Highway tunnel traffic operation environment safety evaluation method and system

Abstract

The invention relates to the technical field of traffic operation environment evaluation, in particular to a highway tunnel traffic operation environment safety evaluation method and system, and the method comprises the following steps: obtaining the basic data, vehicle position, vehicle speed, physical load, vehicle type and vehicle density of a target single-lane highway tunnel; according to the traffic operation data, obtaining a global optimal vehicle-following position and a global optimal vehicle-following speed of the vehicle, and further calculating a single vehicle risk and a global traffic risk; and a dynamic digital twinborn model of the target single-lane highway tunnel is constructed, and then a risk evaluation result is visually displayed. According to the method, the safety of the traffic environment of the single-lane highway tunnel can be well evaluated under the condition that an evaluation index system is not constructed, the refinement and intelligence level of highway tunnel safety management can be improved, and safe and efficient operation of tunnel traffic is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of traffic operation environment evaluation, and particularly to a safety evaluation method and system for the traffic operation environment of highway tunnels. Background Art

[0002] Highway single-lane tunnels have a unique traffic operation environment. Once a vehicle breakdown or driver operation error occurs in the tunnel, it is easy to trigger chain reactions such as rear-end collisions and crashes, resulting in serious traffic accidents. Therefore, accurately evaluating the safety of the traffic operation environment of highway tunnels is of great significance for ensuring the safety, smoothness, and efficient operation of tunnel traffic.

[0003] Currently, in the field of highway traffic safety evaluation, there are already some relatively mature evaluation methods, but there are still some problems. On the one hand, the existing evaluation methods are mainly designed for the open sections of highways, and there are relatively few traffic operation environment safety evaluation methods specifically for highway tunnels, especially for specific types of highway tunnels. On the other hand, most of the existing traffic environment safety evaluations are highway traffic safety level evaluations based on an evaluation index system and index weights. It requires a large amount of manpower, material resources, and time to construct the evaluation index system, and the determination of index weights often relies on the experience and subjective judgment of experts. Moreover, once the evaluation index system and index weights are determined, they often remain unchanged within a certain period, making it difficult to adapt to the dynamic changes of the traffic environment.

[0004] Therefore, it is necessary to explore a new evaluation method for the traffic environment safety of highway tunnels to provide more options and references for the traffic environment safety evaluation of highway tunnels. Summary of the Invention

[0005] Aiming at the defects in the prior art, the present invention provides a safety evaluation method and system for the traffic operation environment of highway tunnels.

[0006] To achieve the above object, in a first aspect, the present invention provides a method for evaluating the safety of the traffic operation environment of a highway tunnel. The method includes the following steps: obtaining the basic data and traffic operation data of the target single-lane highway tunnel, where the traffic operation data includes vehicle position, vehicle speed, physical load, vehicle type, and vehicle density; obtaining the global optimal following position and global optimal following speed of each vehicle in the target single-lane highway tunnel according to the traffic operation data; calculating the single-vehicle risk and global traffic risk based on the traffic operation data, the global optimal following position, and the global optimal following speed; using the basic data and the traffic operation data to construct a dynamic digital twin model of the target single-lane highway tunnel, and then visually displaying the risk evaluation result. The present invention can better evaluate the safety of the traffic environment of a single-lane highway tunnel without constructing an evaluation index system, which is beneficial to improving the refinement and intelligent level of highway tunnel safety management and ensuring the safe and efficient operation of tunnel traffic.

[0007] Optionally, the step of obtaining the global optimal following position and global optimal following speed of each vehicle in the target single-lane highway tunnel according to the traffic operation data includes the following steps: Obtain a reference value for the following distance; After obtaining the reference value for the following distance, with the goal of balancing traffic safety and traffic efficiency, obtain the global optimal following distance and global optimal following speed of the vehicle under constraint conditions; Adjust the vehicle position of the following vehicle in two adjacent vehicles according to the global optimal following distance to obtain the global optimal following position of the following vehicle in two adjacent vehicles.

[0008] Based on obtaining the reference value for the following distance, this method obtains the global optimal following position and speed under constraint conditions with the goal of balancing traffic safety and traffic efficiency, which is beneficial to improving the accuracy of the safety evaluation of the traffic environment of a single-lane highway tunnel.

[0009] Optionally, the step of obtaining the reference value for the following distance includes the following steps: Determine the lighting conditions at the vehicle's location; Improve the safety distance formula in the intelligent driving model according to the lighting conditions, and then calculate the reference value for the following distance.

[0010] The reference value for the following distance of this method further considers vehicle type and lighting factors in the tunnel on the basis of considering vehicle speed, driver reaction time, acceleration, and deceleration, thereby improving the accuracy and reliability of the reference value for the following distance and providing a data basis for accurately evaluating the global optimal following position and global optimal following speed of vehicles in a single-lane highway tunnel.

