad).

[0023] Further, based on the excess adhesion coefficient of the road The vehicle operation risk is evaluated as follows:

[0024] When , the vehicle operation risk is very high; when When the value is 0.15-0.25, the vehicle operation risk is high; when the value is 0.25-0.35, the vehicle operation risk is general; and when the value is 0.35-0.45, the vehicle operation risk is low. When the value is 0.15-0.25, the vehicle operation risk is high; when the value is 0.25-0.35, the vehicle operation risk is general; and when the value is 0.35-0.45, the vehicle operation risk is low. When the value is 0.15-0.25, the vehicle operation risk is high; when the value is 0.25-0.35, the vehicle operation risk is general; and when the value is 0.35-0.45, the vehicle operation risk is low.

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

[0026] The method comprehensively considers multiple factor combinations such as vehicle speed, road adhesion coefficient, road longitudinal slope and overheight condition, not only includes traditional road geometric parameters, but also introduces a lateral acceleration factor when the vehicle changes lanes, so as to be more in line with the actual vehicle-road interaction scene, and the vehicle operation risk evaluation is more scientific and accurate. In this way, not only is it suitable for existing road vehicle operation safety evaluation to provide a basis for highway operation control, but also can provide an important reference for linear optimization design in the road design stage, so as to improve the highway operation safety level.

[0027] Additional aspects and advantages of the application will be set forth in part in the following description, will become apparent from the following description, or will be learned by practice of the application. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description. Obviously, the drawings in the following description only show some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

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

[0030] Figure 2 is a vehicle driving along the center of the lane in the highway curve and slope section of the present application;

[0031] Figure 3 is a vehicle changing lane driving situation schematic diagram of the highway curve and slope section of the present application;

[0032] Figure 4 is a vehicle operation risk evaluation case schematic diagram of the highway curve and slope section of the present application. DETAILED DESCRIPTION

[0033] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0034] As Figures 1-3 shown, a highway curved slope section vehicle operation risk evaluation method, comprising the following steps:

[0035] S1, calculating the lateral acceleration a of the vehicle when driving on the curved slope section 侧 , the formula for calculating a 侧 is:

[0036]

[0037] In the formula, v 运 represents the vehicle operating 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] represents the road horizontal curve curvature (unit: m -1 ), and R is the horizontal curve radius of the road (unit: m);

[0039] ρ represents the maximum trajectory curvature of the vehicle during lane changing on a straight section (unit: m -1 ), which varies with the vehicle operating speed, and the specific value can refer to Table 1.

[0040] Table 1: Reference value of p under different vehicle operating speeds

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

[0042] S2, calculating the friction coefficient μ required for the curved slope section road to provide for the vehicle to meet the lane changing 变道 , the formula for calculating μ 变道 is:

[0043]

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

[0045] S3, from the perspective of the friction circle, calculating the excess coefficient of adhesion of the curved slope section road in addition to the friction coefficient required for the vehicle to meet the lane changing

[0046] Specifically, the friction circle is a visualization 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, describing how the grip is distributed between longitudinal and lateral. When the vehicle is at the border of the friction circle, it has reached the performance limit of the tire.

[0047] In step S3, the maximum friction coefficient μ that the curved slope road can provide to the vehicle in addition to the friction coefficient required by the vehicle to meet the lane change is calculated from the friction circle max Then, based on μ max The excess adhesion coefficient of the road is calculated

[0048] The formula for calculating μ max is as follows:

[0049]

[0050] In the formula, μw represents the road wetness state road adhesion coefficient, generally taken as 0.4.

[0051] The formula for calculating μ is as follows:

[0052]

[0053] i 纵 represents the road longitudinal slope, positive for uphill and negative for downhill (unit: rad).

[0054] S4, based on the excess adhesion coefficient of the road The vehicle operation risk is evaluated, and the evaluation threshold is shown in Table 2

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

[0056]

[0057] As Figure 4 shown is a specific embodiment of the present scheme, taking the vehicle operation speed v 运 as 100 km / h, the road adhesion coefficient as 0.4, the radius R as 800 m road, the longitudinal slope i 纵 as -1.5%, and the superelevation i 超 as 3% of the curved slope road as an example. In this case, a high risk situation occurs, and the following measures should be considered for highway design or operation stage to improve driving safety.

