CN103440774A - Intersection signal timing method capable of converting steering function of lanes within single signal cycle - Google Patents

Abstract

The invention discloses an intersection signal timing method capable of converting the steering function of lanes within a single signal cycle. Firstly, conventional signal phase timing is carried out under the condition that the function of the lanes at an intersection is fixed, and the signal cycle C, a phase time T1,a phase time T2 and a phase time T3 are obtained through calculation. Secondly, under the condition that basic verification is satisfied, by improving the saturability of a through lane at the intersection, the purposes of lowering the saturability of a left-turn lane and transferring the time and space resources of the through lane to the left-turn lane are achieved. Finally, the total signal cycle C is reduced by reducing the phase time T2, optimization circular calculation is carried out, service level evaluation is carried out on the calculation result, and therefore effective usage of the time and space resources of the intersection is achieved, and the single average delay of the intersection is reduced. The intersection signal timing method capable of converting the steering function of the lanes within the single signal cycle can effectively verify whether the existing intersection is adaptive to the traffic technology, and flexible transfer the residual time and space resources of one phase to another phase within the single signal cycle.

Description

Intersection signal timing method for changing lane steering function in single signal cycle

Technical Field

The invention relates to the technical field of road traffic control, in particular to an intersection signal timing method with a lane-changing steering function in a single signal period.

Background

In order to more fully utilize the time-space resources of the intersection, the time-space resources and the air-space resources left in a certain phase in a single signal period are flexibly utilized to another phase, the traffic capacity of the intersection is improved, the steering function of a certain import lane is flexibly changed in the single signal period on the premise of not increasing the scale of the lane, the redundant time-space resources are called to the required part, and the traffic efficiency is improved. The applicant applied a utility model entitled "intersection passing system for changing lane steering function in a single signal cycle" (hereinafter referred to as "intersection passing system") with application number 201220519142.5 in year 2012, 10 and 11, and obtained authorization in year 2013, 3 and 13.

Under the condition of a conventional signal-control plane intersection, the lane function and the signal timing are relatively stable, and for the intersection traffic system, the traffic organization of a certain lane is changed in a single signal period, so that the intersection traffic system bears partial straight-through traffic organization and partial left-turn traffic organization. Therefore, the conventional signal timing method cannot be applied to the traffic technology, and technical expansion and improvement should be carried out on the basis of signal timing at the conventional intersection.

Disclosure of Invention

In view of the above defects of the prior art, the invention provides an intersection signal timing method applicable to an intersection traffic system and having a lane change and steering function in a single signal cycle, which can effectively verify whether the existing intersection is applicable to the intersection traffic system having the lane change and steering function in the single signal cycle, and can flexibly utilize time and space resources left in a certain phase in the single signal cycle to another phase, improve the utilization efficiency of the time and space resources of the intersection, and improve the traffic capacity of the intersection, thereby reducing the parking queuing and average delay of the intersection, and being particularly applicable to an intersection traffic system with the patent number of CN201220519142.5 and named as the lane change and steering function in the single signal cycle.

In order to achieve the above object, the present invention provides an intersection signal timing method with lane change steering function in a single signal cycle, comprising the steps of:

step S101, performing conventional signal timing design:

calculating the total effective time C of the signal period of the intersection and the effective green time T of the straight-going phase₁Effective green time T of left-hand phase₂Right turn phase effective green time T₃And the maximum value of the saturation in the straight-going, left-turning and right-turning directions is X in sequence₁、X₂、X₃And the delay value is D in sequence₁、D₂、D₃Since the conventional signal timing is distributed based on the "phase isochrony" target, X₁≈X₂≈X₃；

Step S102, performing basic verification:

first, X is verified₁<0.8

The method comprises the following steps: carrying out the next step;

otherwise: the lane changing and steering function in a single signal period is not applicable to the intersection, and the calculation is stopped;

② verification of T₁≥T_{Row 1}+T_{Line of}

The method comprises the following steps: carrying out the next step;

otherwise: the lane changing and steering function in a single signal period is not applicable to the intersection, and the calculation is stopped;

wherein,

T_{row 1}: straight phase T₁At the moment when the green light is started, the queued vehicles in the turning lane and the vehicles which have driven into the 'lane function identification area' at the momentA time when the traveling vehicle can completely drive off the stop line;

