CN111243301A - Traffic signal lamp green light duration determination device, method and system - Google Patents

Abstract

The invention discloses a device, method and system for determining the green light duration of a traffic signal, and relates to the field of traffic information perception and control. The method includes: calculating the maximum number of stranded vehicles in a lane group by using the acquired number of incoming vehicles and outgoing vehicles; using the acquired time interval to calculate the saturated headway; acquiring the speed and position information of the vehicle in the on-board unit; Critical traffic flow; the green light duration is calculated using critical traffic flow, preset start loss time and saturated headway. The present invention utilizes the geomagnetic vehicle detector installed in each lane of the intersection and the on-board unit installed on the vehicle to obtain the state information of all vehicles in each lane of the intersection in real time, determines the key traffic flow of the lane according to the state information, and utilizes the key traffic flow, Presetting the starting loss time and the saturated headway to calculate the green light duration can effectively alleviate the problem of low vehicle traffic efficiency caused by unreasonable timing of signal lights at intersections.

Description

A device, method and system for determining the green light duration of a traffic signal

technical field

The invention relates to the field of traffic information perception and control, in particular to a device, method and system for determining the green light duration of a traffic signal.

Background technique

With the continuous increase of car ownership in China, the problem of urban traffic congestion is becoming more and more serious. Optimizing the signal control system of single-point intersection and improving the traffic capacity of the intersection has become an effective means to solve this problem. Single-point intersection signal control refers to the use of traffic lights to allocate the right of way to vehicles and pedestrians running at isolated intersections. Single-point intersection signal control is based on the traffic signal control model, and by reasonably controlling the color change of the intersection signal lights, it can achieve the purpose of alleviating traffic congestion, ensuring smooth urban roads and avoiding traffic accidents. At the same time, single-point intersection signal control, as the basic form of urban road traffic signal control, is also the most important and most basic method of urban road traffic control.

Currently, intersection signal control can be divided into timing control, inductive control and adaptive control according to different control methods. Among them, the timing scheme of timing control is determined based on historical traffic flow data, but due to the randomness and real-time nature of vehicle arrivals, timing control cannot adapt to dynamically changing traffic flow. Inductive control is a control method that uses appropriate signal display to meet the traffic demand according to the real-time traffic conditions of the intersection detected by the traffic detector; although the inductive control is more adaptable to the random arrival of vehicles and the large change of traffic demand , but there are disadvantages of poor coordination and high infrastructure costs. Adaptive control is a signal control method developed on the basis of artificial technology. It can respond flexibly to changes in traffic conditions, and has strong real-time, independence and robustness. This method is very good. It makes up for the shortcomings of the first two methods and has greater research value. However, the traffic conditions considered by the existing adaptive control signal light duration determination method are the relationship between the traffic flow at the intersection and the traffic flow at the intersection in a certain period of time, or the number of vehicles queuing in the cycle, without considering the overall traffic status. lead to low vehicle traffic efficiency. Therefore, the existing method for determining the duration of the signal lamp has the problem of low vehicle traffic efficiency.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a device, method and system for determining the green light duration of a traffic signal, which solves the problem of low vehicle traffic efficiency in the prior method for determining the duration of a signal light.

For achieving the above object, the present invention provides the following scheme:

A device for determining the green light duration of a traffic signal, comprising: a geomagnetic vehicle detector, a vehicle-mounted unit and a roadside unit;

The number of the geomagnetic vehicle detectors is multiple, and each lane is installed with one group of the geomagnetic vehicle detectors;

Each group of the geomagnetic vehicle detectors includes: a first detector and a second detector; the first detector is installed at the stop line of the lane, and the second detector is installed at a distance from the first detector at a preset distance; the area between the first detector and the second detector is a stagnation area;

The geomagnetic vehicle detector is used to obtain the number of vehicles entering and leaving the stranded area, and calculate the number of stranded vehicles and the saturated headway in the stranded area according to the number of vehicles entering and leaving the area;

The on-board unit is installed on the car, and the on-board unit is used for sending the speed and position information of the vehicle to the roadside unit;

The roadside unit is installed at a road intersection, and the roadside unit is used to obtain the number of stranded vehicles and the saturated headway, and according to the number of stranded vehicles, the saturated headway, and the speed of the vehicle and the position information to determine the critical traffic flow, and use the critical traffic flow and the saturated headway to calculate the green light duration.

A method for determining the green light duration of a traffic signal, which is applied to the above-mentioned device for determining the green light duration of a traffic signal, wherein the method for determining the green duration of a traffic signal comprises:

Obtain the initial signal scheme of the signal light, the preset start-up loss time and the signal light phase set;

Initialize the green light duration of the current signal light phase i according to the signal light initial signal scheme; i=1,2,...,n, n represents the total number of phases;

execute the current signal light phase i;

Obtain the number of entering vehicles and the number of exiting vehicles of the lane group corresponding to the signal light phase i+1; the lane group includes multiple lanes in the same driving direction;

Calculate the maximum number of stranded vehicles in the lane group by using the number of entering vehicles and the number of exiting vehicles;

Obtain the time interval during which any two vehicles in the lane continuously pass the stop line;

calculating the saturated headway using the time interval;

Obtain the speed and position information of the vehicle of the on-board unit;

Comparing the speed and position information of the vehicle and the maximum number of stranded vehicles to obtain a critical traffic flow;

The green light duration of the signal light phase i+1 is calculated by using the critical traffic flow, the preset starting loss time and the saturated headway.

