Quick adjustment method for cross-section coordination transition

Abstract

The invention discloses a rapid adjustment method for cross-section coordination transition, and the method comprises the steps: extracting a coordination signal control scheme of each intersection before cross-section, and calculating the relative phase difference of each intersection; extracting a coordination signal control scheme of each intersection after crossing, and calculating a relative phase difference and a relative reference phase difference of each intersection; comparing the relative phase differences of the intersections before and after the crossing, judging whether transition adjustment is needed or not, and if the transition adjustment is needed, traversing to find the minimum phase offset, so that the transition logic period of each intersection in the transition period is within the range of the minimum critical logic period duration and the maximum critical logic period duration; and calculating the transition adjustment amount and the transition logic period of each intersection. According to the method, the reasonable transition logic period is calculated by comparing the logic periods before and after the crossing, the maximum / minimum green of each stage of the intersection in the transition period does not need to be manually set, and the problem that the period reverse change possibly occurs in a traditional coordination transition method is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of intelligent control of traffic signals, and in particular relates to a rapid adjustment method for cross-segment coordinated transition. Background Art

[0002] Coordination control is a common control method for urban road traffic signal control in the coordinated linkage of multiple intersections. According to different traffic demand characteristics, a coordinated control scheme for multiple time periods or multiple flow sections will be set. Different coordinated control schemes need to be coordinated and transitioned across sections due to phase difference and cycle length changes. The existing cross-section coordinated transition method will have two effects on traffic flow. First, hard transition is performed according to the difference in absolute phase difference before and after the cross section, which often requires multiple signal cycles and even unnecessary transitions. The coordination is destroyed during the transition period, which will cause traffic flow release disorder during peak hours and seriously affect the driving experience. Second, the transition cycle during the coordinated transition period will have a reverse change in the cycle length when the flat peak enters the peak, and the cycle length will increase when the peak enters the flat peak. This reverse change in the cycle is particularly obvious in the high-saturation traffic flow during peak hours, and will cause multiple queues and congestion. In order to avoid this phenomenon, traffic managers need to manually customize the maximum and minimum green during the transition period for different traffic conditions, which is a heavy task. Therefore, there is an urgent need for a rapid adjustment method for cross-segment coordinated transition that can minimize the impact on traffic flow, achieve an ideal coordinated transition for multi-period or multi-flow segment coordinated control schemes, ensure rapid transition adjustment, a reasonable transition cycle, and reduce the workload of manual configuration.

[0003] The existing Chinese invention patent application number CN202410922664.7, entitled "A dynamic signal optimization method for actively reducing the number of coordinated transition adjustments", discloses a method for dynamically optimizing the green-to-signal ratio and cycle without transition adjustment in a non-transition state, but the transition method in a transition state is not discussed; the existing Chinese invention patent application number CN202210712569.5, entitled "A coordinated control phase difference transition decision and allocation method", discloses that by comparing the basic duration of the stage with the maximum and minimum green, the maximum number of seconds that can be extended and the maximum number of seconds that can be shortened are calculated, and then the transition plan is calculated based on the transition adjustment amount. This method takes into account the different traffic demands of different directions in different time periods in actual scenarios. The adjustable space of each stage in the cycle is configured on demand on site, reducing the catastrophic impact of the algorithm's preset fixed adjustment ratio on the traffic operation of the intersection; however, the difference in absolute phase difference is simply used when calculating the transition adjustment amount, resulting in a longer transition time; and traffic managers need to customize the maximum and minimum green according to the traffic demands of different directions in different time periods, which is a large workload. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a rapid adjustment method for cross-segment coordinated transition to solve the technical problems in the prior art that the transition is not fast enough and the transition period calculation is unreasonable or inconvenient during cross-segment coordination.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A rapid adjustment method for cross-segment coordinated transition of the present invention comprises the following steps:

[0007] 1) Extract the coordinated signal control scheme of each intersection before the cross-section, including the logic cycle duration, absolute phase difference, phase sequence and phase duration, and calculate the relative phase difference of each intersection;