T_{line of}: the time from the lane function confirmation line to the time of driving off the downstream stop line;

step S103, calculating T₁₁：

Target saturation X for specified straight-through lane_{Straight bar}=0.8, total effective C in fixed signal period, effective green time T in each phase₁、T₂、T₃On the basis of the data, calculating the traffic organization T₁₁Time of the stage: t is₁₁；

According to the formula 2S_{Straight bar}（T₁/C）X₁=Q_{Straight bar}And S_{Straight bar}（T₁+T₁₁/C）X_{Straight bar}=Q_{Straight bar},

To obtain T₁₁=(2X₁-X_{Straight bar})T₁/X_{Straight bar}；S_{Straight bar}Is the saturated flow of the inlet passage, Q, specially for straight going_{Straight bar}: the arrival volume of the straight-driving vehicles in east and west directions at peak time;

step S104, verifying T₁₁：

Verification T₁₁≥T_{Row 1}

The method comprises the following steps: by T₁₁

Otherwise: t is₁₁By T_{Row 1}

Step S105, calculating T₁₂And T_{Row 2}：

T₁₂=T₁-T₁₁

T_{Row 2}Left-hand phase T of east-west₂At the moment when the green light is started, the queued vehicles on the turning lane and the running vehicles which have run into the lane function identification area at the moment can completely run away from the stop line; t is_{Row 2}From T₁₂And calculating(s) the arrival of the vehicles at the entrance road according to the known distribution rule;

step S106, calculating T₂₁：

T₂₁=T₂-T_{Line of}；

Step S107, verifying T₂₁：

Verification T₂₁≥T_{Row 2}

If yes, calculating the maximum saturation of the adjusted left-turn direction:

X₂′=T₂X₂/(T₂+T₂₁)

otherwise, the T is adjusted up by 1 second₁₁Down regulation of T₁₂Calculating T_{Row 2}Let T be_{Row 2}=T₂₁Then, the maximum saturation in the adjusted straight and left turn directions is calculated:

X₁′=2T₁X₁/(T₁+T₁₁)

X₂′=T₂X₂/(T₂+T_{row 2})

The total effective time C and the effective green light time T of the signal period are calculated from the above₁、T₂All are unchanged, T is added into traffic organization₁₁、T₁₂、T₂₁、T₂₂Wherein the saturation of the straight-through lane X₁Increase, left turn saturation X₂Decrease of T₃Remaining unchanged, its saturation X₃Is also unchanged;

step S108, optimizing and circulating trial calculation:

checking yes in step S107 if yes in step S104;

then T is decreased in units of 1 second₂And synchronously reducing the period C, T₁、T₃、T₁₁、T₁₂And (3) keeping unchanged, starting loop trial calculation:

(I) calculating T₂₁：T₂₁′=T₂′-T_{Line of}

(II) verification of T₂₁′≥T_{Row 2}

The method comprises the following steps: calculating the maximum saturation in each direction after a new round of signal adjustment:

X₁″=Q_{straight bar}C′/S_{Straight bar}（T₁+T₁₁）

X₂″=Q_{Left side of}C′/S_{Left side of}（T₂′+T₂₁′）

X₃″=Q_{North and south}C′/S_{North and south}T₃

Wherein,

X₁″，X₂″，X₃"is the maximum saturation in the east-west straight line, east-west left turn, south-north direction after the new round of signal adjustment;

c': the cycle duration(s) after the new round of signal adjustment;

Q_{left side of}: the arrival amount of things turning left in rush hour (pcu/h);

Q_{north and south}: the south-north vehicle arrival amount (pcu/h) in peak hours;

S_{left side of}: the saturation flow of the inlet passage special for the left turn (pcu/h);

S_{north and south}: saturation flow rate of the north-south inlet channel (pcu/h);

otherwise: the cyclic trial calculation is stopped;

(III) trial calculation is circulated until X₂″≈X₃"or verify" no "is complete;

