Traffic signal control method for plane intersection formed by intersection with large road level difference

Abstract

The invention discloses a traffic signal control method for a plane intersection formed by intersection with a large road level difference, and aims to solve the problems that a main road and a branch road of the intersection with the large road level difference are unbalanced in traffic efficiency and serious in traffic flow conflict. The method is based on a traffic signal control intersection and a signal controller capable of adjusting a release mode, and comprises the following steps: calculating an absolute value The of a level difference of connected roads, and judging whether the absolute value The is greater than or equal to a set threshold value T1; collecting small branch opposite entrance straight traffic flow hour flow, calculating an unbalance coefficient beta, and judging whether the unbalance coefficient beta is greater than a set threshold value T2 or not; an early starting inlet is dynamically determined according to the flow; setting a single-release lap joint early start phase for the early start inlet and distributing time; and issuing a scheme and tracking and finely adjusting for one week. According to the method, the channelization of the intersection does not need to be transformed, the efficiency of the main road is guaranteed through double-threshold triggering and dynamic phase design, meanwhile, branch conflict and congestion can be remarkably relieved, and the aim of improving the traffic capacity and order of the intersection efficiently at low cost is achieved.

Description

Technical Field

[0001] This invention relates to the field of urban road traffic signal control, specifically to a traffic signal control method for a planar intersection formed by roads with large differences in road level. Background Technology

[0002] At-grade intersections, as key nodes in urban road networks, are formed by the intersection of two or more roads. When traffic volume reaches a certain scale, traffic lights and supporting control schemes are required to ensure the safe and orderly passage of traffic. The core of traffic signal control schemes lies in phase sequence design and timing optimization. Their rationality directly depends on multiple factors such as intersection road conditions, lane layout, traffic volume characteristics, and driving habits of traffic participants. Only by accurately matching the actual situation of the intersection can traffic order be effectively maintained and traffic capacity improved.

[0003] In urban road systems, due to differences in functional positioning, different roads exhibit significant differences in traffic function hierarchy. When roads with excessively large hierarchical differences intersect to form functionally mismatched intersections, they easily become traffic congestion bottlenecks. A typical scenario is the intersection of urban arterial roads and minor roads. Existing signal control strategies typically prioritize ensuring the efficiency of arterial roads, employing a conflict-free multi-phase release mode with a high green light ratio. However, minor roads, limited by signal cycles, often adopt a full-phase release with simultaneous release of both oncoming entrances. When traffic volume is low, the interference between left-turning vehicles and oncoming through traffic on minor roads is relatively weak, and traffic flow at the intersection is generally smooth. However, during peak hours, as traffic volume on minor roads surges, the traffic flow conflict problem under the full-phase release becomes acutely apparent. Left-turning vehicles and oncoming through traffic interfere with and intertwine with each other, leading to intersection "knots," disorder, and a significant decrease in traffic efficiency.

[0004] If a conflict-free multi-phase release scheme is adopted to resolve conflicts on side roads, it will inevitably prolong the signal cycle at the intersection, reduce the green light ratio on the main road, decrease the traffic efficiency of the main road, and ultimately lead to a decline in the overall operational efficiency of the intersection. Therefore, the industry usually needs to optimize the signal control scheme for such intersections, adjusting the conflict flow direction and congestion nodes through traffic control measures. However, the existing optimization process requires multiple steps, including basic intersection surveys, traffic flow calculation and analysis, scheme design and issuance, and subsequent inspection and maintenance. This process is not only time-consuming, but also often requires physical engineering methods such as intersection channelization to resolve conflicts caused by road design flaws. This results in high traffic management and congestion relief costs, significantly increasing capital investment and workload, making it difficult to achieve the optimization goal of low cost and high efficiency.

[0005] To address the shortcomings of existing technologies, there is an urgent need for a special signal control method adapted to intersections with large road level differences. This method should balance the traffic efficiency of the main road and the traffic demand of the secondary road through precise phase design and control strategies, without requiring any modification to the physical infrastructure of the intersection, thereby alleviating traffic flow conflicts and improving the overall operational efficiency of the intersection. Summary of the Invention

[0006] The main objective of this invention is to overcome the shortcomings and deficiencies of existing technologies and provide a traffic signal control method for intersections formed by roads with large differences in road level. This method involves setting an overlapping phase at the entrance of a minor road at the intersection to initiate early signal control, ensuring the capacity and order of the minor road. Then, by calculating and analyzing traffic flow and combining it with road conditions, an appropriate phase sequence is determined and issued, thereby improving the intersection's capacity and reducing traffic conflicts. This achieves a low-cost solution to traffic congestion and order problems caused by road design flaws at intersections without requiring channelization modifications, saving on traffic management and congestion mitigation costs and workload.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention provides a traffic signal control method for a planar intersection formed by the intersection of roads with large differences in road elevation, comprising the following steps:

