Urban road network trunk green wave line automatic generation and calculation method

Abstract

The invention provides an urban road network trunk green wave line automatic generation and calculation method, and relates to the field of urban traffic signal coordination control. Comprising the following steps: (1) establishing an urban road network intersection topological relation; (2) determining an intersection with the maximum traffic demand; (3) generating forward and reverse green wave lines; (4) fusing the forward and reverse green wave lines; according to the method for automatically generating the green wave line, firstly, the intersection with the largest traffic demand is determined, the intersection serves as a search starting point, the correlation degree between the intersection and the adjacent intersection is calculated, green wave line search is carried out according to the correlation between the intersections, manual participation is not needed in the whole process, and the green wave line is automatically generated; the subjective influence of technicians can be reduced, and the efficiency and scientificity of green wave line determination are further improved. By means of the method, the coordination control scheme of the networked intersections in the urban area can be optimized, and the travel experience of residents is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of coordinated control of urban traffic signals, and in particular to a method for automatically generating and calculating green wave lines of urban road network trunk lines. Background Art

[0002] With the widespread popularity of urban traffic signal networking, the basic internal conditions are provided for the green wave coordination of signals. Green wave coordination can reduce the number of stops and improve the travel experience of drivers. Therefore, traffic management personnel also try their best to enable the signal machines on the road to achieve green wave coordinated control to improve the travel experience of citizens.

[0003] The traditional green wave coordination route design mainly relies on the experience of traffic management personnel, who judge which road sections should be designed with green wave coordination plans based on experience. When designing green wave routes using this method, the rationality and scientificity of the route design are largely affected by the professional level of the technical personnel, which leads to a significant reduction in the final green wave effect and fails to achieve the purpose of improving residents' travel experience. In addition, since the determination of green wave routes relies on manual research and analysis, work efficiency is greatly reduced.

[0004] Therefore, it is necessary to invent a method that can automatically generate green wave routes. This method first determines the intersection with the greatest traffic demand, takes the intersection as the search starting point, calculates the correlation with the adjacent intersections, and searches for green wave routes based on the correlation between intersections. The entire process does not require human participation, and automatically generates green wave routes, which can reduce the subjective influence of technicians and further improve the efficiency and scientificity of green wave route determination. Through this method, the coordinated control plan of networked intersections in urban areas can be optimized, greatly improving the travel experience of residents. Summary of the invention

[0005] In view of the above problems, the present invention provides a method for automatically generating and calculating green wave lines of urban road network trunk lines, which can optimize the coordinated control scheme of network intersections in urban areas and greatly improve the travel experience of residents.

[0006] To solve the above problems, the technical solution adopted by the present invention is:

[0007] A method for automatically generating and calculating green wave lines of urban road network trunk lines, comprising the following steps:

[0008] S1: Establish the topological relationship of the intersections of the urban road network (establish an array set of intersections and intersection connecting sections that meet the requirements).

[0009] S2: Determine the intersection with the greatest traffic demand (calculate the ratio of the queue length of each entrance lane to the length of the road section, select the intersection with the largest ratio, and use this intersection as the starting point for the green wave route search).

[0010] S3: Generate forward and reverse green wave lines (24 hours a day, 5 minutes as a period, generate a 5-minute green wave line set).

[0011] S4: Fusion of forward and reverse green wave lines (the 5-minute green wave lines are first unidirectionally merged and then bidirectionally merged).

[0012] S5: The green wave is merged at 0 o'clock (the green wave line with 0:00 as the starting time and the green wave line with 24:00 as the ending time are merged at the beginning and the end to ensure the integrity of the line).

[0013] Preferably, the S1 establishes the topological relationship of the urban road network intersections, specifically including: establishing a set of urban road intersections and establishing a set of urban road intersection sections.

[0014] Preferably, the S2. determining the intersection with the greatest traffic demand specifically includes:

[0015] Step 1: Divide 24 hours a day into 5-minute time periods, and calculate the ratio of the queue length of the longest queue lane at the entrance of each intersection to the length of the road section in each time period. The calculation formula is as follows:

[0016]

[0017] V ij —Indicates the ratio of the maximum queue length to the road section among all lanes corresponding to a certain entrance road of a certain intersection.

[0018] h ij —Indicates the queue length value corresponding to the longest queue length of a certain entrance lane of a certain intersection (unit: m).

[0019] l ij —Indicates the length corresponding to a certain entrance road at a certain intersection (unit: m).

[0020] Step 2: Determine the intersection with the highest traffic demand in a 5-minute period.

[0021] Calculate the V of each entrance lane at all intersections ij value, take the maximum value as V max , the intersection corresponding to the maximum value is the intersection with the greatest traffic demand. The calculation formula is as follows:

[0022]

[0023] Step 3: Divide the 24 hours of a day into 288 time periods of 5 minutes each. According to the calculation method of step 2, determine the intersection with the largest traffic demand in each time period.

[0024] Preferably, the S3 forward and reverse green wave line generation specifically includes:

[0025] Step 1: After determining the intersection with the greatest demand, use this intersection as the starting point for searching intersections (the forward and reverse green wave line searches are independent and do not affect each other). The correlation between this intersection and the adjacent intersections is determined by the correlation degree and the correlation threshold. The greater the correlation, the stronger the correlation, and this is used to determine the next intersection.

[0026] Correlation calculation:

[0027]

[0028] (1) t is the connecting journey time (minutes).

[0029] (2)q Max The maximum lane flow of the branch (VPH: peak hour flow, explaining q Max The traffic value can be the half-hour accumulation or the average of the 5-minute hourly conversion.

[0030] (3)q t Taking the ZJ section as an example, J is the upstream intersection of Z, and the sum of the flow is the average flow of all lanes of the branch.

[0031] (4) N is the number of lanes flowing into the section between the two intersections (excluding the widened lanes at the entrance).

[0032] Forward search relevance calculation instructions:

[0033] As shown below, if intersection Z is the intersection with the largest traffic demand, a forward search is performed, and the correlation of each branch outflow from intersection Z is calculated. The calculation formula is as follows:

[0034] North Branch:

[0035] I 1=(0.5 / 1+t1)*(max(Q1,Q2)averge(Q1,Q2)-(N1-2))

[0036] Among them, Q1 and Q2 refer to the queue length of the north branch lane; the values ​​of N1 and t1 are determined according to max(Q1,Q2). If Q1>Q2, then N1 is the number of lanes in section ZJ; t1 is the average travel time of section ZJ; if Q2>Q1, then N1 is the number of lanes in section ZP; t1 is the average travel time of section ZP (the same below, the calculation of each branch below is determined according to this method).

