A method for intelligent traffic light dispatching based on traffic sensing signal control maps

Abstract

The application discloses a traffic signal lamp intelligent deployment method based on a traffic sensing signal control diagram, converts the traffic volume of various types of vehicles into equivalent car traffic volume; establishes a Greenhills linear model to obtain the relationship between the speed before entering the intersection entrance and the green light passing speed of the intersection entrance; obtains the initial green light time according to the average vehicle head time interval of the intersection main road vehicles, the distance of the pressure sensor from the stop line, the number of vehicles that can be parked between the detector and the stop line; obtains the unit green light extension time in combination with the total width of the motor vehicle road, the distance of the pressure sensor from the stop line and the speed of the intersection; obtains the shortest green light time in combination with the initial green light time and the unit green light extension time; and draws the sensing signal control diagram in combination with the unit green light extension time, so that the length of the main road sensing signal control is obtained. The application effectively reduces the vehicle parking delay, relieves the urban traffic congestion and improves the travel efficiency.

Description

Technical Field

[0001] This invention belongs to the field of road traffic management and control in traffic engineering, and specifically relates to a method for intelligent dispatching of traffic lights based on traffic sensing signal control diagrams. Background Technology

[0002] With the rapid development of the social economy and the acceleration of urbanization in recent years, the number of motor vehicles has surged, leading to a significant increase in traffic flow at intersections. While traditional timed traffic lights can meet the needs of most intersection sections, during peak hours and under special circumstances, the signal cycle cannot be adjusted according to the volume of traffic, increasing vehicle delays and inducing traffic congestion, resulting in low traffic efficiency and wasted traffic resources. Traffic signals need to consider not only traffic efficiency but also traffic safety. A traffic light control diagram prioritizing the main road reduces accident risks and improves traffic safety by rationally allocating green light time. In the context of pursuing sustainable development, optimizing traffic light configuration can reduce vehicle waiting time and emissions, improve traffic efficiency, and thus promote the achievement of environmental goals. Therefore, under these multifaceted circumstances, a flexible solution is needed to adjust signal timing in real time. Designing a main road control diagram with traffic-sensing signals allows for better adjustment of signal timing based on traffic flow, thereby improving traffic management and planning, reducing delays, and achieving rational resource utilization. Summary of the Invention

[0003] Purpose of the invention: This invention provides a method for intelligent traffic light allocation based on a traffic induction signal control map. It adjusts the green light duration in real time according to intersection traffic flow to reduce traffic delays. The method uses a traffic induction signal control map to calculate the duration T of the main road induction signal control at the intersection, ultimately rationally adjusting the signal cycle to improve traffic efficiency.

[0004] Technical Solution: The present invention provides a method for intelligent traffic light dispatching based on a traffic sensing signal control map, which specifically includes the following steps:

[0005] (1) Collect traffic data at road intersections and convert the traffic volume of each type of vehicle into equivalent passenger car traffic volume.

[0006] (2) Establish a Green Shields linear model to obtain the relationship between the speed V1 before entering the intersection approach lane and the green light speed V2 of the intersection approach lane;

[0007] (3) Based on the average headway h of vehicles on the main road at the intersection t The initial green light time g is obtained by considering the distance l between the pressure sensor and the stop line, and the number n of vehicles that can be parked between the detector and the stop line. i ;

[0008] (4) Combining the total width of the motor vehicle road d and the distance l from the pressure sensor to the stop line, and combining the speed v of vehicles passing through the intersection on the main road, the unit green light extension time g0 is obtained;

[0009] (5) Combined with the initial green light time g i The shortest green light time is obtained by extending the green light duration by g0 and g0. min ;

[0010] (6) Based on the shortest green light time g min Given the unit's green light extension time g0, draw the induction signal control diagram to obtain the duration T of the main road induction signal control.

[0011] Furthermore, the traffic data mentioned in step (1) includes:

[0012] Total width of motor vehicle road d, average headway h of vehicles on the main road at intersection t The number of vehicles that can stop between the detector and the stop line, n; the 85% speed v of vehicles passing through the intersection on the main road; the distance l of the pressure sensor from the stop line; the average time t of two vehicles passing through the pressure sensor strip after the shortest green light time; and the number N of vehicles passing through the pressure sensor after the initial green light on the main road lane during peak hours. max .