[0009] S1. Calculate the grade difference between connected roads: Obtain the grade values ​​P1 and P2 of the two connected roads at the target intersection, calculate the absolute value of the grade difference The = |P1-P2|, and determine whether the absolute value of the grade difference The is greater than or equal to the set threshold T1. If not, end the process; if yes, proceed to step S2. The grade values ​​of the roads correspond as follows: highway grade is 1, expressway grade is 2, main road grade is 3, secondary road grade is 4, main collector road grade is 5, secondary collector road grade is 6, regional road grade is 7, and access road grade is 8.

[0010] S2. Calculate the difference in through traffic flow between opposing entrances: Collect the hourly through traffic flow h1 and h2 at the first and second entrances of the minor branch road, and calculate the flow difference based on h1 and h2. The flow difference is expressed as an imbalance coefficient. Determine if β is greater than the set threshold T2. If not, end the process; if yes, proceed to step S3.

[0011] S3. Determine the early start-up inlet: Compare the sizes of h1 and h2. If h1 > h2, then determine the first inlet as the early start-up inlet; if h1 ≤ h2, then determine the second inlet as the early start-up inlet.

[0012] S4. Generate early start control phase: Set early start control phase for the determined early start entrance, and allocate the timing of each phase based on the intersection survey, control strategy and the queuing situation of vehicles in each direction;

[0013] S5. Phase Adjustment and Tracking: The optimized phase timing scheme is sent to the intersection signal controller, tracked for one week and fine-tuned to determine the final timing scheme.

[0014] As a preferred technical solution, in step S1, the set threshold T1 is 3.

[0015] As a preferred technical solution, in step S1, the target intersection is a traffic signal controlled intersection, and the supporting traffic signal controller can adjust the release mode.

[0016] As a preferred technical solution, in step S1, when the road ranks in the same direction are inconsistent, the maximum value is taken as the road rank value in that direction.

[0017] As a preferred technical solution, in step S2, the set threshold T2 is 0.18.

[0018] As a preferred technical solution, in step S4, the early start control phase is a single-phase overlapping phase, which is used to alleviate traffic conflicts at opposite entrances of minor branch roads.

[0019] As a preferred technical solution, in step S5, the effect tracking is used to evaluate the optimization effect by monitoring the queue length, number of stops and delay indicators of each direction of traffic at the intersection.

[0020] Secondly, the present invention provides a traffic signal control system for a plane intersection formed by roads with large differences in road level, which is applied to the traffic signal control method for the plane intersection formed by roads with large differences in road level, including a road level calculation module, a flow difference calculation module, an early start inlet determination module, an early start control phase generation module, and a phase adjustment and tracking module;

[0021] The road rank calculation module is used to obtain the rank values ​​P1 and P2 of two connected roads at the target intersection, calculate the absolute value of the rank difference The = |P1-P2|, and determine whether the absolute value of the rank difference The is greater than or equal to a set threshold T1. If not, the process ends; if yes, the traffic flow difference calculation module is executed. The rank values ​​of the roads are as follows: highway rank is 1, expressway rank is 2, main road rank is 3, secondary road rank is 4, main collector road rank is 5, secondary collector road rank is 6, regional road rank is 7, and access channel rank is 8.

[0022] The traffic flow difference calculation module is used to collect the hourly traffic flow h1 and h2 of the through traffic at the first and second inlets of the minor branch road, and calculate the traffic flow difference based on h1 and h2. The traffic flow difference is expressed as an imbalance coefficient. Determine if β is greater than the set threshold T2. If not, end the process; if yes, execute the early start import determination module.

[0023] The early start inlet determination module is used to compare the size of h1 and h2. If h1 > h2, the first inlet is determined to be the early start inlet; if h1 ≤ h2, the second inlet is determined to be the early start inlet.

[0024] The early start control phase generation module is used to set the early start control phase for the determined early start entrance, and allocate the timing of each phase in combination with the intersection survey, control strategy and the queuing situation of vehicles in each direction.

[0025] The phase adjustment and tracking module is used to send the optimized phase timing scheme to the intersection signal controller, track and run it for a week and make fine adjustments to determine the final timing scheme.

[0026] Thirdly, the present invention provides an electronic device, the electronic device comprising:

[0027] At least one processor; and,

[0028] A memory communicatively connected to the at least one processor; wherein,

[0029] The memory stores computer program instructions that can be executed by the at least one processor, which enables the at least one processor to perform the traffic signal control method for intersections formed by roads with large road level differences.

