A random optimization method for multi-path coordination at intersections with bus priority
Through the multi-path coordination stochastic optimization method for cross-intersection group that is prioritized for buses, a comprehensive objective function and multi-path coordination optimization model is established, and the problem of poor coordination effect of cross-intersection signal control in the existing technology is solved, and the coordination benefits of bus priority and cars are taken into account, and a more robust signal coordination control solution is obtained.
Patent Information
- Application Number
- CN202111260584.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2021-10-28
- Publication Date
- 2025-03-04
- Estimated Expiration
- 2041-10-28
AI Technical Summary
It is difficult for the existing technology to effectively coordinate intersection signal control, especially under the bus priority strategy, the coordination control effect of cars and buses is affected.
A multi-path coordination random optimization method for intersection groups with priority for buses is proposed. By establishing a comprehensive objective function including green waveband parameters of small cars, bus trajectory parameters and signal control parameters, a multi-path coordination optimization model is constructed, and the randomness of bus operation parameters is considered, and the optimization coordination control scheme is solved.
Multi-path coordination and optimization of any intersection group is achieved, ensuring that bus vehicles are preferred while taking into account the coordination benefits of car traffic. The obtained signal coordination control scheme is more robust.
Smart Images
Figure CN114036729B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of intersection signal control, and in particular to a bus-priority-oriented intersection group multi-path coordination random optimization method. Background Art
[0002] Public transportation has the advantages of being intensive, efficient, energy-saving and environmentally friendly. Transportation should comprehensively improve the speed, convenience, comfort and safety of public transportation, optimize the quality of public transportation services and enhance the attractiveness of public transportation. Ground public transportation is an important part of the public transportation system. The construction of bus lanes, supplemented by bus signal priority strategies, plays an important role in improving the level of public transportation services and enhancing the attractiveness of the public transportation system.
[0003] The existence of bus lanes separates bus traffic from other motor vehicle traffic (mainly car traffic). These two types of traffic have different operating characteristics. Car traffic under coordinated control often exists in the form of a convoy, and the size of the convoy is considered. Buses usually appear one by one. When coordinating signals, it is more important to consider the randomness of parameters such as the travel time during the vehicle's driving process. In addition, active priority strategies such as green light extension, early red light off, and phase insertion may be implemented for buses, which will inevitably have a certain impact on the coordinated control effect of cars. Summary of the invention
[0004] The purpose of the present invention is to overcome the defects of the above-mentioned prior art and provide a multi-path coordinated random optimization method for intersection groups with bus priority.
[0005] The purpose of the present invention can be achieved by the following technical solutions:
[0006] A multi-path coordination random optimization method for intersection groups with bus priority, the method comprising the following steps:
[0007] 1) Based on the green wave band of cars, constraints are imposed on the cycle duration, intersection phase difference, car green wave band position, and consistency between the design speed and actual traffic flow of each coordination unit;
[0008] 2) Based on the bus trajectory, the active priority strategy is considered to constrain the bus travel time, intersection delay and active priority related parameters of each coordination unit;
[0009] 3) Considering the operating benefits of cars and buses at the same time, a comprehensive objective function including car green wave parameters, bus trajectory parameters and signal control parameters is constructed;
[0010] 4) According to the constraints and comprehensive objective functions, a multi-path coordination optimization model for cars and buses at intersections is constructed, and the randomness of the parameters such as the time for buses to enter the road network, the speed of each road section, and the dwell time at each station are considered to obtain the optimal coordination control solution.
[0011] In the step 1), each constraint specifically includes:
[0012] A. Cycle length constraints:
[0013]
[0014]
[0015] The coordination unit φ of the car is composed of n φ Continuous intersections composition, is the inverse of the cycle duration of the kth intersection in the coordination unit φ, is the maximum cycle length of the coordination unit φ, The minimum cycle duration of the coordination unit φ;
[0016] B. Phase difference constraint:
[0017]
[0018] in, is the absolute phase difference of the kth intersection in the coordination unit φ;
[0019] C. Green band position constraints for cars:
[0020]
[0021] Among them, w φ,k is the time difference between the center line of the green wave band and the start time of the green light at the kth intersection in the coordination unit φ, b φ,k is the width of the green wave band for cars on the downstream section of the kth intersection in the coordination unit φ, is the phase time of the jth phase of the kth intersection in the coordination unit φ;
[0022] D. Mutual constraints between adjacent intersections:
[0023]
[0024]
[0025] in, is the difference between the start time of the green light of the jth phase at the kth intersection and the start time of the cycle, t φ,kis the travel time of the car fleet on the downstream section of the kth intersection in the coordination unit φ, d φ,k The distance of the green wave centerline offset at the kth intersection in the coordination unit φ, δ φ,k is an integer variable;
[0026] E. Travel time constraints:
[0027]
[0028] in, is the distance between the kth intersection and the k+1th intersection in the coordination unit φ, v φ,k is the design speed of the green wave band for cars on the downstream section of the k-th intersection in the coordination unit φ;
[0029] F. Green band disconnection constraint:
[0030]
[0031]
[0032] Among them, p φ,k is a 0-1 variable that indicates whether the green wave band at the k-th intersection in the coordination unit φ is disconnected, and M is a very large positive constant;
[0033] G. Consistency constraints between green wave band and actual traffic flow:
[0034]
[0035]
[0036] H. Required bandwidth constraints:
[0037]
[0038] Among them, x φ,k is the required bandwidth of the green wave band of the downstream section of the kth intersection in the coordination unit φ.
