A traffic guidance screen calling control method and system based on road network state information

Abstract

The application discloses a traffic guidance screen calling control method and system based on road network state information. The method comprises the following steps: acquiring traffic state information and environment information in a guidance screen indicating area in a road network; determining guidance content and an initial guidance scheme according to a set guidance model and a solving algorithm; determining a delay degree of the initial guidance scheme; and controlling the state of the guidance screen in the guidance screen indicating area based on the delay degree and the initial guidance scheme. The application comprehensively considers the road network, traffic information publishing demand and guidance time benefit elements, so that the comprehensive benefit of the established guidance model is better.

Description

TECHNICAL FIELD

[0001] The present application belongs to the control technical field of traffic engineering, and particularly relates to a traffic guidance screen calling control method and system based on road network state information. BACKGROUND

[0002] The traffic guidance screen releases traffic information, reasonably guides traffic flow, and thus relieves urban traffic congestion, reduces vehicle unit travel distance, emission and energy consumption. When traffic congestion occurs, the traffic guidance screen installed in the road network correctly releases the optimal guidance path information for avoiding congestion, which can improve the traffic operation efficiency of the road network. When the road network is in a non-congestion state, the traffic guidance screen can be turned off to save power or used for traffic propaganda. However, the existing traffic guidance screen does not well combine the opening and closing and information release with the demand for traffic guidance information, and the guidance screen is usually turned on to release road condition information in all time periods. When the road is smooth and does not need to guide the road condition, the guidance screen still displays the information that all roads are smooth, the released information has no value, and the device resources and power are wasted.

[0003] Therefore, it is necessary to establish an optimal control algorithm for the guidance screen under the condition of detecting the road network state information, to meet the demand for road network traffic guidance information release and the comprehensive utilization of energy saving and environmental protection, and to realize the optimal use of the traffic guidance screen. SUMMARY

[0004] Therefore, the present application provides a traffic guidance screen calling control method and system based on road network state information.

[0005] The purpose of the present application is achieved by the following technical solutions:

[0006] The present application provides a traffic guidance screen calling control method based on road network state information, comprising:

[0007] Real-time acquisition of traffic state information and environmental information in each guidance screen indication area in the road network;

[0008] Using the traffic state information and the environmental information, determining the guidance content and the initial guidance scheme that each guidance screen in the guidance screen indication area needs to release according to a set guidance model and a solving algorithm, wherein the guidance model takes the guidance total time benefit of the road network under the influence of the guidance screen as the objective function of the guidance model, and establishes constraints according to the road section, the path and the time benefit;

[0009] According to the guidance model, determining the road network guidance time benefit and the vehicle guidance time benefit of the traffic in the guidance screen indication area under the guidance condition;

[0010] According to the traffic state information, determining the road network non-guidance time benefit and the vehicle non-guidance time benefit under the non-guidance condition;

[0011] determine a road network induced time benefit difference according to the road network induced time benefit and the road network non-induced time benefit;

[0012] determine a delay degree of the initial induced scheme according to the road network induced time benefit difference, the vehicle induced time benefit and the vehicle non-induced time benefit;

[0013] control the state of the induced screen in the induced screen indication area based on the delay degree and the initial induced scheme, and perform real-time feedback on the working state information of the induced screen.

[0014] The application also provides a traffic induced screen calling control system based on road network state information, which comprises:

[0015] a traffic environment information collection module, which is used for acquiring the traffic running state and the environmental information in the induced screen indication area in real time;

[0016] receive the traffic running state and the environmental information, and determine the traffic induced content and the initial induced scheme to be published by each induced screen in the induced screen indication area according to the set induced model and the set model solving algorithm, wherein the induced model takes the induced total time benefit of the road network under the influence of the induced screen as the objective function of the induced model, and establishes the constraint according to the road section, the path and the time benefit;

[0017] determine the road network induced time benefit and the vehicle induced time benefit of the traffic in the induced screen indication area under the induced condition according to the induced model;

[0018] determine the road network non-induced time benefit and the vehicle non-induced time benefit under the non-induced condition according to the traffic state information;

[0019] determine the road network induced time benefit difference according to the road network induced time benefit and the road network non-induced time benefit;

[0020] an induced information publishing module, which is used for monitoring the running state of each induced screen and the publication of the induced content, and determining the delay degree of the initial induced scheme according to the road network induced time benefit difference, the vehicle induced time benefit and the vehicle non-induced time benefit;

[0021] an induced screen control cloud platform, which is used for controlling the state of the induced screen in the induced screen indication area based on the delay degree, and performing real-time feedback on the working state information of the induced screen.