Optionally, before calculating the green light duration of the signal light phase i+1 by using the critical traffic flow, the preset start loss time and the saturated headway, the method further includes:

Judging whether the key traffic flow is 0, and obtaining a first judgment result;

If the first judgment result is no, execute the step of "calculating the green light duration of the signal light phase i+1 by using the critical traffic flow, the preset starting loss time and the saturated headway distance";

The first judgment result is yes, add 1 to i, and return to the step "obtaining the number of vehicles entering and leaving the lane group corresponding to signal lamp phase i+1";

After the calculation of the green light duration of the signal light phase i+1 by using the critical traffic flow, the preset start loss time and the saturated headway, the method further includes:

Let i increase by 1, and return to the step "execute the current signal light phase i".

Optionally, the calculation to obtain the maximum number of stranded vehicles in the lane group by using the number of incoming vehicles and the number of outgoing vehicles specifically includes:

Calculate the number of stranded vehicles in a single lane of the lane group by using the number of incoming vehicles and the number of outgoing vehicles;

Comparing the number of stranded vehicles in all of the single lanes to obtain the maximum number of stranded vehicles;

The calculating the saturated headway by using the time interval specifically includes:

Get multiple time intervals for any two vehicles to continuously pass the stop line;

An average value of a plurality of the time intervals is calculated, and the average value is the saturated headway.

Optionally, the comparison of the speed and position information of the vehicle and the maximum number of stranded vehicles to obtain a critical traffic flow specifically includes:

determining the number of queued vehicles in the single lane according to the speed and position information of the vehicles;

Judging whether the number of queued vehicles is greater than the maximum number of stranded vehicles, and obtaining a second judgment result;

The second judgment result is yes, determining that the number of queued vehicles is the critical traffic flow;

If the second judgment result is no, it is determined that the maximum number of stranded vehicles is the critical traffic flow.

Optionally, the calculation to obtain the green light duration of the signal light phase i+1 by using the critical traffic flow, the preset start loss time and the saturated headway, specifically includes:

计算得到所述信号灯相位i+1的绿灯时长；According to the formula

Calculate the green light duration of the signal light phase i+1;

表示所述信号灯相位i+1的绿灯时长，

表示所述关键车流量，h表示所述饱和车头时距，t表示预设启动损失时间。in,

represents the green light duration of the signal light phase i+1,

represents the critical traffic flow, h represents the saturated headway, and t represents the preset start loss time.

A system for determining the green light duration of a traffic signal, comprising:

The first acquisition module is used to acquire the initial signal scheme of the signal light, the preset start-up loss time and the signal light phase set;

an initialization module, used for initializing the green light duration of the current signal light phase i according to the signal light initial signal scheme; i=1,2,...,n, n represents the total number of phases;

an execution module, configured to execute the current signal light phase i;

The second obtaining module is used to obtain the number of entering vehicles and the number of exiting vehicles of the lane group corresponding to the signal light phase i+1; the lane group includes a plurality of lanes in the same driving direction;

a module for the maximum number of stranded vehicles, configured to calculate the maximum number of stranded vehicles in the lane group by using the number of incoming vehicles and the number of outgoing vehicles;

a time interval module, used to obtain the time interval during which any two vehicles in the lane continuously pass the stop line;

a saturated headway module, configured to calculate the saturated headway by using the time interval;

The third acquisition module is used to acquire the speed and position information of the vehicle of the on-board unit;

a critical traffic flow module, configured to obtain a critical traffic flow by comparing the speed and position information of the vehicle and the maximum number of stranded vehicles;

A green light duration module, configured to calculate the green light duration of the signal light phase i+1 by using the critical traffic flow, the preset start loss time and the saturated headway.

Optionally, the module for the maximum number of stranded vehicles specifically includes:

A stranded vehicle number unit, configured to calculate the number of stranded vehicles in a single lane of the lane group by using the number of incoming vehicles and the number of outgoing vehicles;

a unit for the maximum number of stranded vehicles, which is used to compare the number of stranded vehicles in all the single lanes to obtain the maximum number of stranded vehicles;

The saturated headway module specifically includes:

The time interval unit is used to obtain a plurality of time intervals for any two vehicles to continuously pass the stop line;

The saturated headway unit is used to calculate the average value of a plurality of the time intervals, and the average value is the saturated headway.

