Variable information sign layout scheme optimization method based on traffic simulation

Abstract

The embodiment of the invention discloses a variable information sign layout scheme optimization method based on traffic simulation. The method comprises the following steps: acquiring a to-be-optimized road section; a VISSIM traffic simulation platform is used for building a congestion scene of the road section, the arrangement position of a variable information sign of the road section in the congestion scene is determined, and the congestion scene comprises a confluence congestion scene or a traffic accident congestion scene; based on the congestion scene, different guidance strategies are published at the layout position, traffic simulation is carried out, evaluation index simulation data of each lane before and after the different guidance strategies are published are collected, and evaluation indexes are indexes used for evaluating a variable information sign layout scheme; according to the evaluation index simulation data, utilizing an entropy weight-grey correlation method to carry out divided lane evaluation on a variable information sign layout scheme of the road section; and according to the evaluation result of each lane, generating an optimization suggestion of the variable information sign layout scheme.

Description

Technical Field

[0001] The embodiments of the present invention relate to the technical field of traffic guidance facility evaluation, and in particular to a method for optimizing variable information sign layout scheme based on traffic simulation. Background Art

[0002] As an important part of the modern transportation system, the operation efficiency and safety of highways have a great impact on social and economic development. With the continuous increase in traffic volume, highway traffic management faces huge challenges. As an intelligent traffic management tool, variable information signs can publish traffic information in real time, such as speed limits, lane control, road conditions and traffic incidents. Whether the layout plan is reasonable is crucial to guiding vehicle flow, improving road traffic efficiency and reducing traffic accidents.

[0003] At present, the evaluation and optimization of variable information sign layout schemes on highways are mainly based on traffic engineering experience and traditional traffic data analysis methods. However, with the complexity of traffic conditions, there is a large amount of unused traffic data in the dynamically changing traffic conditions. Traditional methods cannot consider comprehensive traffic conditions and traffic data, making it difficult to achieve objective and accurate evaluation and optimization. Summary of the invention

[0004] The present invention proposes a variable information sign layout optimization method based on traffic simulation, constructs different traffic condition scenarios and uses traffic data obtained from traffic simulation to solve the above technical problems.

[0005] In a first aspect, an embodiment of the present invention provides a method for optimizing a variable information sign layout scheme based on traffic simulation, comprising:

[0006] Obtain the road section to be optimized;

[0007] Using the VISSIM traffic simulation platform to build a congestion scenario of the road section, and determining the layout position of the variable information sign of the road section in the congestion scenario, wherein the congestion scenario includes a merging congestion scenario or a traffic accident congestion scenario;

[0008] Based on the congestion scenario, different induction strategies are issued at the layout location and traffic simulation is performed, and evaluation index simulation data of each lane before and after the issuance of different induction strategies are collected, wherein the evaluation index is an index used to evaluate the layout scheme of variable information signs;

[0009] According to the simulation data of the evaluation index, the variable information sign layout scheme of the road section is evaluated by lane by lane using the entropy weight-grey association method;

[0010] Based on the evaluation results of each lane, an optimization suggestion for the variable information sign layout plan is generated.

[0011] In a second aspect, an embodiment of the present invention provides an electronic device, including:

[0012] one or more processors;

[0013] a memory for storing one or more programs,

[0014] When the one or more programs are executed by the one or more processors, the one or more processors implement the variable information sign layout scheme optimization method based on traffic simulation described in any of the above embodiments.

[0015] In a third aspect, an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the method for optimizing the layout of variable information signs based on traffic simulation as described in any of the above embodiments.