[0011] Optionally, the constraint conditions include lane speed limits and braking distance constraints.

[0012] Optionally, after obtaining the reference following distance value, with the goal of balancing traffic safety and traffic efficiency, obtaining the global optimal following distance and global optimal following speed of the vehicle under the constraint conditions includes the following steps: After obtaining the reference following distance value, set a state balance equation with the goal of balancing traffic safety and traffic efficiency, which is used to calculate the global risk state score; Respectively calculate the partial derivatives of the global risk state score with respect to the following distance and vehicle speed, and then update the following distance and vehicle speed by the gradient descent method under the constraint conditions: Substitute the updated following distance and vehicle speed into the state balance equation to calculate the global risk state score, and output the global optimal following distance and the global optimal following speed when the maximum number of iterations is reached or the convergence condition is satisfied.

[0013] This method aims to balance traffic safety and traffic efficiency, and obtains the global optimal following distance and speed under the constraint conditions of lane speed limits and braking distances. It not only considers the safety of driving in the tunnel, but also takes into account the traffic efficiency, making the evaluation result more practically guiding. Further, this method sets a state balance equation, uses the gradient descent method to update the following distance and vehicle speed, and outputs the global optimal following distance and speed when the maximum number of iterations is reached or the convergence condition is satisfied, improving the accuracy and reliability of the calculation of the global optimal following distance and speed, and being conducive to improving the intelligent level of the traffic environment safety evaluation of single-lane highway tunnels.

[0014] Optionally, after obtaining the reference following distance value, setting a state balance equation with the goal of balancing traffic safety and traffic efficiency, which is used to calculate the global risk state score includes the following steps: Set a traffic safety term according to the following distance of the vehicle and the reference following distance value, and set a traffic efficiency term according to the vehicle speed and the expected vehicle speed; Set the weights of the traffic safety term and the traffic efficiency term according to the vehicle density and the critical vehicle density, and then use the weighted sum of the traffic safety term and the traffic efficiency term as the state balance equation, which is used to calculate the global risk state score.

[0015] The state balance equation of this method includes a traffic safety term set according to the vehicle-to-vehicle distance and a traffic efficiency term set according to the vehicle speed, which can not only ensure that the vehicle spacing always meets the braking distance constraint, but also avoid the decline of tunnel traffic efficiency caused by the vehicle being overly conservative.

[0016] Optionally, calculating the single-vehicle risk and the global traffic risk based on the traffic operation data, the global optimal following position, and the global optimal following speed includes the following steps: Set a distance deviation term according to the actual following distance of the vehicle and the global optimal following distance, and at the same time set a speed deviation term according to the actual vehicle speed of the vehicle and the global optimal following speed, and use the weighted sum of the distance deviation term and the speed deviation term as the single-vehicle risk; Calculate the average single-vehicle risk as the single-vehicle risk term, and at the same time set a density risk term using the vehicle density and the critical vehicle density, and use the weighted sum of the single-vehicle risk term and the density risk term as the global traffic risk.

[0017] This method calculates the single-vehicle risk and the global traffic risk based on the traffic operation data, the global optimal following position, and the global optimal following speed, which can not only provide an important decision-making basis for tunnel traffic safety management, but also avoid constructing a complex evaluation index system, making the traffic safety evaluation of highway tunnels more convenient.

[0018] Optionally, using the basic data and the traffic operation data to construct a dynamic digital twin model of the target single-lane highway tunnel, and then visually displaying the risk evaluation results includes the following steps: Use the basic data and the traffic operation data to construct a dynamic digital twin model of the target single-lane highway tunnel; Mark the single-vehicle risk and the global traffic risk on the dynamic digital twin model of the target highway tunnel, and then visually display the risk evaluation results.

[0019] This method realizes the visual display of the risk evaluation results by constructing a dynamic digital twin model of the target single-lane highway tunnel and marking the single-vehicle risk and the global traffic risk on the model, enabling managers to understand the traffic safety status in the tunnel in real time and intuitively.

[0020] Optionally, using the basic data and the traffic operation data to construct a dynamic digital twin model of the target single-lane highway tunnel, and then visually displaying the risk evaluation results further includes the following steps: Set a single-vehicle risk threshold and a global traffic risk threshold; Trigger a global warning when the global traffic risk exceeds the global traffic risk threshold; Trigger a single-vehicle warning when the single-vehicle risk exceeds the single-vehicle risk safety threshold.

[0021] This method forms a multi-level early warning mechanism by setting a bicycle risk threshold, a global traffic risk threshold, and a bicycle risk safety threshold, which can timely remind the management personnel to pay attention to the traffic safety status in the tunnel and quickly locate the problem vehicles.