[0030] Fourthly, the present invention provides a computer-readable storage medium storing a program, which, when executed by a processor, implements the traffic signal control method for a planar intersection formed by intersections with large road level differences.

[0031] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0032] This invention creates a phase control scheme that accurately matches the traffic characteristics of a critical intersection with high-level road connections (level difference The≥3) and unbalanced oncoming through traffic flow (β>0.18), without requiring modifications to physical channelization or lane layout. This is achieved through a dual-threshold dynamic triggering mechanism and a flow-driven early-start entry selection strategy. The benefits are: 1) Improved traffic efficiency, increasing the efficiency of side roads without affecting the main road's efficiency; 2) Enhanced safety, mitigating traffic conflicts at oncoming side road entry points through high-flow-rate early-start control, thus improving traffic safety; and 3) Precise resource allocation, saving nearly 450,000 yuan in equipment investment and engineering costs per intersection compared to traditional full-area renovation schemes, based on current market prices for signal system upgrades and road reconstruction. It also reduces the optimization decision-making cycle from 21 days to 3 days, effectively decreasing the time and trial-and-error costs required for intersection optimization. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a flowchart of a traffic signal control method for a planar intersection formed by roads with large differences in road level, according to an embodiment of the present invention.

[0035] Figure 2 This is a schematic diagram of the straight-through flow of two east-west opposing inlets according to an embodiment of the present invention;

[0036] Figure 3 A schematic diagram of the early start phase sequence for the eastern inlet of this invention;

[0037] Figure 4 This is a schematic diagram of the intersection location according to an embodiment of the present invention;

[0038] Figure 5 This is a schematic diagram of the existing channelization at the intersection according to an embodiment of the present invention;

[0039] Figure 6 This is a schematic diagram of the phase sequence before intersection optimization according to an embodiment of the present invention;

[0040] Figure 7 This is a schematic diagram of the phase timing of the east-west full-amplification according to an embodiment of the present invention;

[0041] Figure 8 This is a schematic diagram of the position values ​​of two connected roads at an intersection according to an embodiment of the present invention;

[0042] Figure 9This is a schematic diagram of the straight-through traffic flow at two east-west opposite inlets during the evening peak hours, according to an embodiment of the present invention.

[0043] Figure 10 This is a schematic diagram of the optimized early start phase sequence of the east entrance (phase C represents the early start release of the east entrance) according to an embodiment of the present invention.

[0044] Figure 11 This is a schematic diagram of an optimized intersection according to an embodiment of the present invention;

[0045] Figure 12 This is a block diagram of a traffic signal control system for a planar intersection formed by roads with large differences in road level, according to an embodiment of the present invention.

[0046] Figure 13 This is a structural diagram of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0047] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative effort are within the scope of protection of the present application.

[0048] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0049] Example 1

[0050] This embodiment presents a special control method for addressing traffic conflicts at intersections with significant differences in road class by early activation. Based on the road conditions of the intersecting roads, it calculates and analyzes the traffic function hierarchy difference between the intersecting roads and the traffic flow in both directions of the minor branch road. Based on the calculation results, it determines whether to set an overlapping phase for an early activation at a specific intersection on the minor branch road. After confirming the phase sequence, it sets corresponding timings according to the traffic demand of each intersection and conducts follow-up inspections. This allows the intersection signal control scheme to quickly adapt to the traffic demand of similar special intersections, achieving the effect of alleviating traffic congestion and disorder at the intersection. Thus, without requiring channelization modifications to the intersection, this low-cost method of optimizing the signal control scheme effectively solves the traffic congestion and order problems at the intersection, saving on traffic management and congestion relief costs and workload.

[0051] like Figure 1 As shown in this embodiment, a traffic signal control method for a planar intersection formed by roads with large differences in road level includes the following steps:

[0052] Step 1: Calculate the grade difference between connected roads; first obtain the grade values ​​(P1, P2) of the two connected roads at the target intersection, and calculate the absolute value of the grade difference: The = |P1 - P2|; determine whether the grade difference meets the set threshold T1 condition: The ≥ 3; if not, end the process; if yes, proceed to step 2.

[0053] The order values ​​of road positions correspond as follows: expressway is 1, highway is 2, trunk road is 3, secondary trunk road is 4, main distribution road is 5, secondary distribution road is 6, regional road is 7, and access corridor is 8; as shown in Table 1.