[0016] In summary, this embodiment provides a variable information sign layout optimization method based on traffic simulation, which simulates the role of variable information signs in highway traffic through traffic simulation, so as to objectively and accurately evaluate and optimize the variable information signs. Specifically, the method starts from the traffic induction function of variable information signs, simulates the traffic conditions under no induction strategy and different induction strategies, and collects simulation data of evaluation indicators during the simulation process; finally, the entropy weight-grey correlation method is used to jointly process the simulation data of the evaluation indicators to achieve lane-by-lane evaluation of the variable information sign layout plan, and provide different optimization suggestions based on the evaluation results. The entire method reflects the traffic improvement capabilities of variable information sign layout plans under different induction strategies and different lanes, and objectively and accurately evaluates and optimizes the variable information sign layout plan. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a flow chart of optimizing a variable information sign layout scheme based on traffic simulation provided by an embodiment of the present invention;

[0019] Figure 2 It is a plan schematic diagram of a highway merging congestion scenario provided by an embodiment of the present invention;

[0020] Figure 3It is a plan schematic diagram of a highway traffic accident congestion scene provided by an embodiment of the present invention;

[0021] Figure 4 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0023] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0024] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0025] Figure 1 The present invention provides a flow chart of optimizing the layout of variable information signs based on traffic simulation. The method is applicable to sections of highways prone to congestion and is executed by electronic equipment. Figure 1 As shown, the method specifically includes:

[0026] S110: Obtain a road section to be optimized.

[0027] In this step, a section of the expressway that is prone to traffic congestion is selected as the section to be optimized. In this embodiment, the existing variable information sign layout scheme for the section is evaluated and optimized.

[0028] Optionally, a road section prone to traffic congestion can be selected based on the traffic information of the expressway. In a specific embodiment, the traffic flow data of the main road and the entrance and exit ramps can be collected by the traffic flow detection equipment; the average speed of vehicles in different sections is calculated based on the traffic flow data, and whether the section is prone to traffic congestion is determined based on the traffic congestion level range of the average vehicle speed. Exemplarily, when the average speed of vehicles on a road section is lower than 20km / h, the section is in a serious congestion state; when the average speed of vehicles on a road section is between 20 and 40km / h, the section is in a congestion state; when the average speed of vehicles on a road section is between 40 and 60km / h, the section is in a slow-moving state; when the average speed of vehicles on a road section is between 60 and 80km / h, the section is in a basically unobstructed state; when the average speed of vehicles on a road section is between 80 and 100km / h, the section is in a smooth state; when the average speed of vehicles on a road section is greater than 120km / h, the section is in a smooth and unobstructed state. The specific judgment rule may be determined according to relevant standards or may be set according to experience, and the embodiment of the present invention does not impose any specific limitation thereto.

[0029] S120, using the VISSIM traffic simulation platform to build a congestion scenario for the road section, and determining the layout position of the variable information signs of the road section in the congestion scenario, wherein the congestion scenario includes a merging congestion scenario or a traffic accident congestion scenario.

[0030] Due to the different road network structures, the congestion scenarios in different sections are also different. In traffic simulation, different congestion scenarios need to be modeled separately. Figure 2 and Figure 3 The following example shows two congestion scenarios under different road network structures: Figure 2 The congestion scene at the merging point of the highway entrance ramp is called the merging congestion scene. Figure 3 The single lane traffic accident congestion scene of the normal road section is shown. This embodiment can determine the congestion scene matching it according to the specific road network structure of the road section to be optimized.

[0031] Optional, for Figure 2 For the two congestion scenarios in the paper, we can use the traffic volume composition and vehicle path selection ratio in the VISSIM traffic simulation platform to build a congestion scenario at the merging point of the highway entrance ramp; and use the parking lot module in the VISSIM traffic simulation platform to build a congestion scenario where two or more vehicles have a single-lane traffic accident.

[0032] After the scene is built, the virtual position of the variable information sign on the highway in the congestion scene is determined according to the actual position of the variable information sign on the road section.

[0033] S130. Based on the congestion scenario, different induction strategies are issued at the layout location and traffic simulation is performed, and evaluation index simulation data of each lane before and after the issuance of different induction strategies are collected, wherein the evaluation index is an index used to evaluate the layout plan of variable information signs.