Optionally, the key traffic flow module specifically includes:

A queued vehicle number unit, configured to determine the number of queued vehicles in the single lane according to the speed and position information of the vehicle;

a second judging unit, configured to judge whether the number of queued vehicles is greater than the maximum number of stranded vehicles, and obtain a second judgment result;

The second is a unit, used for determining that the second judgment result is yes, and determining that the number of queued vehicles is the key traffic flow;

A second No unit, configured to determine that the second judgment result is No, and determine that the maximum number of stranded vehicles is the critical traffic flow.

Optionally, the green light duration module specifically includes:

计算得到所述信号灯相位i+1的绿灯时长；Green light duration unit, used according to the formula

Calculate the green light duration of the signal light phase i+1;

表示所述信号灯相位i+1的绿灯时长，

表示所述关键车流量，h表示所述饱和车头时距，t表示预设启动损失时间。in,

represents the green light duration of the signal light phase i+1,

represents the critical traffic flow, h represents the saturated headway, and t represents the preset start loss time.

According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

The invention provides a device, method and system for determining the green light duration of a traffic signal. The method includes: acquiring an initial signal scheme of a signal light, a preset start-up loss time and a set of signal light phases; initializing the green light duration of the current signal light phase i according to the initial signal light scheme; executing the current signal light phase i; and obtaining the lane corresponding to the signal light phase i+1 The number of vehicles entering and leaving the group; the lane group includes multiple lanes in the same driving direction; the maximum number of stranded vehicles in the lane group is calculated by the number of vehicles entering and leaving the lane; any two consecutive vehicles in the lane are obtained Through the time interval of the stop line; use the time interval to calculate the saturated headway; obtain the speed and position information of the vehicle in the on-board unit; compare the speed and position information of the vehicle and the maximum number of stranded vehicles to obtain the key traffic flow; The green light duration of the signal light phase i+1 is calculated by setting the starting loss time and the saturated headway. The present invention utilizes the geomagnetic vehicle detector installed in each lane of the intersection and the On Board Unit (OBU) installed on the vehicle to obtain the status information of all vehicles in each lane of the intersection in real time. The information to determine the key traffic flow of the lane, and use the key traffic flow, the preset starting loss time and the saturated headway to calculate the optimal green light duration of the queuing vehicles in this phase, which can effectively alleviate the traffic caused by the unreasonable timing of the signal lights at the intersection. The problem of low efficiency can effectively reduce vehicle emissions while reducing the queuing time of vehicles at intersections.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some of the present invention. In the embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative labor.

FIG. 1 is a structural diagram of a device for determining the green light duration of a traffic signal provided by an embodiment of the present invention;

2 is a flowchart of a method for determining the green light duration of a traffic signal provided by an embodiment of the present invention;

3 is a system diagram of a system for determining the green light duration of a traffic signal provided by an embodiment of the present invention;

FIG. 4 is a schematic layout diagram of a geomagnetic vehicle detector provided by an embodiment of the present invention.

Among them, 1. Geomagnetic vehicle detector; 2. Vehicle-mounted unit; 3. Roadside unit; 4. Detention area.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

The purpose of the present invention is to provide a device, method and system for determining the green light duration of a traffic signal, which solves the problem of low vehicle traffic efficiency in the prior method for determining the duration of a signal light.

In order to make the above objects, features and advantages of the present invention more clearly understood, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments.

This embodiment provides an apparatus for determining the green light duration of a traffic signal. FIG. 1 is a structural diagram of the apparatus for determining the green light duration of a traffic signal provided by an embodiment of the present invention. Referring to FIG. 1 , the apparatus for determining the green light duration of a traffic signal includes: a geomagnetic vehicle detector 1 , on-board unit 2 and roadside unit 3.

There are multiple sets of geomagnetic vehicle detectors 1 , and one set of geomagnetic vehicle detectors 1 is installed in each lane. The geomagnetic vehicle detector 1 is wirelessly connected to the roadside unit 3 .

Each group of geomagnetic vehicle detectors includes: a first detector and a second detector; the first detector is installed at the stop line of the lane, and the second detector is installed at a preset distance from the first detector; the first detector The area between the detector and the second detector is the stagnant zone. The first detector is used to detect the number of vehicles entering the stagnant area, and the second detector is used to detect the number of vehicles that have exited the stagnant area. The length of the holding area, that is, the preset distance between the second detector and the first detector, may be determined according to the longest vehicle queuing length at the intersection where the traffic signal light is located.

The geomagnetic vehicle detector is used to obtain the number of vehicles entering the detention area and the number of vehicles leaving the detention area, and calculate the number of vehicles staying in the detention area and the saturated headway according to the number of vehicles entering and leaving the area. .

The on-board unit 2 is installed on the car, and the on-board unit 2 is used to transmit the speed and position information of the vehicle to the roadside unit 3 . The vehicle-mounted unit 2 includes a speed sensor, a vehicle positioning sensor, and a vehicle-to-X (V2X communication) module. The on-board unit sends real-time vehicle status information to the roadside unit 3 at a fixed period of 200 milliseconds (ms), and the on-board unit is installed around the on-board navigation system. The real-time state information of the vehicle includes real-time position information and speed information of the vehicle. The on-board unit is wirelessly connected to the roadside unit 3 .