[0013] Furthermore, step (2) is achieved through the following formula:

[0014]

[0015]

[0016] Among them, Q m The maximum traffic flow of the straight-through lane at the intersection entrance. K represents the maximum headway for vehicles in the straight-ahead lane at the intersection entrance. j K represents the congestion density of the through lanes at the intersection entrance, and K1 represents the traffic flow density of vehicles entering the through lanes at the intersection entrance. m V represents the density corresponding to the saturation flow of the through lanes at the intersection entrance. f V1 represents the speed before entering the intersection's approach lane; V2 represents the speed before entering the intersection's approach lane; Q represents the arrival flow of vehicles going straight in the right lane at the intersection's approach lane; and K represents the traffic density in the right lane at the intersection's approach lane.

[0017] Furthermore, the initial green light time g mentioned in step (3) i This can be achieved through the following formula:

[0018] g i =h t·n+k (9)

[0019] Among them, h t denoted as the average headway of vehicles on the main road at the intersection, n is the number of vehicles that can be parked between the detector and the stop line, and k is the vehicle start time.

[0020] Furthermore, the unit green light extension time g0 mentioned in step (4) is achieved by the following formula:

[0021]

[0022] Where d is the total width of the motor vehicle road, l is the distance between the pressure sensor and the stop line, and v is 85% of the speed at which vehicles on the main road pass through the intersection. If no oncoming vehicle is detected within the unit green light extension time, it is judged as a traffic interruption and the green light can be ended. g0 is the unit extension time, which is the extended green light time after the initial green light time ends, when subsequent vehicles are detected to arrive within a certain time interval. If no oncoming vehicle is detected within this period, it is judged as a traffic interruption and the green light can be ended. The unit green light extension time plays a decisive role in the efficiency of inductive signal control. The green light limit extension time is the extension limit of the green light time for each phase to maintain the optimal green signal ratio. When the signal reaches the green light limit extension time, the green light is forcibly ended and the phase is changed.

[0023] Furthermore, the shortest green light time g mentioned in step (5) min This can be achieved through the following formula:

[0024]

[0025] Among them, h t denoted as , where is the average headway of vehicles on the main road of the intersection, n is the number of vehicles that can be parked between the detector and the stop line, k is the vehicle start time, d is the total width of the motor vehicle road, l is the distance between the pressure sensor and the stop line, V1 is the actual speed before entering the intersection approach lane, and Q is the arrival flow of straight-through vehicles at the intersection approach.

[0026] Furthermore, step (6) is implemented as follows:

[0027]

[0028] Where T is the control duration of the induction signal on the main road, N is the number of vehicles passing through the pressure sensor after the initial green light time at the intersection, and t is the average time for the two vehicles in front and behind to pass through the pressure sensor strip after the shortest green light time.

[0029] Furthermore, the counting of vehicles passing the pressure sensor after the initial green light on the main road lane during peak hours is stopped once the vehicles in front and behind pass the pressure sensor for more than 5 seconds.

[0030] Beneficial Effects: Compared with existing technologies, the beneficial effects of this invention are as follows: Based on the principle of main road priority, this invention extends the green light time on main roads with high traffic volume, thereby allowing traffic to pass through intersections more efficiently and reducing the phenomenon of long waiting times for vehicles on main roads during red lights, resulting in blank green light time and wasted resources due to no vehicles (or few vehicles) passing through secondary roads. This design effectively reduces vehicle parking delays, alleviates urban traffic congestion, and improves travel efficiency. This invention can effectively alleviate traffic congestion at intersections, reduce vehicle parking delays, improve the service capacity of intersections, increase traffic efficiency, and is beneficial to urban traffic management and control. Based on a thorough analysis and investigation of intersection infrastructure construction, this invention comprehensively considers traffic density during peak hours, provides reasonable green light times for traffic signals, and adjusts signal timing in real time. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the data measurement location in this invention;

[0032] Figure 2 This is a flowchart of the main road control control diagram for traffic sensing signal control according to the present invention;

[0033] Figure 3 This is the main road control diagram for traffic sensing signal control according to the present invention;

[0034] Figure 4 The vehicle speed is 85% of the speed measured in this invention example. Detailed Implementation

[0035] The present invention will now be described in further detail with reference to the accompanying drawings.