[0034] Different induction strategies for variable message signs will have different effects on the traffic congestion of road sections. Appropriate induction strategies can quickly and effectively solve the traffic congestion problem of road sections. When evaluating the variable message sign layout plan, it is necessary to consider the changes in the evaluation index data of each lane under different induction strategies.

[0035] Optionally, in order to achieve an objective and accurate evaluation, this embodiment constructs a set of evaluation index systems by analyzing the position of variable information signs and the impact of the release of induction strategies on traffic conditions. Specifically, the reasonable layout of variable information signs can reduce the number of equipment and construction costs, and reduce long-term maintenance costs. By improving traffic efficiency and reducing traffic congestion, the overall economic benefits can be improved. By providing real-time road conditions information and warnings, traffic accidents can be effectively prevented and drivers' safety awareness can be improved; variable information signs are laid out on key sections, and the induction strategies released can remind drivers to adjust their behavior in time, reduce the accident rate, and improve the overall safety level of highways. Reasonable layout positions ensure that information is transmitted to drivers at the most needed time, improving the utilization efficiency of information; allowing drivers to have enough time to react and make decisions, improving the efficiency of highway traffic, reducing traffic congestion, and improving utilization. Therefore, the layout scheme evaluation system in the embodiment of the present invention is constructed from three aspects: economy, practicality, and safety, and specifically includes the following evaluation indicators:

[0036] In terms of economy, the evaluation indicators include installation cost and fuel consumption. Among them, the installation cost of variable message signs refers to the total cost required for installation and maintenance on highways, which directly reflects the economic investment of the plan. Fuel consumption is directly related to the economic cost of traffic operation and is an important indicator to measure whether traffic management measures are energy-saving and emission-reducing; the economic efficiency of the variable message sign installation plan can be judged based on its impact on fuel consumption.

[0037] In terms of practicality, the evaluation indicators include induced compliance rate, average speed, queue delay time, and layout distance. Among them, the induced compliance rate refers to the degree of compliance of drivers with the information released by variable information signs; the compliance rate indicates whether the variable information signs can effectively guide driver behavior and measure its practicality in the road section. The average speed refers to the average driving speed of vehicles in the road section. Reasonable layout of variable information signs should be able to increase the average driving speed of vehicles, reduce traffic congestion, and improve traffic efficiency. Queue delay time refers to the delay time caused by traffic queues in the control area of ​​variable information signs. The shorter the delay time, the smoother the traffic flow, and the higher the practicality of variable information signs for traffic flow. The layout distance refers to the distance between the variable information signs of the road section and the place where traffic accidents are prone to occur or the congestion of the entrance ramp. Different layout distances will affect the effect of the induced strategy. If it is within a reasonable distance in front of the traffic congestion, it can have a better effect on alleviating traffic congestion.

[0038] In terms of safety, the evaluation indicators include headway, which refers to the time interval between the front and rear vehicles, and measures driving safety. Reasonable variable information sign layout should be able to increase the headway, reduce the occurrence of rear-end collisions, and improve driving safety.

[0039] Based on the above evaluation index, in a specific implementation, the evaluation index simulation data of each lane before and after issuing different induction strategies can be obtained through the following steps:

[0040] First, based on the congestion scenario, the traffic flow of the road section without an induction strategy is simulated, and data collection points and timers are placed on each lane using the VISSIM platform to collect simulation data of each evaluation indicator on each lane before the induction strategy is released.