[0022] Further, the constraints include a path constraint, a link constraint and a link time benefit constraint, wherein the path constraint is to take the flow of the induced path as an evaluation index, the link constraint is to take the mean and variance of the saturation of each link and the flow of all paths passing through the link as an evaluation index, and the link time benefit constraint is to take the induced traffic link time benefit as an evaluation index, wherein the flow of the induced path is expressed by a formula as follows:

[0023]

[0024]

[0025] wherein m represents the mth path; ω represents the ωth OD pair; W represents a set of OD pairs in the induced area; R ω represents a set of all feasible paths connecting the OD pair ω; represents the flow of the path m on the OD pair ω; Q ω represents the total flow of the OD pair ω;

[0026] saturation S l represents the congestion degree of vehicles on the link l, and is expressed by a formula as follows:

[0027]

[0028] wherein x l represents the link flow of the link l; C l represents the maximum passing capacity of the link l;

[0029] the mean of the saturation of the link l and the variance of the saturation of the link l are respectively expressed by a formula as follows:

[0030]

[0031]

[0032] wherein n represents the number of links on the road network;

[0033] the link flow x l represents the sum of the flows of all paths passing through the link l, and is expressed by a formula as follows:

[0034]

[0035]

[0036] wherein, represents the topological relationship between the path and the link, represents that the path m uses the link l to connect the OD pair ω, and vice versa, L represents a set of links in the induction screen indicating area;

[0037] induced traffic link time benefit T l1 representing the average travel time of link l under the influence of induced information, expressed by the formula:

[0038]

[0039] wherein x l1 representing the traffic volume of link l in the case of the induction screen being turned on, t l0 representing the free travel time of link l; a and b represent calibration parameters, respectively taking 0.15 and 4.0.

[0040] Further, the induction model is:

[0041]

[0042]

[0043] wherein f represents the target function of traffic volume induced time benefit under the influence of induced information, α1 and α2 are upper and lower thresholds of the average value of saturation, β1 and β2 are upper and lower thresholds of the variance of saturation.

[0044] Further, according to the induction model, the road network induced time benefit and the vehicle induced time benefit of traffic in the induction screen indicating area under the induction condition are determined, including:

[0045] According to the induction model, the distribution traffic volume x l1 of link l under the induction condition is determined l1 ;

[0046] According to the distribution traffic volume x l1 and the time benefit T l1 of the induced traffic link, the road network induced time benefit T1 and the vehicle induced time benefit T 1_a are determined, expressed by the formula:

[0047]

[0048]

[0049] Further, according to the traffic state information, the road network uninduced time benefit and the vehicle uninduced time benefit under the uninduction condition are determined, including:

[0050] According to the traffic state information, the traffic volume x l2 of link l under the uninduction condition and the link time benefit T l2 are determined

[0051] According to traffic volume x l2 and link time benefit T l2 , determine the non-induction time benefit T2 of the road network and the non-induction time benefit T 2_a of each vehicle, which is expressed by the formula as follows:

[0052]

[0053]

[0054] Further, the delay degree of the initial induction scheme is determined according to the difference between the road network induction time benefit and the induction time benefit of each vehicle and the non-induction time benefit of each vehicle, and includes:

[0055] When the difference between the road network induction time benefit and the non-induction time benefit T r ≤0, no induction is performed, and the control induction screen is turned off;

[0056] When the difference between the road network induction time benefit and the non-induction time benefit T r >0, the delay degree g is determined;

[0057] When μ1≤g<μ2, the induction content is published in real time,

[0058] When μ2≤g<μ3, the induction content is published after being appropriately delayed for 1-10 minutes,

[0059] When g≥μ3, the induction scheme is re-determined,

[0060] wherein T r =T2-T1, g=T 2_a -T 1_a , and μ1, μ2 and μ3 represent delay degree judgment thresholds.

[0061] Further, the solving algorithm is a genetic algorithm, and specifically includes the following steps:

[0062] S1: initialize the population, including setting the evolution generation number of the population and the maximum evolution generation number and randomly generating a population as an initial population;

[0063] S2: calculate the fitness, i.e. calculate the fitness of each individual in the population, judge whether a preset termination condition is met, if the termination condition is met, output the optimal individual and the final solution, and the solving is ended, if the termination condition is not met, continue to execute S3;

[0064] S3: selection, i.e. according to a preset selection probability P s , apply a selection operator to the population, and through the selection operation, select individuals with high fitness to enter the next generation population;

[0065] S4: crossover, i.e. according to a preset crossover probability P c, and the crossover operation is performed;

[0066] S5: variation, that is, according to a preset variation probability P m The variation operator is applied to the population to obtain a new generation of population, and S2 is returned.