② if the step S104 is verified as "YES", the step S107 is verified as "NO":

then press X₁′=2T₁X₁/(T₁+T₁₁) And X₂′=T₂X₂/(T₂+T_{Row 2}) Calculate X₁′、X₂', the calculation is completed;

step S107, if the step S104 verifies as NO, the step S107 verifies as YES:

performing cyclic trial calculation of₁₁By T_{Row 1}I.e. if no-yes, both yes-yes, but T₁₁=T_{Row 1}；

Fourthly, if the step S104 verifies as NO, the step S107 verifies as NO:

then press X₁′=2T₁X₁/(T₁+T₁₁) And X₂′=T₂X₂/(T₂+T_{Row 2}) Calculate X₁′、X₂', the calculation is completed;

step S109, calculating the delay D₁′、D₂′、D₃', verify service level:

calculating the adjusted phase delay D according to a conventional intersection signal timing formula₁′、D₂′、D₃', and verify intersection service level:

if the service level is in the same level or is above the E level after the level is reduced compared with the conventional timing, the lane changing and steering function in a single signal period can be applied to the intersection, a signal timing diagram is drawn, and timing is finished;

if the intersection service level decreases below level F, the "lane change steering function within a single signal cycle" is not applicable at the intersection and timing ends.

The intersection signal timing method for changing the lane steering function in a single signal period has the advantages that: the invention expands and improves the existing conventional intersection signal timing method, overcomes the defects of the prior art, is suitable for an intersection traffic system, can effectively verify whether the existing intersection is suitable for the intersection traffic system with the function of changing the lane turning in a single signal period, can flexibly utilize the time and space resources left in a certain phase in the single signal period to another phase, improves the utilization efficiency of the time and space resources of the intersection, and improves the traffic capacity of the intersection, thereby reducing the parking queuing and average delay of the intersection, and being particularly suitable for the intersection traffic system with the patent number of CN201220519142.5 and the name of changing the lane turning function in the single signal period.

The conception, the specific structure and the technical effects of the present invention will be further described with reference to the accompanying drawings to fully understand the objects, the features and the effects of the present invention.

Drawings

Fig. 1 is a flowchart of an intersection signal timing method with a lane change steering function in a single signal cycle according to the present embodiment.

Fig. 2 is a schematic diagram of a conventional intersection.

Fig. 3 is an enlarged schematic view of step S102 in fig. 1.

Fig. 4 is an enlarged schematic view of step S104 in fig. 1.

Fig. 5 is an enlarged schematic view of step S108 in fig. 1.

Fig. 6 is an enlarged schematic view of step S109 in fig. 1.

Detailed Description

Fig. 1 is a flowchart of an intersection signal timing method with a lane change steering function in a single signal cycle according to the present embodiment. With reference to fig. 1 and fig. 3 to fig. 6, the present embodiment provides an intersection signal timing method with a lane change steering function in a single signal cycle, including the following steps:

step S101, performing conventional signal timing design:

calculating the total effective time C of the signal period of the intersection and the effective green time T of the straight-going phase₁Effective green time T of left-hand phase₂Right turn phase effective green time T₃And the maximum value of the saturation in the straight-going, left-turning and right-turning directions is X in sequence₁、X₂、X₃And the delay value is D in sequence₁、D₂、D₃Since the conventional signal timing is distributed based on the "phase isochrony" target, X₁≈X₂≈X₃；

Step S102, performing basic verification:

first, X is verified₁<0.8

The method comprises the following steps: carrying out the next step;

otherwise: the lane changing and steering function in a single signal period is not applicable to the intersection, and the calculation is stopped;

② verification of T₁≥T_{Row 1}+T_{Line of}

The method comprises the following steps: carrying out the next step;

otherwise: the lane changing and steering function in a single signal period is not applicable to the intersection, and the calculation is stopped;

wherein,

T_{row 1}: straight phase T₁At the moment when the green light is started, the queued vehicles on the turning lane and the running vehicles which have run into the lane function identification area at the moment can completely run away from the stop line;

T_{line of}: the time from the lane function confirmation line to the time of driving off the downstream stop line;

step S103, calculating T₁₁：

Target saturation X for specified straight-through lane_{Straight bar}=0.8, total effective C in fixed signal period, effective green time T in each phase₁、T₂、T₃On the basis of the data, calculating the traffic organization T₁₁Time of the stage: t is₁₁；