[0041] Then, different induction strategies are simulated and released at the layout position, and traffic flow simulation under different induction strategies is performed; during the simulation process, evaluation index simulation data of each lane after the induction strategy is released is collected. Optionally, speed limits, path selection and proportions can be set for each lane within a certain range before and after the virtual position of the variable information sign to simulate the release of different induction strategies. Further, the induction strategies in this embodiment include variable speed limit induction strategies, and variable speed limit plus vehicle lane change induction strategies. Among them, the variable speed limit induction strategy can be released by setting the speed limit of the leftmost lane to v1, the speed limit of the middle lane to v2, and the speed limit of the rightmost lane to v3, and usually v1, v2 and v3 take different values. The variable speed limit plus vehicle lane change induction strategy can be released by changing the lane where congestion or traffic accidents occur to the lane without congestion or traffic accidents, and setting the speed limit of the leftmost lane to v4, the speed limit of the middle lane to v5, and the speed limit of the rightmost lane to v6. Usually v4, v5 and v6 also take different values, and the units of v1 to v6 are all km / h. After the induction strategy is released, the simulation is started, and the data collection points and timers are placed on each lane using the data collection points in the VISSIM platform to collect the simulation data of each evaluation indicator on each lane.

[0042] S140. According to the evaluation index simulation data, an entropy weight-grey association method is used to perform lane-by-lane evaluation on the variable information sign layout plan of the road section.

[0043] The entropy weight-grey correlation method is a method proposed in this embodiment to jointly calculate the simulation data of the evaluation index using the entropy weight method and the grey correlation method. Among them, the entropy weight method is an objective weighting method based on information theory, and its weight is determined by calculating the entropy value of each index. Entropy is used to measure uncertainty. The greater the discreteness of the index (the greater the uncertainty), the greater the entropy value, indicating that the more information the index value provides, the greater the weight of the index should be. Compared with the subjective weighting method, the entropy weight method objectively reflects the discreteness of the data itself and reduces the influence of subjective factors. The grey correlation method is to regard the factor values ​​of the research object and the influencing factors as points on a line, and compare them with the curve drawn by the factor values ​​of the object to be identified and the influencing factors, compare the closeness between them, and quantify them separately, calculate the correlation between the closeness of the research object and the influencing factors of the object to be identified, and judge the influence of the object to be identified on the research object by comparing the size of each correlation. The combination of the two methods can be adapted to the variable information sign layout scheme for lane division evaluation.

[0044] More specifically, different evaluation indicators have different impacts on the advantages and disadvantages of the variable information sign layout scheme, and it is necessary to assign weights to the evaluation indicators in the embodiment of the present invention; and the same induction strategy has different impacts on the traffic conditions of different lanes. Simply calculating based on the data of the entire section may ignore important changes in a certain lane, and it is necessary to first calculate the evaluation score for each lane; taking into account the weight allocation and lane calculation, the evaluation results obtained in this example can be more effective and accurate.

[0045] Based on the above concept, in a specific implementation, when the variable information sign layout scheme of the road section is evaluated by lane by lane using the entropy weight-grey correlation method, the following operations can be performed for each lane:

[0046] Step 1: Due to the large difference in the dimensions of the evaluation indicators, it is necessary to perform dimensionless processing on the evaluation indicator simulation data of the current lane. Optionally, the following operations can be performed for each evaluation indicator:

[0047] S1-1, take the non-inducing strategy as a situation to be evaluated, take n kinds of inducing strategies as n kinds of situations to be evaluated, and together constitute n+1 kinds of situations to be evaluated; perform average processing on the simulation data of the current evaluation index in the n+1 kinds of situations to be evaluated. The average formula is as follows:

[0048]

[0049] Among them, x ij is the original simulation data of the jth evaluation index (i.e. the current evaluation index) under the condition i to be evaluated, is the average value of the jth evaluation index in the n+1 cases to be evaluated, n is the number of induction strategies, i=0 corresponds to the case of no induction strategy, Represents x ij The averaged value of .

[0050] S1-2, the evaluation index is divided into positive index and negative index, and the averaged values ​​of the positive index and the negative index are dimensionless, respectively, to obtain dimensionless simulation data of each evaluation index. Among them, the larger the positive index value, the better the evaluation index. In this embodiment, the induced compliance rate, average speed and headway are all positive indicators. The smaller the negative index value, the better the evaluation index. In this embodiment, the layout cost, layout distance, fuel consumption and queue delay time are all negative indicators.