The roadside unit 3 is installed at the road intersection, and the roadside unit 3 is used to obtain the number of stranded vehicles and the saturated headway, and determine the key traffic flow according to the number of stranded vehicles, the saturated headway, the speed and position of the vehicle, and use Calculate the green light duration based on critical traffic flow and saturated headway.

This embodiment provides a method for determining the green light duration of a traffic signal, which is applied to a device for determining the green light duration of a traffic signal. FIG. 2 is a flowchart of the method for determining the green duration of a traffic signal provided by the embodiment of the present invention. Referring to Figure 2, the method for determining the green light duration of a traffic signal includes:

Step 101: Obtain the initial signal scheme of the signal lamp, the preset start-up loss time and the signal lamp phase set.

Step 102: Initialize the green light duration of the current signal light phase i according to the signal light initial signal scheme; i represents the phase sequence, that is, the phase serial number, i=1, 2, . . . n, n represents the total number of phases.

Step 103: Execute the current signal light phase i.

Step 104: Acquire the number of entering vehicles and the number of exiting vehicles of the lane group corresponding to the signal light phase i+1; the lane group includes multiple lanes in the same driving direction.

Step 105: Calculate the maximum number of stranded vehicles in the lane group by using the number of entering vehicles and the number of exiting vehicles.

Step 105 specifically includes:

Calculate the number of stranded vehicles in a single lane of the lane group by using the number of incoming vehicles and the number of outgoing vehicles. The number of stranded vehicles in a single lane is the difference between the number of vehicles entering and the number of vehicles leaving the lane.

Compare the number of stranded vehicles in all single lanes to get the maximum stranded vehicle count.

Step 106: Obtain the time interval during which any two vehicles in the lane continuously pass the stop line.

Step 107, using the time interval to calculate the saturated headway.

Step 107 specifically includes:

Get multiple time intervals when any two vehicles pass the stop line in a row. Because of the startup lost time, the time interval between the first three vehicles is excluded when obtaining the time interval.

Calculate the average of multiple time intervals, and the average is the saturated headway.

Step 108: Acquire the speed and position information of the vehicle of the vehicle-mounted unit.

Step 109 , compare the speed and position information of the vehicles and the maximum number of stranded vehicles to obtain the key traffic flow.

Step 109 specifically includes:

Determine the number of queued vehicles in a single lane based on vehicle speed and position information.

It is judged whether the number of queued vehicles is greater than the maximum number of stranded vehicles, and a second judgment result is obtained.

The second judgment result is yes, and the number of queued vehicles is determined as the key traffic flow.

The second judgment result is no, and it is determined that the maximum number of stranded vehicles is the key traffic flow.

Step 110, determine whether the key traffic flow is 0, and obtain a first determination result.

If the first judgment result is no, step 112 is executed to "calculate the green light duration of the signal light phase i+1 by using the critical traffic flow, the preset starting loss time and the saturated headway."

Step 111 , the first judgment result is yes, add 1 to i, and return to step 104 "obtain the number of vehicles entering and exiting the lane group corresponding to signal lamp phase i+1".

Step 112 , calculating the green light duration of the signal light phase i+1 by using the critical traffic flow, the preset starting loss time and the saturated headway.

Step 112 specifically includes:

计算得到信号灯相位i+1的绿灯时长。According to the formula

Calculate the green light duration of the signal light phase i+1.

表示信号灯相位i+1的绿灯时长，

表示关键车流量，h表示饱和车头时距，t表示预设启动损失时间。In the above formula,

Indicates the green light duration of signal light phase i+1,

represents the critical traffic flow, h represents the saturated headway, and t represents the preset starting loss time.

Step 113, add 1 to i, and return to step 103 "execute the current signal light phase i".

This embodiment provides a system for determining the green light duration of a traffic signal. FIG. 3 is a system diagram of the system for determining the green duration of a traffic signal provided by an embodiment of the present invention. Referring to Figure 3, the traffic signal green light duration determination system includes:

The first obtaining module 201 is used to obtain the initial signal scheme of the signal lamp, the preset start-up lost time and the signal lamp phase set.

The initialization module 202 is used to initialize the green light duration of the current signal light phase i according to the signal light initial signal scheme; i represents the phase sequence, that is, the phase serial number, i=1, 2, . . . n, n represents the total number of phases.

The execution module 203 is used to execute the current signal light phase i.

The second obtaining module 204 is configured to obtain the number of entering vehicles and the number of exiting vehicles of the lane group corresponding to the signal light phase i+1; the lane group includes multiple lanes in the same driving direction.

The maximum number of stranded vehicles module 205 is configured to calculate the maximum number of stranded vehicles in the lane group by using the number of inbound vehicles and the number of outbound vehicles.