[0039] In the step 2), each constraint specifically includes:
[0040] I. Cycle length constraints:
[0041]
[0042]
[0043] The coordination unit ψ of the bus is composed of n ψ Continuous intersections composition, is the inverse of the cycle duration of the kth intersection in the coordination unit ψ, is the maximum cycle length of the coordination unit ψ, The minimum cycle duration of the coordination unit ψ;
[0044] J. Phase difference constraint:
[0045]
[0046] in, is the absolute phase difference of the kth intersection in the coordination unit ψ;
[0047] K. Mutual constraints between adjacent intersections:
[0048]
[0049]
[0050]
[0051] in, is the difference between the green light start time and cycle start time of the jth phase of the kth intersection in the coordination unit ψ, is the difference between the departure time of bus y at the kth intersection in the coordination unit ψ and the green light start time, is the travel time of bus y on the downstream section of the kth intersection in the coordination unit ψ, The waiting time of bus y at the kth intersection in the coordination unit ψ, is the time when bus y enters the road network in coordination unit ψ, is an integer variable, Y ψ is the number of buses y;
[0052] L. Travel time constraints:
[0053]
[0054] in, is the distance between the kth intersection and the k+1th intersection in the coordination unit ψ, is the speed of bus y on the downstream section of the kth intersection in the coordination unit ψ, is the station time of bus y on the downstream section of the kth intersection in the coordination unit ψ;
[0055] M. Intersection parking restrictions:
[0056]
[0057]
[0058] in, is a 0-1 variable indicating whether bus y stops at the k-th intersection in the coordination unit ψ, is the phase time of the jth phase of the kth intersection in the coordination unit ψ, is the clearing time of the jth phase of the kth intersection in the coordination unit ψ;
[0059] N. The first arriving bus leaves first constraint:
[0060]
[0061]
[0062]
[0063]
[0064] in, is a 0-1 variable, y1≠y2,k=1,2,…,n ψ , the subscript k′ denotes the k′th intersection in the coordination unit ψ, and the superscripts y1 and y2 denote buses y1 and y2;
[0065] O. Active priority strategy constraints:
[0066]
[0067]
[0068]
[0069] in, is a 0-1 variable indicating whether bus y leaves the k-th intersection during the normal green light period in the coordination unit ψ, is a 0-1 variable indicating whether bus y uses the green light extension strategy to leave the k-th intersection in the coordination unit ψ, is a 0-1 variable indicating whether bus y uses the red light early break strategy to leave the k-th intersection in the coordination unit ψ, is a 0-1 variable indicating whether bus y at the k-th intersection in the coordination unit ψ uses the insertion phase 1 to leave. is a 0-1 variable indicating whether bus y at the k-th intersection in the coordination unit ψ uses the insertion phase 2 to leave;
[0070] P. Normal green light period departure restriction:
[0071]
[0072]
[0073]
[0074] In the step 2), the active priority strategy includes green light extension, red light early disconnection and phase insertion.