[0051] For positive indicators, the dimensionless formula is as follows:

[0052]

[0053] For negative indicators, the dimensionless formula is as follows:

[0054]

[0055] in, and They are respectively represented as the maximum and minimum values ​​of the averaged values ​​of the jth evaluation indicator in the n+1 evaluation cases, that is, n+1 The maximum and minimum values ​​in .

[0056] Step 2: According to the dimensionless simulation data of the current lane evaluation index, the entropy weight method is used to determine the weight coefficient of each evaluation index, wherein the weight coefficient is used to characterize the importance of each evaluation index in the evaluation of the variable information sign layout scheme. Optionally, the following operations can be performed for each evaluation index:

[0057] S2-1. Calculate the proportion of the current evaluation index among the n+1 situations to be evaluated based on the dimensionless simulation data of the current evaluation index before and after the release of different induction strategies.

[0058]

[0059] Among them, q ij It represents the weight of the jth evaluation indicator (i.e. the current evaluation indicator) in the situation i to be evaluated.

[0060] S2-2, according to the proportion of the current evaluation index among the situations to be evaluated, calculate the information entropy of the current evaluation index, wherein the information entropy is used to reflect the amount of information that the evaluation index can provide in the evaluation of the variable information sign layout scheme.

[0061]

[0062] Among them, M j Represents the information entropy of the j-th evaluation indicator.

[0063] After performing S2-1 and S2-2 operations on all evaluation indicators, the information entropy of all evaluation indicators can be obtained, and the weight coefficient of each evaluation indicator can be calculated:

[0064]

[0065] Among them, ω j represents the weight coefficient of the jth evaluation indicator, and m represents the number of evaluation indicators.

[0066] Step 3: Use the dimensionless simulation data of the current evaluation index before the induction strategy is released as a reference sequence, and use the simulation data of each evaluation index in each case to be evaluated as a sequence to be evaluated; according to the reference sequence and each sequence to be evaluated, calculate the grey correlation degree of each evaluation index in each case to be evaluated, wherein the grey correlation degree is used to characterize the improvement of each evaluation index in each case to be evaluated. Optionally, the following double cycle can be performed:

[0067] Perform the following operations for each situation to be evaluated:

[0068] In the current evaluation situation, perform operations from S3-1 to S3-2 for each evaluation indicator:

[0069] S3-1, taking dimensionless simulation data of the current evaluation index in the current situation to be evaluated as the current sequence to be evaluated. If the current situation to be evaluated is a situation without an induction strategy, the current sequence to be evaluated is equal to the reference sequence; if the current situation to be evaluated is a situation with a certain induction strategy, the sequence to be evaluated is different from the reference sequence.

[0070] S3-2, according to the dimensionless simulation data of the current evaluation index in the reference sequence and the current sequence to be evaluated, the grey relational degree of the current evaluation index in the current sequence to be evaluated is calculated, and the calculation formula is as follows:

[0071]

[0072] Among them, ij represents the grey correlation degree of the jth evaluation index (i.e. the current evaluation index) under the situation to be evaluated i (i.e. the current situation to be evaluated); max|x 0j -x ij | and min|x 0j -x ij |represents the dimensionless simulation data of the jth evaluation index in each evaluation case Compared with the dimensionless simulation data without induction strategy The maximum and minimum values ​​of the absolute value of the difference between |x 0j -x 1j |、|x 0j -x 2j |、…|x 0j -x nj | is the maximum and minimum value in; ρ is the resolution coefficient, usually taken as 0.5; ε is an extremely small constant that can be ignored, used to avoid the situation where the numerator is 0.

[0073] Step 4: Calculate the comprehensive score of the current lane according to the weight coefficients of the evaluation indicators and the grey correlation degree in each case to be evaluated. Optionally, firstly, for each case to be evaluated, according to the weight coefficients of the evaluation indicators obtained in step 2, perform weighted summation on the grey correlation degree of each evaluation indicator in the current case to be evaluated, and obtain the score of the current lane in the current case to be evaluated.