[0008] 2) Extract the coordinated signal control scheme of each intersection after the cross-section, including the logic cycle duration, absolute phase difference, stage sequence and stage duration, and calculate the relative phase difference and relative reference phase difference of each intersection;

[0009] 3) Compare the relative phase difference of each intersection before and after the span to determine whether transition adjustment is needed. If transition adjustment is needed, traverse to find the minimum phase offset so that the transition logic cycle of each intersection during the transition period is [C min ,C max ], C min is the minimum critical logic cycle duration during the transition period, C max It is the maximum critical logic cycle duration during the transition period; if no transition adjustment is required, it ends;

[0010] 4) Calculate the transition adjustment amount for each intersection, determine whether transition is required, and calculate the specific transition logic cycle.

[0011] Furthermore, the step 1) specifically includes:

[0012] 11) Extract the coordinated signal control scheme for each intersection before the cross section, including the logic cycle duration C pre , absolute phase difference Phase sequence, phase duration, where i is the intersection number, i∈{1,2,...,I}, and I is the total number of intersections; the logic cycle is the signal cycle of the coordination phase in the first phase sequence;

[0013] 12) Calculate the relative phase difference based on the absolute phase difference of each intersection Will Adjust in [0,C pre ) range, among which is the relative phase difference before the intersection span with intersection number i-1, It is the absolute phase difference before the intersection span with intersection number i-1.

[0014] Furthermore, the step 2) specifically includes:

[0015] 21) Extract the coordinated signal control scheme for each intersection after the cross section, which includes the logic cycle duration C post , absolute phase difference Stage sequence, stage duration;

[0016] 22) Calculate the relative phase difference based on the absolute phase difference of each intersection Will Adjust in [0,C post ) range, among which is the relative phase difference after the intersection with intersection number i-1, is the absolute phase difference after the intersection span with intersection number i-1;

[0017] 23) Calculate the relative reference phase difference based on the absolute phase difference of each intersection Will Adjust in (-C post / 2,C post / 2], among which is the relative reference phase difference after the intersection span with intersection number i-1, It is the absolute phase difference after the intersection span with intersection number i-1.

[0018] Furthermore, the step 3) specifically includes:

[0019] 31) Compare the relative phase differences of each intersection before and after the span. If If the span needs transition adjustment, the process goes to step 32); otherwise, the relative phase difference of all intersections has not changed and no adjustment is required;

[0020] 32) Determine the duration of the logic cycle C post And the logic cycle length C pre The size relationship is, when C post >C pre When the cross-segment coordination logic cycle is adjusted to the large end, C min Set to C pre , C max Greater than C post When C post <C pre When the cross-segment coordination logic cycle is adjusted to a smaller value, C min Less than C post , C max Set to C pre When C post =C preWhen the cross-segment coordination logic cycle remains unchanged, C min Less than C post , C max Greater than C post ;

[0021] 33) Calculate the time difference TD between the estimated coordination restoration time and the coordinated transition time at each intersection i , the expression is as follows:

[0022]

[0023] Where D is the phase offset, D∈N;

[0024] 34) Traverse the phase offset D to find the minimum D that satisfies the following conditions:

[0025]

[0026] in,

[0027]

[0028] And calculate that each intersection can be adjusted to C in advance post The number of signal logic cycles S i , the expression is as follows:

[0029]

[0030] Among them, floor() is a rounding down function.

[0031] Furthermore, the step 4) specifically includes:

[0032] 41) Calculate the transition adjustment RTD of each intersection i ,RTD i =TD i -S i *C post If RTD i = 0, then intersection i does not need to transition and directly switches to C post ; If RTD i ≠0, then go to step 42);

[0033] 42) Calculate the transition plan for each intersection;

[0034] The transition plan is:

[0035]

[0036] in, is the kth transition logic cycle of intersection i;

[0037] Calculate the transition logic period T t , the expression is as follows:

[0038] T t =round(C min +mod(RTD i ,C min ) / floor(RTD i / C min ))

[0039] Among them, round() is the rounding function, floor(RTD i / C min ) is the number of transition logic cycles possessed by intersection i.