[0075] In step 2), the constraints of the active priority strategy are specifically considered as follows:
[0076] Q. Using green lights to extend the time to leave restrictions:
[0077]
[0078]
[0079]
[0080]
[0081]
[0082]
[0083] in, is the green light extension time of bus y at the kth intersection in the coordination unit ψ, is the maximum green light extension time of the kth intersection in the coordination unit ψ, is the distance from the bus lane detector upstream of the kth intersection in the coordination unit ψ to the stop line, ΔT is the time from the bus triggering the detector to the signal light responding;
[0084] R. Using the early red light off time to leave the restriction:
[0085]
[0086]
[0087]
[0088]
[0089]
[0090] Among them, the phase occupied by the red light early-off strategy at the jth phase of the kth intersection in the coordination unit ψ is is the early red light off time of bus y at the k-th intersection in the coordination unit ψ, is the maximum early red light off time of the kth intersection in the coordination unit ψ;
[0091] S. Use the inserted phase 1 time to leave the constraint:
[0092]
[0093]
[0094]
[0095]
[0096]
[0097]
[0098]
[0099] The insertion phase 1 of the jth phase of the kth intersection in the coordination unit ψ should be at phase Γ PI1 (i, j) after which the phase occupancy phase Γ is inserted PI1 (i,j),γ 11 (i,j),γ 12 The phase time of (i,j), F1 ψ,k is the start time of insertion phase 1 of the kth intersection in the coordination unit ψ, is the insertion phase duration of the kth intersection in the coordination unit ψ;
[0100] T, use the insertion phase 2 time to drive away from the constraint:
[0101]
[0102]
[0103]
[0104]
[0105]
[0106]
[0107]
[0108] The insertion phase 1 of the jth phase of the kth intersection in the coordination unit ψ should be at phase Γ PI2 (i, j) after which the phase occupancy phase Γ is inserted PI2 (i,j),γ 21 The phase time of (i,j), F2 ψ,kis the start time of insertion phase 2 of the kth intersection in coordination unit ψ.
[0109] In the step 3), the comprehensive objective function f is expressed as:
[0110] Minf=-f a +f b
[0111] Among them, f a is the part of the objective function related to the car, f b is the bus-related part of the objective function.
[0112] The part of the objective function related to the car f a It is used to ensure that the number of cars that do not stop is as large as possible, the width of the green wave band for cars is as wide as possible, and the deviation of the center line after the green wave band for cars is disconnected is as small as possible. The part of the objective function related to buses f b It is used to ensure that the average number of stops per vehicle in each coordination unit at the intersection is the least, the delay time at the intersection is the shortest, the number of green light extension strategies implemented is the least, the time for implementing green light extension is the shortest, the number of early red light off strategies implemented is the least, the time for implementing early red light off is the shortest, the number of first phase insertion strategies implemented is the least, and the number of second phase insertion strategies implemented is the least.
[0113] The part of the objective function related to the car f a The expression is:
[0114]
[0115] in, are coefficients, is the target traffic flow coordinated at the kth intersection in the coordination unit φ, ζ φ,k is the correction coefficient for the discreteness of the fleet on the downstream section of the kth intersection in the coordination unit φ.
[0116] The bus-related part of the objective function f b The expression is:
[0117]
[0118] in, are coefficients respectively, and satisfy is the cycle duration.
[0119] In step 4), the total number of buses arriving in each coordination unit within one cycle is Y ψ , the time for each bus y to arrive at the first intersection stop line of the coordination unit Driving speed of each road segment The station time of each bus stop are random variables that follow a distribution.
[0120] Compared with the prior art, the present invention has the following advantages:
[0121] 1. The optimization scope of the present invention is any intersection group. When the intersections of each coordination unit are interrelated, multiple coordination units can be optimized at the same time, and the coordination units of cars and buses can be defined separately to accommodate the situation where the coordination paths of cars and buses are inconsistent.
[0122] 2. The present invention takes into account the operating efficiency of both cars and buses. When optimizing signal coordination control parameters such as cycle and phase difference, the possible implementation of the active priority strategy is considered to obtain the optimal solution in a truly meaningful sense.
[0123] 3. The present invention takes into account the randomness of parameters such as the total number of buses arriving within a cycle, the time when buses enter the research road network, the driving speed of each section, the station time at each station, etc., establishes a random optimization model, and solves to obtain a signal coordination control scheme with better robustness. BRIEF DESCRIPTION OF THE DRAWINGS
[0124] Figure 1 This is a schematic diagram of the green wave band variables for cars.
[0125] Figure 2 Schematic diagram of bus trajectory variables.
[0126] Figure 3 Schematic diagram of the intersection location in the embodiment.
[0127] Figure 4 Figure 4 is the space-time diagram of the green wave band of each coordination unit of the car, where (4a) is the space-time diagram of the green wave band when the coordination unit ψ=1, (4b) is the space-time diagram of the green wave band when the coordination unit ψ=2, (4c) is the space-time diagram of the green wave band when the coordination unit ψ=3, (4d) is the space-time diagram of the green wave band when the coordination unit ψ=4, (4e) is the space-time diagram of the green wave band when the coordination unit ψ=5, (4f) is the space-time diagram of the green wave band when the coordination unit ψ=6, (4g) is the space-time diagram of the green wave band when the coordination unit ψ=7, (4h) is the space-time diagram of the green wave band when the coordination unit ψ=8, and (4i) is the space-time diagram of the green wave band when the coordination unit ψ=9.
[0128] Figure 5are the space-time trajectory diagrams of each coordination unit of the bus, among which, Figure (5a) is the space-time diagram of the green wave band when the coordination unit ψ=1, Figure (5b) is the space-time diagram of the green wave band when the coordination unit ψ=2, Figure (5c) is the space-time diagram of the green wave band when the coordination unit ψ=3, and Figure (5d) is the space-time diagram of the green wave band when the coordination unit ψ=4.