[0074]

[0075] Among them, S i Represents the score of the current lane in the situation i to be evaluated.

[0076] After obtaining the scores of the current lane in all the situations to be evaluated, the absolute value of the difference between the scores of the current lane in each of the two situations is calculated, and the maximum value among the absolute values ​​is taken as the comprehensive score of the current lane. The comprehensive score is used to evaluate the ability of the variable information sign layout scheme to improve lane traffic. Specifically, by selecting any two of the n situations to be evaluated, we can obtain the difference between the scores of the two situations to be evaluated in each situation combination, and the maximum value of the absolute values ​​of all the differences is taken as the comprehensive score of the current lane.

[0077] S150: Generate optimization suggestions for the variable information sign layout plan based on the evaluation results of each lane.

[0078] After S130, each lane obtains its own comprehensive score, and the comprehensive scores of all lanes are averaged to obtain the comprehensive score of the road section. According to the comprehensive score of the road section, the variable information sign layout plan of the road section can be retained or optimized.

[0079] Optionally, if the comprehensive score of the road section is at the optimal level, the variable information sign layout plan can be kept unchanged; if the comprehensive score of the road section is at an intermediate level, it can be suggested to fine-tune the position of the variable information signs of the road section, or to keep the current variable information sign layout position; if the comprehensive score of the road section is at the worst level, it can be suggested to increase or reduce the variable information signs of the road section according to the variable information sign setting position regulations of the highway.

[0080] Under the calculation of the above non-quantified data, the comprehensive score of the road section is a value in the interval [0-1]. In a specific implementation, the optimal level refers to a comprehensive score greater than 0.6. When the comprehensive score of the road section is at this level, it indicates that the current variable information sign layout plan of the road section is reasonable, and it can be recommended to retain the current variable information sign; the intermediate level refers to a comprehensive score between [0.4, 0.6]. When the comprehensive score of the road section is at this level, it indicates that the current variable information sign layout plan of the road section is relatively reasonable. It can be recommended to appropriately move the current variable information sign layout position forward and backward, or keep the current variable information sign layout position; the worst level refers to a comprehensive score less than 0.4. When the comprehensive score of the road section is at this level, it indicates that the current variable information sign layout plan of the road section is unreasonable. It is recommended to increase or reduce the variable information signs of the road section according to the regulations on the location of variable information signs on highways.

[0081] Specifically, Figure 2 Taking the merging congestion scenario as an example, if the level obtained by the method of this embodiment for this scenario is the worst level, then according to the variable information sign setting location regulations for highways, it is recommended to remove the variable information signs on this section of the scene, and add new variable information signs 500m to 800m upstream of the merging congestion; after the addition, the new level is determined by the method of this embodiment. If it is the optimal level, the recommended layout position is retained. If it is an intermediate level, the distance is adjusted. Among the above-mentioned optimization methods, if the new level after optimization is the worst level, variable information signs will continue to be added upstream, with a spacing of 5km to 10km; this cycle is repeated until the final level is the optimal level or the intermediate level.

[0082] In summary, this embodiment provides a variable information sign layout optimization method based on traffic simulation, which simulates the role of variable information signs in highway traffic through traffic simulation, so as to objectively and accurately evaluate and optimize variable information signs. Specifically, the method starts from the traffic induction function of variable information signs, simulates the traffic conditions under no induction strategy and different induction strategies; and determines the evaluation indicators of the variable information sign layout plan from the three aspects of economy, practicality and safety, and collects simulation data of the evaluation indicators during the simulation process; finally, the information entropy method is used to determine the weight coefficient of each evaluation indicator, and the gray correlation degree of each indicator is determined by the gray correlation method. Through the weighted summation of the weight coefficient and the gray correlation degree, the variable information sign layout plan is evaluated by lane, and different optimization suggestions are provided according to the evaluation results. The whole method reflects the traffic improvement ability of variable information sign layout plans under different induction strategies and different lanes, and objectively and accurately evaluates and optimizes the variable information sign layout plan.

