Cold region tunnel active safety prevention and control method and system considering multiple constraint conditions

Abstract

The invention discloses a cold region tunnel active safety prevention and control method and system considering multiple constraint conditions, relates to the technical field of traffic safety, and aims to solve the problems that in the prior art, the safety prevention and control effect is poor, and the driving risk is high when a vehicle drives out of a tunnel. The invention provides a cold region tunnel active safety prevention and control method and system considering multiple constraint conditions aiming at the characteristics of poor vehicle driving conditions and easy occurrence of traffic accidents, so that real-time sensing of a road driving environment outside a tunnel exit is realized, and vehicle guidance is carried out. The safety protection effect is good, and it is guaranteed that the vehicle can safely drive away from the tunnel.

Description

Technical Field

[0001] The present invention relates to the field of traffic safety technology, and in particular to a method and system for active safety prevention and control of tunnels in cold regions taking multiple constraints into consideration. Background Art

[0002] The structure of highway tunnels is special, and there are significant differences in driving conditions inside and outside. Traffic accidents are prone to occur at tunnel entrances and exits due to factors such as visibility, ice and snow on the road, and side winds.

[0003] Existing tunnel safety control systems mostly adopt single-factor, passive monitoring and early warning methods. However, due to the complex and changeable environment of highway tunnels in cold regions, the safety control effect of existing systems is poor, and the driving risk of vehicles when exiting tunnels is high. Summary of the invention

[0004] The purpose of the present invention is to provide an active safety control method and system for cold-region tunnels taking into account multiple constraints in order to address the problems of poor safety control effects in the prior art and high driving risks when vehicles exit tunnels.

[0005] The technical solution adopted by the present invention to solve the above technical problems is:

[0006] An active safety control method for cold region tunnels considering multiple constraints includes the following steps:

[0007] Step 1: Obtain tunnel exit visibility information, road ice and snow information, and lateral crosswind information;

[0008] Step 2: Determine the tunnel exit traffic control strategy using tunnel exit visibility information, road ice and snow information, and lateral crosswind information;

[0009] The tunnel exit traffic control strategy is expressed as:

[0010] v cx =min{v h ,v q ,v s}

[0011]

[0012] S=l r +l d +l s

[0013]

[0014] Where: v cx is the safe speed limit for vehicles passing through the tunnel exit, v his the critical speed at which the vehicle does not slip laterally under the action of lateral crosswind, ρ is the air density of the airflow, and v q is the critical speed at which the vehicle does not roll over laterally under the action of lateral crosswind, v s is the maximum safe speed, A is the projected area of ​​the windward surface of the car, C s is the aerodynamic lift coefficient, C c is the lateral aerodynamic coefficient, v wt To detect the crosswind speed, is the angle between the lateral crosswind direction and the vehicle's X-axis, α is the road inclination, m is the vehicle mass, g is the gravitational acceleration, h g is the height of the vehicle's center of mass, b is the vehicle's wheelbase, l r is the reaction distance, l d is the braking distance, l s is the minimum safety distance, t r is the reaction time, t a is the light adaptation time, S is the safe parking sight distance at the tunnel exit, μ v is the longitudinal adhesion coefficient, k Cc is the lateral coefficient, k Cs is the lift coefficient, μ h is the lateral adhesion coefficient, R is the curve radius;

[0015] Step 3: Guide vehicles according to the tunnel exit traffic control strategy.

[0016] Furthermore, the visibility information of the tunnel exit is obtained by a digital camera visibility meter, the ice and snow information of the road surface is obtained by an ice and snow status sensor, and the lateral crosswind information is obtained by an ultrasonic wind speed and direction meter.

[0017] Furthermore, the road ice and snow information includes icy road surface, ice and snow mixed road surface, compacted snow road surface, loose snow road surface and snow removal road surface.

[0018] Furthermore, the lateral crosswind information includes crosswind speed and crosswind direction.

[0019] Furthermore, the ice and snow state sensor is implemented based on FasterR-CNN.