[0037] West Branch:

[0038] I 2=(0.5 / 1+t2)*(max(Q3,Q4) / averge(Q3,Q4)-(N2-2))

[0039] South Branch:

[0040] I 3=(0.5 / 1+t3)*(max(Q5,Q6) / averge(Q5,Q6)-(N3-2))

[0041] East Branch:

[0042] I4=(0.5 / 1+t4)*(max(Q7,Q8) / averge(Q7,Q8)-(N4-2))

[0043] According to the calculation results, if I2 = max(I1, I2, I3, I4) is determined to be the largest, and Q4 = max(Q3, Q4) is used to determine the preliminary coordinated flow direction (and also to compare with the correlation threshold), the next intersection can be preliminarily determined to be intersection J. For details, please refer to the attached Figure 2 .

[0044] Step 2: Search for green wave routes from 0:00 to 24:00 in a time period of 5 minutes, and finally form a set of green wave routes for every 5 minutes.

[0045] (If there are mixed lanes on the entrance road, the following principles will be used to eliminate them:

[0046] For example, for an entrance lane: left turn, straight left, straight ahead, right turn, there are two straight ahead lanes and two left turn lanes, which is equivalent to repeated counting of mixed lanes. The mixed lanes of left turn and straight ahead U-turn are counted as corresponding straight ahead and left turn, and the single U-turn lane is not counted.

[0047] To eliminate mixed paths, if a branch is entirely made up of mixed lanes, simply remove the branch. If there is a dedicated lane, the flow of the mixed lanes will be divided according to the ratio of 0.5. For example: the entrance to the west branch is left turn, straight left, straight ahead, and right turn. The flow of the left turn lane = the flow of the left turn lane + 0.5* the flow of the straight left lane, and the flow of the straight lane = the flow of the straight lane + 0.5* the flow of the straight left lane).

[0048] Reverse search correlation calculation instructions:

[0049] If intersection H is determined to be the intersection with the largest traffic demand, calculate the correlation between intersection H and the eight intersections C (north to south, east to west), G (north to south, west to east), M (west to east, south to north), and I (east to west, south to north). Figure 3 (shown)

[0050] Take the maximum value among the correlations of the 8 locations flowing to intersection H, and the calculation formula is the same as the forward search correlation calculation formula. Take the intersection with the largest correlation value among the 8 intersections, and preliminarily determine it as the upstream intersection. If the upstream intersection of intersection H is intersection I, and the direction corresponding to the maximum value is from east to west of intersection I, if the correlation of intersection I (east to west) is greater than the correlation threshold, the correlation threshold is customizable, and an initial value of 0.01 can be given, or the correlation threshold can be defined according to actual conditions, not a fixed value, then intersection I is the upstream intersection of intersection H. At the same time, it can be preliminarily determined that the upstream intersection of intersection I is intersection J; please refer to the attached for details. Figure 3 .

[0051] Preferably, the S4. forward and reverse green wave line integration specifically includes:

[0052] Step 1: After S3, the 24 hours of a day are divided into a time period of 5 minutes, with a total of 288 green wave lines in the time period. First, the one-way green wave lines generated in each 5-minute period are merged (one-way and two-way lines are merged separately). The one-way green wave fusion is based on the common sequence (for example, whether the common sequence intersections are greater than 4), saturation level (the saturation level is divided into 3 levels: 0-0.3, 0.3-0.6, 0.6-0.9, and the green wave line saturation refers to the average saturation of the coordinated direction of each intersection), time range (for example, at least 30 minutes is required to be considered a qualified line) and other conditions for fusion.

[0053] The specific fusion process of one-way is as follows:

[0054] For example, in the time period of 0:00-0:05, the generated green wave line includes 6 intersections A→B→C→D→E→F (letters represent intersections, the same below), and the saturation of the green wave line is 0.35.

[0055] ② In the time period of 0:05-0:10, the generated green wave line includes 7 intersections: A→B→C→D→E→F→G, and the saturation of the green wave line is 0.33.

[0056] The two 5-minute green wave lines from 0:00-0:05 and 0:05-0:10 have a total sequence of A, B, C, D, E, and F, with a total of 6 intersections. The saturation levels are all within the range of 0.3-0.6, and can be merged. Then, they are merged with the green wave lines generated during the 0:10-0:15 period, and so on. The total fusion time must be at least 30 minutes, or longer, which can be customized. (In the one-way fusion process, as long as there is no saturation or continuous fault at the intersection, fusion can also be performed. For example, the fusion requirements are not met during the 0:00-0:05 and 0:05-0:10 periods, but the 0:00-0:05 period and the 0:10-0:15 period can be merged. Then, the 0:00-0:15 period, which is 15 minutes in total and includes 3 periods, can also be merged).

[0057] Step 2: After completing the one-way green wave fusion, we finally get the key path set K with time division under different search directions m,0,t1,t2 ,K m,1,t1,t2 ,m is the key path number, 0-forward search, 1-reverse search, t1 is the starting time position, t2 is the ending time position.

[0058] Next, two-way fusion is performed, which is also performed based on the common sequence, saturation level, and time range, and finally a series of unidirectional or bidirectional green wave lines are generated.

[0059] The specific two-way green wave fusion is as follows:

[0060] Suppose that within the 30-minute period from 0:00 to 0:30, a positive green wave line is synthesized: A→B→C→D→E→F→G, the saturation of the green wave line is 0.35, and the saturation level is 0.3-0.6.

[0061] At the same time, during the 30-minute period from 0:00 to 0:30, a reverse green wave line was synthesized: G→F→E→D→C→B→A, with a green wave line saturation of 0.45; the saturation level was 0.3-0.6.

[0062] The common sequence of the two-way green wave fusion has 7 intersections, which meets the intersection number requirement (the common sequence is greater than or equal to 4), and the saturation is also at the same level. The time range is 30 minutes, which meets the shortest time requirement. Therefore, in the time period of 0:00-0:30, a two-way green wave route that meets the conditions can be generated.

[0063] If a forward green wave line is generated between 0:00 and 0:30, but a reverse green wave line that can be merged with it is not generated, then the one-way green wave line A→B→C→D→E→F→G can still be output during the time period of 0:00-0:30.

[0064] Preferably, the green wave head-to-tail fusion at S5.0 point specifically includes: after the forward and reverse green wave fusion is completed at S4, the green wave line with 0:00 as the starting time and the green wave line with 24:00 as the ending time are merged according to the saturation level and whether the common sequence meets the requirements, so as to ensure the integrity of the green wave line throughout the day.

[0065] The beneficial effects of the present invention are:

[0066] Compared with the prior art, the present invention is mainly intended to solve some drawbacks of traditional green wave route determination. By designing an intelligent green wave route generation algorithm, green wave routes are automatically generated to reduce the workload of traffic practitioners. Moreover, the automatic generation of green wave routes can reduce the subjective influence of technical personnel, thereby achieving more efficient and scientific green wave route generation. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] Figure 1 Confirm the flow chart for the intersection with the highest traffic demand.

[0068] Figure 2 This is a schematic diagram for searching the forward green wave line.

[0069] Figure 3 Search diagram for reverse green wave line. DETAILED DESCRIPTION

[0070] The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0071] With the widespread popularity of urban traffic signal networking, the basic internal conditions are provided for the green wave coordination of signals. Green wave coordination can reduce the number of stops and improve the travel experience of drivers. Therefore, traffic management personnel also try their best to enable the signal machines on the road to achieve green wave coordinated control to improve the travel experience of citizens.