[0022] In a second aspect, the present invention provides a safety evaluation system for the traffic operation environment of a highway tunnel. The safety evaluation system for the traffic operation environment of a highway tunnel includes: a data collection device, a data output device, a processor, and a storage. The storage includes a computer-readable storage medium, and a computer program is stored in the computer-readable storage medium. The computer program includes program instructions, and when the program instructions are executed by the processor, the processor implements the safety evaluation method for the traffic operation environment of a highway tunnel provided by the present invention. This system can improve the efficiency of the safety evaluation of the traffic operation environment of a highway tunnel, and can improve the practicability of this method, facilitating the popularization of this method. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0024] Figure 1 It is a schematic flow chart of a safety evaluation method for the traffic operation environment of a highway tunnel according to an embodiment of the present invention; Figure 2 It is a schematic framework diagram of a safety evaluation system for the traffic operation environment of a highway tunnel according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The specific embodiments of the present invention will be described in detail below. It should be noted that the embodiments described here are only for illustrative purposes and do not limit the present invention. In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present invention. However, it is obvious to those of ordinary skill in the art that the present invention does not have to be implemented with these specific details. In other instances, well-known circuits, software, or methods have not been specifically described to avoid obscuring the present invention.

[0026] Throughout the specification, references to "an embodiment", "embodiments", "an example", or "examples" mean that a particular feature, structure, or characteristic described in connection with the embodiment or example is included in at least one embodiment of the present invention. Thus, the phrases "in an embodiment", "in embodiments", "an example", or "examples" that appear throughout the specification do not necessarily all refer to the same embodiment or example. In addition, the particular features, structures, or characteristics may be combined in any suitable combination and / or sub-combination in one or more embodiments or examples. Further, those of ordinary skill in the art should understand that the diagrams provided herein are for illustrative purposes only and are not necessarily drawn to scale.

[0027] It should be noted in advance that in an optional embodiment, except for independent descriptions, the same symbols or letters appearing in all formulas have the same meanings and numerical values.

[0028] In an optional embodiment, please refer to Figure 1 , the present invention provides a method for evaluating the safety of the traffic operation environment of a highway tunnel, and the method includes the following steps: S1. Obtain the basic data and traffic operation data of the target single-lane highway tunnel, where the traffic operation data includes vehicle position, vehicle speed, physical load, vehicle type, and vehicle density.

[0029] Specifically, in this embodiment, the target single-lane highway tunnel is hereinafter simply referred to as the tunnel, and its basic data includes geometric structure data, geological condition data, structural health data, and tunnel environment data, etc. The geometric structure data includes, but is not limited to, design parameters such as tunnel cross-section dimensions, slope, curvature, and lining type, thickness, and support structure layout; the geological condition data includes, but is not limited to, data such as rock and soil type, surrounding rock grade, and groundwater distribution; the structural health data includes, but is not limited to, data such as lining cracks, water seepage, and support structure stress; the tunnel environment data mainly refers to the light condition data at different monitoring points in the tunnel and is reflected by the visibility collected by the tunnel visibility detection sensor. The acquisition means of the basic data of the highway tunnel are all existing technical means.

[0030] Furthermore, in this embodiment, the physical load of the vehicle includes the real-time physical load of the vehicle and the empty vehicle mass. The traffic operation data is obtained through the bending plate sensors arranged on the road surface at the tunnel entrance and the high-definition cameras arranged in the tunnel. The general process is as follows: Measure the real-time physical load of the vehicle through the bending plate sensors arranged on the road surface at the tunnel entrance; Collect images of different types of vehicles and annotate the vehicle types, including vehicle brands and models. Then use the annotated images to build a data set to complete the training and verification of the YOLOv8 algorithm. Then use the YOLOv8 algorithm to complete vehicle detection and obtain vehicle types on the images obtained by the high-definition camera. After identifying the vehicle, calculate the number of vehicles per kilometer in the tunnel to obtain the vehicle density. By collecting and integrating information from sources such as announcement data, measured data, industry white papers, manufacturer databases, third-party APIs, etc. of different types of vehicles on the Internet, a database is established that contains parameters such as the weight, maximum acceleration, and comfortable deceleration of different types of vehicles when unloaded. Then, when the vehicle type is identified, its unloaded mass and maximum acceleration and comfortable deceleration when unloaded can be obtained.

[0031] After the vehicle is detected, the homography matrix is ​​obtained through camera calibration, and the pixel coordinates of the vehicle detection frame are mapped to the world coordinate system to obtain the vehicle position, including the front and rear positions; Use target tracking algorithms such as SORT (Simple Online and Realtime Tracking) or DeepSORT to track detected vehicles across frames, obtain the unique ID and motion trajectory of each vehicle, and estimate the actual driving speed of the vehicle, i.e., vehicle speed, by calculating the trajectory length of the vehicle between two adjacent frames and combining it with the time interval between frames.