[0020] An active safety prevention and control system for cold-region tunnels considering multiple constraints, the system comprising an information acquisition module, a traffic strategy module and a guidance module;

[0021] The information acquisition module is used to obtain tunnel exit visibility information, road ice and snow information, and lateral crosswind information;

[0022] The traffic strategy module is used to determine the tunnel exit traffic control strategy using tunnel exit visibility information, road ice and snow information, and lateral crosswind information;

[0023] The tunnel exit traffic control strategy is expressed as:

[0024] v cx =min{v h ,v q ,v s}

[0025]

[0026]

[0027] S=l r +l d +l s

[0028]

[0029] Where: v cx is the safe speed limit for vehicles passing through the tunnel exit, v h is the critical speed at which the vehicle does not slip laterally under the action of lateral crosswind, ρ is the air density of the airflow, and v q is the critical speed at which the vehicle does not roll over laterally under the action of lateral crosswind, v s is the maximum safe speed, A is the projected area of ​​the windward surface of the car, C s is the aerodynamic lift coefficient, C c is the lateral aerodynamic coefficient, v wt To detect the crosswind speed, is the angle between the lateral crosswind direction and the vehicle's X-axis, α is the road inclination, m is the vehicle mass, g is the gravitational acceleration, h g is the height of the vehicle's center of mass, b is the vehicle's wheelbase, l r is the reaction distance, l d is the braking distance, l s is the minimum safety distance, t r is the reaction time, t a is the light adaptation time, S is the safe parking sight distance at the tunnel exit, μ v is the longitudinal adhesion coefficient, k Cc is the lateral coefficient, k Cs is the lift coefficient, μ h is the lateral adhesion coefficient, R is the curve radius;

[0030] The guidance module is used to guide vehicles according to the tunnel exit traffic control strategy.

[0031] Furthermore, the visibility information of the tunnel exit is obtained by a digital camera visibility meter, the ice and snow information of the road surface is obtained by an ice and snow status sensor, and the lateral crosswind information is obtained by an ultrasonic wind speed and direction meter.

[0032] Furthermore, the road ice and snow information includes icy road surface, ice and snow mixed road surface, compacted snow road surface, loose snow road surface and snow removal road surface.

[0033] Furthermore, the lateral crosswind information includes crosswind speed and crosswind direction.

[0034] Furthermore, the ice and snow state sensor is implemented based on FasterR-CNN.

[0035] The beneficial effects of the present invention are:

[0036] In view of the poor driving conditions and the easy occurrence of traffic accidents at the exit of highway tunnels in cold regions due to factors such as visibility, ice and snow on the road surface, and lateral crosswinds, this application proposes an active safety prevention and control method and system for cold region tunnels that considers multiple constraints, which can achieve real-time perception of the road driving environment outside the tunnel exit and guide the vehicle. This application has a good safety protection effect and ensures that the vehicle can safely leave the tunnel. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is the workflow diagram of this application system;

[0038] Figure 2 This is the force analysis diagram of the vehicle under the influence of lateral crosswind;

[0039] Figure 3 This is the structure diagram of the Faster R-CNN model for detecting road ice and snow conditions. DETAILED DESCRIPTION

[0040] It should be particularly noted that, in the absence of conflict, the various embodiments disclosed in this application can be combined with each other.

[0041] Specific implementation method 1: The present implementation method provides an active safety control method for cold-region tunnels taking into account multiple constraints, including:

[0042] Step 1: Collect tunnel exit visibility information, road ice and snow information, and lateral crosswind information;

[0043] Step 2: Considering multiple constraints 3333, a speed control model is established for the exit of cold-region highway tunnels to determine the traffic control strategy for the tunnel exit;

[0044] Step 3: According to the tunnel exit traffic control strategy, vehicle guidance information is sent through variable message boards and tunnel traffic broadcasting.

[0045] In step 1, the visibility information of the tunnel exit is obtained by a digital camera visibility meter, the road ice and snow information is obtained by an ice and snow state sensor, and the lateral crosswind information is obtained by an ultrasonic wind speed and direction meter. The digital camera visibility meter, ice and snow state sensor and ultrasonic wind speed and direction meter are arranged at the tunnel entrance.

[0046] Furthermore, the road ice and snow information includes road ice and snow conditions, which are divided into five conditions: icy road surface, ice and snow mixed road surface, compacted snow road surface, loose snow road surface, and snow removal road surface; the lateral crosswind information includes crosswind speed and crosswind direction.