[0129] Figure 6 The present invention is a flow chart of the method. DETAILED DESCRIPTION
[0130] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.
[0131] The present invention provides a multi-path coordination random optimization method for intersection groups with bus priority. By establishing a multi-path coordination optimization model for cars and buses in an intersection group, taking the intersection group as the control object, considering the mutual connection between multiple coordination units, establishing a unified framework, coordinating the operation of two types of traffic flows on multiple paths, ensuring the priority of buses while taking into account the coordination benefits of car traffic, the method comprises the following steps:
[0132] 1) For any intersection group, the operation of car and bus traffic on multiple paths is optimized simultaneously. The buses adopt active priority strategies such as green light extension, early red light off, and phase insertion, and the randomness of bus operation parameters is considered to obtain a more robust coordinated control scheme. The specific implementation steps are as follows 2) to 5).
[0133] 2) Based on the green wave band of cars, constraints are imposed on the cycle duration, intersection phase difference, car green wave band position, design speed, and consistency with actual traffic flow of each coordination unit, specifically:
[0134] (1) Cycle length constraint:
[0135]
[0136]
[0137] Among them, the coordination unit φ of the car is composed of n φ Continuous intersections composition, is the inverse of the cycle duration of the kth intersection in the coordination unit φ, is the maximum cycle length of the coordination unit φ, The minimum cycle duration of the coordination unit φ;
[0138] (2) Phase difference constraint:
[0139]
[0140] in, is the absolute phase difference of the kth intersection in the coordination unit φ (unit: Cycle);
[0141] (3) Green band position constraints:
[0142]
[0143] Among them, w φ,k is the time difference between the center line of the green wave band and the start time of the green light at the kth intersection in the coordination unit φ, b φ,k is the width of the green wave band for cars on the downstream section of the kth intersection in the coordination unit φ, is the phase time (including green time and clearing time) of the jth phase of the kth intersection in the coordination unit φ, unit: Cycle;
[0144] (4) Mutual constraints between adjacent intersections:
[0145]
[0146]
[0147] in, is the difference between the start time of the green light of the jth phase at the kth intersection and the start time of the cycle, t φ,k is the travel time of the car fleet on the downstream section of the kth intersection in the coordination unit φ, d φ,k The distance of the green wave centerline offset at the kth intersection in the coordination unit φ, δ φ,k It is an integer variable, unit: Cycle;
[0148] (5) Travel time constraints:
[0149]
[0150] in, is the distance between the kth intersection and the k+1th intersection in the coordination unit φ (unit: m), v φ,k is the design speed of the green wave band of cars on the downstream section of the k-th intersection in the coordination unit φ (unit: m / s);
[0151] (6) Green band disconnection constraint:
[0152]
[0153]
[0154] Among them, p φ,k is whether the green wave band at the k-th intersection in the coordination unit φ is disconnected (0-1 variable), M is a very large positive constant;
[0155] (7) Consistency constraints between green wave band and actual traffic flow:
[0156]
[0157]
[0158] (8) Required bandwidth constraints:
[0159]
[0160] Among them, x φ,k is the required bandwidth of the green wave band of the downstream section of the kth intersection in the coordination unit φ (unit: Cycle);
[0161] 3) Based on the bus trajectory, active priority strategies such as green light extension, early red light off, and phase insertion are considered to constrain the bus travel time, intersection delay, and active priority related parameters of each coordination unit, specifically:
[0162] (1) Cycle length constraint:
[0163]
[0164]
[0165] The bus coordination unit ψ is composed of n ψ Continuous intersections composition, is the inverse of the cycle duration of the kth intersection in the coordination unit ψ, is the maximum cycle length of the coordination unit ψ, The minimum cycle duration of the coordination unit ψ;
[0166] (2) Phase difference constraint:
[0167]
[0168] in, is the absolute phase difference of the kth intersection in the coordination unit ψ (unit: Cycle);
[0169] (3) Mutual constraints between adjacent intersections:
[0170]
[0171]
[0172]
[0173] in, is the difference between the green light start time and cycle start time of the jth phase of the kth intersection in the coordination unit ψ, is the difference between the departure time of bus y at the kth intersection in the coordination unit ψ and the green light start time, is the travel time of bus y on the downstream section of the kth intersection in the coordination unit ψ, The waiting time of bus y at the kth intersection in the coordination unit ψ, is the time when bus y enters the road network in coordination unit ψ, It is an integer variable, unit: Cycle;
[0174] (4) Travel time constraints:
[0175]