[0040] Beneficial effects of the present invention:

[0041] (1) The present invention finds the shortest transition adjustment duration by a traversal optimization method, and the coordinated adjustment is faster than the traditional transition method.

[0042] (2) The present invention automatically calculates a reasonable transition logic cycle by comparing the logic cycles of the time periods / flow sections before and after the transition, eliminating the need to manually set the maximum / minimum green at each stage of the intersection during the transition, thereby solving the problem of reverse cycle changes that may occur in traditional coordinated transition methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 Flow chart of the method of the present invention.

[0044] Figure 2 It is a schematic diagram of transition adjustment of the present invention. DETAILED DESCRIPTION

[0045] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with embodiments and drawings. The contents mentioned in the implementation modes are not intended to limit the present invention.

[0046] Reference Figure 1-Figure 2 As shown, a fast adjustment method for cross-segment coordinated transition of the present invention, in an example, the steps are as follows:

[0047] 1) Extract the coordinated signal control scheme of each intersection before the cross-section, including the logic cycle duration, absolute phase difference, phase sequence and phase duration, and calculate the relative phase difference of each intersection;

[0048] 11) Extract the coordinated signal control scheme for each intersection before the cross section, including the logic cycle duration C pre =80 seconds, absolute phase difference

[0049]

[0050] 12) Relative phase difference

[0051] 2) Extract the coordinated signal control scheme of each intersection after the cross-section, including the logic cycle duration, absolute phase difference, stage sequence and stage duration, and calculate the relative phase difference and relative reference phase difference of each intersection;

[0052] 21) Extract the coordinated signal control scheme for each intersection after the cross-section, including the logic cycle duration C post =100 seconds, absolute phase difference

[0053] 22) Relative phase difference

[0054] 23) Relative reference phase difference

[0055] 3) Compare the relative phase difference of each intersection before and after the span to determine whether transition adjustment is needed. If transition adjustment is needed, traverse to find the minimum phase offset so that the transition logic cycle of each intersection during the transition period is [C min ,C max ], C min is the minimum critical logic cycle duration during the transition period, C max It is the maximum critical logic cycle duration during the transition period; if no transition adjustment is required, it ends;

[0056] 31) If This indicates that the span needs transition adjustment, and then proceeds to step 32);

[0057] 32) Because C post >C pre , indicating that the cycle needs to be adjusted to a larger value after the cross-segment, and C is set min =80, C max =110;

[0058] 33) Calculate the time difference TD between the estimated coordination restoration time and the coordinated transition time at each intersection i , the expression is as follows:

[0059]

[0060] Where D∈N is the phase offset.

[0061] 34) Traversing the phase offset D, it is found that D=260 is the minimum value that satisfies the following conditions:

[0062]

[0063] in,

[0064]

[0065] Calculation shows that S1=1, S2=0, S3=1, S4=0, S5=2, S6=0, S7=1, S8=0.

[0066] 4) Calculate the transition adjustment amount of each intersection, determine whether transition is needed, and calculate the specific transition logic cycle;

[0067] 41) Calculate the transition adjustment amount for each intersection; RTD 1 =160, RTD 2 =220,RTD 3 =80, RTD 4 =240, RTD 5 =80, RTD 6 =240, RTD 7 =0, RTD 8 =160; so intersection 7 does not need transition, and other intersections need to calculate the transition logic cycle;

[0068] 42) Calculate the transition logic cycle of each intersection;

[0069] The transition logic cycle of intersection 1 is

[0070] The transition logic cycle of intersection 2 is

[0071] The transition logic cycle of intersection 3 is

[0072] The transition logic cycle of intersection 4 is

[0073] The transition logic cycle of intersection 5 is

[0074] The transition logic cycle of intersection 6 is

[0075] The transition logic cycle of intersection 8 is

[0076] The present invention has many specific application paths. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principle of the present invention. These improvements should also be regarded as the protection scope of the present invention.