[0036] This invention provides a method for intelligent traffic light dispatching based on traffic sensing signal control maps, the specific implementation steps of which are as follows:

[0037] Step 1, collect data as follows Figure 1 The traffic data shown is as follows. First, investigate the distance d between opposite roads at the intersection, and the average headway h of vehicles on the main road at the intersection. t The following are the possible vehicle numbers between the detector and the stop line (n), the 85% speed (v) of vehicles passing through the intersection on the main road, the distance (l) of the pressure sensor from the stop line, the average time (t) between two vehicles passing the pressure sensor strip after the shortest green light time, and the number of vehicles (N) passing the pressure sensor after the initial green light time during peak hours (counting stops if two vehicles pass the pressure sensor for more than 5 seconds). max The survey points. First, for one week, the average headway h of vehicles on the main road at the intersection was surveyed. t Record the number of vehicles that can be parked between the detector and the stop line, and calculate the initial green light time using the formula in step 4.

[0038] Secondly, the distance *l* from the pressure sensor to the stop line and the distance *d* between the opposing roads at the intersection were measured, and the maximum headway of the straight lane at the intersection entrance was measured. The arrival flow Q of the straight-ahead lane at the intersection approach, and the speed V1 before entering the intersection approach lane. The average time t for two vehicles to pass through the pressure sensor strip after the shortest green light time. Then, during peak hours, with one signal cycle as the node, investigate the number of vehicles N passing through the pressure sensor after the shortest green light time. max All vehicles were categorized into small, medium, and large vehicles, and separate surveys were conducted for each category. Traffic data for each category was collected, and the traffic volume was statistically analyzed and converted into equivalent passenger car traffic volume. The calculation method for converting the traffic volume of large, medium, and small vehicles into equivalent passenger car traffic volume is as follows:

[0039] Q = ∑Q i E i

[0040] Where Q is the converted equivalent passenger car traffic volume, and E i Q is the conversion factor for vehicle class i. i This represents the traffic volume of vehicle type i. my country's highway traffic is a mixed traffic system with a wide variety of vehicles and complex vehicle types. The power performance of different vehicle types varies significantly, resulting in large differences in the time and space occupied by different vehicle types on the road. When conducting capacity studies, the traffic volumes of different vehicle types are not comparable. Therefore, it is necessary to convert the traffic volumes of different vehicle types to those of a standard vehicle type to quantify the impact of different vehicle types on capacity. Vehicle conversion ensures data consistency.

[0041] Step 2: Based on the moderate traffic flow density, establish a Green Shields linear relationship model to obtain the relationship between the speed V1 before entering the intersection approach lane and the green light speed V2 of the intersection approach lane.

[0042]

[0043] Among them, Q m The maximum traffic flow of the straight-through lanes at the intersection entrance, in vehicles per hour; K represents the maximum headway between vehicles in the straight-ahead lane at an intersection entrance, expressed in seconds per vehicle. j K1 represents the congestion density of the through lanes at the intersection entrance, in vehicles / km; K2 represents the traffic flow density of vehicles entering the through lanes at the intersection entrance, in vehicles / km; V represents the density corresponding to the saturation flow of the through lanes at the intersection entrance, in vehicles / km. fv1 represents the initial speed before entering the intersection's approach lane, in km / h; v2 represents the actual speed before entering the intersection's approach lane, in km / h; v2 represents the green light speed at the intersection's approach lane, in km / h; Q represents the converted equivalent passenger car traffic volume, in vehicles / hour; K represents the traffic density of the right lane at the intersection's approach, in vehicles / km.

[0044] Step 3: Establish a traffic-sensor-controlled main road control diagram based on the average headway h of vehicles on the main road at the intersection. t The initial green light time g can be calculated from the distance l of the pressure sensor from the stop line and the number n of vehicles that can be parked between the detector and the stop line. i :

[0045] g i =h t ·n+k (9)

[0046] Among them, g i Initial green light duration on the main road, in seconds; h t is the average headway of vehicles on the main road of the intersection, in vehicles / second; n is the number of vehicles that can be parked between the detector and the stop line, in vehicles; k is the vehicle start time, usually taken as 3s.

