A green wave control scheme generation method based on time-distance diagram

Abstract

The application discloses a green wave control scheme generation method based on a time-distance diagram, and comprises the following steps: S100, acquiring all intersection information of coordinated direction intersections in a target region; S200, determining the green light time range that can be occupied by each intersection coordinated direction, and the maximum and minimum values of the positive and reverse green wave bandwidths through the intersection information; S300, taking the green wave occupied green light time t i ≤ the green light time range T i of each intersection coordinated direction as a constraint condition, sequentially traversing the reverse phase difference of the starting intersection, the reverse green wave bandwidth, and the positive green wave bandwidth, and determining the maximum positive and reverse green wave bandwidths and the optimal starting intersection phase difference that satisfy the constraint condition; and S400, calculating and generating the intersection phase sequence, phase time and phase difference according to the maximum positive and reverse bandwidths and the positive and reverse phase differences of the starting intersection. The application realizes the rapid determination of the maximum bandwidth of the green wave and the starting intersection phase difference based on the characteristics of the green wave time-distance diagram and through the simulation of manual debugging.

Description

Technical Field

[0001] The present invention relates to the field of urban intelligent traffic control, and in particular to a method for generating a green wave control scheme based on a time-distance graph. Background Art

[0002] Green wave control is a traffic signal control method that predefines a fixed period for main lines, phase differences between adjacent intersections, and signal control phases at each intersection based on road and intersection conditions and traffic characteristics. This ensures that vehicles receive continuous green lights when passing through several adjacent intersections. Green wave control is a commonly used control strategy in current signal control optimization practices and can effectively improve traffic efficiency on main roads. Numerous algorithms exist for generating green wave control schemes, which can be categorized into two main types: graphical and numerical methods.

[0003] Graphical method, that is, using time-distance diagram (abbreviated as "time-distance diagram", refer to Figure 1 As shown in the figure, the phase difference of each intersection is continuously adjusted to determine the optimal phase difference, speed, and corresponding timing scheme. However, the implementation process is complex and requires manual trial and error. When there are many intersections requiring green wave control, the complexity and workload increase significantly, and it is difficult to obtain the optimal solution.

[0004] The numerical solution method uses a formula to find the optimal coordinated speed to minimize the deviation between the intersection spacing and the ideal spacing, thereby obtaining a green wave control scheme with the best coordination effect. However, its basic principle makes it difficult to fully meet the requirement of no stopping in practical applications. Although it can obtain relatively good results in theory, the application effect is poor. In addition, the calculation process combined with heuristic algorithms often requires a large number of iterative calculations, making the solution time-consuming. Summary of the Invention

[0005] The purpose of the present invention is to provide a method based on the characteristics of the green wave time distance diagram to solve the above problems, and to quickly determine the maximum bandwidth of the green wave and the phase difference of the starting intersection by simulating manual debugging, thereby realizing a method for generating a green wave control scheme.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0007] A method for generating a green wave control scheme based on a time-distance graph comprises the following steps:

[0008] S100, obtaining all intersection information of the coordinated direction intersections in the target area, the intersection information includes the green signal ratio of each intersection in the non-coordinated direction, the distance L between adjacent intersections i and the green wave speed v between adjacent intersections i ;

[0009] S200, determine the green light time range T that can be occupied by the coordinated direction of each intersection through the intersection information i And the maximum value of the forward and reverse green wave bandwidth and minimum value

[0010] S300, the green light time t occupied by the green wave at each intersection i ≤The green light time range that can be occupied by the coordinated direction of each intersection T i As a constraint condition, traverse the reverse phase difference of the starting intersection in turn Reverse green wave bandwidth b - , Forward green wave bandwidth b + , determine the maximum forward and reverse green wave bandwidths and the optimal starting intersection phase difference that meet the constraints;

[0011] S400, based on the maximum forward and reverse bandwidth b + 、b - The positive and reverse phase difference with the starting intersection Calculate and generate the phase sequence, phase time and phase difference of each intersection.

[0012] In particular, the green light time range T that can be occupied by the coordinated direction of each intersection in step S200 i The method for determining includes the following steps:

[0013] S210, determine the coordination period C, calculate the total time of the non-coordinated direction phase according to the green signal ratio of the non-coordinated direction of the intersection

[0014]

[0015] in represents the sum of the phase time in the direction of branch i of the intersection; Indicates the time of the independent left turn phase of the main road. When the main road allows single-port release and there is no left turn waiting area, The value of is determined by the product of the green-to-signal ratio required to meet the maximum permissible saturation in the corresponding direction and the coordination period C;

[0016] S220, calculate the green light time range T that can be occupied by the coordinated direction of each intersection i :

[0017]

[0018] Regarding the coordination cycle C, the solution of the present invention is based on the needs of practical applications. The coordination cycles C of each intersection in the same green wave coordination direction should be or are approximately consistent. If they are inconsistent, the green wave ratio of the coordinated direction can be increased or decreased while satisfying the green wave ratio of the non-coordinated direction of each intersection, so as to achieve consistency of the coordination cycle C. The maximum allowable saturation refers to the ratio of the maximum exchange volume to the saturated traffic capacity of the lane, which is used to determine the green wave ratio of the turning lane.