[0058] Design stage: If the evaluation result shows high risk, the terrain and geological conditions can be considered comprehensively in the design stage to optimize and adjust the curve curvature, longitudinal slope and super-elevation design of the road to reduce the risk of vehicle operation.

[0059] Operation stage: If high-risk sections are found in actual operation, speed control measures can be taken or warning signs can be added in appropriate positions in front of dangerous sections to remind drivers to pay attention, thereby improving the safety level of vehicle driving.

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

[0061] (1) An evaluation method for vehicle operation risk on curved slope sections is proposed: the method comprehensively considers multiple factors such as vehicle speed, road surface adhesion coefficient, road longitudinal slope and super-elevation conditions, and is more practical for vehicle-road interaction scenarios. Compared with the prior art, the present application fills the gap in the evaluation method for vehicle operation risk on curved slope sections in the field of highway engineering safety evaluation, making the vehicle operation risk evaluation more scientific and accurate.

[0062] (2) Introducing the lateral acceleration influencing factor: the method not only considers traditional road geometric parameters, but also introduces the lateral acceleration factor when the vehicle changes lanes. This innovation makes the vehicle operation risk evaluation more comprehensive, and compared with the prior art, the present application has a significant advantage in evaluating the operation risk of vehicles during lane changing.

[0063] (3) Quantitative evaluation method of vehicle operation risk based on friction circle theory: based on the excess adhesion coefficient on curved slope roads, the present application provides a new quantitative evaluation method of vehicle operation risk from the level of friction circle. This method not only provides a scientific basis for road design and traffic safety management, but also helps to reduce traffic accidents and improve the safety level of mountainous highway operation. Through this evaluation method, the operation risk of curved slope key sections can be evaluated, which has strong engineering application value.

[0064] (4) Improve the rationality and safety of road geometric design: the systematic risk evaluation method provided by the present application can effectively guide the actual road design and reconstruction. Considering multiple influencing factors, the rationality of road geometric design is improved, thereby ensuring the driving safety of drivers on curved slope sections. The present application 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 the present application, the highway operation unit and the traffic safety management department can more scientifically and conveniently identify the high-risk curve and slope road section, so as to formulate more targeted safety management measures. This will greatly improve the effectiveness of traffic safety management and further protect the safe traffic of mountainous highways.

[0066] Although some embodiments of the present application have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present application, and all of these are within the protection scope of the claims of the present application.

Claims

1. A method for evaluating a risk of vehicle operation on a curved ramp section, characterized by, comprising the steps of: S1, calculating lateral acceleration of the vehicle when driving on a curved slope road section ; The formula for the calculation of the ​ In the formula, V represents the vehicle running speed (unit: m / s), which is calculated according to the JTG B05-2015 Highway Project Safety Evaluation Specification or selected according to the measured value; K represents the road horizontal curve curvature (unit: m -1 ), R represents the horizontal curve radius of the road (unit: m); Kmax represents the maximum trajectory curvature of the vehicle during lane changing on a straight road section (unit: m -1 ). S2, calculating the friction coefficient that the curved ramp road segment provides to the vehicle to meet the need of lane changing ; calculate The formula is: In the formula, represents the superelevation value (unit: rad) of the road curved ramp section. S3. From the perspective of the friction circle, calculate the excess coefficient of adhesion of the road on the curved ramp section that provides the road surplus to the vehicle to meet the required friction coefficient for lane changing ; calculate The formula is: In the formula, μ represents the road wet state road surface adhesion coefficient, generally 0.4; θ represents the road longitudinal slope, positive for uphill and negative for downhill (unit: rad); S4, based on the road excess adhesion coefficient evaluating the risk of vehicle operation; When <0.15, the vehicle operation risk is very high; when 0.15-0.25, the vehicle operation risk is high; When 0.25-0.35, the vehicle operation risk is general; when >0.35, the vehicle operation risk is low.

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