[0067] The beneficial effects of the present application are:

[0068] The present application proposes to establish a planning induction screen opening and closing control optimization model (i.e. induction model, also known as induction control model) based on induced time benefits, comprehensively considers the road network and traffic information release demand, and the induced time benefit elements, so that the comprehensive benefits achieved by the established induction model are more optimal. In addition, after the optimal solution, i.e. the initial induction scheme, is determined according to the model, the induction benefit under the influence of the induction screen and the benefit without the influence of the induction screen are determined, and the initial induction scheme is further determined by comparing the two to determine whether induction is needed. In the case of needing induction, the vehicle average time benefit under the induction condition and the vehicle average time benefit under the non-induction condition are further determined to determine whether to release the induction content in real time, or to release the induction content with appropriate delay, or to develop a new induction scheme. Therefore, the final determined induction scheme can be more reasonable and more energy-saving and environment-friendly through the method of the present application. At the same time, by setting the induction screen, vehicles can be induced to select paths and road sections with better traffic capacity, reducing the possibility of congestion events and other traffic accidents, and reducing environmental problems caused by incomplete combustion of fuel due to congestion. In addition, by opening or closing the induction screen under different road traffic conditions, the induction screen can be used reasonably, thereby reducing resource waste and being more energy-saving and environment-friendly.

[0069] Other advantages, objects, and features of the present application will be in part apparent and in part pointed out hereinafter in the specification, and will be learned from a reading of the following specification and by practice of the present application. The objects and other advantages of the present application will be realized and attained by the structure particularly pointed out in the specification. BRIEF DESCRIPTION OF DRAWINGS

[0070] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings, in which:

[0071] Fig. 1 is a schematic diagram of a traffic induction screen calling control system module based on road network state information according to an embodiment of the present application;

[0072] Figure 2 Fig. 1 is a schematic diagram of a traffic induction screen calling control system module based on road network state information according to an embodiment of the present application;

[0073] Figure 3 is a schematic diagram of constraints shown according to an embodiment of the present application;

[0074] Figure 4 is a schematic flow chart of a genetic algorithm shown according to an embodiment of the present application. DETAILED DESCRIPTION

[0075] The preferred embodiments of the present application will be described in detail with reference to the drawings. It should be understood that the preferred embodiments are only for illustrating the present application, and are not intended to limit the protection scope of the present application.

[0076] Figure 1A and 1B is a module diagram of a traffic guidance screen calling control system based on road network state information according to an embodiment of the present application. As shown in Figure 1A and Figure 1B , the traffic guidance screen calling control system 100 can include a traffic environment information collection module (also referred to as an “information collection module”) 110, a guidance information processing module (also referred to as an “information processing module”) 120, a guidance information publishing module (also referred to as an “information publishing module”) 130, and a guidance screen control cloud platform 140. The traffic environment information collection module 110 can be configured to collect traffic information and environment information of road segments in an indication area of a guidance screen in real time. In some embodiments, the guidance screen control cloud platform 140 can first obtain the indication area of the guidance screen it controls, i.e., a set of road segments associated with the guidance screen, and then the traffic environment information collection module 110 can obtain traffic state information and environment information in the indication area. In some embodiments, the traffic environment information collection module 110 can include some data collection devices, such as road segment geomagnetic detectors, traffic state recognition cameras, traffic radar detectors, etc. The traffic state information can include traffic flow, traffic congestion, speed, position, etc. of each vehicle on each road segment. The environment information can include distribution association of each road segment, distribution of the guidance screen, etc. The information collected by the traffic environment information collection module 110 can be transmitted through wireless or wired communication by a data transmission device, and sent to the guidance information processing module for information processing.