[0072] The traditional green wave coordination route design mainly relies on the experience of traffic management personnel, who judge which road sections should be designed with green wave coordination plans based on experience. When designing green wave routes using this method, the rationality and scientificity of the route design are largely affected by the professional level of the technical personnel, which leads to a significant reduction in the final green wave effect and fails to achieve the purpose of improving residents' travel experience. In addition, since the determination of green wave routes relies on manual research and analysis, work efficiency is greatly reduced.

[0073] Therefore, it is necessary to invent a method that can automatically generate green wave routes. This method first determines the intersection with the greatest traffic demand, takes the intersection as the search starting point, calculates the correlation with the adjacent intersections, and searches for green wave routes based on the correlation between intersections. The entire process does not require human participation, and automatically generates green wave routes, which can reduce the subjective influence of technicians and further improve the efficiency and scientificity of green wave route determination. Through this method, the coordinated control plan of networked intersections in urban areas can be optimized, greatly improving the travel experience of residents.

[0074] In order to solve the above problems, a method for automatically generating and calculating green waves for urban road network trunk lines is proposed. The method mainly includes the following steps:

[0075] 1. Establish the topological relationship of the intersections in the urban road network, and create an array set of intersections and intersection connecting sections that meet the requirements.

[0076] 2. Determine the intersection with the greatest traffic demand (calculate the ratio of the queue length of each import lane to the length of the road section, select the intersection with the largest ratio, that is, the intersection with the greatest traffic demand, and use this intersection as the starting point for the green wave route search).

[0077] 3. Generation of positive and reverse green wave lines (24 hours a day, 5 minutes as a period, generate a 5-minute green wave line set, the generation of positive and reverse green wave lines does not affect each other and is independent of each other).

[0078] 4. Fusion of positive and reverse green wave lines (the generated 5-minute green wave lines are first fused unidirectionally and then bidirectionally according to the saturation level, common sequence and time range).

[0079] 5. Fusion of the beginning and end of the green wave at 0 o'clock (after completing the fusion of the positive and reverse green waves, the green wave line with 0:00 as the starting period and the green wave line with 24:00 as the ending time are then merged based on the saturation level and whether the common sequence meets the requirements, to ensure the integrity of the green wave line throughout the day).

[0080] S1: Establish the topological relationship of urban road network intersections

[0081] The establishment of topological relations of intersections in urban road networks includes the definition of intersections and the definition of intersection connecting sections.

[0082] (1) Define intersection

[0083] Define all the intersections in the city, denoted as ai (i represents the intersection number), store all intersections in array A, remove abnormal signal-controlled intersections (including yellow flashing, evergreen, and temporary traffic lights), and update array A.

[0084] (2) Define intersection connection sections

[0085] Define the connecting road section of two intersections, denoted as Rai, aj (Rai, aj means intersection ai to intersection aj; Raj, ai means intersection aj to intersection ai), and store all the connecting road sections in the road section set R. Eliminate the road sections with a length greater than 800 meters and more than one roadside opening every 500 meters, disconnect the intersection topological relationship on both sides of the eliminated road sections, and update the road section set R.

[0086] S2: Identify the intersection with the greatest traffic demand

[0087] The purpose of determining the intersection with the greatest traffic demand is to use this intersection as the starting intersection for searching the green wave route. The specific steps for determining the demand intersection are as follows: Figure 1 ) as shown.

[0088] S3: Forward and reverse green wave line generation

[0089] The generation of forward and reverse green wave lines is independent and does not interfere with each other.

[0090] 1. Forward green wave line generation

[0091] Step 1: Select the intersection with the largest traffic demand in the intersection set array A. If the intersection with the largest demand is the intersection Z in the middle, calculate the correlation of the outflow from north to south, south to north, west to east, and east to west at this intersection. The calculation process is analyzed as follows:

[0092] The formula for calculating the correlation degree is:

[0093]

[0094] ①t is the connecting journey time (minutes).

[0095] ②q Max The maximum lane flow rate (VPH) of a branch can be the superposition of half an hour flow rate or the average of 5 minutes converted into hourly flow rate.

[0096] ③q t Taking the ZJ section as an example, J is the upstream intersection of Z, and the sum of the flow is the average flow of all lanes of the branch; (Z and J represent intersections).

[0097] ④ The number of lanes flowing into the road section between the two intersections (excluding the widened lanes at the entrance) is used to calculate the correlation of the intersection Z flowing out from north to south, south to north, west to east, and east to west.

[0098] Q1 and Q2 are the lanes with the largest left-turn and straight-through traffic at the north branch of intersection Z; Q3 and Q4 are the lanes with the largest left-turn and straight-through traffic at the west branch of intersection Z; Q5 and Q6 are the lanes with the largest left-turn and straight-through traffic at the south branch of intersection Z; Q7 and Q8 are the lanes with the largest left-turn and straight-through traffic at the east branch of intersection Z. (The schematic diagram of the intersection is shown in the figure below) Figure 2 (shown)

[0099] Calculate the correlation of the four branches:

[0100] North Branch:

[0101] I 1=(0.5 / 1+t1)*(max(Q1,Q2)averge(Q1,Q2)-(N1-2))

[0102] West Branch:

[0103] I2=(0.5 / 1+t2)*(max(Q3,Q4) / averge(Q3,Q4)-(N2-2))

[0104] South Branch:

[0105] I 3=(0.5 / 1+t3)*(max(Q5,Q6) / averge(Q5,Q6)-(N3-2))

[0106] East Branch:

[0107] I4=(0.5 / 1+t4)*(max(Q7,Q8) / averge(Q7,Q8)-(N4-2))

[0108] According to the calculation results, if I2=max(I1,I2,I3,I4) is determined to be the largest, and at the same time, according to Q4=max(Q3,Q4), the preliminary coordinated flow direction is determined (it also needs to be compared with the correlation threshold, that is, if it is greater than or equal to the custom correlation threshold, it means there is a correlation, then point to the next intersection, and if it is less than it means there is no correlation, then the search ends), then the next intersection can be preliminarily determined to be intersection J.

[0109] Step 2: Calculate the relevance of the ZJ section. The calculation formula is as follows:

[0110] I=(0.5 / 1+t(FG))*(max(Q3,Q4) / averge(Q3,Q4)-(N(ZJ)-2))

[0111] The calculated result is compared with the separation threshold (IS). If it is greater than the separation threshold, that is, I>IS, the next intersection can be finally determined to be intersection J. If the threshold is not met, the intersection search ends.

[0112] Step 3: If the relevance of road section ZJ meets the separation threshold, then according to G1 = max(G1, Q2), the downstream intersection of intersection J is judged to be C or according to G2 = max(G1, Q2), the downstream intersection of intersection J is judged to be K, and the preliminary coordinated flow direction is determined (also compared with the relevance threshold). If G2 = max(G1, Q2) is established, the downstream intersection of intersection J is preliminarily judged to be intersection K.