[0054] Table 1. Rank values ​​corresponding to different road types

[0055]

[0056] Step 2: Calculate the difference in through traffic flow between opposing inlets; collect the hourly through traffic flow (inlet 1: h1, inlet 2: h2) at the first and second inlets (inlet 2) of the opposing branch road; calculate the flow difference (imbalance coefficient): Determine if the flow difference meets the trigger condition: β > 0.18; if not, end the process; if yes, proceed to step 3.

[0057] like Figure 2 As shown, the hourly traffic flow distribution of the through traffic at the two east-west entrances of the target intersection is illustrated. The through traffic flow at the east entrance (entrance 1) is 205 ch / h, and at the west entrance (entrance 2) it is 128 ch / h. This clearly demonstrates the specific numerical difference in through traffic flow between the two east-west entrances, providing crucial data support for subsequent calculations of the traffic imbalance coefficient β (with a set threshold T2), determining whether triggering conditions are met, and identifying the early-starting entrance.

[0058] Imbalance coefficient

[0059] Step 3: Determine the early start import; allocate priority according to the relationship between flow size, and dynamically select the high demand import through the flow difference; if h1>h2: early start import = import 1; otherwise: early start import = import 2.

[0060] Step 4: Generate early start control phases; determine the early start control phases at the early start entrances, and reasonably allocate the timing of each phase based on the survey results and intersection control strategies, combined with the queuing situation of vehicles in each direction.

[0061] like Figure 3 As shown, the positions of the north-south straight-through phase (A), north-south left-turn phase (B), east single-lobe tower connection phase (C), and east-west full-lobe phase (D), as well as the newly added east entrance early start phase (i.e., single-lobe overlap phase), in the overall phase sequence are shown.

[0062] Step 5: Scheme Distribution and Effect Tracking; The optimized phase scheme is distributed to the intersection signal controller and tracked and fine-tuned for one week to finally determine the specific timing scheme and achieve the final optimization goal.

[0063] Example 2

[0064] like Figure 4 As shown, in this embodiment, the cross-shaped intersection S1 (hereinafter referred to as "S1 intersection") is located in Xicheng District, Beijing. It is a cross-shaped intersection with north-south roads connecting to the east and west. S1 intersection is located under an expressway overpass, making it an underpass intersection. Several schools and residential communities are located around the intersection. Figure 5 The diagram showing the current channelization of the intersection focuses on the S1 crossroads located under the expressway overpass in Xicheng District, Beijing. It clearly presents the core physical characteristics and traffic facility distribution of the intersection: First, the road connection relationships, clearly indicating the hierarchical attributes and intersection patterns of the north-south roads (main roads) and the east-west roads (minor roads); second, the channelization details, including the lane function division of each approach (such as the setting of straight, left-turn, and right-turn lanes), traffic marking layout, and pedestrian crossing area planning; third, environmental information, indirectly reflecting the large spatial span of the intersection. This provides a concrete basis for subsequent analysis of the physical causes of severe conflicts between non-motorized vehicles at the east approach and left-turning motorized vehicles at the west approach when the east-west direction adopts a "full-range" traffic flow. It serves as an important spatial reference for judging the impact of road hierarchy differences, identifying the root causes of traffic congestion, and formulating phase optimization schemes.

[0065] This embodiment provides a traffic signal control method for a planar intersection formed by roads with significant differences in elevation, comprising the following steps:

[0066] Step 1: Calculate the grade difference between connected roads; first obtain the grade values ​​(P1, P2) of the two connected roads at the target intersection, and calculate the absolute value of the grade difference: The = |P1 - P2|; determine whether the grade difference meets the threshold condition: The ≥ 3; if not, end the process; if yes, proceed to step 2.

[0067] Specifically, based on a week of on-site investigation, due to the large span of the intersection, it is necessary to ensure both overall traffic efficiency and pedestrian crossing issues (such as...). Figure 7As shown in the image, when releasing traffic in the east-west direction, a full release method is used, and the road grades differ significantly between the east and west sides. This results in severe conflicts between non-motorized vehicles exiting from the east entrance and left-turning motorized vehicles from the west entrance, posing significant traffic safety hazards and impacting the traffic efficiency of both entrances. Congestion and conflicts are particularly pronounced during peak hours. The phase sequence diagram before intersection optimization is shown below. Figure 6 As shown.

[0068] like Figure 8 As shown, after investigation and analysis, the north-south road is the main road, and the east and west roads are minor roads. The rank values ​​(P1, P2) of the two connected roads at the S1 intersection are (7, 3). When the ranks of the same-direction (lateral) roads are inconsistent, the maximum value is taken (the rank of the east road is 7).