[0047] Furthermore, the ice and snow state sensor obtains the ice and snow conditions of the road surface by detecting the microscopic characteristics of ice and snow on the road surface through the Faster R-CNN method.

[0048] Furthermore, the Faster R-CNN includes four parts: feature extraction layer, RPN layer, ROI pooling layer and classification regression layer. The feature extraction layer uses the ResNet-18 network for feature extraction, the RPN layer generates and screens the candidate regions that are most likely to contain the target, the ROI pooling layer normalizes the feature sub-graphs of different sizes, and sends the feature sub-graphs of the same size to the subsequent fully connected layer for target classification and position adjustment. The classification regression layer determines the feature sub-graph category and regresses the bounding box to determine the precise shape and position of the candidate box. The ice and snow state sensor obtains the road surface image and inputs the image into the Faster R-CNN to obtain the output road surface ice and snow information.

[0049] The multiple constraints in step 2 include tunnel exit visibility conditions, road ice and snow conditions, and lateral crosswind conditions.

[0050] Furthermore, the process of establishing the exit speed control model of cold-region highway tunnels and formulating traffic control strategies considering multiple constraints is as follows:

[0051] Step 21: Establish the crosswind impact model:

[0052] According to automobile aerodynamics, when a vehicle is driving, it will be affected by the lateral crosswind of the road, and the vehicle will be affected by aerodynamic lift and lateral aerodynamic force, among which:

[0053] The calculation formula for aerodynamic lift is:

[0054] The calculation formula of lateral aerodynamic force is:

[0055] Where: ρ is the air density of the air flow, A is the projected area of ​​the windward surface of the car, C s is the aerodynamic lift coefficient, C cThe lateral aerodynamic coefficient, v t is the synthesis speed, Among them, v, v wt are the vehicle speed and the wind speed perpendicular to the windward side of the vehicle respectively; Among them, v wt To detect the crosswind speed, is the angle between the crosswind direction and the vehicle's X-axis, When the angle between wind direction and X-axis is less than 90°, it is positive; when it is greater than 90°, it is negative.

[0056] Table 1 Model parameter values ​​for different vehicle models

[0057]

[0058] Step 22: Establish a vehicle lateral slip force analysis model:

[0059] In order to prevent the vehicle from sliding laterally under the influence of lateral crosswind, the lateral force of the vehicle must be less than or equal to the lateral adhesion between the vehicle tires and the road surface, that is:

[0060] X≤Yμ h

[0061] Where: X is the force on the vehicle in the horizontal direction of the road, Y is the force on the vehicle in the vertical direction, μ h is the lateral adhesion coefficient.

[0062] From the vehicle force analysis diagram, we can see that X, Y and F are:

[0063] X=F c +Fcosα-mgsin

[0064] Y=mgcosα-F s +Fsinα

[0065]

[0066] Where: α is the road inclination angle, which is negative when the road is superelevated; F is the vehicle centrifugal force, which is positive when the angle between the F direction and the X-axis is less than 90° and negative when it is greater than 90°; m is the vehicle mass; and g is the acceleration due to gravity.

[0067] The critical speed v at which the vehicle does not slip laterally under the action of lateral crosswind is calculated. h for:

[0068]

[0069] Step 23: Establish a vehicle lateral rollover force analysis model:

[0070] In order to prevent the vehicle from rolling over laterally under the action of lateral crosswind, the vehicle rolling moment must be less than or equal to the vehicle stability moment, that is:

[0071] Xh g ≤Yb / 2

[0072] Where: h g is the height of the vehicle's center of mass, b is the vehicle's wheelbase, X is the force on the vehicle in the horizontal direction of the road, and Y is the force on the vehicle in the vertical direction.

[0073] From the vehicle force analysis diagram, we can see that X and Y are:

[0074] X=F c +Fcosα-mgsinα-μ h Y

[0075] Y=mgcosα-F s +Fsinα

[0076] The critical speed v at which the vehicle does not roll over laterally under the action of lateral crosswind is calculated. q for:

[0077]

[0078] Step 24: Establish a safe parking sight distance model for vehicles at tunnel exits under icy and snowy conditions:

[0079] The maximum safe driving speed of the vehicle is calculated based on the visibility at the tunnel exit section meeting the vehicle stopping sight distance. The safe stopping sight distance at the tunnel exit is:

[0080] S=l r +l d +l s

[0081] Where: l r is the reaction distance, l d is the braking distance, l s is the minimum safety distance, take l s 5m. r , l d They are:

[0082]

[0083] Where: v s is the maximum safe speed, t r is the reaction time, take t r 2.5s, t a is the light adaptation time, taken as t a =3s, μ v is the longitudinal adhesion coefficient.

