Traffic signal lamp intelligent allocation method based on traffic sensing signal control chart

Abstract

The invention discloses a traffic signal lamp intelligent allocation method based on a traffic sensing signal control chart. The method comprises the following steps: converting collected traffic volumes of vehicles of various models into equivalent car traffic volumes; establishing a Greilz linear model, and obtaining a relationship between the speed before entering the intersection entrance lane and the green light passing speed of the intersection entrance lane; according to the average time headway of vehicles on the main road at the intersection, the distance between a pressure sensor and a stop line and the number of vehicles parked between a detector and the stop line, the initial green light time is obtained; combining the total width of a motor vehicle road, the distance between the pressure sensor and the stop line and the speed of the intersection to obtain unit green light prolonging time; obtaining the shortest green light time by combining the initial green light time and the unit green light prolonging time; and drawing an induction signal control chart in combination with the unit green light prolonging time so as to obtain the main path induction signal control duration. According to the invention, vehicle parking delay is effectively reduced, urban traffic jam is relieved, and travel efficiency is improved.

Description

Technical Field

[0001] The present invention belongs to the field of road traffic management and control in traffic engineering, and in particular relates to an intelligent traffic signal lamp allocation method based on a traffic sensing signal control diagram. Background Art

[0002] With the development of social economy in recent years, the process of urbanization has accelerated, and the number of motor vehicles has increased sharply, resulting in a significant increase in traffic flow at intersections. Although traditional timed traffic lights can meet the needs of most intersections, in some peak hours and special circumstances, the signal cycle of traffic lights cannot change with the number of vehicles, which increases the delay time of vehicle parking, thereby inducing traffic congestion, resulting in low traffic efficiency and waste of traffic resources. Traffic signals need to consider not only traffic efficiency, but also traffic safety. The main road priority signal control diagram reduces accident risks and improves traffic safety by reasonably 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 realization of environmental protection goals. Therefore, in the context of multiple parties, a flexible solution is needed to adjust signal timing in real time. The main road control diagram of traffic sensing signals can better adjust the time of signal lights according to the traffic flow, so as to better manage and plan traffic, reduce delays, and achieve rational use of resources. Summary of the invention

[0003] Purpose of the invention: The present invention provides a method for intelligently adjusting traffic lights based on a traffic sensing signal control diagram. The method adjusts the green light duration in real time according to the intersection flow rate to reduce traffic delays. The traffic sensing signal control diagram is used to calculate the duration T of the intersection main road sensing signal control, and finally the signal cycle is reasonably adjusted to improve traffic efficiency.

[0004] Technical solution: The intelligent traffic light allocation method based on the traffic sensing signal control diagram described in the present invention specifically includes the following steps:

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

[0006] (2) Establish the Greenshields linear model to derive the relationship between the speed V1 before entering the intersection entrance and the green light speed V2 at the intersection entrance;

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

[0008] (4) Combining the total width of the motor vehicle road d, the distance l between the pressure sensor and the stop line, and 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 And the unit green light extension time g0, get the shortest green light time g min ;

[0010] (6) Based on the shortest green light time g min And the unit green light extension time g0, draw the induction signal control diagram, and then get the duration T of the main road induction signal control.

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

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

[0013] Furthermore, the step (2) is implemented by the following formula:

[0014]

[0015]

[0016] Among them, Q m is the maximum traffic flow of the through lane at the intersection entrance, K is the limit headway time of vehicles in the through lane at the intersection entrance, j is the blocking density of the through lane at the intersection entrance, K1 is the traffic density of through vehicles entering the through lane at the intersection entrance, and K m is the density corresponding to the saturated flow of the through lane at the intersection entrance, V f is the smooth traffic speed before entering the intersection entrance, V1 is the actual speed before entering the intersection entrance, V2 is the green light speed at the intersection entrance, Q is the arrival flow of straight vehicles in the right lane of the intersection entrance; K is the traffic density of the right lane of the intersection entrance.

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

[0018] g i =h t·n+k (9)

[0019] Among them, h t is the average headway time 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, and k is the vehicle start time.

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

[0021]

[0022] Among them, 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 of vehicles on the main road passing through the intersection; if no oncoming vehicle is detected within the unit green light extension time, it is determined that the traffic is interrupted and the green light can be ended; g0 is the unit extension time, and the unit green light extension time is the green light time extended when the subsequent vehicle arrives within a certain time interval after the initial green light time ends; if no oncoming vehicle is detected during this period of time, it is determined that the traffic is interrupted and the green light can be ended; the unit green light extension time plays a decisive role in the efficiency of the induction signal control; the green light limit extension time is the extension limit of the green light time stipulated for each phase in order to maintain the best green-to-signal ratio; when the signal reaches the green light limit extension, the green light is forced to end and the phase is changed.

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

[0024]

[0025] Among them, h t is the average headway time 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 entrance, and Q is the arrival flow of through vehicles at the intersection entrance.

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

[0027]

[0028] Among them, T is the sensing signal control duration of the main road, N is the number of vehicles passing through the pressure sensor after the initial green light time of the intersection, and t is the average time for the front and rear vehicles to pass through the pressure sensor belt after the shortest green light time.

[0029] Furthermore, the counting of vehicles passing through the pressure sensor after the initial green light of the main road lane during the peak period is stopped if the front and rear vehicles pass through the pressure sensor for more than 5 seconds.