[0069] If the two connecting roads have a large step difference, the next step is to calculate the absolute value of the step difference The to further determine whether the step difference meets the threshold condition: The≥3.

[0070] Calculation formula:

[0071] The = |P1-P2|;

[0072] The = |3-7|;

[0073] The = 4;

[0074] The≥3;

[0075] Based on the settlement result The≥3, the position difference meets the threshold condition. Further investigation and analysis of the straight traffic flow of the east-west branch roads at the intersection can be conducted to further confirm another setting condition and further determine the release method.

[0076] Step 2: Calculate the difference in through traffic flow between opposing inlets; collect the hourly through traffic flow at the two opposing inlets (inlet 1: h1, inlet 2: h2); calculate the flow difference (imbalance coefficient): Determine if the flow difference meets the trigger condition: β > 0.18; if not, end the process; if yes, proceed to step 3.

[0077] Based on the analysis results in step 1, the traffic conflicts and congestion at this intersection are mainly concentrated at the east and west entrances during peak hours. The current traffic flow method at the intersection is not suitable for the current situation. The hourly flow rates of the straight-through traffic at the two east and west entrances are collected (entrance 1: h1, entrance 2: h2); the evening peak hourly flow rates are taken as h1 = 205 pch / h and h2 = 128 pch / h.

[0078] Traffic flow situation as follows Figure 9As shown, the east and west inlet traffic is large and uneven during the evening peak. Next, it is necessary to calculate the traffic difference (imbalance coefficient) β to determine whether the east and west straight traffic difference meets the trigger condition: β > 0.18, so as to provide a basis for the next step of phase optimization design.

[0079] The calculation formula is as follows:

[0080]

[0081] β≈0.23;

[0082] β > 0.18;

[0083] Based on the settlement result β>0.18, the difference in traffic flow between east and west meets the threshold condition. Consider setting an early start phase for one of the directions to address the traffic flow differences. Further investigation and analysis of the traffic flow characteristics of east and west at the intersection can be conducted to further determine the optimization scheme.

[0084] Step 3: Determine the early start import; allocate priority according to the relationship between flow size, and dynamically select the high demand import through the flow difference; if h1>h2: early start import = import 1; otherwise: early start import = import 2.

[0085] Based on step 2, the difference in east-west through traffic flow is >0.18. Comparing the hourly through traffic flow at the east and west entrances, the east entrance: entrance 1 = h1 = 205 pch / h, and the west entrance: entrance 2 = h2 = 128 pch / h.

[0086] The comparative analysis is as follows:

[0087] 205 pch / h > 128 pch / h

[0088] h1 > h2

[0089] Early start of imports = Import 1 = East imports

[0090] Based on the comparative analysis, an early start phase needs to be set for the east and west entrances. The straight-through traffic flow at the east entrance is significantly greater than that at the west entrance. Therefore, the east entrance is determined to be the early start entrance. Thus, the optimized scheme of setting an east single-pass overlapping phase for the east entrance is selected to meet the traffic demand.

[0091] Step 4: Generate early start control phases; determine the early start control phases at the early start entrances, and reasonably allocate the timing of each phase based on the survey results and intersection control strategies, combined with the queuing situation of vehicles in each direction.

[0092] Based on step 3, an early-start phase is determined at the east entrance. This involves adding an east-single-allowed overlapping phase (C phase) to the traffic release method. This addresses the high traffic demand at the east entrance, alleviates severe traffic conflicts when both east and west are open, and improves the overall traffic efficiency of the intersection. The optimized traffic release method is as follows: Figure 10 As shown.

[0093] Based on the traffic flow characteristics during peak hours at the intersection, the traffic flow is relatively large during peak hours, with the north-south direction being the main flow direction. More time needs to be allocated to ensure traffic efficiency. A single-phase overlap is set up at the east entrance for early start. In combination with the traffic flow demand in all directions at the intersection, the timing scheme of each phase is shown in Table 2. Phase C is the early start release for the east entrance.

[0094] Table 2. Timing schemes after phase adjustment

[0095]

[0096] Step 5: Scheme Distribution and Effect Tracking; The optimized phase scheme is distributed to the intersection signal controller and tracked and fine-tuned for one week to finally determine the specific timing scheme and achieve the final optimization goal.

[0097] Based on the optimization scheme obtained in step 4, the scheme was sent to the intersection signal controller and put into operation. After a week of tracking and inspection, the final timing scheme and optimization effect of the intersection are shown in Table 3. The evaluation of the optimized Internet data traffic operation indicators is shown in Table 4. Figure 11 As shown in the figure, the optimized intersection has good order and traffic conflicts have been alleviated.