According to the formula 2S_{Straight bar}（T₁/C）X₁=Q_{Straight bar}And S_{Straight bar}（T₁+T₁₁/C）X_{Straight bar}=Q_{Straight bar},

To obtain T₁₁=(2X₁-X_{Straight bar})T₁/X_{Straight bar}；S_{Straight bar}Is the saturated flow of the inlet passage, Q, specially for straight going_{Straight bar}: the arrival volume of the straight-driving vehicles in east and west directions at peak time;

step S104, verifying T₁₁：

Verification T₁₁≥T_{Row 1}

The method comprises the following steps: by T₁₁

Otherwise: t is₁₁By T_{Row 1}

Step S105, calculating T₁₂And T_{Row 2}：

T₁₂=T₁-T₁₁

T_{Row 2}Left-hand phase T of east-west₂At the moment when the green light is started, the queued vehicles on the turning lane and the running vehicles which have run into the lane function identification area at the moment can completely run away from the stop line; t is_{Row 2}From T₁₂And calculating(s) the arrival of the vehicles at the entrance road according to the known distribution rule;

step S106, calculating T₂₁：

T₂₁=T₂-T_{Line of}；

Step S107, verifying T₂₁：

Verification T₂₁≥T_{Row 2}

If yes, calculating the maximum saturation of the adjusted left-turn direction:

X₂′=T₂X₂/(T₂+T₂₁)

otherwise, the T is adjusted up by 1 second₁₁Down regulation of T₁₂Calculating T_{Row 2}Let T be_{Row 2}=T₂₁Then, the maximum saturation in the adjusted straight and left turn directions is calculated:

X₁′=2T₁X₁/(T₁+T₁₁)

X₂′=T₂X₂/(T₂+T_{row 2})

The total effective time C and the effective green light time T of the signal period are calculated from the above₁、T₂All are unchanged, T is added into traffic organization₁₁、T₁₂、T₂₁、T₂₂Wherein the saturation of the straight-through lane X₁Increase, left turn saturation X₂Decrease of T₃Remaining unchanged, its saturation X₃Is also unchanged;

step S108, optimizing and circulating trial calculation:

checking yes in step S107 if yes in step S104;

then T is decreased in units of 1 second₂And synchronously reducing the period C, T₁、T₃、T₁₁、T₁₂And (3) keeping unchanged, starting loop trial calculation:

(I) calculating T₂₁：T₂₁′=T₂′-T_{Line of}

(II) verification of T₂₁′≥T_{Row 2}

The method comprises the following steps: calculating the maximum saturation in each direction after a new round of signal adjustment:

X₁″=Q_{straight bar}C′/S_{Straight bar}（T₁+T₁₁）

X₂″=Q_{Left side of}C′/S_{Left side of}（T₂′+T₂₁′）

X₃″=Q_{North and south}C′/S_{North and south}T₃

Wherein,

X₁″，X₂″，X₃"is the maximum saturation in the east-west straight line, east-west left turn, south-north direction after the new round of signal adjustment;

c': the cycle duration(s) after the new round of signal adjustment;

Q_{left side of}: the arrival amount of things turning left in rush hour (pcu/h);

Q_{north and south}: the south-north vehicle arrival amount (pcu/h) in peak hours;

S_{left side of}: the saturation flow of the inlet passage special for the left turn (pcu/h);

S_{north and south}: saturation flow rate of the north-south inlet channel (pcu/h);

otherwise: the cyclic trial calculation is stopped;

(III) trial calculation is circulated until X₂″≈X₃"or verify" no "is complete;

② if the step S104 is verified as "YES", the step S107 is verified as "NO":

then press X₁′=2T₁X₁/(T₁+T₁₁) And X₂′=T₂X₂/(T₂+T_{Row 2}) Calculate X₁′、X₂', the calculation is completed;

step S107, if the step S104 verifies as NO, the step S107 verifies as YES:

performing cyclic trial calculation of₁₁By T_{Row 1}I.e. if no-yes, both yes-yes, but T₁₁=T_{Row 1}；

Fourthly, if the step S104 verifies as NO, the step S107 verifies as NO:

then press X₁′=2T₁X₁/(T₁+T₁₁) And X₂′=T₂X₂/(T₂+T_{Row 2}) Calculate X₁′、X₂', the calculation is completed;

step S109, calculating the delay D₁′、D₂′、D₃', verify service level:

calculating the adjusted phase delay D according to a conventional intersection signal timing formula₁′、D₂′、D₃', and verify intersection service level:

if the service level is in the same level or is above the E level after the level is reduced compared with the conventional timing, the lane changing and steering function in a single signal period can be applied to the intersection, a signal timing diagram is drawn, and timing is finished;

if the intersection service level decreases below level F, the "lane change steering function within a single signal cycle" is not applicable at the intersection and timing ends.