[0113] Step 4: Calculate the relevance of the JK section. The calculation formula is as follows:

[0114] I=(0.5 / 1+t(FG))*(max(G1,G2) / averge(G1,G2)-(N(JK)-2))

[0115] The calculated result is compared with the separation threshold (IS). If it is greater than the separation threshold, that is, I>IS, the next intersection can be finally determined to be intersection J. If the threshold is not met, the intersection search ends.

[0116] (If it is judged here that G1=max(G1,Q2) holds, then the initial green wave line trend is a turning type, i.e. Z→J→C. This turning type of line cannot integrate the two-way green wave).

[0117] Step 5: According to the above steps, continue to search for the next intersection until all intersections are searched, and output a one-way green wave route. If the number of intersections on the route does not meet 4, release all intersections in the route, eliminate the first intersection, and then find the intersection with the largest traffic demand, and return to step 1 for a cyclic search; please refer to the attached Figure 2 .

[0118] 2. Reverse green wave line generation

[0119] Step 1: Select the intersection with the largest traffic demand in the intersection set array A. If the intersection with the largest demand is intersection H in the middle, calculate the correlation between intersection H and the eight adjacent intersections C (north to south, east to west), G (north to south, west to east), M (west to east, south to north), and I (east to west, south to north) (correlation calculation will not be repeated here).

[0120] Step 2: In the calculation results of step 1, select the intersection corresponding to the maximum correlation value, which is the upstream intersection. If the maximum correlation value is intersection I from east to west, determine the correlation value of the intersection IH section and the correlation threshold. If the condition is met (the correlation is greater than the correlation threshold), then it can be known that the upstream intersection of intersection H is intersection I, and it is preliminarily determined that the upstream intersection of intersection I is intersection J; if the condition that the correlation is greater than the correlation threshold is not met, then the upstream intersection does not exist.

[0121] Step 3: Calculate the correlation between the two flow directions J (south to north) and J (east to west) of the J intersection flow to the JI section, and take the value with the largest correlation between the two flow directions. If the flow direction J (south to north) is larger and the correlation of the JI section is greater than the correlation threshold, the upstream intersection is intersection O, and the upstream intersections are searched in sequence.

[0122] Step 4: According to the above steps, continue to search for the next intersection until all intersections are searched, and output a one-way green wave route. If the number of intersections on the route does not meet 4, release all intersections in the route, eliminate the first intersection, and then find the intersection with the largest traffic demand, and return to step 1 for a cyclic search; please refer to the attached Figure 3 .

[0123] S4: Fusion of forward and reverse green wave lines

[0124] After the generation and calculation of the green wave line in step three, the 24 hours of a day are divided into a period of 5 minutes, and the forward search key path set and the reverse search key path set are obtained. The generated green wave paths are all 5 minutes (for example, one or more green wave paths are generated in the 00:00-00:05 period, or no green wave line may be generated; one or more green wave lines may be generated in the 00:05-00:10 period, or no green wave line may be generated, and so on). At this time, all the generated green wave lines are one-way green wave lines, so green wave fusion is required. Green wave fusion involves two fusion processes, first one-way green wave fusion and then two-way green wave fusion.

[0125] 1. One-way green wave fusion

[0126] One-way green wave fusion refers to the fusion of each 5-minute green wave line generated in chronological order. During the fusion process, it is necessary to consider whether the two 5-minute green wave lines before and after have a common sequence (common intersection), whether the total duration of the common sequence is more than half an hour (or more than 1 hour, which can be customized), and whether it meets the saturation level requirements (0-0.3, 0.3-0.6, 0.6-0.9, the saturation is divided into the following 3 levels, and those within the range belong to the same level of saturation). The following are the steps to fuse the green wave lines generated in each 5-minute period:

[0127] Step 1: Loop through all critical paths in order.

[0128] (1) If the critical path has not been marked for use, proceed to step 2.

[0129] (2) If the critical path has been marked as used, continue looping to the next critical path.

[0130] Step 2: If the critical path of the current loop is at time t, Kh,i,t , the initialization does not meet the condition statistics n = 0.

[0131] If there is a next time t+1, then check all the critical paths that are not marked for use at time t+1. If there is no critical path K h,j,t+1 , or the common sequence length L<4, then n=n+1, and the path at time t is the common sequence.

[0132] If n<2, continue searching to the next time t+2.

[0133] If n>=2, stop searching.

[0134] If there is a critical path K h,j,t+1 , and the common sequence length L>=4, then calculate K h,i,t With K h,j,t+1 If the common sequence is found, and the intersection saturation of the common sequence is in the same saturation range (0-0.3, 0.3-0.6, 0.6-0.9) (the constraint can also be relaxed to require that more than 80% of the intersection saturations are in the same range), then record the common sequence, as well as time t, t+1, saturation range mark, K h,i,t With K h,j,t+1 Mark as temporarily used (three usage states: unused-0, used-1, temporarily used-2) and continue to check whether the key path at time t+2 contains this common sequence.

[0135] If a new consensus sequence of L>=4 is included or formed, and the intersection saturation of the consensus sequence meets the same range requirement, then continue to expand the time record to t+2, record the new consensus sequence, and continue to check t+3, t+4... and other future times (while loop).

[0136] If a certain moment in the middle does not meet the saturation constraint, then n=n+1, and continue to check the subsequent moments.

[0137] If n>=2, terminate the search and perform a check on the common sequence time length. If the time from t to the current time t+n satisfies half an hour (it can also be strictly constrained to more than 1 hour), record the common sequence and start time, mark the critical path as used, and save the output.

[0138] If the half-hour duration is not met, all critical paths K from time t+1 to time t+n are h,i,t+1 With K h,j,t+n The mark is restored as unused (that is, if no suitable similar coordinated intersection is found at time t, it will not be used anymore, but similar coordinated intersections may still be found at time t+1 and later, so it is restored as unused for the next search).

[0139] If there is no next time t+1, then check the length of the common sequence. If the time from t to the current time t+n meets the half-hour length (it can also be strictly constrained to more than 1 hour), then record the common sequence and the starting time, K h,i,t With K h,j,t+1 Mark for use, save the output.

[0140] If the half-hour duration is not met, all critical paths K from time t+1 to time t+n are h,i,t+1 With K h,j,t+n Restore marked as unused.

[0141] Step 3: Final output, K m,0,t1,t2 ,K m,1,t1,t2 ,m is the key path number, 0-forward search, 1-reverse search, t1 is the starting time position, t2 is the ending time position.

[0142] The following example illustrates the fusion process of one-way green wave lines.

[0143] Step 1: Calculate the green wave line saturation generated in each 5-minute period.

[0144] The saturation of a green wave line refers to the average saturation of the coordinated directions of each intersection on the line.

[0145] The saturation calculation formula for a single intersection in the coordinated direction is:

[0146] C—indicates saturation.

[0147] q—represents the average flow rate of the current 5 minutes in the past 7 days, converted into hourly flow rate.