[0176] in, is the distance between the kth intersection and the k+1th intersection in the coordination unit ψ (unit: m), is the speed of bus y on the downstream section of the kth intersection in the coordination unit ψ (unit: m / s), is the station time of bus y at the downstream section of the kth intersection in the coordination unit ψ (unit: s);
[0177] (5) Intersection parking restrictions:
[0178]
[0179]
[0180] in, is whether bus y stops at the kth intersection in the coordination unit ψ (0-1 variable), is the phase time of the jth phase of the kth intersection in the coordination unit ψ (including green light time and clearing time, unit: Cycle), is the clearing time of the jth phase of the kth intersection in the coordination unit ψ (unit: s);
[0181] (6) The first arriving bus leaves first constraint:
[0182]
[0183]
[0184]
[0185]
[0186] in, is a 0-1 variable, y1≠y2,k=1,2,…,n ψ ;
[0187] (7) Active priority strategy constraints:
[0188]
[0189]
[0190]
[0191] in, is whether bus y leaves the k-th intersection during the normal green light period in the coordination unit ψ, is the coordination unit ψ in which bus y uses the green light extension strategy to leave the k-th intersection. To coordinate whether bus y uses the red light early break strategy to leave at the k-th intersection in unit ψ, is whether bus y at the kth intersection in the coordination unit ψ uses the insertion phase 1 to leave, is whether bus y at the k-th intersection in the coordination unit ψ uses the insertion phase 2 to leave, a 0-1 variable;
[0192] (8) Restrictions on leaving during normal green light period:
[0193]
[0194]
[0195]
[0196] (9) Using green lights to extend the time to leave the restriction:
[0197]
[0198]
[0199]
[0200]
[0201]
[0202]
[0203] in, is the green light extension time of bus y at the kth intersection in the coordination unit ψ, is the maximum green light extension time of the kth intersection in the coordination unit ψ, unit: Cycle; is the distance from the bus lane detector upstream of the kth intersection in the coordination unit ψ to the stop line (unit: m), ΔT is the time from the bus triggering the detector to the signal light responding (unit: s);
[0204] (10) Using the early red light off time to leave the restriction:
[0205]
[0206]
[0207]
[0208]
[0209]
[0210] Among them, the phase occupied by the red light early-off strategy at the jth phase of the kth intersection in the coordination unit ψ is is the early red light off time of bus y at the k-th intersection in the coordination unit ψ, is the maximum early red light off time of the kth intersection in the coordination unit ψ, unit: Cycle;
[0211] (11) Use the inserted phase 1 time departure constraint:
[0212]
[0213]
[0214]
[0215]
[0216]
[0217]
[0218]
[0219] The insertion phase 1 of the jth phase of the kth intersection in the coordination unit ψ should be at phase Γ PI1 (i, j) after which the phase occupancy phase Γ is inserted PI1 (i,j),γ 11 (i,j),γ 12 Phase time of (i,j); F1 ψ,kis the start time of insertion phase 1 of the kth intersection in the coordination unit ψ, is the insertion phase duration of the kth intersection in the coordination unit ψ, unit: Cycle;
[0220] (12) Use the inserted phase 2 time departure constraint:
[0221]
[0222]
[0223]
[0224]
[0225]
[0226]
[0227]
[0228] The insertion phase 1 of the jth phase of the kth intersection in the coordination unit ψ should be at phase Γ PI2 (i, j) after which the phase occupancy phase Γ is inserted PI2 (i,j),γ 21 Phase time of (i,j); F2 ψ,k is the start time of insertion phase 2 of the kth intersection in the coordination unit ψ, unit: Cycle;
[0229] 4) The optimization objective takes into account the operating benefits of cars and buses at the same time, and establishes a comprehensive objective function including car green wave band parameters, bus trajectory parameters, and signal control parameters. The objective function is:
[0230] Min f=-f a +f b
[0231] Among them, f a For the part related to cars in the objective function, it is ensured that ① the number of cars that do not stop is as large as possible, ② the width of the green wave band for cars is as large as possible, and ③ the deviation of the center line after the green wave band for cars is disconnected is as small as possible.
[0232]
[0233] f bFor the bus-related part of the objective function, ensure that on average each vehicle in each coordination unit ① has the least number of stops at intersections, ② has the shortest delay time at intersections, ③ has the least number of green light extension strategies, ④ has the shortest green light extension time, ⑤ has the least number of red light early-off strategies, ⑥ has the shortest red light early-off time, ⑦ has the least number of first phase insertion strategies, and ⑧ has the least number of second phase insertion strategies.
[0234]
[0235] in, is the target traffic flow of the kth intersection in the coordination unit φ (unit: pcu / h), ζ φ,k is the correction coefficient of the convoy dispersion on the downstream section of the kth intersection in the coordination unit φ;
[0236] 5) Considering the randomness of parameters such as the time of entering the road network, the driving speed of each section, and the stay time at each station during bus operation, solve the coordinated control plan.