[0084] The maximum safe speed v can be obtained from the formula s for:

[0085]

[0086] The road adhesion coefficients under different road conditions of ice and snow are shown in Table 2:

[0087] Table 2 Road adhesion coefficient

[0088]

[0089] The road adhesion coefficient is divided into the lateral adhesion coefficient and the longitudinal adhesion coefficient, where μ h =0.6μ,μ v =0.8μ.

[0090] Step 25: Determine the tunnel exit traffic control strategy:

[0091] According to the model analysis and calculation of step 22, step 23 and step 24, the vehicle speed limit values ​​under different driving conditions are obtained. In order to ensure that the vehicle can safely drive out of the tunnel entrance and maintain safe driving conditions, let:

[0092] v cx =min{v h ,v q ,v s}

[0093] Where: v cx It is the safe speed limit for vehicles passing through the tunnel exit.

[0094] Furthermore, since the model parameter values ​​of small cars and large cars are different, the safe speed limit values ​​of small cars and large cars passing through the tunnel exit should be calculated separately.

[0095] The guidance information sent to the driver in step 3 is divided into two situations:

[0096] (1) When the vehicle's safe speed limit is less than the minimum safe speed limit

[0097] When the road conditions outside the tunnel are no longer suitable for driving, for vehicles in the tunnel, a danger warning message is sent to the driver through the variable message board installed in the tunnel and the tunnel traffic broadcast, reminding the driver to slow down. For vehicles not entering the tunnel, a danger warning message is sent to the driver through the variable message board installed outside the tunnel entrance, reminding the driver to slow down.

[0098] Furthermore, when the vehicle safety speed limit value is less than the minimum safety speed limit, abnormal event information should be sent to the road management department.

[0099] (2) When the vehicle's safe speed limit is greater than the minimum safe speed limit

[0100] The speed limit information is sent to the driver through the variable information board set up inside the tunnel. The speed limit information includes the safe speed limit value for small vehicles and the safe speed limit value for large vehicles;

[0101] Furthermore, the minimum safe speed limit in step 3 refers to the safe speed limit when the road condition is no longer suitable for vehicles to pass;

[0102] Furthermore, in step three, to ensure that drivers outside the tunnel and drivers inside the tunnel can react promptly and slow down after observing the warning information, the distance between the variable information board and the tunnel entrance and tunnel exit should be no less than 160m.

[0103] The present application also includes an active safety control system for cold-region tunnels that takes into account multiple constraints, and the system includes an information collection subsystem, an information processing subsystem, and an information release subsystem.

[0104] The information collection subsystem is used to collect tunnel exit visibility information, road ice and snow information, and lateral crosswind information;

[0105] In the step 1, the visibility information of the tunnel exit is obtained by a digital camera visibility meter, the road ice and snow information is obtained by an ice and snow state sensor, and the lateral crosswind information is obtained by an ultrasonic wind speed and direction meter;

[0106] Further, the road ice and snow information includes road ice and snow conditions, which are divided into five conditions: icy road, ice and snow mixed road, compacted snow road, loose snow road, and snow removal road; the lateral crosswind information includes crosswind speed and crosswind direction;

[0107] Furthermore, the ice and snow state sensor obtains the road ice and snow state by detecting the road ice and snow through the Faster R-CNN method;

[0108] Furthermore, the Faster R-CNN includes four parts: feature extraction layer, RPN layer, ROI pooling layer and classification regression layer. The feature extraction layer uses the ResNet-18 network for feature extraction; the RPN layer generates and screens the candidate regions that are most likely to contain the target; the ROI pooling layer normalizes the feature sub-graphs of different sizes, and sends the feature sub-graphs of the same size to the subsequent fully connected layer for target classification and position adjustment; the classification regression layer determines the feature sub-graph category, and regresses the bounding box to determine the precise shape and position of the candidate box.