Fig. 2 is a schematic diagram of a conventional intersection. Specifically, in the present embodiment, intersection signal timing calculation is performed on the conventional intersection shown in fig. 2, where it is known that information of traffic flow (vehicle/hour) of each lane of the conventional intersection is shown in table 1:

TABLE 1 traffic flow information for each lane of a conventional intersection

Firstly, according to a conventional intersection signal timing method, the following parameter values are obtained:

sum of flow ratio: y = max { Y₁+y₂+y₃}=0.57

Optimum cycle duration C₀= L/(1-Y) =21s, and in order to meet the shortest time for pedestrians to cross the street, the cycle time length C =100s is selected

Total effective green time G_e=C-L=100s-9s=91s

T₁=Ge*max(y₁) Y =91 x 0.18/0.57=28s (i.e. east-west straight phase effective green time)

T₂=Ge*max(y₂) Y =91 x 0.25/0.57=40s (i.e. east-west left-turn phase effective green time)

T₃=Ge*max(y₃) Y =91 x 0.14/0.57=28s (i.e. effective green time of north-south basic phase)

X₁=q₁/CAP₁=600/(2*1650*0.28)=0.64

X₂=q₂/CAP₂=380/(1550*0.40)=0.62

X₃=q₃/CAP₃=230/(1596*0.23)=0.63

D₁: delay of average signal control of east-west straight lanes by 31.5 s;

D₂: delay of the average signal control of the east-west left-turn lane for 24.3 s;

D₃: the average signal control delay of the south-north lane is 26.7 s;

d: the average signal control delay at the intersection is 25 s.

The evaluation indexes of green time, saturation, delay and the like of each signal phase are calculated according to a conventional intersection signal timing formula.

Secondly, when intersection signal timing is performed by combining the intersection signal timing method with the lane change steering function in a single signal cycle of the embodiment, the specific steps are as follows by combining the steps shown in fig. 1:

the known parameters are:

T_{row 1}: 16s (lane authentication length is 80m, vehicle speed is calculated according to 30km/h temporarily, can be determined according to field conditions in practical application)

T_{Row 2}: 10s (the length of the lane queue is 60m, the vehicle speed is calculated according to 30km/h temporarily, and can be determined according to the field conditions in practical application)

T_{Line of}: 9s (vehicle speed is calculated according to 30km/h temporarily, and can be determined according to field conditions in practical application)

S_{Straight bar}：1650（pcu/h）；

Q_{Straight bar}：600（pcu/h）;

S_{Left side of}：1550（pcu/h）；

Q_{Left side of}：380（pcu/h）;

S_{Straight left side}：1596（pcu/h）；

Q_{Straight left side}：230（pcu/h）;

(1) Pass technology suitability verification

X₁=0.64<0.8 meets the requirements

T₁=28s>T_{Row 1}+T_{Line of}=16s +9s =25s satisfies the requirement

(2) Calculating T₁₁

Suppose X_{Straight bar}=0.8

T₁₁=(2X₁-X_{Straight bar})T₁/X_{Straight bar}=(2*0.64-0.8)*28/0.8=16.8s≈17s>T_{Row 1}=16s

T₁₂=T₁-T₁₁=28-17=11s

(3) Calculating T₁₂

T₂₁=T₂-T_{Line of}=40-9=31s>T_{Row 2}=10s

T₂₂=T₂-T₂₁=40-31=9s

Calculating the saturation after adjustment

X₁′=2T₁X₁/(T₁+T₁₁)=2*28*0.64/（28+17）=0.796

X₂′=T₂X₂/(T₂+T_{Row 2})=40*0.62/（40+10）=0.496

(4) Optimizing periodic loop calculations

Reducing the left-hand phase T in units of 1s₂Duration of (1), hold T₁、T₃The time length of the period is not changed, and the saturation of the east-west left-turn lane is improved.