[0077] The induction information processing module 120 can be configured to process the information to generate a start-up scheme (e.g., an initial start-up scheme, also referred to as an "initial induction scheme") for the induction screens. In some embodiments, the induction information processing module 120 can receive the traffic operating status and environmental information collected by the information collection module, and determine the traffic induction content and the initial induction scheme to be issued by each induction screen in the indication area of the induction screen according to a set induction model and using a set model solving algorithm, wherein the induction model takes the total time benefit of the road network under the influence of the induction screen as the objective function of the induction model, and establishes constraints according to the road segments, paths, and time benefits. In some embodiments, the induction information processing module 120 can also determine the road network induction time benefit and the vehicle average induction time benefit of the traffic in the indication area of each induction screen under the induction condition according to the induction model. In some embodiments, the induction information processing module 120 can also determine the road network non-induction time benefit and the vehicle average non-induction time benefit under the non-induction condition according to the traffic status information. In some embodiments, the induction information processing module 120 can also determine the road network induction time benefit difference according to the road network induction time benefit and the road network non-induction time benefit.

[0078] In some embodiments, the induction information processing module 120 can also be configured to solve the induction model using a solving algorithm to determine the initial start-up scheme of the induction screen. The solving of the induction model can use any algorithm for solving an optimal solution, such as a genetic algorithm, a particle swarm algorithm, an ant colony algorithm, a simulated annealing algorithm, etc. The following will be described by taking the genetic algorithm as an example, and the details can be referred to Figure 4 and the related description thereof.

[0079] In some embodiments, as Figure 1BAs shown, the guidance information processing module 120 can include a data server, a data publishing / receiving server, a calculation server and an external interface server (for example, can include a city traffic service platform, a GIS service platform, an Internet travel platform, etc.). The module includes data processing functions, data calculation functions and certain data publishing functions. The data server can be used for data storage, which can store real-time data and historical data, and also provide remote data query. Real-time data can include acquired traffic state information, such as real-time acquisition of traffic flow, traffic congestion, speed, position and other information of each vehicle. Historical data can include historical traffic flow information of road segments, etc. The data server can also exchange data with the external interface server. The data processing server can receive data collected by the information collection module and / or exchanged data. The calculation server can perform guidance calculation, and the publishing server can handle the control and information publishing of the guidance screen. For example, the calculation server can calculate the guidance screen activation scheme under the constraint condition based on the current point layout of the guidance screen and the traffic information according to the preset solving algorithm, and deliver it to the guidance information publishing server. The external interface server can provide auxiliary data source for the calculation server as an auxiliary data source, or provide services by acquiring the required guidance information through the external interface server.

[0080] The guidance information publishing module 130 can monitor the running state of each guidance screen in the system and be used for controlling the publishing of guidance information. In some embodiments, the guidance information publishing module 130 can also determine the delay degree of the activation scheme, so as to determine the final guidance scheme according to the delay degree and the initial guidance scheme. For example, the guidance information publishing module 130 can be used to monitor the running state of each guidance screen in the road network and the publishing of guidance content, and determine the delay degree of the initial activation scheme according to the road network guidance time benefit difference and the vehicle guidance time benefit and the vehicle non-guidance time benefit. After determining the initial activation scheme and the delay scheme of the guidance screen, the guidance screen activation scheme and the delay scheme can be sent to the guidance screen control cloud platform 140, and the guidance screen control cloud platform 140 controls the state of the guidance screen in the indicated area based on the delay scheme, and performs real-time feedback on the road state.

[0081] Figure 2 is a schematic flow chart of a traffic guidance screen calling control method based on road network state information according to an embodiment of the present application.

[0082] In step 210, traffic status information and environmental information can be acquired in real time. This step can be performed by the traffic environment information acquisition module 110. The traffic environment information acquisition module 110 can be used to acquire traffic information and environmental information of road segments within the guidance screen's indication area in real time. In some embodiments, the guidance screen control cloud platform 140 can first acquire the indication area of ​​the guidance screens it controls, that is, a set of road segments associated with these guidance screens. Then, the traffic environment information acquisition module 110 can acquire traffic status information and environmental information within the indication area. In some embodiments, the traffic environment information acquisition module 110 may include some data acquisition devices, such as geomagnetic sensors, cameras, radar, etc. Traffic status information may include traffic flow, traffic congestion, speed, and location of each vehicle on each road segment. Environmental information may include the distribution and association of each road segment, the distribution of guidance screens, etc.