The maximum number of stranded vehicles module 205 specifically includes:

The number of stranded vehicles is used to calculate the number of stranded vehicles in a single lane of the lane group by using the number of inbound vehicles and the number of outbound vehicles. The number of stranded vehicles in a single lane is the difference between the number of vehicles entering and the number of vehicles leaving the lane.

The unit of the maximum number of stranded vehicles is used to compare the number of stranded vehicles in all single lanes to obtain the maximum number of stranded vehicles.

The time interval module 206 is configured to obtain the time interval during which any two vehicles in the lane continuously pass the stop line.

The saturated headway module 207 is used to calculate the saturated headway by using the time interval.

The saturated headway module 207 specifically includes:

The time interval unit is used to obtain multiple time intervals during which any two vehicles continuously pass the stop line. Because of the startup lost time, the time interval between the first three vehicles is excluded when obtaining the time interval.

The saturated headway unit is used to calculate the average value of multiple time intervals, and the average value is the saturated headway.

The third obtaining module 208 is configured to obtain the speed and position information of the vehicle of the vehicle-mounted unit.

The critical traffic flow module 209 is used to obtain the critical traffic flow by comparing the speed and position information of the vehicles and the maximum number of stranded vehicles.

The key traffic flow module 209 specifically includes:

The unit for the number of queued vehicles is used to determine the number of queued vehicles in a single lane according to the speed and position information of the vehicles.

The second judging unit is configured to judge whether the number of queued vehicles is greater than the maximum number of stranded vehicles, and obtain a second judgment result.

The second is a unit for determining the number of queued vehicles as the key traffic flow when the second judgment result is yes.

The second no unit is used for determining that the second judgment result is no, and determining the maximum number of stranded vehicles as the key traffic flow.

The first judgment module 210 is used for judging whether the critical traffic flow is 0, and obtaining a first judgment result; if the first judgment result is no, execute the green light duration module 212; if the first judgment result is yes, execute the first yes module 211.

The first is the module 211 for adding 1 to i and executing the second obtaining module 204 .

The green light duration module 212 is configured to calculate the green light duration of the signal light phase i+1 by using the critical traffic flow, the preset starting loss time and the saturated headway.

The green light duration module 212 specifically includes:

计算得到信号灯相位i+1的绿灯时长。Green light duration unit, used according to the formula

Calculate the green light duration of the signal light phase i+1.

表示信号灯相位i+1的绿灯时长，

表示关键车流量，h表示饱和车头时距，t表示预设启动损失时间。In the above formula,

Indicates the green light duration of signal light phase i+1,

represents the critical traffic flow, h represents the saturated headway, and t represents the preset starting loss time.

Returning to block 213, for adding 1 to i, and executing block 203.

This embodiment also provides a method for intelligently adjusting the green light duration of a traffic signal at a single intersection based on information fusion technology. A set of geomagnetic vehicle detectors are arranged in each entry lane of the intersection, and the first detector of the geomagnetic vehicle detector and the The second detectors are respectively used to detect the number of vehicles exiting the entry lane and entering the entry lane; vehicles passing through the intersection are equipped with on-board units, which are provided with speed sensors, vehicle positioning sensors and V2X communication modules. 200ms is a fixed period to send the real-time status information of the vehicle to the roadside unit of the entrance lane. The installation position of the vehicle-mounted unit is consistent with the vehicle navigation system; the roadside unit combines the detection data of the geomagnetic vehicle detector and the real-time vehicle status information to calculate each entrance lane. The real-time number of queuing vehicles and the saturated headway, and determine the key traffic flow of each lane group, and calculate the optimal green light duration of the current phase with the right of way based on the key traffic flow, and determine the green light of the next phase when the phase ends Duration; the drive test unit sends the optimal green light duration to the traffic light signal controller at the intersection to realize the control of the green light duration of the traffic signal, so as to achieve the real-time dynamic signal green duration adjustment that adapts to the current traffic state, and optimize the traffic flow at the intersection. efficiency.

The intelligent adjustment method of green light duration includes:

(1) Real-time traffic status perception

The real-time traffic status perception is realized by the geomagnetic vehicle detector and the vehicle-mounted unit:

The geomagnetic vehicle detector uses a geomagnetic coil. When the vehicle passes through the geomagnetic coil, the vehicle will generate a sensing signal for cutting the magnetic field, and the sensing signal is transmitted to the roadside unit wirelessly. FIG. 4 is a schematic diagram of the arrangement of the geomagnetic vehicle detector provided by the embodiment of the present invention. Referring to FIG. 4 , a group of geomagnetic vehicle detectors are arranged in each entrance lane, and each group of geomagnetic vehicle detectors includes: a first detector D ( out) and a second detector D(in), the first detector D(out) is installed at the stop line of the entry lane, and the second detector D(in) is installed at a preset distance from the first detector. The area between the first detector D(out) and the second detector D(in) is the stagnant area 4, and the length of the stagnant area 4 is greater than or equal to the historical maximum queue length of the intersection. In this embodiment, the preset distance, That is, the length of the detention area is 100 meters. The first detector is used to detect the number of vehicles that have left the stagnant area, and the second detector is used to detect the number of vehicles that have entered the stagnant area. The installation position of the roadside unit is consistent with the position of the traffic light signal controller installed at the intersection.