[0083] Figure 4A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention is shown in FIG. Figure 4 As shown, the device includes a processor 60, a memory 61, an input device 62 and an output device 63; the number of processors 60 in the device can be one or more. Figure 4 A processor 60 is taken as an example; the processor 60, the memory 61, the input device 62 and the output device 63 in the device can be connected by a bus or other means. Figure 4 The example of connecting through bus is taken in the following.

[0084] The memory 61, as a computer-readable storage medium, can be used to store software programs, computer executable programs and modules, such as program instructions / modules corresponding to the method for dynamically updating node routing in a wireless short-range communication network in the embodiment of the present invention. The processor 60 executes various functional applications and data processing of the device by running the software programs, instructions and modules stored in the memory 61, that is, realizing the above-mentioned method for dynamically updating node routing in a wireless short-range communication network.

[0085] The memory 61 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system and at least one application required for a function; the data storage area may store data created according to the use of the terminal, etc. In addition, the memory 61 may include a high-speed random access memory, and may also include a non-volatile memory, such as at least one disk storage device, a flash memory device, or other non-volatile solid-state storage device. In some instances, the memory 61 may further include a memory remotely arranged relative to the processor 60, and these remote memories may be connected to the device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0086] The input device 62 may be used to receive input digital or character information and generate key signal input related to user settings and function control of the device. The output device 63 may include a display device such as a display screen.

[0087] An embodiment of the present invention further provides a computer-readable storage medium on which a computer program is stored. When the program is executed by a processor, the method for dynamically updating node routing in a wireless short-range communication network of any embodiment is implemented.

[0088] The computer storage medium of the embodiment of the present invention can adopt any combination of one or more computer-readable media. The computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. The computer-readable storage medium can be, for example, but not limited to, a system, device or device of electricity, magnetism, light, electromagnetic, infrared, or semiconductor, or any combination of the above. More specific examples (non-exhaustive list) of computer-readable storage media include: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, a computer-readable storage medium can be any tangible medium containing or storing a program, which can be used by an instruction execution system, a device or a device or used in combination with it.

[0089] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, which carry computer-readable program code. Such propagated data signals may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. Computer-readable signal media may also be any computer-readable medium other than a computer-readable storage medium, which may send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device.

[0090] The program code embodied on the computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.

[0091] Computer program code for performing the operations of the present invention may be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, C++, and conventional procedural programming languages ​​such as C or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., through the Internet using an Internet service provider).

[0092] 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 above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace part or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the technical solutions of the embodiments of the present invention. .

Claims

1. A variable information sign layout optimization method based on traffic simulation, characterized in that: include: Obtain the road section to be optimized; Using the VISSIM traffic simulation platform to build a congestion scenario of the road section, and determining the layout position of the variable information sign of the road section in the congestion scenario, wherein the congestion scenario includes a merging congestion scenario or a traffic accident congestion scenario; Based on the congestion scenario, different induction strategies are issued at the layout location and traffic simulation is performed, and evaluation index simulation data of each lane before and after the issuance of different induction strategies are collected, wherein the evaluation index is an index used to evaluate the layout scheme of variable information signs; According to the simulation data of the evaluation index, the variable information sign layout scheme of the road section is evaluated by lane by lane using the entropy weight-grey association method; Based on the evaluation results of each lane, an optimization suggestion for the variable information sign layout plan is generated.

2. The method according to claim 1, characterized in that The obtaining of the road section to be optimized comprises: Obtain traffic flow data for each road section; Calculating the average speed of vehicles on each road section based on the traffic flow data; According to the average speed of the vehicles, a road section prone to congestion is selected as the road section to be optimized.