Determining T through cyclic trial calculation₂When reduced to 28s, X₂And X₃Equalization is achieved.

C′=C-12S=88（s）；

X₁″=Q_{Straight bar}C′/S_{Straight bar}（T₁+T₁₁）=900*88/[1650*(28+17)]=0.711

X₂″=Q_{Left side of}C′/S_{Left side of}（T₂′+T₂₁′）=380*88/[1550*(28+19)]=0.459

X₃″=Q_{North and south}C′/S_{North and south}T₃=230*88/(1596*28)=0.452

Calculating the adjusted intersection signal control delay:

D₁': average traffic delay 28.15s for east-west direct traffic lanes;

D₂': delay of 25.33s for average signal control of east-west left-turn lanes;

D₃': the average signal control delay of the south-north lane is 19.1 s;

D′：22s；

the phase times suitable for the prevailing technology are thus obtained as:

T₁: 28s, wherein T₁₁Is 17s, T₁₂Is 11 s;

T₂': 28s, wherein T₂₁' is 19s, T₂₂' is 9 s;

T₃：28s

thirdly, comparing the saturation degree and the delay of the intersection between the conventional intersection timing and the intersection timing applying the embodiment:

TABLE 2 saturation contrast

Name (R)	Saturation X1	Saturation X2	Saturation X3	Average degree of saturation
					Conventional intersection timing	0.64	0.62	0.63	0.62
Traffic technology intersection timing	0.71	0.46	0.45	0.49

TABLE 3 delay contrast

Therefore, after the traffic technology is adopted, the average saturation of the intersection is reduced, the delay is reduced, and the effect of effectively utilizing space-time resources by the traffic technology is fully proved.

The relevant parameters related to this embodiment are explained as follows:

T₁₁: in the east-west straight-going phase, the lane-changeable is the time for straight-going vehicles to pass;

T₁₂: in the east-west straight-ahead phase, the lane-changeable is the time for the left-turn vehicle to wait;

T₂₁: in the east-west left-turn phase, the lane-changeable is the time for the left-turn vehicle to pass;

T₂₁: in the east-west left-turn phase, the lane-changeable is the time for the straight-going vehicle to wait;

T_{row 1}: in the east-west straight-going phase, at the moment when the green light is started, the queuing length of the lane and the running vehicle which has driven into the lane function identification area at the moment can be changedA time when the vehicle can completely drive off the stop line;

T_{line of}: the time from the lane function confirmation line to the time of driving off the downstream stop line;

X_{straight bar}: the allowable maximum saturation of the straight special lane is 0.8;

S_{straight bar}: the saturation flow of the straight special inlet channel (pcu/h);

S_{left side of}: the saturation flow of the inlet passage special for the left turn (pcu/h);

S_{north and south}: saturation flow rate of the north-south inlet channel (pcu/h);

Q_{straight bar}: the east-west straight traffic arrival amount (pcu/h) in the peak period;

Q_{left side of}: the arrival amount of things turning left in rush hour (pcu/h);

Q_{north and south}: the south-north vehicle arrival amount (pcu/h) in peak hours;

T_{row 2}: east-west left-hand phase T₂And (5) at the moment of starting the green light, the queuing vehicles with the variable lanes and the running vehicles which run into the lane function identification area at the moment can completely drive away from the stop line(s).

X₁': the straight lane saturation after the 1 st adjustment;

X₂': the left-turn lane saturation after the 1 st adjustment;

X₁″，X₂″，X₃": adjusting the maximum saturation in the east-west straight line, east-west left turn and south-north direction for the 2 nd signal;

c': the cycle duration(s) after the new round of signal adjustment;

D₁': after adjustment, the average signal control delay of the east-west straight lane is delayed;

D₂': after adjustment, the average signal control delay of the east-west left-turn lane is delayed;

D₃': the average signal control delay of the south-north lane is adjusted;

d': and the average signal control of the whole intersection is delayed after adjustment.