A lane group consists of one or more lanes in the same direction of travel.

驶出车辆数为

左转车道组左转车道的驶入车辆数为

驶出车辆数为

根据公式(1)计算直行车道组单车道内的滞留车辆数：A set of geomagnetic vehicle detectors can accurately determine the number of vehicles in the detention area at each moment, specifically: this embodiment does not consider right-turn vehicles at the intersection, so the lane group at the intersection includes a straight-through lane group and a left-turn lane group. , the straight lane group includes two straight lanes, and the left-turn lane group includes one left-turn lane. Let the number of vehicles entering the straight lane of the straight lane group be

The number of outgoing vehicles is

The number of vehicles entering the left-turn lane in the left-turn lane group is

The number of outgoing vehicles is

Calculate the number of stranded vehicles in a single lane of the straight-through lane group according to formula (1):

表示第j个直行车道滞留区内的滞留车辆数，

表示第j个直行车道的驶入车辆数，

表示第j个直行车道的驶出车辆数。In the above formula, j represents the serial number of the straight lane, j=1,2,...,J, J represents the total number of straight lanes;

represents the number of stranded vehicles in the j-th through lane stranded area,

represents the number of vehicles entering the j-th straight lane,

Indicates the number of vehicles exiting the j-th straight lane.

Calculate the number of stranded vehicles in a single lane of the left-turn lane group according to formula (2):

表示第p个左转车道滞留区内的滞留车辆数，

表示第p个左转车道的驶入车辆数，

表示第p个左转车道的驶出车辆数。In the above formula, p represents the serial number of the left-turn lane, p=1,2,...,P, and P represents the total number of left-turn lanes;

represents the number of stranded vehicles in the p-th left-turn lane stranded area,

represents the number of vehicles entering the p-th left-turn lane,

Indicates the number of vehicles exiting the p-th left-turn lane.

Calculate the maximum number of straight-going vehicles in all straight-going lanes according to formula (3)

表示第j个直行车道滞留区内的滞留车辆数。In the above formula, j represents the serial number of the straight lane, j=1,2,...,J, J represents the total number of straight lanes;

Indicates the number of stranded vehicles in the j-th through lane stranded area.

Calculate the maximum number of left-turn stranded vehicles Q ^l* in all left-turn lanes according to formula (4):

表示第p个左转车道滞留区内的滞留车辆数。In the above formula, p represents the serial number of the left-turn lane, p=1,2,...,P, and P represents the total number of left-turn lanes;

Indicates the number of stranded vehicles in the p-th left-turn lane stranded area.

The saturated headway is the average of any two vehicles in the same lane of the entry lane passing through the stop line continuously, that is, the average value of the time interval of the first detector D(out). time interval.

Considering that the vehicle entering the intersection changes between the straight lane and the left-turn lane, the length of the solid line dividing the lane between the straight-going lane and the left-turn lane can be appropriately extended to prevent the vehicle from going straight and left in the stagnant zone of the entry lane. Transformation between turns.

When the vehicle enters the receiving range of the signal of the roadside unit at the intersection, the V2X communication module of the vehicle onboard unit sends the vehicle's own speed and position information to the roadside unit at a cycle of 200ms. The roadside unit determines whether the vehicle is parked according to the speed of the vehicle. If the speed of the vehicle is zero, the vehicle is in the parked state; otherwise, the vehicle is not in the parked state, and then judges whether the vehicle enters the queued state, and the vehicle in the parked state is in the queued state. At the same time, the roadside unit determines whether the vehicle is in the detention area according to the position information of the vehicle and the setting position of the detention area; finally, the roadside unit determines the detention area according to the speed and position information. The number of queuing vehicles in each single lane. If the vehicle speed is zero and the position is in the detention area, the vehicle is determined as a queuing vehicle; otherwise, it is determined that the vehicle is not a queuing vehicle.

The roadside unit compares the maximum number of stranded vehicles of the geomagnetic vehicle detector with the number of queuing vehicles of the on-board unit. If the number of queuing vehicles is greater than the maximum number of stranded vehicles, the number of queuing vehicles is determined as the key traffic flow; if the number of queuing vehicles is less than or equal to the maximum number of stranded vehicles number of vehicles, then determine the maximum number of stranded vehicles as the key traffic flow.

(2) Calculation of the optimal green light duration for the phase

Obtain the initial signal scheme of the signal light at the intersection, and determine the phase set {P _i }, where i=1, 2, ..., n, where n represents the total number of phases. At the signal-controlled intersection, each control state (a right of way), that is, the combination of different light colors displayed in different directions of various entrances, is called a signal light phase. From the moment when the green light of the current phase ends, that is, the moment when the yellow light starts, according to (1) real-time traffic status perception, determine the key traffic flow in the detention area of the lane group with the right of way in the next phase

即下一具有通行权的信号灯相位的绿灯时长：According to the critical traffic flow, the preset starting loss time and the saturated headway, the travel time required for the critical traffic flow in any lane to pass through the intersection is calculated by formula (5).