[0237] In the present invention, the total number of buses Y arriving in each coordination unit within one cycle is ψ , and the time when each bus y arrives at the first intersection stop line of the coordination unit Driving speed of each road segment The station time of each bus stop Parameters such as are not determined, but are random variables that obey a certain distribution.
[0238] Example
[0239] The model is verified and analyzed using an intersection group consisting of 13 signalized intersections in Shinan District, Qingdao City as a case road network. The main roads consisting of intersections S1-S2-S3-S4 and intersections S11-S12-S13 need to optimize both the two-way car traffic and the bus traffic on the dedicated lanes (active priority strategy can be implemented). Intersections S1-S5-S11 and intersections S4-S7-S8-S9-S10-S13 are two main roads without buses passing through, only coordinating car traffic, and the remaining roads are branches with smaller traffic flows. Among them, the main road consisting of intersections S5-S6-S7 is a one-way street from east to west.
[0240] There are 9 coordination units in total for the car:
[0241] 1)φ=1,n φ =4, coordinated intersections and phases: {(1,3),(2,1),(3,1),(4,1)};
[0242] 2)φ=2,n φ=4, coordinate intersections and phases: {(4,1),(3,1),(2,1),(1,3)};
[0243] 3)φ=3,n φ =3, coordinate intersections and phases: {(11,2),(12,1),(13,3)};
[0244] 4)φ=4,n φ =3, coordinate intersections and phases: {(13,3),(12,1),(11,2)};
[0245] 5)φ=5,n φ =3, coordinate intersections and phases: {(1,2),(5,1),(11,4)};
[0246] 6)φ=6,n φ =3, coordinate intersections and phases: {(11,4),(5,1),(1,2)};
[0247] 7)φ=7,n φ =6, coordinated intersections and phases: {(4,2),(7,2),(8,1),(9,1),(10,2),(13,2)};
[0248] 8)φ=8,n φ =6, coordinated intersections and phases: {(13,2),(10,2),(9,1),(8,1),(7,2),(4,2)};
[0249] 9)φ=9,n φ =3, coordinate intersections and phases: {(5,3),(6,2),(7,3)};
[0250] There are 4 coordination units for buses:
[0251] 1)ψ=1,n ψ =3, coordinated intersections and phases: {(11,2),(12,1),(13,3)}, there is a bus stop between intersections S11 and S12;
[0252] 2)ψ=2,n ψ =3, coordinated intersections and phases: {(13,3),(12,1),(11,2)}, there is a bus stop between intersections S13 and S12;
[0253] 3)ψ=3,n ψ =4, coordinated intersections and phases: {(1,3),(2,1),(3,1),(4,1)}, with bus stops between intersections S1 and S2 and between S3 and S4;
[0254] 4)ψ=4,n ψ =4, coordinated intersections and phases: {(4,1),(3,1),(2,1),(1,3)}, there are bus stops between intersections S4 and S3, and between S2 and S1.
[0255] Assuming that each bus coordination unit has an average of one bus arriving every two minutes, we randomly generate 20 minutes of trajectory data (about 10 bus trajectories) as sample data to describe the distribution of the random variable. Input according to the actual situation. The initial cycle time of the 13 intersections is 154 seconds. Assuming that the cycle time remains unchanged, only the phase difference scheme is optimized. The phase time g(i,j) of each intersection is:
[0256] Table 1 Phase time of each intersection
[0257]
[0258]
[0259] The settings of other related parameters are as follows: GE max,i =0.08, RT max,i =0.08,PI i =0.08, LD i =50,ΔT=1.
[0260] According to the constraints and objective function, a random linear programming model is obtained, and the PH algorithm is used to solve the model. The objective function value f related to the car is obtained a =1414.30, bus-related objective function value f b =173.99, the corresponding phase difference schemes of each intersection are: O1=0.00; O2=0.28; O3=0.31; O4=0.20; O5=0.31; O6=0.32; O7=0.53; O8=0.69; O9=0.16; O 10 =0.13;O 11 =0.89; O 12 =0.04; O 13 =0.05.
[0261] After optimization, the green wave band space-time diagram of each coordinated unit of the car is as follows: Figure 4 As shown in Figure 2, the sample trajectories of each coordination unit of the bus are as follows: Figure 5 shown.
[0262] In summary, the present invention proposes a multi-path coordinated random optimization method for intersection groups with bus priority, which takes the intersection group as the control object, considers the mutual connection between multiple coordination units, establishes a unified framework, and simultaneously optimizes the operation of car traffic and bus traffic on multiple paths, ensuring the priority of buses while taking into account the coordination efficiency of car traffic. Among them, buses can adopt active priority strategies such as green light extension, early red light off, phase insertion, etc., and the randomness of bus operation parameters is taken into account.