[0083] In step 220, a guidance model (also known as a "guidance control model") can be established. This step can be completed by the guidance information processing module 120. For example, traffic state information and environmental information can be used to determine the guidance content and initial guidance scheme to be published by each guidance screen within the guidance screen indication area, based on the established guidance model and solution algorithm. The guidance model uses the total time benefit of the road network under the influence of the guidance screen as the objective function of the guidance model, and establishes constraints based on road segments, paths, and time benefits. Figure 3 This is a schematic diagram illustrating constraints according to an embodiment of this application. Figure 3 As shown, the constraints include path constraints, road segment constraints, and road segment time efficiency constraints. Path constraints use the traffic flow of the induced path as the evaluation index. Road segment constraints use the mean and variance of the saturation of each road segment, as well as the sum of the traffic flows of all paths passing through that road segment, as evaluation indices. For the same road segment, a higher saturation indicates greater congestion, resulting in a lower level of road service and a longer travel time. Large mean and variance of saturation indicate an unbalanced distribution of traffic flow in the road network, suggesting localized traffic congestion, which constitutes a constraint on traffic operation. Road segment time efficiency constraints use the time efficiency of the induced traffic road segment as the evaluation index.

[0084] The flow of the induced path can be expressed by the formula:

[0085]

[0086]

[0087] Where m represents the m-th path; ω represents the ω-th OD pair; W represents the set of OD pairs within the induced region; R ω This represents the set of all feasible paths connecting OD to ω; denotes the flow of path m on OD pair ω; Q ω denotes the total flow of OD pair ω.

[0088] saturation S l denotes the congestion level of vehicles on link l, which can be expressed as:

[0089]

[0090] where x l denotes the link flow of link l; C l denotes the maximum capacity of link l.

[0091] the average saturation of link l and the saturation variance which can be expressed as:

[0092]

[0093]

[0094] where n denotes the number of links in the road network;

[0095] link flow x l is the dynamic mapping relationship between OD pair volume, which represents the sum of the flows of all paths passing through link l, and can be expressed as:

[0096]

[0097]

[0098] where, denotes the topological relationship between paths and links, denotes that path m uses link l to connect OD pair ω, and vice versa, L denotes the set of links in the induced screen indication area.

[0099] induced traffic link time benefit T l1 denotes the average travel time of link l under the influence of induced information (i.e. when the induced screen is on), indicating the time benefit of the induced scheme, which can be calculated by the link impedance function, and can be expressed as:

[0100]

[0101] where x l1 denotes the traffic volume of link l when the induced screen is on, t l0 denotes the free travel time of link l; a and b denote the calibration parameters, which are 0.15 and 4.0, respectively.

[0102] In some embodiments, the induced model is expressed in a formula as follows:

[0103]

[0104]

[0105] wherein f represents a target function of traffic volume induced time benefit under the influence of induced information, a1 and a2 are upper and lower thresholds of saturation mean, b1 and b2 are upper and lower thresholds of saturation variance. The model takes the total induced time benefit of the road network under the influence of the induced screen as the target function of the model, and performs distribution under the induced condition by constraining the parameters such as road segments, paths and time benefits.

[0106] In step 230, the induced model can be solved to determine the initial start-up scheme of each induced screen and the traffic induced content to be published by each induced screen. This step can be completed by the induced information processing module 120. In some embodiments, any algorithm for solving the optimal solution can be used for solving the induced screen control model, such as genetic algorithm, particle swarm algorithm, ant colony algorithm, simulated annealing algorithm, etc. The genetic algorithm is taken as an example for illustration below, and the details can be referred to Figure 4 and the related description.

[0107] In step 240, the delay degree of the initial start-up scheme can be determined. This step can be completed by the induced information processing module 120 or the information publishing module 130. In some embodiments, according to the initial start-up scheme of the induced screen, the induced benefit of the regional traffic under the induced path (i.e. under the induced condition) and the normal path (i.e. under the non-induced condition) is calculated to determine the delay degree of the induced screen start-up scheme. In some embodiments, the road network induced time benefit and the vehicle induced time benefit of the traffic in the indication area of each induced screen under the induced condition can be determined according to the induced model; then, the road network non-induced time benefit and the vehicle non-induced time benefit under the non-induced condition are determined according to the traffic state information; then, the road network induced time benefit difference is determined according to the road network induced time benefit and the road network non-induced time benefit; finally, the delay degree of the initial induced scheme is determined according to the road network induced time benefit difference and the vehicle induced time benefit and the vehicle non-induced time benefit. It should be noted that the steps shown above are only exemplary and are not intended to limit the present application. In some embodiments, the order of some steps can be changed, or some steps can be executed simultaneously, which is not limited herein.