[0032] The methods for acquiring traffic operation data are all existing technical means, so they will not be described in detail here.

[0033] S2. Obtaining a global optimal following position and a global optimal following speed of each vehicle in the target single-lane highway tunnel according to the traffic operation data.

[0034] Wherein, step S2 specifically includes the following steps: S21. Obtain a following vehicle distance reference value.

[0035] Wherein, step S21 specifically includes the following steps: S211. Determine the light condition at the location of the vehicle.

[0036] S212: improving the safety distance formula in the intelligent driving model according to the light conditions, and then calculating a following distance reference value.

[0037] Specifically, in this embodiment, the mutual influence between adjacent lanes does not need to be considered in a single-lane highway tunnel. Therefore, this embodiment improves the safety distance formula in the intelligent driving model based on the light conditions and vehicle types in the tunnel to calculate the following distance reference value of each vehicle. The following distance reference value satisfies the following relationship:

[0038] Among them, is the following-distance reference value for the vehicle, is the standard visibility, is the measured visibility at the position where the vehicle is located, is the static safety distance, is the vehicle speed, is the driver's reaction time, is the speed difference between the vehicle and the vehicle in front in the same lane, is the maximum acceleration of the vehicle, is the comfortable deceleration of the vehicle, and are both related to the physical load.

[0039] More specifically, the static safety distance is taken as 2m. The non-rainy day standard visibility is taken as 150m, and the rainy day standard visibility is taken as 100m. The standard visibility needs to be automatically switched according to the environmental conditions monitored by the environmental sensors outside the tunnel. The driver's reaction time is taken as 1.5s. If the vehicle is the leading vehicle, then 、 and are both taken as 0.

[0040] This embodiment calculates the following-distance reference value based on the intelligent driving model and the light conditions at the position where the vehicle is located, considering the influence of the complex and changeable light environment in the tunnel on the following distance, making the calculated following-distance reference value more in line with the actual situation, helping to improve the accuracy of the subsequent global optimal following position and speed, and further being beneficial to improving the accuracy of the traffic environment safety evaluation of the single-lane highway tunnel.

[0041] Furthermore, when calculating the following-distance reference value, the empirical coefficient method is used to quickly determine the final values of the maximum acceleration and the comfortable deceleration, that is:

[0042]

[0043] Among them, is the maximum acceleration of the vehicle under no-load, is the comfortable deceleration of the vehicle under no-load, is the no-load mass of the vehicle, is the real-time physical load of the vehicle.

[0044] S22. After obtaining the following-distance reference value, with the goal of balancing traffic safety and traffic efficiency, the global optimal following distance and the global optimal following speed of the vehicle are obtained under the constraint conditions.

[0045] The reference value of the following-distance is actually an ideal following state of the rear vehicle with respect to the front vehicle. However, driving directly according to the reference value of the following-distance will ignore the distribution of vehicles and the traffic flow conditions within the entire tunnel, which may lead to traffic congestion or unsmooth local traffic flow in some cases, thereby bringing potential safety hazards and affecting the overall traffic efficiency of the tunnel. Therefore, after obtaining the reference value of the following-distance for each vehicle, it is also necessary to aim at balancing traffic safety and traffic efficiency, and obtain the global optimal following-distance and global optimal following-speed of the vehicle that conform to the distribution of vehicles and the traffic flow conditions within the tunnel under the constraint conditions.

[0046] Step S22 specifically includes the following steps: S221. After obtaining the reference value of the following-distance, set a state balance equation with the goal of balancing traffic safety and traffic efficiency, which is used to calculate the global risk state score.

[0047] Among them, step S221 specifically includes the following steps: S2211. Set the traffic safety item according to the following-distance of the vehicle and the reference value of the following-distance, and set the traffic efficiency item according to the vehicle speed and the expected vehicle speed.

[0048] Specifically, in this embodiment, the traffic safety item can be expressed as , and the traffic efficiency item can be expressed as . N is the total number of vehicles, is the following-distance of the i-th vehicle, is the reference value of the following-distance of the i-th vehicle, is the vehicle speed of the i-th vehicle, is the expected vehicle speed.

[0049] S2212. Set the weights of the traffic safety item and the traffic efficiency item according to the vehicle density and the critical vehicle density, and then use the weighted sum of the traffic safety item and the traffic efficiency item as the state balance equation, which is used to calculate the global risk state score.