[0148] S—indicates the traffic capacity under the current operating plan.

[0149] Step 2: Merge each adjacent 5-minute green wave line.

[0150] Each adjacent 5-minute section is merged. The following example illustrates the fusion process (the shortest total duration of the green wave route is tentatively 30 minutes, which is a valid green wave route). The following is the green wave route generated in 30 minutes from 0:00 to 0:30. (Assume that only one path is generated every 5 minutes. If there are multiple paths within 5 minutes, each path is merged separately if it is merged in the previous time period).

[0151] Green Wave Line Situation 1

[0152] ① In the time period of 0:00-0:05, the generated green wave line includes the intersections A→B→C→D→E→F, 6 intersections (letters represent intersections, the same below), and the saturation of the green wave line is 0.35.

[0153] ② In the time period of 0:05-0:10, the generated green wave line includes the intersections A→B→C→D→E→F→G, 7 intersections, and the saturation of the green wave line is 0.33.

[0154] ③ In the time period of 0:10-0:15, the generated green wave route includes the intersections G→A→B→C→D→E→F→G, 7 intersections, and the green wave saturation is 0.75.

[0155] ④ In the time period of 0:15-0:20, the generated green wave route includes the intersections A→B→C→D→E, 5 intersections, and the green wave saturation is 0.36.

[0156] ⑤ In the time period of 0:15-0:20, the generated green wave line includes the intersections G→A→B→C→D→E, 6 intersections, and the green wave saturation is 0.36.

[0157] ⑥In the time period of 0:15-0:20, the generated green wave route includes the intersections G→A→B→C→D→E→F, 7 intersections, and the green wave saturation is 0.39.

[0158] According to the above green wave lines, the common sequence and saturation level of the green wave lines are used to determine whether a one-way green wave line that meets the conditions can be generated. The specific judgment process is as follows:

[0159] Step 1: Determine the common sequence of green wave lines

[0160] The 0:00-0:05 and 0:05-0:10 time periods are merged, and the common sequence obtained is A→B→C→D→E→F; then the common sequence is merged with the line of the 0:10-0:15 time period, and the new common sequence is A→B→C→D→E→F, which is merged with the following time periods in turn. Finally, the common sequence of the 0:00-0:30 time period is A→B→C→D→E, with a total of 5 intersections, which meets the intersection number condition (the common sequence is greater than or equal to 4), and then the saturation level is judged; (Note: If there is a 5-minute time period without a common sequence during the fusion process, but this situation does not occur continuously, for example, the line generated from 0:15-0:20 does not include the 5 intersections A→B→C→D→E, but the line generated from 0:20-0:25 includes the 5 intersections A→B→C→D→E, it can still be merged).

[0161] Step 2: Saturation level determination

[0162] In the time period of 0:00-0:30, except for the time period of 0:10-0:15, the saturation level is not in the range of 0.3-0.6, and the others are all in the range of 0.3-0.6. As long as there is no continuous saturation fault phenomenon, it can be merged. The following will give examples to illustrate the non-compliant situation.

[0163] Therefore, during the time period of 0:00-0:30, an effective one-way green wave line can be generated.

[0164] Green Wave Line Situation 2

[0165] ① In the time period of 0:00-0:05, the generated green wave line includes the intersections A→B→C→D→E→F, 6 intersections (letters represent intersections, the same below), and the saturation of the green wave line is 0.35.

[0166] ② In the time period of 0:05-0:10, the generated green wave line includes the intersections A→B→C→D→E→F→G, 7 intersections, and the saturation of the green wave line is 0.33.

[0167] ③In the time period of 0:10-0:15, the generated green wave line includes 7 intersections: G→H→I→J→K→Y→F→Z, and the green wave saturation is 0.40.

[0168] ④ In the time period of 0:15-0:20, the generated green wave line includes 5 intersections: G→H→I→J→K, and the green wave saturation is 0.36.

[0169] ⑤ In the time period of 0:15-0:20, the generated green wave line includes the intersections G→A→B→C→D→E, 6 intersections, and the green wave saturation is 0.36.

[0170] ⑥In the time period of 0:15-0:20, the generated green wave route includes the intersections G→A→B→C→D→E→F, 7 intersections, and the green wave saturation is 0.39.

[0171] In the period of 0:00-0:30, the saturation levels are all within the range of 0.3-0.6, so the saturation fusion meets the requirements. However, in the periods of 0:10-0:15 and 0:15-0:20, there is a common sequence continuous fault phenomenon. Therefore, a complete green wave line cannot be formed in 0:00-0:30.

[0172] In actual situations, if no effective green wave line is formed between 0:00 and 0:30, the fusion time will be from 0:05 to 0:10, and it will be merged with the next 5-minute period in turn until the entire cycle is completed.

[0173] Green wave line situation 3

[0174] ① In the time period of 0:00-0:05, the generated green wave line includes the intersections A→B→C→D→E→F, 6 intersections (letters represent intersections, the same below), and the saturation of the green wave line is 0.35.

[0175] ② In the time period of 0:05-0:10, the generated green wave line includes the intersections A→B→C→D→E→F→G, 7 intersections, and the saturation of the green wave line is 0.33.

[0176] ③In the time period of 0:10-0:15, the generated green wave route includes the intersections G→A→B→C→D→E→F→G, 7 intersections, and the green wave saturation is 0.77.

[0177] ④ In the time period of 0:15-0:20, the generated green wave route includes the intersections A→B→C→D→E, 5 intersections, and the green wave saturation is 0.78.

[0178] ⑤ In the time period of 0:15-0:20, the generated green wave line includes the intersections G→A→B→C→D→E, 6 intersections, and the green wave saturation is 0.36.

[0179] ⑥In the time period of 0:15-0:20, the generated green wave route includes the intersections G→A→B→C→D→E→F, 7 intersections, and the green wave saturation is 0.39.

[0180] In the time period of 0:00-0:30, the common sequence is A→B→C→D→E, with a total of 5 intersections, which meets the intersection quantity condition (the number of intersections on the green wave line is greater than or equal to 4), and there is no fault phenomenon, so the common sequence fusion is satisfied. However, in the two 5-minute time periods of 0:10-0:15 and 0:15-0:20, the intersection saturation range is at the 0.6-0.9 level, and the saturation in other time periods is at the 0.3-0.6 level, so there is a continuous saturation fault phenomenon. Therefore, this line is an invalid green wave line.

[0181] In actual situations, if no effective green wave line is formed between 0:00 and 0:30, the fusion time will be from 0:05 to 0:10, and it will be merged with the next 5-minute period in turn until the entire cycle is completed.

[0182] 2. Two-way green wave integration

[0183] After completing the one-way green wave fusion, we finally get the key path set K with time division under different search directions. m,0,t1,t2 ,K m,1,t1,t2 ,m is the key path number, 0-forward search, 1-reverse search, t1 is the starting time position, t2 is the ending time position.

[0184] Next, we will carry out two-way green wave fusion. The following is the basic idea of ​​two-way green wave fusion.