[0109] The information processing subsystem is used to receive the tunnel exit visibility information, road ice and snow information and lateral crosswind information sent by the information collection subsystem, establish a cold zone highway tunnel exit speed control model under multiple constraints, and determine the tunnel exit traffic control strategy;

[0110] Furthermore, the cold region highway tunnel exit speed control model under multiple constraints includes a lateral crosswind influence model, a vehicle lateral sliding force analysis model, a vehicle lateral overturning force analysis model and a tunnel exit safe parking sight distance model under vehicle road conditions of ice and snow;

[0111] Furthermore, the lateral crosswind impact model is:

[0112] According to automobile aerodynamics, when a vehicle is driving, it will be affected by the lateral crosswind of the road, and the vehicle will be affected by aerodynamic lift and lateral aerodynamic force, among which:

[0113] The calculation formula for aerodynamic lift is:

[0114] The calculation formula of lateral aerodynamic force is:

[0115] Where: ρ is the air density of the air flow, A is the projected area of ​​the windward surface of the car, C s is the aerodynamic lift coefficient, C c The lateral aerodynamic coefficient, v t is the synthesis speed, Among them, v, v wt are the vehicle speed and the wind speed perpendicular to the windward side of the vehicle respectively; Among them, v wt To detect the crosswind speed, is the angle between the crosswind direction and the vehicle's X-axis, When the angle between wind direction and X-axis is less than 90°, it is positive; when it is greater than 90°, it is negative.

[0116] Furthermore, the vehicle lateral slip force analysis model is:

[0117] In order to prevent the vehicle from sliding laterally under the influence of lateral crosswind, the lateral force of the vehicle must be less than or equal to the lateral adhesion between the vehicle tires and the road surface, that is:

[0118] X≤Yμ h

[0119] Where: X is the force on the vehicle in the horizontal direction of the road, Y is the force on the vehicle in the vertical direction, μ h is the lateral adhesion coefficient, μ h =0.6μ.

[0120] From the vehicle force analysis diagram, we can see that X, Y and F are:

[0121] X=F c +Fcosα-mgsinα

[0122] Y=mgcosα-F s +Fsinα

[0123]

[0124] Where: α is the road inclination angle, which is negative when the road is superelevated; F is the vehicle centrifugal force, which is positive when the angle between the F direction and the X-axis is less than 90° and negative when it is greater than 90°; m is the vehicle mass; and g is the acceleration due to gravity.

[0125] The critical speed v at which the vehicle does not slip laterally under the action of lateral crosswind is calculated. h for:

[0126]

[0127] Furthermore, the vehicle lateral rollover force analysis model is:

[0128] In order to prevent the vehicle from rolling over laterally under the action of lateral crosswind, the vehicle rolling moment must be less than or equal to the vehicle stability moment, that is:

[0129] Xh g ≤Yb / 2

[0130] Where: h g is the height of the vehicle's center of mass, b is the vehicle's wheelbase, X is the force on the vehicle in the horizontal direction of the road, and Y is the force on the vehicle in the vertical direction.

[0131] From the vehicle force analysis diagram, we can see that X and Y are:

[0132] X=F c +Fcosα-mgsinα-μ h Y

[0133] Y=mgcosα-F s +Fsinα

[0134] The critical speed v at which the vehicle does not roll over laterally under the action of lateral crosswind is calculated. q for:

[0135]

[0136] Furthermore, the vehicle lateral rollover force analysis model is:

[0137] The maximum safe driving speed of the vehicle is calculated based on the visibility at the tunnel exit section meeting the vehicle stopping sight distance. The safe stopping sight distance at the tunnel exit is:

[0138] S=l r +l d +ls

[0139] Where: l r is the reaction distance, l d is the braking distance, l s is the minimum safety distance, take l s 5m. r , l d They are:

[0140]

[0141] Where: v s is the maximum safe speed, t r is the reaction time, take t r 2.5s, t a is the light adaptation time, taken as t a 3s, μ v is the longitudinal adhesion coefficient, μ v =0.8μ.