[0108] In some embodiments, the determination of the road network induced time benefit and the vehicle induced time benefit of the traffic in the indication area of each induced screen under the induced condition according to the induced model can include:

[0109] According to the induced model, the distribution traffic volume x of the link l in the induced case (i.e. the case when the induction screen is on and the influence of the induction screen) is determined l1 and the link time benefit T of the induced traffic l1 ;

[0110] According to the distribution traffic volume x of the link l1 and the link time benefit T of the induced traffic l1 , the network induced time benefit T1 and the vehicle induced time benefit T are determined 1_a , which are expressed by the following formulas:

[0111]

[0112]

[0113] In some embodiments, according to the traffic state information, the network uninduced time benefit and the vehicle uninduced time benefit in the uninduced case (i.e. the case when the induction screen is off and not influenced by the induction screen) are determined, which includes:

[0114] According to the traffic state information, the traffic volume x of the link l in the uninduced case is determined l2 and the link time benefit T l2 ;

[0115] According to the traffic volume x of the link l2 and the link time benefit T l2 , the network uninduced time benefit T2 and the vehicle uninduced time benefit T are determined 2_a , which are expressed by the following formulas:

[0116]

[0117]

[0118] In some embodiments, the delay degree of the initial start-up scheme according to the network induced time benefit difference and the vehicle induced time benefit and the vehicle uninduced time benefit can include:

[0119] When the network induced time benefit difference T r ≤ 0, it indicates that the influence of the induced scheme on the link time benefit is small, at this time, the link is in the congestion or free flow state, and the induction is not performed, and the induction screen is controlled to be off;

[0120] When the network induced time benefit difference T r > 0, the delay degree g is determined, and then whether to publish the induced content in real time, or to delay the publication of the induced content, or to re-develop the induced scheme is determined according to the delay degree g.

[0121] For example, when μ1≤g<μ2, the real-time release of the guidance content is performed; when μ2≤g<μ3, the guidance content is released after a delay of 1-10 minutes; and when g≥μ3, the guidance scheme is re-established, wherein T r =T2-T1, g=T 2_a -T 1_a μ1, μ2 and μ3 represent delay degree judgment thresholds.

[0122] At step 250, a final guidance screen control scheme can be determined based on the delay degree and the initial guidance scheme, and the state of the guidance screen in the guidance screen indication area can be controlled according to the final guidance screen control scheme. In some embodiments, the traffic guidance screen indication area can be controlled by the traffic guidance screen control cloud platform. In some embodiments, the working state information of the guidance screen can also be fed back in real time and the guidance information can be corrected.

[0123] Figure 4 is a schematic flow chart of a genetic algorithm according to an embodiment of the present application.

[0124] S1: initializing a population, including encoding the decision variables of the upper model, setting the evolution generation number of the population and the maximum evolution generation number and randomly generating a population as an initial population;

[0125] S2: calculating the fitness, i.e., calculating the fitness of each individual in the population, judging whether a preset termination condition is met, if the termination condition is met, outputting the optimal individual and the final solution, and ending the solving, if the termination condition is not met, continuing to perform S3; in some embodiments, the termination condition can be a preset number of iteration times.

[0126] S3: selection, i.e., according to a preset selection probability P s , applying a selection operator to the population, through the selection operation, selecting individuals with high fitness to enter the next generation population;

[0127] S4: crossover, i.e., performing a crossover operation according to a preset crossover probability P c

[0128] S5: mutation, i.e., according to a preset mutation probability P m , applying a mutation operator to the population to obtain a new generation of population, and returning to S2.

[0129] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application but not limit the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the purpose and scope of the technical solutions, which should be covered in the scope of the claims of the present application.​

Claims

1. A traffic guidance screen call control method based on road network state information, characterized by, The method comprises the following steps: real-time acquisition of traffic state information and environmental information in the indication area of each induction screen in the road network; determination of the induction content and initial induction scheme to be published by each induction screen in the indication area of the induction screen according to the set induction model and solving algorithm, wherein the induction model takes the total time benefit of the road network under the influence of the induction screen as the objective function of the induction model, and establishes constraints according to the road section, path and time benefit; determination of the road network induction time benefit and vehicle induction time benefit of the traffic in the indication area of each induction screen under the induction condition according to the induction model; determination of the road network non-induction time benefit and vehicle non-induction time benefit under the non-induction condition according to the traffic state information; determination of the road network induction time benefit difference according to the road network induction time benefit and the road network non-induction time benefit; determination of the delay degree of the initial induction scheme according to the road network induction time benefit difference and the vehicle induction time benefit and the vehicle non-induction time benefit; control of the state of the induction screen in the indication area of the induction screen based on the delay degree and the initial induction scheme, and real-time feedback of the working state information of the induction screen; wherein the determination of the delay degree of the initial induction scheme according to the road network induction time benefit difference and the vehicle induction time benefit and the vehicle non-induction time benefit comprises: When the road network induction time benefit difference T r ≤0, no induction is performed, and the control induction screen is closed. When the road network induced time benefit difference T r > 0, determine the delay degree g; when μ1≤g<μ2, the induction content is published in real time, when μ2≤g<μ3, the induction content is published after being appropriately delayed for 1-10 minutes, when g≥μ3, the induction scheme is re-established, where T r = T2- T1, g = T 2_a - T 1_a , μ1, μ2 and μ3 represent the delay degree judgment threshold values.