[0019] Regarding the coordinated direction and the non-coordinated direction, the coordinated direction is the direction of the green wave control of the present invention, which is also the main line of the intersection, while the non-coordinated direction refers to other turns except the main line at the intersection. It is worth noting that for the turns of going straight and turning left on the main line, usually the straight and turning left on the same main line belong to one-way traffic. In one-way traffic, green wave control can be generated if the positive direction is passable, but the reverse direction is not; there are also cases where only left turns are allowed, so the maximum value of the positive and reverse green wave bandwidths is set. and minimum value The determination method is as follows:

[0020] Step S201: Calculate the maximum possible green light time for the forward and reverse coordinated directions of each intersection and

[0021]

[0022]

[0023] in Refers to the minimum green light phase time required for forward and reverse left turns to meet the maximum saturation constraint;

[0024] Step S202: Calculate the maximum forward and reverse green wave bandwidths

[0025]

[0026]

[0027] Step S203: Calculate the minimum value of the forward and reverse green wave bandwidths

[0028]

[0029]

[0030] Where α represents the minimum ratio requirement of green wave bandwidth to total cycle duration.

[0031] Compared with existing technologies, the present invention has the following beneficial effects: It is based on the needs of practical applications and, based on the characteristics of the green wave time-distance diagram, simulates manual debugging to quickly determine the maximum bandwidth of the green wave and the phase difference at the starting intersection, thereby generating timing plans for each intersection in the green wave band. While meeting the needs of practical applications, it significantly improves the efficiency of optimizing the green wave control plan. Furthermore, based on achieving a two-way green light, it can quickly determine the forward and reverse common bandwidth and the phase difference at the starting intersection. Based on the bandwidth optimization results, it can simultaneously output the optimal phase sequence, achieving better results than general numerical solutions and meeting various specific optimization requirements, including fixed partial phase times and specified saturation. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Schematic diagram illustrating green wave control for time-distance diagram;

[0033] Figure 2 This is a logic block diagram of the solution of the present invention;

[0034] Figure 3 This is the algorithm logic block diagram of step S300 of the present invention;

[0035] Figure 4 This is an example of a single intersection where the method of the present invention generates a solution. DETAILED DESCRIPTION

[0036] The present invention will be further described in detail below with reference to the embodiments in the accompanying drawings, but this does not constitute any limitation to the present invention.

[0037] The present invention aims to integrate the characteristics of green waves on the time-distance diagram into the calculation, and use the total length of the green light occupation time of the positive and reverse green wave bands at the intersection to quickly determine the maximum bandwidth and the positive and reverse phase difference of the starting intersection. At the same time, according to the phase difference and phase sequence of the starting intersection, the timing plan of each intersection is generated. Figure 2 、 3 4. The present invention proposes a method for generating a green wave control scheme based on a time-distance graph:

[0038] S100, obtaining all intersection information of the coordinated direction intersections in the target area, the intersection information includes the green signal ratio of each intersection in the non-coordinated direction, the distance L between adjacent intersections i and the green wave speed v between adjacent intersections i ;

[0039] The green-to-signal ratio of the non-coordinated direction of each intersection is based on the requirement of the saturation of each turn in the non-coordinated direction. The green wave speed v between adjacent intersections i It can be a preset green wave speed or a speed limit between adjacent intersections;

[0040] S200, determine the green light time range T that can be occupied by the coordinated direction of each intersection through the intersection information i , the method is as follows:

[0041] S210, determine the coordination period C, calculate the total time of the non-coordinated direction phase according to the green signal ratio of the non-coordinated direction of the intersection

[0042]

[0043] in represents the sum of the phase time in the direction of branch i of the intersection; Indicates the time of the independent left turn phase of the main road. When the main road allows single-port release and there is no left turn waiting area, The value of is determined by the product of the green-to-signal ratio required to meet the maximum permissible saturation in the corresponding direction and the coordination period C;

[0044] S220, calculate the green light time range T that can be occupied by the coordinated direction of each intersection i :

[0045]

[0046] The time for independent left turns on the main road is calculated here to distinguish between one-way release scenarios. In one-way release scenarios, green waves are permitted in the forward direction, but not in the reverse direction. Different release scenarios should be considered to calculate the green light time range that can be occupied in the coordinated direction.