[0047] Step 4: Combine the total width of the motor vehicle road d and the distance l of the pressure sensor from the stop line, and combine the speed v of the vehicles passing through the intersection on the main road, to obtain the unit extension time g0.

[0048]

[0049] Where d is the total width of the motor vehicle road, in meters; l is the distance between the pressure sensor and the stop line, in meters; g0 is the unit green light extension time, in seconds; and v is 85% of the speed at which vehicles on the main road pass through the intersection, in kilometers per hour.

[0050] Step 5, initial green light time g i Adding the unit green light extension time g0 gives the shortest green light time g. min If the detector detects an upcoming vehicle, the green light is extended by g0 for each detected vehicle. If no vehicle is detected within the extended time, the phase switches; if vehicles are continuously detected, the green light is continuously extended. However, it will not extend indefinitely; a preset "limit extension time g" will be reached. max Even if a vehicle is detected approaching from behind, the phase must be switched.

[0051] Among them, g min The shortest green light time, in seconds; g ig is the initial green light time, in seconds; g0 is the extended green light time, in seconds. max This is the preset maximum green light time, in seconds. min The shortest green light time is the shortest time for vehicles to pass under any given signal phase.

[0052] To ensure vehicles arriving after the initial green light period can pass safely, a "unit green light extension time" needs to be preset. Therefore, the shortest green light time is actually the sum of the initial green light time and the unit green light extension time. If no vehicle is detected passing the pressure sensor within the extended time, the phase switches; if a vehicle passes the pressure sensor from behind, the green light is extended by one unit green light time. However, it will not extend indefinitely; it will eventually reach a preset "limit extension time g". max Even if a vehicle is detected passing behind, the pressure sensor will switch phases.

[0053] Step 6, based on the shortest green light time g min Given a unit extension time g0, draw a traffic sensing signal control diagram, such as... Figure 2 , Figure 3 As shown, an initial green light g is preset. i If no vehicles arrive within a preset time after the initial green light ends, the light will turn red; if vehicles arrive, the time will be extended by g0 until the preset maximum green light time g is reached. max Regardless of whether any vehicles are arriving at that moment, the light will turn red. Adjustments will be made based on the actual conditions at each intersection. i ,g0,g max The value of this value is used to better reduce delays and alleviate traffic congestion. Therefore, the duration T of the main road inductive signal control can be obtained:

[0054]

[0055] Where T is the duration of the main road induction signal control, in seconds; N is the number of vehicles passing the pressure sensor after the shortest green light time at the intersection (counting stops when two vehicles pass the pressure sensor in front and behind after more than 5 seconds), in vehicles; and t is the average time for two vehicles to pass the pressure sensor strip after the shortest green light time, in seconds.

[0056] like Figure 4 As shown, the pressure sensor was measured to be 45m from the stop line, and the width of the secondary road at the intersection was 25m. Using a radar speedometer at the 85% speed survey point, the 85% speed of vehicles in the straight lane on the main road passing through the intersection was measured. The measured data is shown in the figure. 85% speed V mThe speed is 54 km / h. At the intersection, the average headway for vehicles proceeding straight on the main road is 2.5 seconds, with a maximum headway of 2.1 seconds. During peak hours, there are 350 vehicles proceeding straight on the main road at the intersection. The number of vehicles that can stop between the detector and the stop line is 8, resulting in a vehicle loss time of 3 seconds. Substituting these values, the initial green light time is calculated to be 23 seconds, and the unit green light time is 9 seconds. Based on the calculated initial green light time, the average interval between vehicles passing the pressure sensor after the initial green light time on the main road is measured to be 2.8 seconds, rounded to 3 seconds. The number of vehicles passing the pressure sensor after the initial green light time on the main road is measured to be 6.

[0057]

[0058] Substituting the above data into equation (13), we can obtain that the duration of the green light on the main road is between 32 and 56 seconds.

