1. An intersection signal control method adopting an intermittent lane is used for a multi-lane intersection, and the multi-lane intersection at least comprises a left-turn special lane and a straight special lane and is characterized in that the straight special lane adjacent to the left-turn special lane is set as the intermittent lane; the method for setting the intermittent lane comprises the steps that an intermittent zone stop line is arranged on a corresponding straight special lane, an area between the intermittent zone stop line and an intersection stop line is defined as an intermittent zone, and a left-turning vehicle and a straight vehicle alternately drive in the intermittent zone under the control of a signal; the signal control method comprises the following steps:

s1, setting control signals for the stop line of the intermittent zone and the stop line of the intersection, wherein the control signals are respectively defined as an intermittent zone pre-signal and a main signal, and the four roads of the intersection are sequentially defined as A1, A2, A3 and A4 in the clockwise direction, so that the control signals of A1 and A3 are consistent, and the control signals of A2 and A4 are consistent; according to the definition of an intermittent zone, the intermittent zone pre-signal comprises a straight-going pre-signal and a left-turning pre-signal, the straight-going pre-signal means that a straight-going vehicle enters the intermittent zone according to the straight-going pre-signal, the left-turning pre-signal means that a left-turning vehicle enters the intermittent zone according to the left-turning pre-signal, and the corresponding main signal comprises a straight-going signal and a left-turning signal;

s2, defining the signal phase of the straight-ahead vehicle entering the intermittent zone according to the straight-ahead pre-signal as a straight-ahead pre-signal phase Z1, wherein in the straight-ahead pre-signal phase Z1, the straight-ahead vehicles A1 and A3 enter the intermittent zone; defining the signal phase of the straight-going vehicles in A1 and A3 passing through the intersection according to the straight-going signal as a straight-going phase Q1, wherein in the straight-going phase Q1, the straight-going vehicles in the intermittent zones in the lanes of the intermittent zones of A1 and A3 pass through the intersection, and the straight-going vehicles outside the intermittent zones directly enter the intermittent zones and pass through the intersection; the start and end times of the straight line phase Q1 are both later than the straight line pre-signal phase Z1;

s3, defining the signal phase of the left-turning vehicle entering the intermittent zone according to the left-turning pre-signal as a left-turning pre-signal phase T2, entering a left-turning pre-signal phase T2 after the intermittent zone straight phase Q1 is finished, and enabling the left-turning vehicles A1 and A3 to enter the intermittent zone in the left-turning pre-signal phase T2; defining the signal phase of the left-turn vehicles in a1 and A3 passing through the intersection according to the left-turn signal as a left-turn phase Y2, in the left-turn phase Y2, the left-turn vehicles in the intermittence area of a1 and A3 in the intermittence area pass through the intersection, and the left-turn vehicles outside the intermittence area directly enter the intermittence area and pass through the intersection; the start and end times of the left turn phase Y2 are both later than the left turn pre-signal phase T2;

s4, defining the signal phase of the straight-ahead vehicle entering the intermittent zone according to the straight-ahead pre-signal as a straight-ahead pre-signal phase Z3, entering a straight-ahead pre-signal phase Z3 after the left-turn pre-signal phase T2 is finished, and enabling the straight-ahead vehicles A2 and A4 to enter the intermittent zone in a straight-ahead pre-signal phase Z3; defining the signal phase of the straight-ahead vehicles in A2 and A4 passing through the intersection according to the straight-ahead signal as a main straight-ahead phase Q3, in the straight-ahead phase Q3, the straight-ahead vehicles in the intermittent zone lanes of A2 and A4 in the intermittent zone pass through the intersection, and the straight-ahead vehicles outside the intermittent zone directly enter the intermittent zone and pass through the intersection; the start and end times of the straight line phase Q3 are both later than the straight line pre-signal phase Z3;