[0098] Table 3. Optimized Intersection Timing Scheme for the Entire Day

[0099]

[0100] Table 4 Evaluation of the Optimized Internet Data Traffic Operation Indicators

[0101] Flow direction Queue length Number of parking times Delay Before optimization, the morning rush hour... Eastern import 139 1.6 94 Optimized morning rush hour Eastern import 101 1.5 77 change -27.34％ -6.25％ -18.08％ Flow direction Queue length Number of parking times Delay Optimize the evening rush hour Eastern import 171 1.6 74 Optimized evening rush hour Eastern import 89 1.1 55 change -47.95％ -31.25％ -25.68％

[0102] Following optimization and adjustments, and a week of follow-up investigation, the intersection showed good order and reduced traffic conflicts. Evaluation of the effectiveness of the traffic signal control timing optimization at the intersection was based on internet-based road traffic operation index data. All indicators for the east entrance during morning and evening rush hours decreased; for example, queue length during the evening rush hour decreased by 47.95%, number of stops decreased by 31.25%, and traffic delay decreased by 25.68%, indicating reduced congestion and improved traffic efficiency. In conclusion, the east entrance achieved its expected optimization goals after the optimization adjustments.

[0103] It should be noted that, for the sake of simplicity, the aforementioned method embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, because according to the present invention, some steps can be performed in other orders or simultaneously.

[0104] Based on the same concept as the traffic signal control method for intersections formed by road segments with large road segment differences in the above embodiments, this invention also provides a traffic signal control system for intersections formed by road segments with large road segment differences. This system can be used to execute the above-described traffic signal control method for intersections formed by road segments with large road segment differences. For ease of explanation, the structural schematic diagram of the embodiment of the traffic signal control system for intersections formed by road segments with large road segment differences only shows the parts related to the embodiments of this invention. Those skilled in the art will understand that the illustrated structure does not constitute a limitation on the device, and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0105] Please see Figure 12 In another embodiment of this application, a traffic signal control system 100 for a plane intersection formed by roads with large differences in road level is provided. The system includes a road level calculation module 101, a traffic flow difference calculation module 102, an early start inlet determination module 103, an early start control phase generation module 104, and a phase adjustment and tracking module 105.

[0106] The road rank calculation module 101 is used to obtain the rank values ​​P1 and P2 of two connected roads at the target intersection, calculate the absolute value of the rank difference The = |P1-P2|, and determine whether the absolute value of the rank difference The is greater than or equal to a set threshold T1. If not, the process ends; if yes, the traffic flow difference calculation module is executed. The rank values ​​of the roads are as follows: highway rank is 1, expressway rank is 2, trunk road rank is 3, secondary trunk road rank is 4, main collector road rank is 5, secondary collector road rank is 6, regional road rank is 7, and access channel rank is 8.

[0107] The flow difference calculation module 102 is used to collect the hourly flow rates h1 and h2 of the through traffic at the first and second inlets of the minor branch road, and calculate the flow difference based on h1 and h2. The flow difference is represented as an imbalance coefficient. Determine if β is greater than the set threshold T2. If not, end the process; if yes, execute the early start import determination module.

[0108] The early start inlet determination module 103 is used to compare the size of h1 and h2. If h1 > h2, the first inlet is determined to be the early start inlet; if h1 ≤ h2, the second inlet is determined to be the early start inlet.

[0109] The early start control phase generation module 104 is used to set the early start control phase for the determined early start entrance, and allocate the timing of each phase in combination with the intersection survey, control strategy and the queuing vehicles in each direction.

[0110] The phase adjustment and tracking module 105 is used to send the optimized phase timing scheme to the intersection signal controller, track and run it for one week and make fine adjustments to determine the final timing scheme.

[0111] It should be noted that the traffic signal control system for intersections formed by roads with large road level differences in this invention corresponds one-to-one with the traffic signal control method for intersections formed by roads with large road level differences in this invention. The technical features and beneficial effects described in the embodiments of the traffic signal control method for intersections formed by roads with large road level differences are applicable to the embodiments of traffic signal control for intersections formed by roads with large road level differences. For details, please refer to the description in the embodiments of this invention, which will not be repeated here.

[0112] Furthermore, in the implementation of the traffic signal control system for a plane intersection formed by roads with large differences in road level in the above embodiments, the logical division of each program module is only an example. In actual applications, the above functions can be assigned to different program modules as needed, for example, for the sake of corresponding hardware configuration requirements or software implementation convenience. That is, the internal structure of the traffic signal control system for a plane intersection formed by roads with large differences in road level is divided into different program modules to complete all or part of the functions described above.