[0047] Determine the maximum forward and reverse green wave bandwidths based on intersection information and minimum value The method is as follows:

[0048] Step S201: Calculate the maximum possible green light time for the forward and reverse coordinated directions of each intersection and

[0049]

[0050]

[0051] in Refers to the minimum green light phase time required for forward and reverse left turns to meet the maximum saturation constraint;

[0052] Step S202: Calculate the maximum forward and reverse green wave bandwidths

[0053]

[0054]

[0055] Step S203: Calculate the minimum value of the forward and reverse green wave bandwidths

[0056]

[0057]

[0058] Where α represents the minimum ratio of green wave bandwidth to total cycle duration;

[0059] The minimum green light phase time for forward and reverse left turns here refers to the independent left turn phase on the main road plus the one-way release. It is used to calculate the maximum possible green light time in the coordinated direction. The minimum ratio of green wave bandwidth to total cycle time requires different calculation values ​​based on actual requirements, while also taking into account the coordination cycle C.

[0060] S300, the green light time t occupied by the green wave at each intersection i ≤The green light time range that can be occupied by the coordinated direction of each intersection T i As a constraint condition, traverse the reverse phase difference of the starting intersection in turn Reverse green wave bandwidth b - , Forward green wave bandwidth b + , determine the maximum forward and reverse green wave bandwidths and the optimal starting intersection phase difference that meet the constraints, the method is as follows:

[0061] S301, using the maximum bandwidth as the starting traversal condition, assigning the forward bandwidth

[0062] S302, if If established, go to S303, otherwise go to S312;

[0063] S303, assign reverse bandwidth

[0064] S304, if If it is established, go to S305; otherwise, let b + = + -1, return to S302; here the forward green wave bandwidth b is traversed for the last time + ;

[0065] S305, let the forward phase difference of the starting intersection Reverse phase difference

[0066] S306, calculate the start time of the positive green wave band of the starting intersection in sequence End Time and the start time of the reverse green wave band End Time

[0067]

[0068]

[0069]

[0070]

[0071] S307, based on the distance L between adjacent intersections i and the green wave speed v between adjacent intersections i Calculate the start and end time of the forward and reverse green wave bands at each intersection:

[0072]

[0073]

[0074]

[0075]

[0076] Where m and n are positive integers, and C is the coordination period; Indicates the start time of the positive green wave band at intersection i. When it is greater than C, subtract the integer multiple of C to make it a positive number less than C; Indicates the start time of the reverse green wave band at intersection i. If it is a negative value, add an integer multiple of C to make it a positive number less than C; L i Indicates the distance between intersection i and the previous intersection; v i represents the green wave speed between intersection i and the previous intersection;

[0077] S308, calculate the green light time occupied by the green wave at each intersection:

[0078]

[0079] S309, if the starting intersection satisfies t0≤T0, proceed to S310; otherwise, let b - = - -1, return to S304; here, the reverse green wave bandwidth b is traversed twice - ;

[0080] S310, when all intersections meet t i ≤T i When , the current bandwidth is the maximum bandwidth, the current starting intersection phase difference is the optimal phase difference, and the process goes to S311; otherwise, let Return to S306; here we first traverse the reverse phase difference of the starting intersection

[0081] S311: Output forward and reverse bandwidth b + 、b - The positive and reverse phase difference with the starting intersection

[0082] S312: Outputting no feasible green wave solution.

[0083] S400, based on the maximum forward and reverse bandwidth b + 、b - The positive and reverse phase difference with the starting intersection The method for calculating and generating the phase sequence, phase time, and phase difference of each intersection is as follows:

[0084] S401, based on the start and end time of the forward and reverse green wave bands at each intersection Determine the possible phase sequence, refer to Figure 4 Example, The possible phase sequence combinations are {reverse single-port release, forward and reverse straight, forward single-port release}, {forward and reverse straight, forward and reverse left turn}, {forward and reverse straight, forward single-port release, forward and reverse left turn};

[0085] S402, according to the requirements of the forward and reverse left turn green light Determine the phase sequence combination to Figure 4 For example, when or When the vehicle is in transit, the combination of {reverse single-port release, forward and reverse straight-through, forward single-port release} should be adopted;

[0086] S403, determine the phase difference according to the phase sequence combination and the phase order combination to meet the requirements of each turn green light. Figure 4 For example,

[0087] The above embodiments are preferred implementation modes of the present invention and are only used to facilitate the explanation of the present invention. They are not intended to limit the present invention in any form. Any person with ordinary knowledge in the technical field can, without departing from the scope of the technical features of the present invention, make partial changes or modifications to the technical contents disclosed in the present invention and make equivalent embodiments without departing from the technical features of the present invention. Such modifications still fall within the scope of the technical features of the present invention.