That is, the green light duration of the next signal light phase with right of way:

表示信号灯相位i+1的绿灯时长，

表示关键车流量，h表示饱和车头时距，t表示预设的启动损失时间，t一般为2s。若某一相位无车辆通行的需求，即关键车流量为零，则不计算该相位的绿灯时长。若所有相位均没有等待车辆，即关键车流量为零，则按照预设绿灯时长进行循环，避免所有进口均显示红灯，预设绿灯时长为30s。In the above formula,

Indicates the green light duration of signal light phase i+1,

Represents the critical traffic flow, h represents the saturated headway, t represents the preset starting loss time, and t is generally 2s. If there is no demand for vehicles in a certain phase, that is, the critical traffic flow is zero, the green light duration of this phase is not calculated. If there are no waiting vehicles in all phases, that is, the critical traffic flow is zero, the cycle will be performed according to the preset green light duration to prevent all entrances from displaying red lights, and the preset green light duration is 30s.

The optimal green light duration calculated by the present invention can meet the optimal traffic demand of the intersection, and the optimal green light duration matches the actual number of queuing vehicles. The time for the queuing vehicles to pass through the intersection is set as the green light time as many vehicles are queuing. It avoids the secondary queuing of vehicles caused by the long green light time and the vacant green light caused by the short green light time. At the same time, the present invention is an intelligent adjustment method, that is, it responds to dynamically changing traffic flow at any time, and has stronger robustness and better real-time performance than the fixed timing control mode of traffic signals and the inductive signal control mode. To sum up, it can effectively reduce the delay time of vehicles at the intersection and improve the efficiency of vehicle passing at the intersection.

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same and similar parts between the various embodiments can be referred to each other. For the system disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant part can be referred to the description of the method.

In this paper, specific examples are used to illustrate the principles and implementations of the present invention. The descriptions of the above embodiments are only used to help understand the methods and core ideas of the present invention; meanwhile, for those skilled in the art, according to the present invention There will be changes in the specific implementation and application scope. In conclusion, the contents of this specification should not be construed as limiting the present invention.

Claims (10)

1. A device for determining the green light duration of a traffic signal, comprising: a geomagnetic vehicle detector, a vehicle-mounted unit and a roadside unit; The number of the geomagnetic vehicle detectors is multiple, and each lane is installed with one group of the geomagnetic vehicle detectors; Each group of the geomagnetic vehicle detectors includes: a first detector and a second detector; the first detector is installed at the stop line of the lane, and the second detector is installed at a distance from the first detector at a preset distance; the area between the first detector and the second detector is a stagnation area; The geomagnetic vehicle detector is used to obtain the number of vehicles entering and leaving the stranded area, and calculate the number of stranded vehicles and the saturated headway in the stranded area according to the number of vehicles entering and leaving the area; The on-board unit is installed on the car, and the on-board unit is used for sending the speed and position information of the vehicle to the roadside unit; The roadside unit is installed at a road intersection, and the roadside unit is used to obtain the number of stranded vehicles and the saturated headway, and according to the number of stranded vehicles, the saturated headway, and the speed of the vehicle and the position information to determine the critical traffic flow, and use the critical traffic flow and the saturated headway to calculate the green light duration. 2. A method for determining the duration of a green light of a traffic signal, characterized in that, applied to the device for determining the duration of a green light of a traffic signal as claimed in claim 1, the method for determining the duration of a green light of a traffic signal comprises: Obtain the initial signal scheme of the signal light, the preset start-up loss time and the signal light phase set; Initialize the green light duration of the current signal light phase i according to the signal light initial signal scheme; i=1,2,...,n, n represents the total number of phases; execute the current signal light phase i; Obtain the number of entering vehicles and the number of exiting vehicles of the lane group corresponding to the signal light phase i+1; the lane group includes multiple lanes in the same driving direction; Calculate the maximum number of stranded vehicles in the lane group by using the number of entering vehicles and the number of exiting vehicles; Obtain the time interval during which any two vehicles in the lane continuously pass the stop line; calculating the saturated headway using the time interval; Obtain the speed and position information of the vehicle of the on-board unit; Comparing the speed and position information of the vehicle and the maximum number of stranded vehicles to obtain a critical traffic flow; The green light duration of the signal light phase i+1 is calculated by using the critical traffic flow, the preset starting loss time and the saturated headway. 3 . The method for determining the green light duration of a traffic signal according to claim 2 , wherein the signal light phase is obtained by calculating the key traffic flow, the preset start loss time and the saturated headway. 4 . Before the green light duration of i+1, it also includes: Judging whether the key traffic flow is 0, and obtaining a first judgment result; If the first judgment result is no, execute the step of "calculating the green light duration of the signal light phase i+1 by using the critical traffic flow, the preset starting loss time and the saturated headway distance"; The first judgment result is yes, add 1 to i, and return to the step "obtaining the number of vehicles entering and leaving the lane group corresponding to signal lamp phase i+1"; After the calculation of the green light duration of the signal light phase i+1 by using the critical traffic flow, the preset start loss time and the saturated headway, the method further includes: Let i increase by 1, and return to the step "execute the current signal light phase i". 4 . The method for determining the duration of a green light of a traffic signal according to claim 2 , wherein the calculating the maximum number of stranded vehicles in the lane group by using the number of vehicles entering and the number of vehicles leaving, specifically comprising: 5 . : Calculate the number of stranded vehicles in a single lane of the lane group by using the number of incoming vehicles and the number of outgoing vehicles; Comparing the number of stranded vehicles in all of the single lanes to obtain the maximum number of stranded vehicles; The calculating the saturated headway by using the time interval specifically includes: Get multiple time intervals for any two vehicles to continuously pass the stop line; An average value of a plurality of the time intervals is calculated, and the average value is the saturated headway. 5 . The method for determining the green light duration of a traffic signal according to claim 2 , wherein the comparing the speed and position information of the vehicle and the maximum number of stranded vehicles to obtain a key traffic flow, specifically comprising: 6 . determining the number of queued vehicles in the single lane according to the speed and position information of the vehicles; Judging whether the number of queued vehicles is greater than the maximum number of stranded vehicles, and obtaining a second judgment result; The second judgment result is yes, determining that the number of queued vehicles is the critical traffic flow; If the second judgment result is no, it is determined that the maximum number of stranded vehicles is the critical traffic flow. 6 . The method for determining the green light duration of a traffic signal according to claim 2 , wherein the signal light phase i is obtained by calculating the key traffic flow, the preset start loss time and the saturated headway. 7 . +1 for the duration of the green light, including: According to the formula