[0185] Step 1: K m,0,t1,t2 Based on, loop each unused critical path K i,1,t1,t2 , loop through each intersection in the path sequence and check K m,1,t1,t2 The critical path K of the intersection is included j,1,t1,t2 .

[0186] If the length of the common sequence is greater than 4, the intersection of the check time range is greater than half an hour (or strictly to one hour, which can be customized by the user), and the check saturation range mark is consistent, then save the solution set J, the path contains the common sequence, the intersection of the time range, the saturation range, and the bidirectional mark, and check the remaining intersection sequences in the two paths i and j.

[0187] If the one-way sequence length is met, the solution set J is saved, and the two paths contain the remaining sequence, time range, saturation range, and one-way mark respectively.

[0188] If the saturation range marks are inconsistent, then save the solution set J, the path contains two paths (i or j, non-common parts) sequence, time range, saturation range, one-way mark.

[0189] If the length of the common sequence is less than 4, check the two paths i and j separately, save the solution set J, the path contains the forward and reverse path (i or j, non-common part) sequence, time range, saturation range, one-way mark, check the remaining intersection sequence after removing the common sequence from the path with small saturation.

[0190] If the one-way sequence length is met, the solution set J is saved, and the paths contain the remaining sequence, time range, saturation range, one-way mark, and the key path K is marked. i,0,t1,t2 , K j,0,t1,t2 Already used.

[0191] Step 2: Repeat the line processing in forward and reverse directions

[0192] In the current logic, the difference between forward and reverse directions is determined by the different traffic flow directions at the two intersections A-E. Forward: calculate the traffic flow at A to B; reverse: calculate the traffic flow at B back to A. When only one route is generated in the group, it may appear that when the path ABCDE has been generated, the search for the reverse path still starts from A (because the forward and reverse paths both start from the intersection with the greatest traffic demand). The previous paths do not meet the conditions, but starting from E, the conditions are met, and the reverse generation is also ABCDE. In fact, the two green wave routes are exactly the same. In fact, the generated forward and reverse paths may contain this repeated part.

[0193] The routes generated from 12:30 to 14:30 based on actual analysis are as follows:

[0194] 12:30-12:55 The route is W→X→Y→Z→A→B→C→D

[0195] 13:00-14:00 The routes are W→X→Y→Z→A→B→C→D and A→B→C→D→1→2→3→4.

[0196] 14:05-14:30 The route is A→B→C→D→1→2→3→4

[0197] The two routes have a common section A→B→C→D from 13:00 to 14:00.

[0198] Based on the above situation analysis, the forward and reverse paths in the processing process have linear differences, and the union is calculated; some sections have bifurcations (left turns), and the flow differences of the difference sections (left turn sections) are judged, and the sections with large flow are taken as output sections.

[0199] The final route generated during the time period from 12:30 to 14:30 is as follows:

[0200] 12:30-12:55 The route is W→X→Y→Z→A→B→C→D

[0201] 13:00-14:00 The route is W→X→Y→Z→A→B→C→D→1→2→3→4 14:05-14:30 The route is A→B→C→D→1→2→3→4

[0202] The two-way green wave fusion mainly considers the common sequence of the line saturation range, the time period range, and whether the requirements are met. The following will give a specific example to illustrate the two-way green wave fusion process.

[0203] Green Wave Line Situation 1

[0204] Suppose that within the 30-minute period from 0:00 to 0:30, a positive green wave line is synthesized: A→B→C→D→E→F→G, the saturation of the green wave line is 0.35, and the saturation level is 0.3-0.6.

[0205] At the same time, during the 30-minute period from 0:00 to 0:30, a reverse green wave line was synthesized: G→F→E→D→C→B→A, with a green wave line saturation of 0.45; the saturation level was 0.3-0.6.

[0206] The common sequence of the two-way green wave fusion has 7 intersections, which meets the requirement of the number of intersections (the common sequence is greater than or equal to 4), and the saturation is also at the same level. The time range is 30 minutes, which meets the shortest time requirement; therefore, within the time period of 0:00-0:30, a two-way green wave route that meets the conditions can be generated.

[0207] Green Wave Line Situation 2

[0208] Suppose that within the 30-minute period from 0:00 to 0:30, a positive green wave line is synthesized: A→B→C→D→E→F→G, the saturation of the green wave line is 0.65, and the saturation level is 0.6-0.9.

[0209] At the same time, during the 30-minute period from 0:00 to 0:30, a reverse green wave line was synthesized: G→F→E→D→C→B→A, with a green wave line saturation of 0.45; the saturation level was 0.3-0.6.

[0210] The bidirectional green wave fusion common sequence has 7 intersections, which meets the intersection number requirement (the common sequence is greater than or equal to 4), and the time range is 30 minutes, which meets the minimum time requirement. However, the saturation is not at the same level, so a valid green wave route cannot be generated in the 0:00-0:30 time period.

[0211] Green wave line situation 3

[0212] Suppose that within the 30-minute period from 0:00 to 0:30, a positive green wave line is synthesized: A→B→C→D→E→F→G, the saturation of the green wave line is 0.35, and the saturation level is 0.3-0.6.

[0213] At the same time, during the 15-minute period from 0:00 to 0:15, a reverse green wave line was synthesized: G→F→E→D→C→B→A, with a green wave line saturation of 0.45; the saturation level was 0.3-0.6.

[0214] During the 15-minute period from 0:15 to 0:30, a reverse green wave line was synthesized: M→L→K→Y→P→R→T, with a green wave line saturation of 0.45; the saturation level was 0.3-0.6.

[0215] In the time period of 0:00-0:15, although the bidirectional green wave fusion common sequence has 7 intersections, which meets the intersection number requirement (the common sequence is greater than or equal to 4), the saturation is also at the same level, but it does not meet the shortest time requirement (the shortest line time is greater than or equal to 30 minutes). Therefore, in the time period of 0:00-0:30, a valid green wave line cannot be generated.

[0216] Green Wave Line Situation 4

[0217] Suppose that within the 30-minute period from 0:00 to 0:30, a positive green wave line is synthesized: A→B→C→D→E→F→G, the saturation of the green wave line is 0.35, and the saturation level is 0.3-0.6.

[0218] At the same time, during the 15-minute period from 0:00 to 0:30, a reverse green wave line was synthesized: Q→W→S→T→G→F→E, with a green wave line saturation of 0.45; the saturation level was 0.3-0.6.

[0219] The time range is 30 minutes, which meets the minimum time requirement, and the saturation is also at the same level. However, the common sequence of the two-way green wave fusion is only 3 intersections, which does not meet the intersection number requirement (the common sequence is greater than or equal to 4). Therefore, a valid green wave route cannot be generated during the 0:00-0:30 time period.

[0220] In short, in order to generate an effective two-way green wave line, the three conditions of time range, saturation level range and common sequence must be met at the same time, and none of them can be missing.

[0221] S5: 0 o'clock green wave fusion

[0222] After completing the single or two-way green wave fusion in the time period of 0:00-24:00, it is necessary to return to 0:00.