s5, defining the signal phase of the left-turning vehicle entering the intermittent zone according to the left-turning pre-signal as a left-turning pre-signal phase T4, entering a left-turning pre-signal phase T4 after the intermittent zone straight phase Q3 is finished, and enabling the left-turning vehicles A2 and A4 to enter the intermittent zone in the left-turning pre-signal phase T4; defining the signal phase of the left-turn vehicles in a2 and a4 passing through the intersection according to the left-turn signal as a left-turn phase Y4, in the left-turn phase Y4, the left-turn vehicles in the intermittence area of a2 and a4 in the intermittence area pass through the intersection, and the left-turn vehicles outside the intermittence area directly enter the intermittence area and pass through the intersection; the start and end times of the left turn phase Y4 are both later than the left turn pre-signal phase T4;

and S6, after the left-turning pre-signal phase T4 is finished, continuing to move the pre-signal phase Z1.

Background

The intersection geometric design and signal coordination control optimization are main means for solving urban traffic jam, improving urban road traffic efficiency and reducing travel delay and air pollution by traffic engineers. The left-turn vehicles are used as key factors influencing the running efficiency of the intersection, and how to improve the lane utilization efficiency by coordinating the time length ratio of the left-turn phase and the straight-going phase so as to reduce the number of parking times and vehicle delay of the intersection is still a hot spot in the current traffic field.

The traditional method provides a geometric design scheme of intersections such as symmetrical intersections, U-turns, super streets and waiting areas for vehicles to eliminate the influence caused by left-turning vehicles, wherein the waiting areas are applied to practice, a better research result is obtained, the vehicles can pass through the intersection stop lines in advance due to the arrangement of the waiting areas, and the vehicles can pass through the intersections within a shorter time when main signals are started, so that the running efficiency of the intersections is improved.

In the aspect of intersection signal control, signal coordination control, pre-signal setting and the like are the key points of the current research, and green wave passing of vehicles can be realized, and the number of parking times can be reduced. Therefore, unconventional intersections such as variable guide lanes, left-turn intersections of exit lanes, continuous flow intersections, arrayed intersections and the like are provided, wherein the arrayed intersections combine the queuing principle and pre-signal control of the waiting area and become current research hotspots. The method can fully utilize the entrance lane, improve the traffic capacity of the intersection, but the vehicles generate multiple lane changing behaviors in the queuing area in a short time, and the problem of the stagnation of the queuing area is easily caused by the inadaptability of a driver, thereby reducing the traffic efficiency of the vehicles. The length of the queuing area is set by considering the flow, the time difference, the vehicle emptying time and other factors.

In conclusion, the service level of the intersection in the existing control scheme is limited by the lengths of the waiting area and the queuing area, and the vehicles can stop for the second time and change lanes for multiple times, so that the existing control scheme has great environmental pollution and potential safety hazard.

Disclosure of Invention

Aiming at the problems, the invention provides an intersection control method based on main and pre-signal phase coordination and adopting an intermittent lane, aiming at solving the problems of secondary parking and potential safety hazard, improving the traffic capacity of left-turn vehicles and considering the overall operation efficiency of the intersection, wherein the length of an intermittent zone is not limited by the traffic flow and the road length of the intersection, so that the capacity of the intersection can be improved to the maximum extent, the vehicles in the intersection can be evacuated, the parking times can be reduced, and the delay cost and the oil consumption cost of the vehicles at the intersection can be reduced.

The technical scheme of the invention is as follows:

an intersection signal control method adopting an intermittent lane is used for a multi-lane intersection, and the multi-lane intersection at least comprises a left-turn special lane and a straight special lane and is characterized in that the straight special lane adjacent to the left-turn special lane is set as the intermittent lane; the method for setting the intermittent lane comprises the steps that an intermittent zone stop line is arranged on a corresponding straight special lane, an area between the intermittent zone stop line and an intersection stop line is defined as an intermittent zone, and a left-turning vehicle and a straight vehicle alternately drive in the intermittent zone under the control of a signal; the signal control method comprises the following steps:

s1, setting control signals for the stop line of the intermittent zone and the stop line of the intersection, wherein the control signals are respectively defined as an intermittent zone pre-signal and a main signal, and the four roads of the intersection are sequentially defined as A1, A2, A3 and A4 in the clockwise direction, so that the control signals of A1 and A3 are consistent, and the control signals of A2 and A4 are consistent; according to the definition of an intermittent zone, the intermittent zone pre-signal comprises a straight-going pre-signal and a left-turning pre-signal, the straight-going pre-signal means that a straight-going vehicle enters the intermittent zone according to the straight-going pre-signal, the left-turning pre-signal means that a left-turning vehicle enters the intermittent zone according to the left-turning pre-signal, and the corresponding main signal comprises a straight-going signal and a left-turning signal;

s2, defining a signal phase of a straight-going vehicle entering an intermittent zone according to a straight-going pre-signal as a straight-going pre-signal phase P1, defining a signal phase of a1 and A3 of the straight-going vehicle entering the intermittent zone in a straight-going pre-signal phase P1, defining a signal phase of a1 and A3 of the straight-going vehicle passing through an intersection according to the straight-going signal as a straight-going phase P1, and defining a straight-going vehicle located in the intermittent zone in a straight-going phase P1 of lanes of the intermittent zone A1 and A3 of the straight-going vehicle passing through the intersection and a straight-going vehicle located outside the intermittent zone directly entering the intermittent zone and passing through the intersection; the start time and the end time of the straight-line phase P1 are both later than the straight-line pre-signal phase P1;

s3, after the straight-going phase P1 of the intermittence area is finished, the vehicles enter a left-turning pre-signal phase P2, in the left-turning pre-signal phase P2, the left-turning vehicles of A1 and A3 enter the intermittence area, the signal phase of the left-turning vehicles in A1 and A3 passing through the intersection according to the left-turning signals is defined as a left-turning phase P2, in the left-turning phase P2, the left-turning vehicles in the intermittence area of A1 and A3 pass through the intersection, and the left-turning vehicles outside the intermittence area directly enter the intermittence area and pass through the intersection; the start and end times of the left turn phase P2 are both later than the left turn pre-signal phase P2;

s4, after the left-turn pre-signal phase P2 is finished, the vehicle enters a straight-ahead pre-signal phase P3, in the straight-ahead pre-signal phase P3, straight-ahead vehicles of A2 and A4 enter an intermittent zone, signal phases of the straight-ahead vehicles in A2 and A4 passing through an intersection according to a straight-ahead signal are defined as a main straight-ahead phase P3, in the straight-ahead phase P3, straight-ahead vehicles in the intermittent zone in lanes of A2 and A4 pass through the intersection, and straight-ahead vehicles outside the intermittent zone directly enter the intermittent zone and pass through the intersection; the start time and the end time of the straight-line phase P3 are both later than the straight-line pre-signal phase P3;

s5, after the straight-going phase P3 of the intermittence area is finished, the vehicles enter a left-turning pre-signal phase P4, in the left-turning pre-signal phase P4, the left-turning vehicles of A2 and A4 enter the intermittence area, the signal phase of the left-turning vehicles in A2 and A4 passing through the intersection according to the left-turning signals is defined as a left-turning phase P4, in the left-turning phase P4, the left-turning vehicles in the intermittence area of A2 and A4 pass through the intersection, and the left-turning vehicles outside the intermittence area directly enter the intermittence area and pass through the intersection; the start and end times of the left turn phase P4 are both later than the left turn pre-signal phase P4;

and S6, after the left-turning pre-signal phase P4 is finished, continuing to move the pre-signal phase P1.

Compared with the prior art, the invention has the advantages and effects that:

(1) the problem that the intersection of the waiting area has secondary parking can be reduced, the integral passing efficiency of the intersection is considered, and the method can be suitable for various traffic conditions.

(2) Compared with the common intersection of the waiting area and the intersection of the signal coordination waiting area, the method can effectively reduce the total delay, the oil consumption cost and the parking times of the intersection under the condition of the same saturation.

(3) Under the conditions that the total flow of the intersection is high and the left-turning traffic accounts for a large proportion, the method can reduce the saturation of the intersection to the maximum extent and enhance the robust performance of the intersection under the condition that the delay level of the intersection is not increased.