[0263] The optimization scope of the present invention is any intersection group. When the intersections of each coordination unit are interrelated, multiple coordination units can be optimized at the same time. The coordination units of cars and buses are defined separately to accommodate the situation where the coordination paths of cars and buses are inconsistent. The operating efficiency of both cars and buses is taken into account at the same time. When optimizing signal coordination control parameters such as cycle and phase difference, the possible implementation of the active priority strategy is taken into account to obtain the optimal solution in the true sense. The randomness of parameters such as the total number of buses arriving within a cycle, the time when buses enter the research road network, the driving speed of each section, and the station time of each station are taken into account, and a random optimization model is established to solve a signal coordination control solution with better robustness.
Claims
1. A multi-path coordination random optimization method for intersection groups with bus priority, characterized in that: The method comprises the following steps: 1) Based on the green wave band of cars, constraints are imposed on the cycle duration, intersection phase difference, car green wave band position, and consistency between the design speed and actual traffic flow of each coordination unit; 2) Based on the bus trajectory, the active priority strategy is considered to constrain the bus travel time, intersection delay and active priority related parameters of each coordination unit; 3) Considering the operating benefits of cars and buses at the same time, a comprehensive objective function including car green wave parameters, bus trajectory parameters and signal control parameters is constructed; 4) Construct a multi-path coordination optimization model for cars and buses at intersections based on constraints and comprehensive objective functions, and consider the randomness of the parameters of the time of entering the road network, the speed of each road section, and the dwell time of each station during the operation of the bus, and solve to obtain the optimized coordination control scheme; in the step 1), the constraints specifically include: A. Cycle length constraints: The coordination unit φ of the car is composed of n φ Continuous intersections composition, is the inverse of the cycle duration of the kth intersection in the coordination unit φ, is the maximum cycle length of the coordination unit φ, The minimum cycle duration of the coordination unit φ; B. Phase difference constraint: in, is the absolute phase difference of the kth intersection in the coordination unit φ; C. Green band position constraints for cars: Among them, w φ,k is the time difference between the center line of the green wave band and the start time of the green light at the kth intersection in the coordination unit φ, b φ,k is the width of the green wave band for cars on the downstream section of the kth intersection in the coordination unit φ, is the phase time of the jth phase of the kth intersection in the coordination unit φ; D. Mutual constraints between adjacent intersections: in, is the difference between the start time of the green light of the jth phase at the kth intersection and the start time of the cycle, t φ,k is the travel time of the car fleet on the downstream section of the kth intersection in the coordination unit φ, d φ,k The distance of the green wave centerline offset at the kth intersection in the coordination unit φ, δ φ,k is an integer variable; E. Travel time constraints: in, is the distance between the kth intersection and the k+1th intersection in the coordination unit φ, v φ,k is the design speed of the green wave band for cars on the downstream section of the k-th intersection in the coordination unit φ; F. Green band disconnection constraint: Among them, p φ,k is a 0-1 variable that determines whether the green wave band at the k-th intersection in the coordination unit φ is disconnected, and M is a very large positive constant; G. Consistency constraints between green wave band and actual traffic flow: H. Required bandwidth constraints: Among them, x φ,k is the required bandwidth of the green wave band of the downstream section of the kth intersection in the coordination unit φ; in the step 2), each constraint specifically includes: I. Cycle length constraints: The coordination unit ψ of the bus is composed of n ψ Continuous intersections composition, is the inverse of the cycle duration of the kth intersection in the coordination unit ψ, is the maximum cycle length of the coordination unit ψ, The minimum cycle duration of the coordination unit ψ; J. Phase difference constraint: in, is the absolute phase difference of the kth intersection in the coordination unit ψ; K. Mutual constraints between adjacent intersections: in, is the difference between the green light start time and cycle start time of the jth phase of the kth intersection in the coordination unit ψ, is the difference between the departure time of bus y at the kth intersection in the coordination unit ψ and the green light start time, is the travel time of bus y on the downstream section of the kth intersection in the coordination unit ψ, The waiting time of bus y at the kth intersection in the coordination unit ψ, is the time when bus y enters the road network in coordination unit ψ, is an integer variable, Y ψ is the number of buses y; L. Travel time constraints: in, is the distance between the kth intersection and the k+1th intersection in the coordination unit ψ, is the speed of bus y on the downstream section of the kth intersection in the coordination unit ψ, is the station time of bus y on the downstream section of the kth intersection in the coordination unit ψ; M. Intersection parking restrictions: in, is a 0-1 variable indicating whether bus y stops at the k-th intersection in the coordination unit ψ, is the phase time of the jth phase of the kth intersection in the coordination unit ψ, is the clearing time of the jth phase of the kth intersection in the coordination unit ψ; N. The first arriving bus leaves first constraint: in, is a 0-1 variable, The subscript k′ refers to the k′th intersection in the coordination unit φ, and the superscripts y1 and y2 refer to buses y1 and y2; O. Active priority strategy constraints: in, is a 0-1 variable indicating whether bus y leaves the k-th intersection during the normal green light period in the coordination unit ψ, is a 0-1 variable indicating whether bus y uses the green light extension strategy to leave the k-th intersection in the coordination unit ψ, is a 0-1 variable indicating whether bus y uses the red light early break strategy to leave the k-th intersection in the coordination unit ψ, is a 0-1 variable indicating whether bus y at the k-th intersection in the coordination unit ψ uses the insertion phase 1 to leave. is a 0-1 variable indicating whether bus y at the k-th intersection in the coordination unit φ uses the insertion phase 2 to leave; P. Normal green light period departure restriction:
2. The multi-path coordination random optimization method for intersection groups with bus priority according to claim 1 is characterized in that: In the step 2), the active priority strategy includes green light extension, red light early disconnection and phase insertion.