[0113] Please see Figure 13 In one embodiment, an electronic device is provided for implementing a traffic signal control method for a planar intersection formed by roads with large differences in road level. The electronic device 200 may include a first processor 201, a first memory 202 and a bus, and may also include a computer program stored in the first memory 202 and executable on the first processor 201, such as a traffic signal control program 203 for a planar intersection formed by roads with large differences in road level.

[0114] The first memory 202 includes at least one type of readable storage medium, including flash memory, portable hard drive, multimedia card, card-type memory (e.g., SD or DX memory), magnetic memory, magnetic disk, optical disk, etc. In some embodiments, the first memory 202 can be an internal storage unit of the electronic device 200, such as the portable hard drive of the electronic device 200. In other embodiments, the first memory 202 can be an external storage device of the electronic device 200, such as a plug-in portable hard drive, smart media card (SMC), secure digital card (SD), flash card, etc., equipped on the electronic device 200. Furthermore, the first memory 202 can include both internal and external storage units of the electronic device 200. The first memory 202 can be used not only to store application software and various types of data installed on the electronic device 200, such as the code of the traffic signal control program 203 for intersections formed by road level differences, but also to temporarily store data that has been output or will be output.

[0115] In some embodiments, the first processor 201 may be composed of integrated circuits, such as a single packaged integrated circuit or multiple integrated circuits with the same or different functions, including combinations of one or more central processing units (CPUs), microprocessors, digital processing chips, graphics processors, and various control chips. The first processor 201 is the control unit of the electronic device, connecting various components of the entire electronic device through various interfaces and lines. It executes programs or modules stored in the first memory 202 and calls data stored in the first memory 202 to perform various functions of the electronic device 200 and process data.

[0116] Figure 13 Only electronic devices with components are shown; it will be understood by those skilled in the art that... Figure 13 The structure shown does not constitute a limitation on the electronic device 200, and may include fewer or more components than shown, or combine certain components, or have different component arrangements.

[0117] The traffic signal control program 203 for intersections formed by roads with large road level differences, stored in the first memory 202 of the electronic device 200, is a combination of multiple instructions. When run in the first processor 201, it can achieve the following:

[0118] S1. Calculate the grade difference between connected roads: Obtain the grade values ​​P1 and P2 of the two connected roads at the target intersection, calculate the absolute value of the grade difference The = |P1-P2|, and determine whether the absolute value of the grade difference The is greater than or equal to the set threshold T1. If not, end the process; if yes, proceed to step S2. The grade values ​​of the roads correspond as follows: highway grade is 1, expressway grade is 2, main road grade is 3, secondary road grade is 4, main collector road grade is 5, secondary collector road grade is 6, regional road grade is 7, and access road grade is 8.

[0119] S2. Calculate the difference in through traffic flow between opposing entrances: Collect the hourly through traffic flow h1 and h2 at the first and second entrances of the minor branch road, and calculate the flow difference based on h1 and h2. The flow difference is expressed as an imbalance coefficient. Determine if β is greater than the set threshold T2. If not, end the process; if yes, proceed to step S3.

[0120] S3. Determine the early start-up inlet: Compare the sizes of h1 and h2. If h1 > h2, then determine the first inlet as the early start-up inlet; if h1 ≤ h2, then determine the second inlet as the early start-up inlet.

[0121] S4. Generate early start control phase: Set early start control phase for the determined early start entrance, and allocate the timing of each phase based on the intersection survey, control strategy and the queuing situation of vehicles in each direction;

[0122] S5. Phase Adjustment and Tracking: The optimized phase timing scheme is sent to the intersection signal controller, tracked for one week and fine-tuned to determine the final timing scheme.

[0123] Furthermore, if the modules / units integrated in the electronic device 200 are implemented as software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium. The computer-readable medium may include: any entity or device capable of carrying the computer program code, a recording medium, a USB flash drive, a portable hard drive, a magnetic disk, an optical disk, a computer memory, or a read-only memory (ROM).

[0124] Those skilled in the art will understand that all or part of the processes in the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments described above. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM), etc.