[0142] The maximum safe speed v can be obtained from the formula s for:

[0143]

[0144] Furthermore, the tunnel exit traffic control strategy is determined as follows:

[0145] According to the cold region highway tunnel exit speed control model under multiple constraints, the vehicle speed limit under different driving conditions is obtained. In order to ensure that the vehicle can safely exit the tunnel entrance and maintain safe driving conditions,

[0146] v cx =min{v h ,v q ,v s}

[0147] Where: v cx It is the safe speed limit for vehicles passing through the tunnel exit.

[0148] Furthermore, since the model parameter values ​​of small cars and large cars are different, the safe speed limit values ​​of small cars and large cars passing through the tunnel exit should be calculated separately.

[0149] The information release subsystem is used to receive the tunnel exit traffic control strategy sent by the information processing subsystem, and send vehicle guidance information through the variable message board and tunnel traffic broadcasting.

[0150] Furthermore, the induction information sent to the driver is divided into two situations:

[0151] (1) When the vehicle's safe speed limit is less than the minimum safe speed limit

[0152] When the road conditions outside the tunnel are no longer suitable for driving, for vehicles in the tunnel, a danger warning message is sent to the driver through the variable message board installed in the tunnel and the tunnel traffic broadcast, reminding the driver to slow down. For vehicles not entering the tunnel, a danger warning message is sent to the driver through the variable message board installed outside the tunnel entrance, reminding the driver to slow down.

[0153] Furthermore, when the vehicle safety speed limit value is less than the minimum safety speed limit, abnormal event information should be sent to the road management department.

[0154] (2) When the vehicle's safe speed limit is greater than the minimum safe speed limit

[0155] The speed limit information is sent to the driver through the variable information board set up inside the tunnel. The speed limit information includes the safe speed limit value for small vehicles and the safe speed limit value for large vehicles;

[0156] Furthermore, the minimum safe speed limit in step 3 refers to the safe speed limit when the road condition is no longer suitable for vehicles to pass;

[0157] Furthermore, in step three, to ensure that drivers outside the tunnel and drivers inside the tunnel can react promptly and slow down after observing the warning information, the distance between the variable information board and the tunnel entrance and tunnel exit should be no less than 160m.

[0158] Example:

[0159] Assume that the cold zone expressway tunnel is 1140m long, with a design speed of 80km / h. The tunnel exit is connected to a curved section with a circular curve radius of 2500m. The road is set to superelevate by 3%. The digital camera visibility meter measures that the driver's visibility outside the tunnel is 190m. The ice and snow state sensor measures that the road surface ice and snow state is loose snow road surface. At this time, the road surface adhesion coefficient μ=0.21. The ultrasonic wind speed and direction meter measures that the lateral crosswind of the road surface is from right to left along the vehicle's driving direction, and the angle with the X-axis is is 10°.

[0160] The critical speed v at which a small car does not slip lateraly under the action of lateral crosswind is calculated by the vehicle lateral slip force analysis model. h The critical speed v without lateral overturning is 59 km / h. q The critical speed v at which a large vehicle does not slip laterally under the influence of lateral crosswind is 57 km / h. h The critical speed v without lateral overturning is 55 km / h. q The maximum safe driving speed v of small and large vehicles that meet the vehicle stopping sight distance under icy and snowy conditions is 52 km / h. s=64km / h. Therefore, the current speed limit information on the variable information board in the tunnel is 55km / h for small vehicles and 50km / h for large vehicles.

[0161] It should be noted that the specific implementation is only an explanation and description of the technical solution of the present invention, and cannot be used to limit the scope of protection of the rights. Any partial changes made according to the claims and description of the present invention should still fall within the scope of protection of the present invention.