The embodiment is particularly suitable for being applied to an intersection passing system with the patent number of CN201220519142.5 and named as "lane turning function changing in single signal cycle", and the passing technology is the lane turning function changing in single signal cycle ", which can be specifically summarized as that in a single signal cycle, in the green end (time when a green light is about to end) period of a straight passing phase, the density of straight vehicles at a certain entrance lane is reduced, and at the moment, the" straight passing "function of a certain straight lane is changed into a" left-turn waiting "function; in the initial stage of the following left-turn passing phase, the lane continues to pass through the left-turn function. The detailed description of the embodiments and the drawings in the patent No. CN201220519142.5 can be combined, and will not be repeated herein.

As can be seen from the above, in the present embodiment, the signal period C and each phase time T are calculated when the conventional signal phase timing is performed under the condition that the lane function at the intersection is fixed (1 left, 2 right, 1 right)₁、T₂、T₃。

Secondly, under the condition of meeting basic verification, the saturation of the straight lane at the intersection is improved, so that the saturation of the left-turn lane is reduced, and the transfer of space-time resources of the straight lane to the left-turn lane is realized.

Finally, by reducing the phase time T₂The total signal period C is reduced, optimization cycle trial calculation is carried out, and service level evaluation is carried out on the calculation result, so that effective utilization of time and space resources of the intersection is realized, and average intersection signal delay is reduced.

In conclusion, the embodiment expands and improves the existing conventional intersection signal timing method, overcomes the defects of the prior art, is suitable for an intersection traffic system, can effectively verify whether the existing intersection is suitable for the intersection traffic system with the function of changing lane steering in a single signal cycle, can flexibly utilize the time and space resources left in a certain phase in the single signal cycle to another phase, improves the utilization efficiency of the time and space resources of the intersection, and improves the traffic capacity of the intersection, thereby reducing the parking queuing and average delay of the intersection, and being particularly suitable for the intersection traffic system with the patent number of CN201220519142.5 and the name of "changing lane steering function in a single signal cycle".

The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.

Claims (1)

1. An intersection signal timing method for changing lane steering function in a single signal period is characterized by sequentially comprising the following steps:

step S101, performing conventional signal timing design:

calculating the total effective time C of the signal period of the intersection and the effective green time T of the straight-going phase₁Effective green time T of left-hand phase₂Right turn phase effective green time T₃And the maximum value of the saturation in the straight-going, left-turning and right-turning directions is X in sequence₁、X₂、X₃And extendError value is D in sequence₁、D₂、D₃Since the conventional signal timing is distributed based on the "phase isochrony" target, X₁≈X₂≈X₃；

Step S102, performing basic verification:

first, X is verified₁<0.8

The method comprises the following steps: carrying out the next step;

otherwise: the lane changing and steering function in a single signal period is not applicable to the intersection, and the calculation is stopped;

② verification of T₁≥T_{Row 1}+T_{Line of}

The method comprises the following steps: carrying out the next step;

otherwise: the lane changing and steering function in a single signal period is not applicable to the intersection, and the calculation is stopped;

wherein,

T_{row 1}: straight phase T₁At the moment when the green light is started, the queued vehicles on the turning lane and the running vehicles which have run into the lane function identification area at the moment can completely run away from the stop line;

T_{line of}: the time from the lane function confirmation line to the time of driving off the downstream stop line;

step S103, calculating T₁₁：

Target saturation X for specified straight-through lane_{Straight bar}=0.8, total effective C in fixed signal period, effective green time T in each phase₁、T₂、T₃On the basis of the data, calculating the traffic organization T₁₁Time of the stage: t is₁₁；

According to the formula 2S_{Straight bar}（T₁/C）X₁=Q_{Straight bar}And S_{Straight bar}（T₁+T₁₁/C）X_{Straight bar}=Q_{Straight bar},