[0050] Specifically, in this embodiment, the weights of the traffic safety item and the traffic efficiency item are successively represented by and respectively. The weight of the traffic safety item and the state balance equation respectively satisfy the following relationships:

[0051]

[0052] Among them, Q is the global risk state score, is the vehicle density, is the critical vehicle density. , is the maximum speed limit of the lane, is the minimum speed limit of the lane. It needs to be set by comprehensively considering factors such as the length of the tunnel, the designed traffic capacity, the traffic flow, and the common vehicle types passing through, and there is no fixed value. It should be noted that when i = 1, .

[0053] More specifically, in the state balance equation, the following-distance is the length of the center line of the road surface between two adjacent vehicles. Specifically, for a given pair of adjacent vehicles, the following-distance of the rear vehicle refers to the actual length of the center line of the road surface between the rear of the front vehicle and the front of the rear vehicle, which is obtained by numerical integration. For a specific tunnel scenario, the center line of its road surface can be obtained in the following way: The key points of the center line of the road surface are manually marked by professionals, such as the endpoints of straight sections and curve control points; in the case of determining the positions of the key points in the actual world coordinate system, a spline curve or polynomial fitting method is used to generate a smooth center line.

[0054] The state balance equation of this embodiment includes a traffic safety term set according to the inter-vehicle distance and a traffic efficiency term set according to the vehicle speed. It can not only ensure that the vehicle spacing always meets the braking distance constraint, but also avoid the decline of the tunnel traffic efficiency caused by the vehicle being overly conservative, making the evaluation result more practically guiding. At the same time, the state balance equation of this embodiment can adaptively adjust the weights according to the vehicle density, so that the state balance equation focuses on different terms to different extents in different situations, ensuring the traffic environment safety and traffic efficiency of the tunnel.

[0055] S222. According to the state balance equation, calculate the partial derivatives of the global risk state score with respect to the real-time following-distance and vehicle speed respectively, and then update the following-distance and vehicle speed by the gradient descent method under the constraint conditions.

[0056] Specifically, in this embodiment, the constraint conditions include lane speed limits and braking distance constraints. Among them, the braking distance constraint satisfies , is the road surface friction coefficient, is the acceleration due to gravity.

[0057] Further, update the following-distance and vehicle speed according to the following formula:

[0058]

[0059] Among them, is the learning rate, and its value is 0.05 to ensure smooth update.

[0060] S223. Substitute the updated following distance and vehicle speed into the state balance equation to calculate the global risk state score, and output the global optimal following distance and the global optimal following speed when the maximum number of iterations is reached or the convergence condition is satisfied.

[0061] Specifically, in this embodiment, substitute the updated following distance and vehicle speed into the state balance equation to recalculate the global risk state score, and determine whether the maximum number of iterations is reached or the convergence condition is satisfied. If the maximum number of iterations is not reached or the convergence condition is not satisfied, return to step S222. Repeat steps S222 to S223 until the maximum number of iterations is reached or the convergence condition is satisfied, and finally output the global optimal following distance and the global optimal following speed of each vehicle.

[0062] More specifically, the maximum number of iterations is 50 times, and the convergence condition is , is the global risk state score obtained in the j-th iteration, is the global risk state score obtained in the (j - 1)-th iteration.

[0063] In this embodiment, by setting up the state balance equation, using the gradient descent method to update the following distance and vehicle speed, and outputting the global optimal following distance and speed when the maximum number of iterations is reached or the convergence condition is satisfied, the accuracy and reliability of calculating the global optimal following distance and speed are improved, which is beneficial to improving the intelligent level of the traffic environment safety evaluation of a single-lane highway tunnel.

[0064] It should be noted that since this embodiment only obtains the global optimal following distance and the global optimal following speed of each vehicle through the algorithm as a reference for judging the traffic environment in the tunnel, it is not necessary to consider whether there will be a collision if each vehicle adjusts to the corresponding global optimal following distance and global optimal following speed.

[0065] S23. Adjust the vehicle position of the rear vehicle in two adjacent vehicles according to the global optimal following distance to obtain the global optimal following position of the rear vehicle in two adjacent vehicles.

[0066] Specifically, in this embodiment, adjust the vehicle position according to the global optimal following distance so that the following distance of the rear vehicle in two adjacent vehicles is the corresponding global optimal following distance. For two adjacent vehicles, first, project the position of the rear end of the front vehicle onto the center line of the road surface, and then determine a point on the center line of the road surface behind the front vehicle whose distance from the projection point is the global optimal following distance as the target following point, and the position where the target following point is located is the global optimal following position of the rear vehicle.

[0067] Furthermore, in this embodiment, it is considered that when all vehicles travel at their global optimal following positions and global optimal following speeds, it can not only ensure the safety of the tunnel traffic operation environment, but also enable the tunnel to have better traffic efficiency. Therefore, subsequent safety evaluations of the tunnel traffic operation environment will be carried out based on the global optimal following positions and global optimal following speeds of the vehicles.