Claims

1. An active safety control method for cold-region tunnels considering multiple constraints, characterized in that The following steps are involved: Step 1: Obtain tunnel exit visibility information, road ice and snow information, and lateral crosswind information; Step 2: Determine the tunnel exit traffic control strategy using tunnel exit visibility information, road ice and snow information, and lateral crosswind information; The tunnel exit traffic control strategy is expressed as: v cx =min{v h ,v q ,v s } S＝l r +l d +l s Where: v cx is the safe speed limit for vehicles passing through the tunnel exit, v h is the critical speed at which the vehicle does not slip laterally under the action of lateral crosswind, ρ is the air density of the airflow, and v q is the critical speed at which the vehicle does not roll over laterally under the action of lateral crosswind, v s is the maximum safe speed, A is the projected area of ​​the windward surface of the car, C s is the aerodynamic lift coefficient, C c is the lateral aerodynamic coefficient, v wt To detect the crosswind speed, is the angle between the lateral crosswind direction and the vehicle's X-axis, α is the road inclination, m is the vehicle mass, g is the gravitational acceleration, h g is the height of the vehicle's center of mass, b is the vehicle's wheelbase, l r is the reaction distance, l d is the braking distance, l s is the minimum safety distance, t r is the reaction time, t a is the light adaptation time, S is the safe parking sight distance at the tunnel exit, μ v is the longitudinal adhesion coefficient, k Cc is the lateral coefficient, k Cs is the lift coefficient, μ h is the lateral adhesion coefficient, R is the curve radius; Step 3: Guide vehicles according to the tunnel exit traffic control strategy.

2. According to claim 1, a cold region tunnel active safety control method considering multiple constraints is characterized in that The tunnel exit visibility information is obtained through a digital camera visibility meter, the road ice and snow information is obtained through an ice and snow state sensor, and the lateral crosswind information is obtained through an ultrasonic wind speed and direction meter.

3. According to claim 1, a cold region tunnel active safety control method considering multiple constraints is characterized in that The road ice and snow information includes icy road surface, ice and snow mixed road surface, compacted snow road surface, loose snow road surface and snow removal road surface.

4. According to claim 1, a cold region tunnel active safety control method considering multiple constraints is characterized in that The lateral crosswind information includes the crosswind speed and the crosswind direction.

5. According to claim 2, a cold region tunnel active safety control method considering multiple constraints is characterized in that The ice and snow state sensor is implemented based on Faster R-CNN.

6. An active safety control system for cold-region tunnels considering multiple constraints, characterized by The system includes an information acquisition module, a traffic strategy module and a guidance module; The information acquisition module is used to obtain tunnel exit visibility information, road ice and snow information, and lateral crosswind information; The traffic strategy module is used to determine the tunnel exit traffic control strategy using tunnel exit visibility information, road ice and snow information, and lateral crosswind information; The tunnel exit traffic control strategy is expressed as: v cx =min{v h ,v q ,v s } S＝l r +l d +l s Where: v cx is the safe speed limit for vehicles passing through the tunnel exit, v h is the critical speed at which the vehicle does not slip laterally under the action of lateral crosswind, ρ is the air density of the airflow, and v q is the critical speed at which the vehicle does not roll over laterally under the action of lateral crosswind, v s is the maximum safe speed, A is the projected area of ​​the windward surface of the car, C s is the aerodynamic lift coefficient, C c is the lateral aerodynamic coefficient, v wt To detect the crosswind speed, is the angle between the lateral crosswind direction and the vehicle's X-axis, α is the road inclination, m is the vehicle mass, g is the gravitational acceleration, h g is the height of the vehicle's center of mass, b is the vehicle's wheelbase, l r is the reaction distance, l d is the braking distance, l s is the minimum safety distance, t r is the reaction time, t a is the light adaptation time, S is the safe parking sight distance at the tunnel exit, μ v is the longitudinal adhesion coefficient, k Cc is the lateral coefficient, k Cs is the lift coefficient, μ h is the lateral adhesion coefficient, R is the curve radius; The guidance module is used to guide vehicles according to the tunnel exit traffic control strategy.

7. The active safety control system for cold-region tunnels considering multiple constraints according to claim 6 is characterized in that The tunnel exit visibility information is obtained through a digital camera visibility meter, the road ice and snow information is obtained through an ice and snow state sensor, and the lateral crosswind information is obtained through an ultrasonic wind speed and direction meter.

8. The active safety control system for cold-region tunnels considering multiple constraints according to claim 6 is characterized in that The road ice and snow information includes icy road surface, ice and snow mixed road surface, compacted snow road surface, loose snow road surface and snow removal road surface.

9. The active safety control system for cold-region tunnels considering multiple constraints according to claim 6 is characterized in that The lateral crosswind information includes the crosswind speed and the crosswind direction.

10. The active safety control system for cold-region tunnels considering multiple constraints according to claim 7 is characterized in that The ice and snow state sensor is implemented based on FasterR-CNN.

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