3. The multi-path coordination random optimization method for intersection groups with bus priority according to claim 2 is characterized in that: In step 2), the constraints of the active priority strategy are specifically considered as follows: Q. Using green lights to extend the time to leave restrictions: in, is the green light extension time of bus y at the kth intersection in the coordination unit ψ, is the maximum green light extension time of the kth intersection in the coordination unit ψ, is the distance from the bus lane detector upstream of the kth intersection in the coordination unit ψ to the stop line, ΔT is the time from the bus triggering the detector to the signal light responding; R. Using the early red light off time to leave the restriction: Among them, the phase occupied by the red light early-off strategy at the jth phase of the kth intersection in the coordination unit ψ is is the early red light off time of bus y at the k-th intersection in the coordination unit ψ, is the maximum early red light off time of the kth intersection in the coordination unit ψ; S. Use the inserted phase 1 time to leave the constraint: The insertion phase 1 of the jth phase of the kth intersection in the coordination unit ψ should be at phase Γ PI1 (i, j) after which the phase occupancy phase Γ is inserted PI1 (i,J),γ 11 (I,j),γ 12 Phase time of (I,J), f1 ψ,k is the start time of insertion phase 1 of the Kth intersection in the coordination unit ψ, is the insertion phase duration of the kth intersection in the coordination unit ψ; T, use the insertion phase 2 time to drive away from the constraint: The insertion phase 1 of the jth phase of the kth intersection in the coordination unit ψ should be at phase Γ PI2 (i, j) after which the phase occupancy phase Γ is inserted PI2 (i,j),γ 21 The phase time of (i,j), F2 ψ,k is the start time of insertion phase 2 of the kth intersection in coordination unit ψ.
4. The multi-path coordination random optimization method for intersection groups with bus priority according to claim 3 is characterized in that: In the step 3), the comprehensive objective function f is expressed as: Min f=-f a +f b Among them, f a is the part of the objective function related to the car, f b is the bus-related part of the objective function.
5. The multi-path coordination random optimization method for intersection groups with bus priority according to claim 4 is characterized in that: The part of the objective function related to the car f a It is used to ensure that the number of cars that do not stop is as large as possible, the width of the green wave band for cars is as wide as possible, and the deviation of the center line after the green wave band for cars is disconnected is as small as possible. The part of the objective function related to buses f b It is used to ensure that the average number of stops per vehicle in each coordination unit at the intersection is the least, the delay time at the intersection is the shortest, the number of green light extension strategies implemented is the least, the time for implementing green light extension is the shortest, the number of early red light off strategies implemented is the least, the time for implementing early red light off is the shortest, the number of first phase insertion strategies implemented is the least, and the number of second phase insertion strategies implemented is the least.
6. The multi-path coordination random optimization method for intersection groups with bus priority according to claim 5 is characterized in that: The part of the objective function related to the car f a The expression is: in, are coefficients, is the target traffic flow coordinated at the kth intersection in the coordination unit φ, ζ φ,k is the correction coefficient for the discreteness of the fleet on the downstream section of the kth intersection in the coordination unit φ.
7. The multi-path coordination random optimization method for intersection groups with bus priority according to claim 5 is characterized in that: The bus-related part of the objective function f b The expression is: in, are coefficients respectively, and satisfy is the cycle duration.
8. The multi-path coordination random optimization method for intersection groups with bus priority according to claim 1 is characterized in that: In step 4), the driving speed of each road section The station time of each bus stop are random variables that follow a distribution.
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