[0125] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0126] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A traffic signal control method for a planar intersection formed by roads with large differences in elevation, characterized in that, Includes the following steps: S1. Calculate the grade difference between connected roads: Obtain the grade values ​​P1 and P2 of the two connected roads at the target intersection, calculate the absolute value of the grade difference The = |P1-P2|, and determine whether the absolute value of the grade difference The is greater than or equal to the set threshold T1. If not, end the process; if yes, proceed to step S2. The grade values ​​of the roads correspond as follows: highway grade is 1, expressway grade is 2, main road grade is 3, secondary road grade is 4, main collector road grade is 5, secondary collector road grade is 6, regional road grade is 7, and access road grade is 8. S2. Calculate the difference in through traffic flow between opposing entrances: Collect the hourly through traffic flow h1 and h2 at the first and second entrances of the minor branch road, and calculate the flow difference based on h1 and h2. The flow difference is expressed as an imbalance coefficient. Determine if β is greater than the set threshold T2. If not, end the process; if yes, proceed to step S3. S3. Determine the early start-up inlet: Compare the sizes of h1 and h2. If h1 > h2, then determine the first inlet as the early start-up inlet; if h1 ≤ h2, then determine the second inlet as the early start-up inlet. S4. Generate early start control phase: Set early start control phase for the determined early start entrance, and allocate the timing of each phase based on the intersection survey, control strategy and the queuing situation of vehicles in each direction; S5. Phase Adjustment and Tracking: The optimized phase timing scheme is sent to the intersection signal controller, tracked for one week and fine-tuned to determine the final timing scheme.

2. The traffic signal control method for a planar intersection formed by roads with large hierarchical differences according to claim 1, characterized in that, In step S1, the set threshold T1 is 3.

3. The traffic signal control method for a planar intersection formed by roads with large differences in elevation according to claim 1, characterized in that, In step S1, the target intersection is a traffic signal controlled intersection, and the corresponding traffic signal controller can adjust the release method.

4. The traffic signal control method for a planar intersection formed by roads with large differences in elevation according to claim 1, characterized in that, In step S1, when the road ranks in the same direction are inconsistent, the maximum value is taken as the road rank value in that direction.

5. The traffic signal control method for a planar intersection formed by roads with large differences in elevation according to claim 1, characterized in that, In step S2, the set threshold T2 is 0.

18.

6. The traffic signal control method for a planar intersection formed by roads with large differences in elevation according to claim 1, characterized in that, In step S4, the early start control phase is a single-phase overlapping phase, which is used to alleviate traffic conflicts at opposite entrances of minor branch roads.

7. The traffic signal control method for a planar intersection formed by roads with large differences in elevation according to claim 1, characterized in that, In step S5, the effect tracking evaluates the optimization effect by monitoring the queue length, number of stops, and delay indicators of each flow direction at the intersection.

8. A traffic signal control system for a planar intersection formed by roads with significant differences in elevation, characterized in that, The traffic signal control method for a plane intersection formed by the intersection of roads with large road level differences as described in any one of claims 1-7 includes a road level calculation module, a flow difference calculation module, an early start entrance determination module, an early start control phase generation module, and a phase adjustment and tracking module. The road rank calculation module is used to obtain the rank values ​​P1 and P2 of two connected roads at the target intersection, calculate the absolute value of the rank difference The = |P1-P2|, and determine whether the absolute value of the rank difference The is greater than or equal to a set threshold T1. If not, the process ends; if yes, the traffic flow difference calculation module is executed. The rank values ​​of the roads are as follows: highway rank is 1, expressway rank is 2, main road rank is 3, secondary road rank is 4, main collector road rank is 5, secondary collector road rank is 6, regional road rank is 7, and access channel rank is 8. The traffic flow difference calculation module is used to collect the hourly traffic flow h1 and h2 of the through traffic at the first and second inlets of the minor branch road, and calculate the traffic flow difference based on h1 and h2. The traffic flow difference is expressed as an imbalance coefficient. Determine if β is greater than the set threshold T2. If not, end the process; if yes, execute the early start import determination module. The early start inlet determination module is used to compare the size of h1 and h2. If h1 > h2, the first inlet is determined to be the early start inlet; if h1 ≤ h2, the second inlet is determined to be the early start inlet. The early start control phase generation module is used to set the early start control phase for the determined early start entrance, and allocate the timing of each phase in combination with the intersection survey, control strategy and the queuing situation of vehicles in each direction. The phase adjustment and tracking module is used to send the optimized phase timing scheme to the intersection signal controller, track and run it for a week and make fine adjustments to determine the final timing scheme.

9. An electronic device, characterized in that, The electronic device includes: At least one processor; and, A memory communicatively connected to the at least one processor; wherein, The memory stores computer program instructions that can be executed by the at least one processor, which, when executed by the at least one processor, enables the at least one processor to perform the traffic signal control method for intersections formed by road intersections with large road level differences as described in any one of claims 1-7.

10. A computer-readable storage medium storing a program, characterized in that, When the program is executed by the processor, it implements the traffic signal control method for planar intersections formed by intersections with large road level differences as described in any one of claims 1-7.

Images