Drawings

FIG. 1 is a timing diagram of the phase of an intermittent lane crossing;

FIG. 2 is a schematic diagram of vehicle clearance during signal phases, wherein (a) is the phase 4 and phase 1 switching periods; (b) during phase 1; (c) during phase 1 and phase 2 switching; (d) during phase 2;

fig. 3 is a diagram of an intermittent lane crossing signal light pattern.

Detailed Description

The technical solutions of the present invention will be described clearly and completely with reference to the accompanying drawings, so that those skilled in the art can better understand the present invention.

The invention is mainly based on intermittent lanes, and the intermittent lane signal control based on the intersection of the to-be-driven area means that the leftmost straight lane is backed for a certain distance to serve as an intermittent area, left-turning traffic and straight traffic orderly enter the intermittent area and pass through the intersection by utilizing the coordination control between the pre-signal and the main signal, and other lanes leave the intersection according to the guidance of the main signal. Taking a four-lane intersection as an example, a left-turn special lane, an intermittent lane, a straight special lane and a right-turn special lane are respectively arranged from left to right. The lane traffic flow is organized as follows:

an intermittent lane: when a left-turn vehicle behind the intermittent area turns left and pre-signals a green light, a ground diversion line is utilized to enter the intermittent area from the leftmost lane through one lane change; the straight-going vehicles wait in line at the intermittent zone pre-stop line and enter the intermittent zone when the straight-going pre-signal is green. Therefore, the lane utilization conditions of the intermittent zone changing along with the signal period are divided into: straight line occupation, left turn occupation, and no occupation.

A left-turn special lane: the left-turning vehicle can run without pre-signal control, and can queue up to a left-turning waiting area except occupying a pedestrian crossing. If the left-turning green lamp of the intermittent zone is turned on in the left-turning vehicle queuing process, the left-turning vehicles can sequentially change lanes to enter the intermittent zone.

③ the straight special lane: the straight-going vehicles can run, the organization of the straight-going vehicles is the same as the traffic flow organization of a straight-going lane at a real intersection, and the vehicles can be queued to a straight-going waiting area.

Fourthly, turning right the special lane: the right-turning vehicle can directly pass through the intersection in consideration of no interweaving conflict with other vehicles.

As shown in fig. 1, in order to ensure that vehicles do not collide with each other, the main and preliminary signals at the intersection are designed as a variable information board for the driver to know the types of vehicles which can enter and leave the intermittence area at present.

The operation mode in one period of the intersection phase is described as follows:

firstly, a straight-ahead pre-signal of an intermittent zone in the east-west direction is started, and straight-ahead traffic flow queued behind the intermittent zone enters the intermittent zone.

And secondly, providing green signals for the straight vehicles by the main signals for straight traveling in the east-west direction, wherein the straight vehicles in the intermittent area do not stop for the second time and pass through the intersection at a constant speed.

And thirdly, closing a straight-ahead pre-signal of the intermittent zone in the east-west direction, opening a left-turning pre-signal, and changing a lane of a left-turning vehicle behind the intermittent zone to enter the intermittent zone.

And fourthly, starting the main left-turning signal in the east-west direction, releasing the left-turning vehicles, wherein the left-turning vehicles in the intermittent area do not stop for the second time and pass through the intersection at a constant speed, and then the main left-turning signal is changed into a red light.

Fifthly, starting a straight-ahead pre-signal of the intermittent zone in the north-south direction, and enabling straight-ahead traffic flow queued behind the intermittent zone to enter the intermittent zone.

And sixthly, providing green signals for the straight vehicles by the main signals of the straight vehicles in the north-south direction, wherein the straight vehicles in the intermittent zone do not stop for the second time and pass through the intersection at a constant speed.

And seventhly, turning off the straight advance signal of the north-south direction intermittent area, turning on the left turn advance signal, and changing the lane of the left turn vehicle behind the intermittent area into the intermittent area.