Calculate the green light duration of the signal light phase i+1; in,

represents the green light duration of the signal light phase i+1,

represents the critical traffic flow, h represents the saturated headway, and t represents the preset start loss time. 7. A system for determining the green light duration of a traffic signal, comprising: The first acquisition module is used to acquire the initial signal scheme of the signal light, the preset start-up loss time and the signal light phase set; an initialization module, used for initializing the green light duration of the current signal light phase i according to the signal light initial signal scheme; i=1,2,...,n, n represents the total number of phases; an execution module, configured to execute the current signal light phase i; The second obtaining module is used to obtain the number of entering vehicles and the number of exiting vehicles of the lane group corresponding to the signal light phase i+1; the lane group includes a plurality of lanes in the same driving direction; a module for the maximum number of stranded vehicles, configured to calculate the maximum number of stranded vehicles in the lane group by using the number of incoming vehicles and the number of outgoing vehicles; a time interval module, used to obtain the time interval during which any two vehicles in the lane continuously pass the stop line; a saturated headway module, configured to calculate the saturated headway by using the time interval; The third acquisition module is used to acquire the speed and position information of the vehicle of the on-board unit; a critical traffic flow module, configured to obtain a critical traffic flow by comparing the speed and position information of the vehicle and the maximum number of stranded vehicles; A green light duration module, configured to calculate the green light duration of the signal light phase i+1 by using the critical traffic flow, the preset start loss time and the saturated headway. 8. The system for determining the green light duration of a traffic signal according to claim 7, wherein the module for the maximum number of stranded vehicles specifically comprises: A stranded vehicle number unit, configured to calculate the number of stranded vehicles in a single lane of the lane group by using the number of incoming vehicles and the number of outgoing vehicles; a unit for the maximum number of stranded vehicles, which is used to compare the number of stranded vehicles in all the single lanes to obtain the maximum number of stranded vehicles; The saturated headway module specifically includes: The time interval unit is used to obtain a plurality of time intervals for any two vehicles to continuously pass the stop line; The saturated headway unit is used to calculate the average value of a plurality of the time intervals, and the average value is the saturated headway. 9. The system for determining the green light duration of a traffic signal according to claim 7, wherein the key traffic flow module specifically comprises: A queued vehicle number unit, configured to determine the number of queued vehicles in the single lane according to the speed and position information of the vehicle; a second judging unit, configured to judge whether the number of queued vehicles is greater than the maximum number of stranded vehicles, and obtain a second judgment result; The second is a unit, used for determining that the second judgment result is yes, and determining that the number of queued vehicles is the key traffic flow; A second No unit, configured to determine that the second judgment result is No, and determine that the maximum number of stranded vehicles is the critical traffic flow. 10. The system for determining the green light duration of a traffic signal according to claim 7, wherein the green light duration module specifically comprises: Green light duration unit, used according to the formula

Calculate the green light duration of the signal light phase i+1; in,

represents the green light duration of the signal light phase i+1,

represents the critical traffic flow, h represents the saturated headway, and t represents the preset start loss time.

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