Claims

1. A rapid adjustment method for cross-segment coordinated transition, characterized in that: Here are the steps: 1) Extract the coordinated signal control scheme of each intersection before the cross-section, including the logic cycle duration, absolute phase difference, phase sequence and phase duration, and calculate the relative phase difference of each intersection; 2) Extract the coordinated signal control scheme of each intersection after the cross-section, including the logic cycle duration, absolute phase difference, stage sequence and stage duration, and calculate the relative phase difference and relative reference phase difference of each intersection; 3) Compare the relative phase difference of each intersection before and after the span to determine whether transition adjustment is needed. If transition adjustment is needed, traverse to find the minimum phase offset so that the transition logic cycle of each intersection during the transition period is [C min ,C max ], C min is the minimum critical logic cycle duration during the transition period, C max The maximum critical logic cycle duration during the transition period; if no transition adjustment is required, it ends; 4) Calculate the transition adjustment amount for each intersection, determine whether transition is required, and calculate the specific transition logic cycle.

2. The rapid adjustment method for cross-segment coordinated transition according to claim 1 is characterized in that: The step 1) specifically includes: 11) Extract the coordinated signal control scheme for each intersection before the cross section, including the logic cycle length C pre , absolute phase difference Phase sequence, phase duration, where i is the intersection number, i∈{1,2,...,I}, and I is the total number of intersections; the logic cycle is the signal cycle of the coordination phase in the first phase sequence; 12) Calculate the relative phase difference based on the absolute phase difference of each intersection Will Adjust in [0,C pre ) range, among which is the relative phase difference before the intersection span with intersection number i-1, It is the absolute phase difference before the intersection span with intersection number i-1.

3. The rapid adjustment method for cross-segment coordinated transition according to claim 2 is characterized in that: The step 2) specifically includes: 21) Extract the coordinated signal control scheme for each intersection after the cross section, which includes the logic cycle duration C post , absolute phase difference Stage sequence, stage duration; 22) Calculate the relative phase difference based on the absolute phase difference of each intersection Will Adjust in [0,C post ) range, among which is the relative phase difference after the intersection with intersection number i-1, is the absolute phase difference after the intersection span with intersection number i-1; 23) Calculate the relative reference phase difference based on the absolute phase difference of each intersection Will Adjust in (-C post / 2,C post / 2], among which is the relative reference phase difference after the intersection span with intersection number i-1, It is the absolute phase difference after the intersection span with intersection number i-1.

4. The rapid adjustment method for cross-segment coordinated transition according to claim 3 is characterized in that: The step 3) specifically includes: 31) Compare the relative phase differences of each intersection before and after the span. If If the span needs transition adjustment, the process goes to step 32); otherwise, the relative phase difference of all intersections has not changed and no adjustment is required; 32) Determine the duration of the logic cycle C post And the logic cycle length C pre The size relationship is, when C post >C pre When the cross-segment coordination logic cycle is adjusted to the large end, C min Set to C pre , C max Greater than C post ; When C post <C pre When the cross-segment coordination logic cycle is adjusted to a smaller value, C min Less than C post , C max Set to C pre ; When C post =C pre When the cross-segment coordination logic cycle remains unchanged, C min Less than C post , C max Greater than C post ; 33) Calculate the time difference TD between the estimated coordination restoration time and the coordinated transition time at each intersection i , the expression is as follows: Where D is the phase offset, D∈N; 34) Traverse the phase offset D to find the minimum D that satisfies the following conditions: in, And calculate that each intersection can be adjusted to C in advance post The number of signal logic cycles S i , the expression is as follows: Among them, floor() is a rounding down function.

5. The rapid adjustment method for cross-segment coordinated transition according to claim 4 is characterized in that: The step 4) specifically includes: 41) Calculate the transition adjustment RTD of each intersection i ,RTD i =TD i -S i *C post If RTD i = 0, then intersection i does not need to transition and directly switches to C post ; If RTD i ≠0, then go to step 42); 42) Calculate the transition plan for each intersection; The transition plan is: in, is the kth transition logic cycle of intersection i; Calculate the transition logic period T t , the expression is as follows: T t =round(C min +mod(RTD i ,C min ) / floor(RTD i / C min )) Among them, round() is the rounding function, floor(RTD i / C min ) is the number of transition logic cycles possessed by intersection i.

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