[0223] The synthetic green wave lines with the starting time and the ending time of 24:00 are merged head to tail (the head to tail fusion is only performed when there are green wave lines in both the 0:00 and 24:00 time periods; if there are no green wave lines in any time period, no fusion is required). The following are the specific steps for the head to tail fusion of the green wave:

[0224] On the basis of the forward and reverse fusion set J, a subset J1 of the set J whose end time is the last time of the day is screened, and a subset J2 of the set J whose start time is the first time of the day is screened.

[0225] For each path i in the loop J1, according to the path unidirectional or bidirectional mark, if it is unidirectional, search for the unidirectional path j in another subset J2; then compare the same sequence length greater than 4 and the saturation range mark is the same.

[0226] The time range is extended to the start time of path i corresponding to J1 and the end time of path j corresponding to J2 to form a new green wave scheme and save it in J, and the corresponding two paths i and j are deleted from J; if it is bidirectional, search for the bidirectional path k in another subset J2.

[0227] If there is only one intersection difference or the two paths are exactly the same, and the saturation range mark is the same, then the time range is extended to the start time of J1 corresponding to path i and the end time of J2 corresponding to path j, and the intersections of the two paths are combined to form a new green wave plan and save it in J, and delete the corresponding two paths i and j from J. Finally, the relevant one-way and two-way fusion paths that meet the conditions are output, including the time range and the included intersections.

[0228] The following will use a specific example to illustrate the 0-point head-to-tail fusion process.

[0229] Assuming 0:00 is the starting time, a two-way green wave route is generated in the time period of 0:00-0:30, with intersections ABCDEF, a total of 6 intersections, and a saturation level of 0.3-0.6.

[0230] Case 1

[0231] Taking 24:00 (for ease of understanding, the end time is 24:00) as the end time, a two-way green wave line is generated during the period of 23:30-24:00, the intersection is ABCDEF (or GABCDEFH), the common sequence is ABCDEF, a total of 6 intersections (the number of intersections is greater than or equal to 4), and the saturation level is 0.3-0.6. Under this condition, the end and end can be merged at 0 o'clock, and the merged two-way green wave line is ABCDEF.

[0232] Case 2

[0233] Taking 24:00 (for ease of understanding, the end time is 24:00) as the end time, a two-way green wave line is generated during the period of 23:30-24:00, the intersections are ABCDEF (or GABCDEFD), the common sequence is ABCDEF, a total of 6 intersections (the number of intersections is greater than or equal to 4), and the saturation level is 0.6-0.9, which does not meet the requirements (the line with 0:00 as the start time, the saturation level is 0.3-0.6). In this case, the end-to-end fusion cannot be performed at 0 o'clock.

[0234] Case 3

[0235] Taking 24:00 (for ease of understanding, the end time is 24:00) as the end time, a two-way green wave line is generated in the period of 23:30-24:00, and the intersection is GTMYUP. It has no common sequence with the line generated with 0:00 as the start time (or the number of common sequence intersections is less than 4), and does not meet the intersection number requirement; the saturation level is 0.3-0.6 (the saturation level meets the requirements). Under this situation, the end-to-end fusion cannot be performed at 0 o'clock.

[0236] Case 4

[0237] With 24:00 (for ease of understanding, the end time is 24:00) as the end time, a one-way green wave line is generated during the period of 23:30-24:00, and a two-way green wave line is generated with 0:00 as the start time. In this case, the end and end are not merged at 0 o'clock.

[0238] Therefore, when performing head-to-tail fusion at 0 point, it is necessary to consider the saturation level, the common sequence range, and whether they are all bidirectional green waves (or all unidirectional green waves) at the same time. Only when all conditions are met can head-to-tail fusion be performed.

[0239] The determination of traditional green wave routes mainly relies on manual experience, which is inefficient and lacks scientificity. The present invention is mainly to solve some drawbacks of traditional green wave route determination. By designing an intelligent green wave route generation algorithm, green wave routes are automatically generated to reduce the workload of traffic practitioners. Moreover, the automatic generation of green wave routes can reduce the subjective influence of technicians, thereby achieving more efficient and scientific green wave route generation.

[0240] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for automatically generating and calculating green wave lines of urban road network trunk lines, characterized in that: The following steps are involved: S1. Establish the topological relationship of the intersection of the urban road network; S2, determining the intersection with the greatest traffic demand according to the topological relationship of the urban road network intersections established in step S1, and taking the intersection as the starting point for searching the green wave route; S3, generating forward and reverse green wave routes according to the green wave route search starting point in step S2; S4, merging the forward and reverse green wave lines according to the forward and reverse green wave lines generated in step S3; S5. The green wave line with 0:00 as the starting time and the green wave line with 24:00 as the ending time are merged end to end to ensure the integrity of the line.

2. The method for automatically generating and calculating green wave lines of urban road network trunk lines according to claim 1 is characterized in that: The establishment of the topological relationship of the urban road network intersections in S1 specifically includes: the establishment of an urban road intersection set and the establishment of an urban road intersection section set.

3. The method for automatically generating and calculating green wave lines of urban road network trunk lines according to claim 1 is characterized in that: Determining the intersection with the largest traffic demand in S2 specifically includes the following steps: Step 1: Divide 24 hours a day into 5-minute time periods, and calculate the ratio of the queue length of the longest queue lane at the entrance of each intersection to the length of the road section in each time period. The calculation formula is as follows: i represents the intersection number, j represents the entrance road number; V ij —Indicates the ratio of the maximum queue length to the road section in all lanes corresponding to a certain entrance road of a certain intersection; h ij —Indicates the queue length value corresponding to the longest queue length of a certain entrance lane of a certain intersection, unit: m; l ij —Indicates the length of a certain entrance road at a certain intersection, unit: m; Step 2: Determine the intersection with the highest traffic demand in a 5-minute period; calculate the V of each entrance road of all intersections ij value, take the maximum value as V max , the intersection corresponding to the maximum value is the intersection with the largest traffic demand; the calculation formula is as follows: Step 3: Divide the 24 hours of a day into 288 time periods of 5 minutes each. According to the calculation method of step 2, determine the intersection with the largest traffic demand in each time period.