3. The method according to claim 1, characterized in that The evaluation indicators include economic indicators, practical indicators and safety indicators; The economic indicators include deployment cost and fuel consumption; The practical indicators include induced compliance rate, average speed, queue delay time, and layout distance; According to safety indicators including headway.

4. The method according to claim 1, characterized in that: The method of evaluating the variable information sign layout scheme of the road section by lane by using the entropy weight-grey association method according to the evaluation index simulation data includes: Perform the following operations for each lane: According to the simulation data of each evaluation index of the current lane, the entropy weight method is used to determine the weight coefficient of each evaluation index, wherein the weight coefficient is used to characterize the importance of each evaluation index in the evaluation of the variable information sign layout plan; The simulation data of each evaluation index before the release of the induction strategy is used as the reference sequence; The non-inducing strategy and each inducing strategy are respectively regarded as a situation to be evaluated, and the simulation data of each evaluation index in each situation to be evaluated are respectively regarded as a sequence to be evaluated; According to the reference sequence and each sequence to be evaluated, respectively calculating the grey relational degree of each evaluation index in each case to be evaluated, wherein the grey relational degree is used to characterize the improvement of each evaluation index in each case to be evaluated; The comprehensive score of the current lane is calculated according to the weight coefficient of each evaluation index and the grey correlation degree in each case to be evaluated, wherein the comprehensive score is used to evaluate the ability of the variable information sign layout scheme to improve lane traffic.

5. The method according to claim 4, characterized in that The method of using the entropy weight method to determine the weight coefficient of each evaluation index based on the simulation data of each evaluation index of the current lane includes: The non-guiding strategy and each guiding strategy are respectively regarded as a situation to be evaluated, and the proportion of the same evaluation index in each situation to be evaluated is calculated according to the simulation data of the same evaluation index of the current lane in each situation to be evaluated; Calculate the information entropy of the same evaluation indicator according to the proportion of the same evaluation indicator in each situation to be evaluated, wherein the information entropy is used to reflect the amount of information that the evaluation indicator can provide in the evaluation of the variable information sign layout plan; According to the information entropy of each evaluation indicator, the weight coefficient of each evaluation indicator is calculated.

6. The method according to claim 4, characterized in that The step of calculating the grey relational degree of each evaluation index in each case to be evaluated according to the reference sequence and each sequence to be evaluated comprises: Take the sequence to be evaluated in any case to be evaluated as the current sequence to be evaluated; According to the simulation data of the same evaluation index in the reference sequence and the current sequence to be evaluated, the grey relational degree of the same evaluation index in any of the cases to be evaluated is calculated.

7. The method according to claim 4, characterized in that The comprehensive score of the current lane is calculated according to the weight coefficient of each evaluation index and the grey correlation degree in each case to be evaluated, including: For each situation to be evaluated: according to the weight coefficient of each evaluation index, the grey correlation degree of each evaluation index in the current evaluation situation is weighted and summed to obtain the score of the current lane in the current situation to be evaluated; The absolute value of the difference between the scores of the current lane in each of the two situations is calculated, and the maximum value among the absolute values ​​is taken as the comprehensive score of the current lane.

8. The method according to claim 1, characterized in that Generating optimization suggestions for the variable information sign layout scheme according to the evaluation results of each lane includes: If the average evaluation result of each lane is at the optimal level, generating a suggestion to keep the variable message sign layout plan unchanged; If the average evaluation result of each lane is at an intermediate level, generating an optimization suggestion for adjusting the position of the variable message sign; If the average estimation result of each lane is at the worst level, an optimization suggestion for adjusting the number of variable information signs is generated.

9. An electronic device, characterized in that: include: one or more processors; a memory for storing one or more programs, When the one or more programs are executed by the one or more processors, the one or more processors implement the variable information sign layout scheme optimization method based on traffic simulation as described in any one of claims 1-8.

10. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the program is executed by a processor, the method for optimizing the layout scheme of variable information signs based on traffic simulation as described in any one of claims 1-8 is implemented.

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