To obtain T₁₁=(2X₁-X_{Straight bar})T₁/X_{Straight bar}；S_{Straight bar}Is the saturated flow of the inlet passage, Q, specially for straight going_{Straight bar}: the arrival volume of the straight-driving vehicles in east and west directions at peak time;

step S104, verifying T₁₁：

Verification T₁₁≥T_{Row 1}

The method comprises the following steps: by T₁₁

Otherwise: t is₁₁By T_{Row 1}

Step S105, calculating T₁₂And T_{Row 2}：

T₁₂=T₁-T₁₁

T_{Row 2}Left-hand phase T of east-west₂At the moment when the green light is started, the queued vehicles on the turning lane and the running vehicles which have run into the lane function identification area at the moment can completely run away from the stop line; t is_{Row 2}From T₁₂And calculating(s) the arrival of the vehicles at the entrance road according to the known distribution rule;

step S106, calculating T₂₁：

T₂₁=T₂-T_{Line of}；

Step S107, verifying T₂₁：

Verification T₂₁≥T_{Row 2}

If yes, calculating the maximum saturation of the adjusted left-turn direction:

X₂′=T₂X₂/(T₂+T₂₁)

otherwise, the T is adjusted up by 1 second₁₁Down regulation of T₁₂Calculating T_{Row 2}Let T be_{Row 2}=T₂₁Then, the maximum saturation in the adjusted straight and left turn directions is calculated:

X₁′=2T₁X₁/(T₁+T₁₁)

X₂′=T₂X₂/(T₂+T_{row 2})

The total effective time C and the effective green light time T of the signal period are calculated from the above₁、T₂All are unchanged, T is added into traffic organization₁₁、T₁₂、T₂₁、T₂₂Wherein the saturation of the straight-through lane X₁Increase, left turn saturation X₂Decrease of T₃Remaining unchanged, its saturation X₃Is also unchanged;

step S108, optimizing and circulating trial calculation:

checking yes in step S107 if yes in step S104;

then T is decreased in units of 1 second₂And synchronously reducing the period C, T₁、T₃、T₁₁、T₁₂And (3) keeping unchanged, starting loop trial calculation:

(I) calculating T₂₁：T₂₁′=T₂′-T_{Line of}

(II) verification of T₂₁′≥T_{Row 2}

The method comprises the following steps: calculating the maximum saturation in each direction after a new round of signal adjustment:

X₁″=Q_{straight bar}C′/S_{Straight bar}（T₁+T₁₁）

X₂″=Q_{Left side of}C′/S_{Left side of}（T₂′+T₂₁′）

X₃″=Q_{North and south}C′/S_{North and south}T₃

Wherein,

X₁″，X₂″，X₃"is the maximum saturation in the east-west straight line, east-west left turn, south-north direction after the new round of signal adjustment;

c': the cycle duration(s) after the new round of signal adjustment;

Q_{left side of}: the arrival amount of things turning left in rush hour (pcu/h);

Q_{north and south}: the south-north vehicle arrival amount (pcu/h) in peak hours;

S_{left side of}: the saturation flow of the inlet passage special for the left turn (pcu/h);

S_{north and south}: saturation flow rate of the north-south inlet channel (pcu/h);

otherwise: the cyclic trial calculation is stopped;

(III) trial calculation is circulated until X₂″≈X₃"or verify" no "is complete;

② if the step S104 is verified as "YES", the step S107 is verified as "NO":

then press X₁′=2T₁X₁/(T₁+T₁₁) And X₂′=T₂X₂/(T₂+T_{Row 2}) Calculate X₁′、X₂', the calculation is completed;

step S107, if the step S104 verifies as NO, the step S107 verifies as YES:

performing cyclic trial calculation of₁₁By T_{Row 1}I.e. if no-yes, both yes-yes, but T₁₁=T_{Row 1}；

Fourthly, if the step S104 verifies as NO, the step S107 verifies as NO:

then press X₁′=2T₁X₁/(T₁+T₁₁) And X₂′=T₂X₂/(T₂+T_{Row 2}) Calculate X₁′、X₂', the calculation is completed;

step S109, calculating the delay D₁′、D₂′、D₃', verify service level:

calculating the adjusted phase delay D according to a conventional intersection signal timing formula₁′、D₂′、D₃', and verify intersection service level:

if the service level is in the same level or is above the E level after the level is reduced compared with the conventional timing, the lane changing and steering function in a single signal period can be applied to the intersection, a signal timing diagram is drawn, and timing is finished;

if the intersection service level decreases below level F, the "lane change steering function within a single signal cycle" is not applicable at the intersection and timing ends.

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