And (8) turning on the main left-turning signal in the south and north directions to release the left-turning vehicles, wherein the left-turning vehicles in the intermittent area do not stop for the second time and pass through the intersection at a constant speed, and then the main left-turning signal is changed into a red light.

Particularly, the pre-signals of the left-turn lane and the straight lane in each direction are kept green, and the vehicle can enter the waiting area to wait for the main signal to be released. Fig. 2 illustrates the driving flow lines of the vehicles in each phase, the yellow line indicates the left-turn flow, and the red line indicates the straight flow. FIGS. 3, 1-3, illustrate red, green and yellow light patterns, respectively, for a left turn signal; 4-6 illustrate red, green and yellow light patterns, respectively, for the straight signal.

The scheme of the invention is applied to the practical situation that the related parameters mainly comprise the length of a waiting area, the length of an intermittent area, the total red time of a phase, the phase difference of a main signal and a pre-signal, and the specific calculation mode takes a four-lane intersection as an example:

for ease of understanding, the southbound approach is taken as an example. The following general parameters are defined first: j denotes an intersection lane, named from left to right. VI (j) is the driving speed of each lane; g (m, k) represents the green time, y (m, k) represents the phase yellow time, and r (m, k) represents the phase full red time, typically 3 s. Where m is a {1,2}, k is a {1,2,3,4}, m is a main signal of 1, m is a pre-signal of 2, k is a direct phase, and k is a left-hand phase of {2,4 }.

The relevant parametric constraints are described as follows:

(1) length of the intermittent zone PL: lb is less than or equal to PL is less than or equal to 100

Lb is the travel distance of the queued vehicles when the traffic forms a saturated traffic, and is generally 35 m.

(2) Phase difference between main and pre-signals

Parallel main pre-signal phase difference

Advanced opening time delta g of intermittent zone straight-going signal_k,1：

t₂For the constant speed running time before the straight running traffic flow passes through the pre-signal stop line, t₃A (2) is the acceleration of the straight-ahead traffic flow for the time required for the pre-signal green light to turn on until the straight-ahead traffic flow passes the pre-signal stop line.

Advanced closing time delta g of intermittent zone straight-going signal_k,2：

The left-turn main pre-signal phase difference:

△g_k',1＝△g_k,2+y(1,k)+r(1,k)-y(2,k),k'∈{2,4},k∈{1,3}

the scheme of the invention also aims to solve the problem of cost, and the invention also provides a calculation mode of the optimal signal scheme by combining the problem of cost.

(1) Delay cost, which takes the delay cost of passengers at the intersection within one hour as a measurement index:

d_jfor cumulative delays in the lane, a delay triangle can be used for the calculation, c_pIs the unit hour cost.

(2) Cost of oil consumption

W₁Traffic flow energy consumption at intersection c_gFor gasoline prices, W is the heating value of gasoline.

(3) Optimization model

min M＝Md+Mg

Wherein the constraint conditions are as follows:

max(g1_min,g2_min)≤g(m,k)≤g2_max

g1_mindesigning a standard for the minimum green light duration of the pedestrian; g2_minDesigning a standard for the minimum green light duration of the vehicle; g2_minAnd designing a standard for the maximum green light duration of the vehicle.

The above problem can be solved by searching for the optimal solution by using a genetic algorithm, and the algorithm flow is as follows:

step 1: and generating an initial population. And carrying out real number coding on the parameter to be solved.

Step 2: and (5) calculating the fitness. And (4) calculating the comprehensive cost (delay cost and oil consumption cost), and ending the circulation under the condition that the maximum iteration number is reached or the fitness error of 1000 adjacent times is not more than 0.1%.

Step 3: and (4) dominant individual selection. And selecting reserved individuals by using roulette, and reserving the optimal individuals as elite populations without participating in the crossing and mutation processes.

Step 4: and (4) performing cross exchange. And selecting a part of populations according to the cross probability to carry out gene cross operation.

Step 5: numerical mutation. The mutation probability is adjusted based on simulated annealing, and individual parameters are randomly selected to regenerate the parameters.

Step 6: returning to Step 2.