2. The road network state information-based traffic guidance screen call control method according to claim 1, characterized by, the constraints comprise path constraints, road section constraints and road section time benefit constraints, wherein the path constraints take the flow of the induction path as the evaluation index, the road section constraints take the mean and variance of the saturation of each road section and the flow of all paths passing through the road section as the evaluation index, and the road section time benefit constraints take the induction traffic road section time benefit as the evaluation index, wherein the flow of the induction path is represented by the formula: where m denotes the mth path; ω denotes the ωth OD pair; W denotes the set of OD pairs within the induction area; R ω denotes the set of all feasible paths connecting OD pair ω; denotes the flow on path m for OD pair ω; Q ω denotes the total flow for OD pair ω; Saturation S l denotes the degree of congestion of the vehicles on the road segment I and is expressed by the formula: wherein x l represents the link flow of link l; C l represents the maximum capacity of link l; average value of saturation of the link l and variance of saturation are respectively expressed by wherein n represents the number of road sections on the road network; link flow x l denotes the sum of the flows of all paths through link l, which is expressed in the equation as wherein, represents the topological relationship of the path and the link, represents that the path m uses the link l to connect the OD pair ω, and vice versa, L represents the set of links in the inductive screen indication area; Induced traffic link time benefit T l1 The average travel time of link / under the influence of induced information is denoted by T and is expressed by the formula: where x l1 represents the traffic volume of the road segment I in the case of the opening of the induction screen, t l0 represents the free travel time of the road segment I; a and b represent calibration parameters, respectively 0.15 and 4.

0.

3. The traffic guidance screen call control method based on road network state information according to claim 2, characterized by, the induction model is: wherein f represents the target function of the traffic flow induction time benefit under the influence of the induction information, α1 and α2 are the upper and lower thresholds of the saturation mean, and β1 and β2 are the upper and lower thresholds of the saturation variance.

4. The traffic guidance screen call control method based on road network state information according to claim 2, characterized by, determination of the road network induction time benefit and vehicle induction time benefit of the traffic in the indication area of each induction screen under the induction condition according to the induction model comprises: According to the induced model, the distribution traffic volume x of the link I under the induced condition is determined l1 and the induced traffic link time benefit T l1 ; According to the flow distribution traffic volume x l1 and the time benefit T of the induced traffic section l1 , the induced time benefit T1 of the road network and the induced time benefit T 1_a of the vehicle are determined, and expressed by the formula:

5. The traffic guidance screen based on road network state information calling control method according to claim 4, characterized by, determination of the road network non-induction time benefit and vehicle non-induction time benefit under the non-induction condition according to the traffic state information comprises: Based on the traffic state information, the traffic volume x of the road segment I under the non-induction condition is determined l2 and the road segment time benefit T l2 ; According to the traffic volume x l2 and the link time benefit T l2 , the network uninduced time benefit T2 and the uninduced time benefit T per vehicle 2_a are determined, and expressed by the formula:

6. The road network state information-based traffic guidance screen call control method according to claim 1, characterized by, the solving algorithm is a genetic algorithm, and specifically comprises the following steps: S1: initialization of the population, including setting the evolution generation number of the population and the maximum evolution generation number and randomly generating a population as the initial population; S2: calculation of the fitness, i.e. calculation of the fitness of each individual in the population, judgment of whether the preset termination condition is met, output of the optimal individual and the final solution if the termination condition is met, and termination of the solving if the termination condition is not met, and execution of S3; S3: selection, i.e. according to a preset selection probability P s The selection operator is applied to the population, and through the selection operation, individuals with high fitness are selected into the next generation population; S4: crossover, i.e. performing a crossover operation according to a preset crossover probability P c , performing a crossover operation according to a preset crossover probability P S5: variation, i.e. according to a preset variation probability P m The variation operator is applied to the population to obtain a new generation of population, and returns to S2.