[0068] S3. Calculate the single-vehicle risk and the global traffic risk according to the traffic operation data, the global optimal following position, and the global optimal following speed.

[0069] In this embodiment, calculating the single-vehicle risk and the global traffic risk according to the traffic operation data, the global optimal following position, and the global optimal following speed can not only provide an important decision-making basis for tunnel traffic safety management, but also avoid constructing a complex evaluation index system, making the safety evaluation of highway tunnels more convenient. Step S3 specifically includes the following steps: S31. Set a distance deviation term according to the actual following distance of the vehicle and the global optimal following distance, and at the same time set a speed deviation term according to the actual vehicle speed of the vehicle and the global optimal following speed, and use the weighted sum of the distance deviation term and the speed deviation term as the single-vehicle risk.

[0070] Specifically, in this embodiment, the single-vehicle risk satisfies the following relationship:

[0071] Among them, is the distance deviation term, is the speed deviation term, is the single-vehicle risk of the i-th vehicle, is the weight of the distance risk term, is the actual following distance of the i-th vehicle, is the global optimal following distance of the i-th vehicle, is the weight of the speed risk term, is the actual vehicle speed of the i-th vehicle, is the global optimal following speed of the i-th vehicle. and Take 0.6 and 0.4 respectively.

[0072] S32. Calculate the average single-vehicle risk as the single-vehicle risk term, and at the same time set a density risk term using the vehicle density and the critical vehicle density, and use the weighted sum of the single-vehicle risk term and the density risk term as the global traffic risk.

[0073] Specifically, in this embodiment, the global traffic risk satisfies the following relationship:

[0074] Among them, is the global traffic risk, N is the total number of vehicles, is the vehicle density in the tunnel, is the critical vehicle density. and both take 0.5.

[0075] S4. Use the basic data and the traffic operation data to construct a dynamic digital twin model of the target single-lane highway tunnel, and then visually display the risk assessment results.

[0076] Step S4 specifically includes the following steps: S41. Use the basic data and the traffic operation data to construct a dynamic digital twin model of the target single-lane highway tunnel.

[0077] S42. Mark the single-vehicle risk and the global traffic risk on the dynamic digital twin model of the target highway tunnel, and then visually display the risk assessment results.

[0078] In this embodiment, by constructing a dynamic digital twin model of the target single-lane highway tunnel and marking the single-vehicle risk and the global traffic risk on the model, the visual display of the risk assessment results is realized, enabling the management personnel to understand the traffic safety status in the tunnel in real time and intuitively.

[0079] S43. Set the single-vehicle risk threshold and the global traffic risk threshold.

[0080] Specifically, in this embodiment, the setting of the single-vehicle risk threshold needs to consider factors including but not limited to the geological conditions of the tunnel, traffic flow, and accident occurrence frequency, etc., and needs to be adjusted regularly according to the accident frequency and degree in the tunnel. The following is an example.

[0081] For tunnels with complex geological conditions, such as fault fracture zones and karst development, their risk tolerance is relatively low, and a lower single-vehicle risk threshold should be set. For tunnels with better geological conditions and higher surrounding rock grades, the single-vehicle risk threshold can be appropriately increased. For example, if the tunnel passes through a karst development area with rich groundwater and is prone to disasters such as water inrush and mud outburst, the single-vehicle risk threshold can be set to 0.6.

[0082] For tunnels with large traffic flow, the mutual influence between vehicles is more significant, and the risk of accidents also increases accordingly. For example, for tunnels with a daily average traffic flow exceeding 50,000 vehicle trips, the single-vehicle risk threshold can be set to 0.65. For tunnels with a relatively small daily average traffic flow, the single-vehicle risk threshold can be appropriately relaxed.

[0083] Statistically analyze the accident occurrence frequency of the tunnel in the past 5 years. If accidents occur frequently, it indicates that the tunnel has a low risk tolerance, and a smaller single-vehicle risk threshold should be set. Conversely, the single-vehicle risk threshold can be appropriately relaxed. For example, if there are more than 5 traffic accidents per year on average in the tunnel, the single-vehicle risk threshold can be set to 0.6; otherwise, the single-vehicle risk threshold can be appropriately relaxed.

[0084] Furthermore, the setting of the global traffic risk threshold needs to consider factors including but not limited to the geological conditions of the tunnel, traffic flow, and accident occurrence frequency, etc., and needs to be adjusted regularly according to the accident frequency and severity in the tunnel. The following is an example.

[0085] For tunnels with complex geological conditions, such as those with fault fracture zones and karst development, their risk tolerance is relatively low, and a lower global traffic risk threshold should be set. For tunnels with better geological conditions and higher surrounding rock grades, the global traffic risk threshold can be appropriately increased. For example, if the tunnel passes through a karst development area with rich groundwater and is prone to disasters such as water inrush and mud outburst, the global traffic risk threshold is set to 0.7.