[0059] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A traffic signal light intelligent deployment method based on traffic-induced signal control map, characterized in that, It comprises the following steps: (1) collecting road intersection traffic data, converting the traffic volume of each type of vehicle into equivalent car traffic volume; (2) establishing a Greenhills linear model to obtain the relationship between the speed V1 before entering the intersection entrance and the green light passing speed V2 of the intersection entrance; (3) According to the average headway h of the vehicles on the main road at the intersection t and the distance l of the pressure sensor from the stop line, the number n of vehicles that can be parked between the detector and the stop line, the initial green time g is obtained i ; (4) combining the total width d of the motor vehicle road and the distance l of the pressure sensor from the stop line, and combining the speed v of the vehicle passing through the intersection on the main road, to obtain the unit green light extension time g0; (5) the initial green time g i and the unit green extension time g0, to obtain the minimum green time g min ; (6) According to the shortest green light time g min And the unit green light extension time g0, draw the inductive signal control chart, so as to get the length T of the main road inductive signal control. The unit green light extension time g0 in step (4) is realized by the following formula: Wherein, d is the total width of the road, l is the distance between the pressure sensor and the stop line, v is the 85% speed of the vehicle passing through the intersection on the main road; The limit headway of the vehicle on the straight lane of the intersection entrance; if no vehicle is measured within the unit green light extension time, the green light is ended due to traffic interruption; g0 is the unit extension time; the unit green light extension time is the green light time extended when the subsequent vehicle is measured within a certain time interval after the initial green light time ends; if no vehicle is measured within the time interval, the green light is ended due to traffic interruption; the unit green light extension time plays a decisive role in the efficiency of the actuated signal control; the limit extension time of the green light is the limit of the green light time extended for each phase in order to maintain the optimal green ratio; when the signal reaches the limit extension time of the green light, the green light is ended and the phase is changed. The shortest green light time g described in step (5) min This is achieved by the following equation: where h t is the average headway of the main road vehicles at the intersection, n is the number of vehicles that can be parked between the detector and the stop line, k is the vehicle start-up time, d is the total width of the motor vehicle road, l is the distance of the pressure sensor from the stop line, V1 is the actual speed before entering the intersection approach, and Q is the arrival flow of straight vehicles at the intersection approach. The step (6) is realized by the following: Wherein, T is the induction signal control time length of the main road, N is the vehicle passing through the pressure sensor after the initial green light time of the intersection, t is the average time of the two vehicles passing through the pressure sensor belt after the shortest green light time, N max is the vehicle passing through the pressure sensor after the initial green light of the main road lane in the peak period. 2.The traffic signal light intelligent deployment method based on traffic responsive signal control diagram according to claim 1, wherein, The traffic data in step (1) comprises: Total width of the road d, average headway h of vehicles at the intersection of the main road t , number of vehicles that can be parked between the detector and the stop line n, speed of 85% of vehicles passing through the intersection on the main road v, distance of the pressure sensor from the stop line l, average time of two vehicles passing through the pressure sensor belt after the shortest green time t, number of vehicles passing through the pressure sensor after the initial green light on the main road during peak hours N max . 3.The traffic signal lamp intelligent deployment method based on traffic signal control map according to claim 1, wherein, The step (2) is realized by the following formula: Wherein, Q m is the maximum traffic flow of the straight lane of the intersection entrance, is the limit headway of the vehicle of the straight lane of the intersection entrance, K j is the jam density of the straight lane of the intersection entrance, K1 is the traffic density of the straight vehicle entering the straight lane of the intersection entrance, K m is the density corresponding to the saturated flow of the straight lane of the intersection entrance, V f is the free-flow speed before entering the intersection entrance, V1 is the actual speed before entering the intersection entrance, V2 is the green light passing speed of the intersection entrance, Q is the arrival flow of the straight vehicle of the right lane of the intersection entrance; K is the traffic density of the right lane of the intersection entrance.

4. The traffic signal lamp intelligent deployment method based on traffic- induced signal control graph according to claim 1, characterized in that, The initial green light time g described in step (3) i This is achieved by the following equation: g i = h t • n + k (9) where h t is the average headway of the main road vehicles at the intersection, n is the number of vehicles that can be parked between the detector and the stop line, and k is the vehicle start-up time.

5. The traffic signal lamp intelligent deployment method based on traffic- induced signal control graph according to claim 2, characterized in that, The vehicle passing through the pressure sensor after the initial green light of the peak period main road lane is the front and rear vehicles passing through the pressure sensor more than 5s, that is, the counting is stopped.

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