Claims

1. A method for generating a green wave control scheme based on a time-distance graph, characterized in that: The following steps are involved: S100, obtaining all intersection information of the coordinated direction intersections in the target area, the intersection information including the green signal ratio of each intersection in the non-coordinated direction, the distance between adjacent intersections L i and the green wave speed between adjacent intersections v i ; S200, determine the green light time range that can be occupied by the coordinated direction of each intersection through the intersection information T i And the maximum value of the forward and reverse green wave bandwidth 、 and minimum value ; S300, using the green light time occupied by the green wave at each intersection t i ≤The green light time range that can be occupied by the coordinated direction of each intersection T i As a constraint condition, traverse the reverse phase difference of the starting intersection in turn , reverse green wave bandwidth , Forward green wave bandwidth , determine the maximum forward and reverse green wave bandwidths and the optimal starting intersection phase difference that meet the constraints, which includes the following steps: S301, using the maximum bandwidth as the starting traversal condition, assigning the forward bandwidth ; S302, if If established, go to S303, otherwise go to S312; S303, assign reverse bandwidth ; S304, if If it is established, go to S305; otherwise, make , return to S302; S305, let the forward phase difference of the starting intersection , reverse phase difference ; S306, calculate the start time of the positive green wave band of the starting intersection in sequence , end time , and the reverse green wave band start time , end time : S307, based on the distance between adjacent intersections L i and the green wave speed between adjacent intersections v i Calculate the start and end time of the forward and reverse green wave bands at each intersection: in Indicates intersection The positive green wave band starts when it is greater than When an integer multiple of A positive number; Indicates intersection The reverse green wave band start time, when it is a negative value, add an integer multiple of A positive number; Indicates intersection The distance from the previous intersection; Indicates intersection Green wave speed between the intersection and the previous one; S308, calculate the green light time occupied by the green wave at each intersection: ； S309, if the starting intersection meets , enter S310; otherwise, let , return to S304; S310, when all intersections meet When , the current bandwidth is the maximum bandwidth, the current starting intersection phase difference is the optimal phase difference, and the process goes to S311; otherwise, let , return to S306; S311: Output forward and reverse bandwidth 、 The positive and reverse phase difference with the starting intersection 、 ; S312: Output no feasible green wave solution; S400, based on the maximum forward and reverse bandwidth The positive and reverse phase difference with the starting intersection , calculate and generate the phase sequence, phase time and phase difference of each intersection.

2. A method for generating a green wave control scheme based on a time-distance graph according to claim 1, characterized in that: The green light time range that can be occupied by the coordinated direction of each intersection in step S200 T i The method for determining includes the following steps: S210, determine the coordination period C, calculate the total time of the non-coordinated direction phase according to the green signal ratio of the non-coordinated direction of the intersection : in Indicates intersection The sum of the phase times in the branch direction; Indicates the time of the independent left turn phase of the main road. When the main road allows single-port release and there is no left turn waiting area, ; 、 The value of is determined by the product of the green-to-signal ratio required to meet the maximum permissible saturation in the corresponding direction and the coordination period C; S220, calculate the green light time range that can be occupied by the coordinated direction of each intersection T i : 。 3. The method for generating a green wave control scheme based on a time-distance graph according to claim 2, characterized in that: The maximum value of the forward and reverse green wave bandwidths in step S200 、 and minimum value The method for determining includes the following steps: Step S201: Calculate the maximum possible green light time for the forward and reverse coordinated directions of each intersection and in Refers to the minimum green light phase time required for forward and reverse left turns to meet the maximum saturation constraint; Step S202: Calculate the maximum forward and reverse green wave bandwidths 、 : Step S203: Calculate the minimum value of the forward and reverse green wave bandwidths : in Indicates the minimum ratio requirement of green wave bandwidth to total cycle duration.

4. The method for generating a green wave control scheme based on a time-distance graph according to claim 3, characterized in that: The method for generating the phase sequence, phase time and phase difference of each intersection in step S400 is as follows: S401: First, according to the start and end time of the forward and reverse green wave bands at each intersection , determine its possible phase sequence; S402: Secondly, according to the minimum green light stage time for forward and reverse left turns , determine the phase sequence combination; S403: Final basis The combination and phase sequence combination determine the phase difference to meet the requirements of each turn green light.

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