7. A traffic guidance screen call control system based on road network state information, characterized by, The method comprises the following steps: a traffic environment information acquisition module for real-time acquisition of the traffic running state and environmental information in the indication area of the induction screen; an induction information processing module for The traffic operation state and environment information are received, and an initial traffic guidance scheme and traffic guidance content to be published by each guidance screen in a guidance screen indication area are determined according to a set guidance model and by using a set model solution algorithm, wherein the guidance model takes the total time benefit of the road network under the influence of the guidance screen as an objective function of the guidance model, and establishes constraints according to road sections, paths and time benefits; According to the guidance model, the road network guidance time benefit and the vehicle average guidance time benefit of the traffic in the guidance screen indication area under the guidance condition are determined; According to the traffic state information, the road network non-guidance time benefit and the vehicle average non-guidance time benefit under the non-guidance condition are determined; According to the road network guidance time benefit and the road network non-guidance time benefit, the road network guidance time benefit difference is determined; The guidance information publishing module is used for monitoring the operation condition of each guidance screen and the publication of the guidance content, and determining the delay degree of the initial guidance scheme according to the road network guidance time benefit difference and the vehicle average guidance time benefit and the vehicle average non-guidance time benefit; The guidance information publishing module is used for monitoring the operation condition of each guidance screen and the publication of the guidance content, and determining the delay degree of the initial guidance scheme according to the road network guidance time benefit difference and the vehicle average guidance time benefit and the vehicle average non-guidance time benefit; The guidance screen control cloud platform is used for controlling the state of the guidance screen in the guidance screen indication area based on the delay degree, and feeding back the working state information of the guidance screen in real time; The delay degree of the initial guidance scheme is determined according to the road network guidance time benefit difference and the vehicle average guidance time benefit and the vehicle average non-guidance time benefit, which includes: When the road network induction time benefit difference T r ≤0, no induction is performed, and the control induction screen is closed. When the road network induced time benefit difference T r is greater than 0, determine the delay degree g; When μ1≤g<μ2, the guidance content is published in real time, When μ2≤g<μ3, the guidance content is published after being appropriately delayed for 1-10 minutes, When g≥μ3, the guidance scheme is re-determined, where T r = T2- T1, g = T 2_a - T 1_a , μ1, μ2 and μ3 represent the delay degree judgment threshold values.

8. The road network state information-based traffic guidance screen call control system according to claim 7, characterized by, The constraints include path constraints, road section constraints and road section time benefit constraints, wherein the path constraints take the flow of the guidance path as an evaluation index, the road section constraints take the mean and variance of the saturation of each road section and the flow of all paths passing through the road section as evaluation indexes, and the road section time benefit constraints take the guidance traffic road section time benefit as an evaluation index, The flow of the guidance path is expressed by a formula: where m denotes the mth path; ω denotes the ωth OD pair; W denotes the set of OD pairs within the induction area; R ω denotes the set of all feasible paths connecting OD pair ω; denotes the flow on path m for OD pair ω; Q ω denotes the total flow for path pair ω; Saturation S l denotes the degree of congestion of the vehicles on the road segment I and is expressed by the formula: wherein x l denotes the link flow of link l; C l denotes the maximum capacity of link l; average value of saturation of the link l and variance of saturation are respectively expressed by Wherein, n represents the number of road sections on the road network; link flow x l The sum of the flows of all paths through link l is denoted by x and is expressed in formula as wherein, represents the topological relationship of the path and the link, represents that the path m uses the link l to connect the OD pair ω, and vice versa, L represents the set of links in the inductive screen indication area; Induced traffic link time benefit T l1 The average travel time of link / under the influence of induced information is denoted by T and is expressed by the formula: where x l1 represents the traffic volume of the road segment I in the case of the opening of the induction screen, t l0 represents the free travel time of the road segment I; a and b represent calibration parameters, respectively 0.15 and 4.

0.

9. The road network state information-based traffic guidance screen call control system according to claim 8, characterized by, The guidance model is: Wherein, f represents the objective function of the traffic flow guidance time benefit under the influence of the guidance information, α1 and α2 are the upper and lower thresholds of the mean of the saturation, and β1 and β2 are the upper and lower thresholds of the variance of the saturation.

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