[0086] For extra-long tunnels or tunnels with large longitudinal slopes, the probability and scope of accidents during vehicle driving may be greater, and the risk tolerance is relatively weak. For example, for an extra-long tunnel with a length exceeding 3000 meters, its global traffic risk threshold can be set to 0.75, while the global traffic risk threshold for general-length tunnels can be set to 0.8.

[0087] Statistically analyze the accident occurrence frequency of the tunnel in the past 5 years. If accidents occur frequently, it indicates that the tunnel has a low risk tolerance, and a smaller global traffic risk threshold should be set. Conversely, the global traffic risk threshold can be appropriately relaxed. For example, if there are more than 5 traffic accidents per year on average in the tunnel, the global traffic risk threshold can be set to 0.75; otherwise, the global traffic risk threshold can be appropriately relaxed.

[0088] S44. Trigger a global warning when the global traffic risk exceeds the global traffic risk threshold.

[0089] Specifically, in this embodiment, when the global traffic risk exceeds the global traffic risk threshold, a global warning prompt sound is triggered to achieve global risk warning.

[0090] S45. Trigger a single-vehicle warning when the single-vehicle risk exceeds the single-vehicle risk safety threshold.

[0091] Specifically, in this embodiment, when the single-vehicle risk exceeds the single-vehicle risk safety threshold, the corresponding vehicle is marked in red and a single-vehicle warning prompt sound is triggered to achieve single-vehicle risk warning.

[0092] This embodiment also forms a multi-level warning mechanism by setting a single-vehicle risk threshold and a global traffic risk threshold, which can timely remind the management personnel to pay attention to the traffic safety status in the tunnel and quickly locate the problem vehicles.

[0093] It should be noted that in some cases, the actions described in the specification can be executed in a different order and still achieve the desired results. In this embodiment, the given step order is only for making the embodiment look clearer and more convenient for explanation, rather than a limitation.

[0094] In an optional embodiment, please refer to Figure 2 , in order to improve the efficiency of the safety evaluation of the highway tunnel traffic operation environment and the practicability of this method, the present invention also provides a highway tunnel traffic operation environment safety evaluation system. The highway tunnel traffic operation environment safety evaluation system includes: a data acquisition device 1, a data output device 2, a processor 3, and a storage 4. The storage 4 includes a computer-readable storage medium, and a computer program is stored in the computer-readable storage medium. The computer program includes program instructions, and when the program instructions are executed by the processor 3, the processor 3 implements a highway tunnel traffic operation environment safety evaluation method provided by the present invention.

[0095] In summary, this embodiment provides an optional new method for the safety evaluation of the traffic operation environment of a single-lane highway tunnel.

[0096] First, based on the intelligent driving model, this method further considers factors such as vehicle type and the light conditions at the position of the vehicle to calculate the reference value of the following distance, making the calculated reference value of the following distance more in line with the actual situation, which helps to improve the accuracy of the subsequent global optimal following position and speed.

[0097] Then, this method sets a state balance equation with the goal of balancing traffic safety and traffic efficiency, and uses the gradient descent method to obtain the global optimal following distance and speed under the constraints of lane speed limit and braking distance, which not only considers the safety of driving in the tunnel but also takes into account the traffic efficiency, and is beneficial to improving the accuracy of the safety evaluation of the single-lane highway tunnel traffic environment.

[0098] Next, this method takes the global optimal following distance and speed of each vehicle as a reference and compares them with the real-time traffic operation data in the tunnel, and evaluates the safety of the tunnel traffic operation environment by calculating the single-vehicle risk and the global traffic risk.

[0099] Finally, the method sets corresponding risk thresholds and constructs a dynamic digital twin model for single-lane highway tunnels, realizing the visual display and real-time early warning of risk assessment results, enabling managers to understand the traffic safety conditions in the tunnel in real time and intuitively.

[0100] In addition, this embodiment also provides a system adapted to the method, improving the efficiency of the traffic operation environment safety assessment of highway tunnels and the practicability of this method.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered by the scope of the claims and the specification of the present invention.

Claims

1. A safety evaluation method for the traffic operation environment of highway tunnels, characterized in that, It includes the following steps: Obtain the basic data and traffic operation data of the target single-lane highway tunnel, where the traffic operation data includes vehicle position, vehicle speed, physical load, vehicle type, and vehicle density; Obtain the global optimal following position and global optimal following speed of each vehicle in the target single-lane highway tunnel according to the traffic operation data; Calculate the single-vehicle risk and global traffic risk based on the traffic operation data, the global optimal following position, and the global optimal following speed; Use the basic data and the traffic operation data to construct a dynamic digital twin model of the target single-lane highway tunnel, and then visually display the risk assessment results.