4. The method for automatically generating and calculating green wave lines of urban road network trunk lines according to claim 1 is characterized in that: The generation of positive and reverse green wave lines in S3 specifically includes the following steps: Step 1: After determining the intersection with the greatest demand, start searching for intersections at this intersection, where the forward and reverse green wave line searches are independent and do not affect each other; the correlation between this intersection and the adjacent intersections is determined by the correlation degree and the correlation threshold. The greater the correlation, the stronger the correlation, and the next intersection is determined accordingly; Correlation calculation: (1) t is the connecting travel time, unit: minute; (2)q Max The traffic volume of the largest lane on the branch can be accumulated in half an hour or averaged after converting the traffic volume of 5 minutes into an hour. (3)q t Take the ZJ section as an example, J is the upstream intersection of Z, and the sum of the flow is the average flow of all lanes of the branch; (4) N is the number of lanes flowing into the section between the two intersections, excluding the widened lanes at the entrance; Forward search relevance calculation instructions: As shown in the figure below, if intersection Z is the intersection with the largest traffic demand, a forward search is performed, and the correlation of each branch outflow from intersection Z is calculated. The calculation formula is as follows: North Branch: I 1=(0.5 / 1+t1)*(max(Q1,Q2)averge(Q1,Q2)-(N1-2)) Where Q1 and Q2 refer to the queue length of the north branch lane; N1 and t1 are determined according to max(Q1,Q2). If Q1>Q2, N1 is the number of lanes in section ZJ; t1 is the average travel time in section ZJ; if Q2>Q1, N1 is the number of lanes in section ZP; t1 is the average travel time in section ZP; West Branch: I 2=(0.5 / 1+t2)*(max(Q3,Q4) / averge(Q3,Q4)-(N2-2)) South Branch: I 3=(0.5 / 1+t3)*(max(Q5,Q6) / averge(Q5,Q6)-(N3-2)) East Branch: I4=(0.5 / 1+t4)*(max(Q7,Q8) / averge(Q7,Q8)-(N4-2)) According to the calculation results, if it is determined that I2 = max(I 1, I2, I3, I4) is the largest, and according to Q4 = max(Q3, Q4), the preliminary coordinated flow direction is determined, then the next intersection can be preliminarily determined to be intersection J; Step 2: Search for green wave routes from 0:00 to 24:00 in a 5-minute period, and finally form a set of green wave routes for every 5 minutes; Reverse search correlation calculation instructions: If intersection H is determined to be the intersection with the largest traffic demand, calculate the correlation between intersection H and intersection C: north to south, east to west; G: north to south, west to east; M: west to east, south to north; I: east to west, south to north; 8 positions flow to intersection H; The maximum value is taken from the correlations of the 8 locations flowing to intersection H. The calculation formula is the same as the forward search correlation calculation formula. The corresponding intersection with the largest correlation value among the 8 intersections is taken and preliminarily determined to be the upstream intersection. If the upstream intersection of intersection H is intersection I, and the direction corresponding to the maximum value is from east to west of intersection I, if the correlation of intersection I (east to west) is greater than the correlation threshold, then intersection I is the upstream intersection of intersection H. At the same time, it can be preliminarily determined that the upstream intersection of intersection I is intersection J.

5. The method for automatically generating and calculating green wave lines of urban road network trunk lines according to claim 4 is characterized in that: If there are mixed lanes on the entrance road in step 2, they will be removed using the following principles: Lanes of a certain entrance road: left turn, straight left, straight ahead, right turn, there are two straight ahead lanes, two left turn lanes, which is equivalent to repeated counting of mixed lanes, left turn and U-turn mixed lanes of straight ahead and U-turn are counted as corresponding straight ahead and left turn, and single U-turn lanes are not counted; To eliminate mixed paths, if a branch is entirely made up of mixed lanes, simply remove the branch. If there is a dedicated lane, the traffic in the mixed lane will be divided at a ratio of 0.

5.

6. The method for automatically generating and calculating green wave lines of urban road network trunk lines according to claim 1 is characterized in that: The integration of positive and reverse green wave lines in S4 specifically includes: Step 1: After S3, the 24 hours of a day are divided into 5-minute time periods, with a total of 288 time periods of green wave lines. First, the one-way green wave lines generated in each 5-minute period are merged. The one-way green wave fusion is based on the common sequence and saturation level. The specific fusion process of one-way is as follows: For example, in the time period of 0:00-0:05, the generated green wave line includes 6 intersections A→B→C→D→E→F, and the saturation of the green wave line is 0.

35. ② In the time period of 0:05-0:10, the generated green wave line includes 7 intersections: A→B→C→D→E→F→G, and the saturation of the green wave line is 0.

33. The two 5-minute green wave routes from 0:00-0:05 and 0:05-0:10 have a total of 6 intersections in the sequence of A, B, C, D, E, and F. The saturation levels are all in the range of 0.3-0.6, and can be merged. Then, they are merged with the green wave routes generated during the 0:10-0:15 period, and so on. The total fusion time must be at least 30 minutes, or longer, which can be customized. Step 2: After completing the one-way green wave fusion, we finally get the key path set K with time division under different search directions m,0,t1,t2 ,K m,1,t1,t2 ,m is the key path number, 0-forward search, 1-reverse search, t1 is the starting time position, t2 is the ending time position; Next, two-way fusion is performed, which is also performed based on the common sequence, saturation level, and time range, and finally a series of one-way or two-way green wave lines are generated; The specific two-way green wave fusion is as follows: If a positive green wave line is synthesized during the 30-minute period from 0:00 to 0:30: A→B→C→D→E→F→G, the saturation of the green wave line is 0.35, and the saturation level is 0.3-0.6; At the same time, in the 30-minute period from 0:00 to 0:30, a reverse green wave line is synthesized: G→F→E→D→C→B→A, with a green wave line saturation of 0.45; the saturation level is 0.3-0.6; The two-way green wave fusion sequence has 7 intersections, which meets the intersection quantity requirement, and the saturation is also at the same level. The time range is 30 minutes, which meets the shortest time requirement. Therefore, within the time period of 0:00-0:30, a two-way green wave route that meets the conditions can be generated; If a forward green wave line is generated between 0:00 and 0:30, but a reverse green wave line that can be merged with it is not generated, then the one-way green wave line A→B→C→D→E→F→G can still be output during the time period of 0:00-0:

30.

7. The method for automatically generating and calculating green wave lines of urban road network trunk lines according to claim 6 is characterized in that: The above saturation levels are divided into three levels: 0-0.3, 0.3-0.6, and 0.6-0.

9. The green wave line saturation refers to the average value of the saturation of the coordinated directions of each intersection and the fusion of the time range.

8. According to the method for automatically generating and calculating the green wave line of the urban road network trunk line of claim 1, the fusion of the beginning and the end of the green wave at 0 in S5 specifically comprises: After S4 completes the fusion of forward and reverse green waves, the green wave lines with 0:00 as the starting time and the green wave lines with 24:00 as the ending time are then fused based on the saturation level and whether the common sequence meets the requirements to ensure the integrity of the green wave lines throughout the day.

9. The method for automatically generating and calculating green wave lines of urban road network trunk lines according to claim 1 is characterized in that: In step S3, a 5-minute green wave line set is generated for 24 hours a day, with 5 minutes as a period; in step S4, the 5-minute green wave lines are first unidirectionally merged and then bidirectionally merged.

10. The method for automatically generating and calculating green wave lines of urban road network trunk lines according to claim 1, characterized in that: The intersection with the largest traffic demand is determined in step S2 according to the following steps: the ratio of the queue length of each entrance lane to the length of the road section is calculated, and the intersection with the largest ratio is selected as the intersection with the largest traffic demand, and the intersection is used as the starting point for the green wave route search.

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