2. The safety evaluation method for the traffic operation environment of a highway tunnel according to claim 1, wherein, The step of obtaining the global optimal following position and global optimal following speed of each vehicle in the target single-lane highway tunnel according to the traffic operation data includes the following steps: Obtain a reference value for the following distance; After obtaining the reference value for the following distance, with the goal of balancing traffic safety and traffic efficiency, obtain the global optimal following distance and global optimal following speed of the vehicle under constraint conditions; Adjust the vehicle position of the rear vehicle in two adjacent vehicles according to the global optimal following distance to obtain the global optimal following position of the rear vehicle in two adjacent vehicles.

3. The safety evaluation method for the traffic operation environment of a highway tunnel according to claim 2, characterized in that The step of obtaining the reference value for the following distance includes the following steps: Determine the light condition at the vehicle's location; Improve the safety distance formula in the intelligent driving model according to the light condition, and then calculate the reference value for the following distance.

4. According to the method for evaluating the safety of the traffic operation environment of a highway tunnel as described in claim 2, characterized in that: The constraint conditions include lane speed limit and braking distance constraint.

5. The safety evaluation method for the traffic operation environment of a highway tunnel according to claim 2, characterized in that The step of, after obtaining the reference value for the following distance, with the goal of balancing traffic safety and traffic efficiency, obtaining the global optimal following distance and global optimal following speed of the vehicle under constraint conditions includes the following steps: After obtaining the reference value for the following distance, set a state balance equation with the goal of balancing traffic safety and traffic efficiency for calculating the global risk state score; Respectively calculate the partial derivatives of the global risk state score with respect to the following distance and vehicle speed, and then update the following distance and vehicle speed by the gradient descent method under the constraint conditions: Substitute the updated following distance and vehicle speed into the state balance equation to calculate the global risk state score, and output the global optimal following distance and the global optimal following speed when the maximum number of iterations is reached or the convergence condition is met.

6. The safety evaluation method for the traffic operation environment of a highway tunnel according to claim 5, characterized in that, The step of, after obtaining the reference value for the following distance, setting a state balance equation with the goal of balancing traffic safety and traffic efficiency for calculating the global risk state score includes the following steps: Set a traffic safety term according to the following distance of the vehicle and the reference value for the following distance, and set a traffic efficiency term according to the vehicle speed and the expected vehicle speed; Set the weights of the traffic safety term and the traffic efficiency term according to the vehicle density and the critical vehicle density, and then use the weighted sum of the traffic safety term and the traffic efficiency term as the state balance equation for calculating the global risk state score.

7. A method for evaluating the safety of the traffic operation environment in a highway tunnel according to claim 6, characterized in that, Calculating the single-vehicle risk and the global traffic risk based on the traffic operation data, the global optimal following position, and the global optimal following speed includes the following steps: Set a distance deviation term according to the actual following distance of the vehicle and the global optimal following distance, and at the same time set a speed deviation term according to the actual vehicle speed of the vehicle and the global optimal following speed, and use the weighted sum of the distance deviation term and the speed deviation term as the single-vehicle risk; Calculate the average single-vehicle risk as the single-vehicle risk term, and at the same time set a density risk term using the vehicle density and the critical vehicle density, and use the weighted sum of the single-vehicle risk term and the density risk term as the global traffic risk.

8. The safety evaluation method for the traffic operation environment of a highway tunnel according to claim 1, characterized in that, Using the basic data and the traffic operation data to construct the dynamic digital twin model of the target single-lane highway tunnel, and then visualizing the risk assessment results includes the following steps: Use the basic data and the traffic operation data to construct the dynamic digital twin model of the target single-lane highway tunnel; Mark the single-vehicle risk and the global traffic risk on the dynamic digital twin model of the target highway tunnel, and then visualize the risk assessment results.

9. The safety evaluation method for the traffic operation environment of a highway tunnel according to claim 8, characterized in that, Using the basic data and the traffic operation data to construct the dynamic digital twin model of the target single-lane highway tunnel, and then visualizing the risk assessment results further includes the following steps: Set a single-vehicle risk threshold and a global traffic risk threshold; Trigger a global warning when the global traffic risk exceeds the global traffic risk threshold; Trigger a single-vehicle warning when the single-vehicle risk exceeds the single-vehicle risk safety threshold.

10. A safety evaluation system for the traffic operation environment of a highway tunnel, characterized in that, The described highway tunnel traffic operation environment safety evaluation system includes: a data acquisition device, a data output device, a processor, and a storage device. The storage device includes a computer-readable storage medium, and a computer program is stored in the computer-readable storage medium. The computer program includes program instructions, and when the program instructions are executed by the processor, the processor implements a highway tunnel traffic operation environment safety evaluation method according to any one of claims 1-9.

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