[0030] Beneficial effects: Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention extends the green light time on the main road with heavy traffic flow based on the principle of main road priority, thereby allowing traffic to pass through the intersection more efficiently, reducing the long waiting time of vehicles on the main road during the red light period, and the phenomenon of blank green light time caused by no vehicles (or a small number of vehicles) passing through the secondary road, resulting in waste of resources; this design effectively reduces vehicle parking delays, alleviates urban traffic jams, and improves travel efficiency; the present invention can effectively alleviate car congestion at intersections, reduce vehicle parking delays, improve the service capacity of intersections, improve traffic efficiency, and is conducive to the management and control of urban traffic; the present invention, based on a full analysis and investigation of the construction of intersection facilities, comprehensively considers the traffic density during peak traffic hours, provides a reasonable green light time for traffic lights, and adjusts signal timing in real time. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a schematic diagram of the data measurement position of the present invention;

[0032] Figure 2 This is a flow chart of the main road control diagram of the traffic sensing signal control of the present invention;

[0033] Figure 3 This is a main road control diagram for controlling traffic sensing signals of the present invention;

[0034] Figure 4 It is the 85% vehicle speed measured in the example of the present invention. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below based on the accompanying drawings.

[0036] The present invention provides a method for intelligently adjusting traffic lights based on a traffic sensing signal control diagram, and the specific implementation steps are as follows:

[0037] Step 1: Collect Figure 1 Traffic data shown. First, investigate the distance d between the opposite roads at the intersection and the average headway h of the vehicles on the main road at the intersection. t , the number of vehicles that can be parked between the detector and the stop line n, the 85% speed v of vehicles on the main road passing through the intersection, the distance l between the pressure sensor and the stop line, the average time t for the two vehicles to pass through the pressure sensor belt after the shortest green light time, and the number of vehicles passing through the pressure sensor after the green light time at the beginning of the peak period (the counting will be stopped if the two vehicles pass through the pressure sensor for more than 5 seconds) N max First, we surveyed the average headway time h of vehicles on the main road of the intersection for a week. t And record, then record the number of vehicles that can be parked between the detector and the stop line, and calculate the initial green light time through the formula in step 4.

[0038] Secondly, measure the distance l between the pressure sensor and the stop line, the distance d between the opposite roads of the intersection, and the limit headway time of the straight lane of the intersection entrance road. The arrival flow rate Q of the straight lane at the intersection entrance, and the speed V1 before entering the intersection entrance. The average time t of the two vehicles passing through the pressure sensor belt after the shortest green light time, and then at the peak time, with a signal cycle as a node, investigate the vehicles N passing through the pressure sensor after the shortest green light time max All vehicles are divided into small, medium and large vehicles, and surveys are conducted separately. The collected traffic data includes the traffic volume of small, medium and large vehicles, which is counted and converted into equivalent car traffic volume. The calculation method for converting the traffic volume of large, medium and small vehicles into equivalent car traffic volume is:

[0039] Q=∑Q i E i

[0040] Among them, Q is the equivalent car traffic volume after conversion, E i is the conversion factor for type i vehicles, Q i is the traffic volume of type i vehicles. my country's highway traffic is a mixed traffic of various vehicles, and there are many types of vehicles, complex vehicle models, and the power performance of various models varies greatly, resulting in different time and space occupied by different models when driving on the road. When conducting capacity research, the traffic volume of different models is not comparable. Therefore, the traffic volume of different models needs to be converted into the traffic volume of a certain standard model to quantify the impact of different models on the capacity. The data is consistent when the vehicle is converted.

[0041] Step 2, based on the moderate traffic flow density, the Greenshields linear relationship model is established to obtain the relationship between the speed V1 before entering the intersection entrance and the green light speed V2 of the intersection entrance.

[0042]

[0043] Among them, Q m The maximum traffic flow of the through lane at the intersection entrance, unit: vehicles / hour; K is the maximum headway time of vehicles on the through lane at the intersection entrance, unit: seconds / vehicle; j is the blocking density of the through lane at the intersection entrance, unit: vehicle / km; K1 is the traffic density of through vehicles entering the through lane at the intersection entrance, unit: vehicle / km; K2 is the density corresponding to the saturated flow of the through lane at the intersection entrance, unit: vehicle / km; V fis the free-flowing speed before entering the intersection entrance, unit: km / h; v1 is the actual speed before entering the intersection entrance, unit: km / h; v2 is the green light speed of the intersection entrance, unit: km / h; Q is the equivalent car traffic volume after conversion, unit: vehicles / hour; K is the traffic density of the right lane at the intersection entrance, unit: vehicles / km.

[0044] Step 3: Establish a traffic sensing signal control main road control diagram, based on the average headway time h of the vehicles on the main road of the intersection t The initial green light time g can be 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 :

[0045] g i =h t ·n+k(9)

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

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

[0048]

[0049] Wherein, d is the total width of the motor vehicle road, unit: meter; l is the distance between the pressure sensor and the stop line, unit: meter; g0 is the unit green light extension time, unit: second; v is the 85% speed of vehicles on the main road passing through the intersection, unit: km / h.

[0050] Step 5, initial green light time g i Add the unit green light extension time g0 to get the shortest green light time g min If the detector detects that a following vehicle has arrived, the green light will be extended by one g0 for each vehicle detected. If no following vehicle is detected during the extended time, the phase is switched; if there are continuous vehicles, the green light will be extended continuously. However, it will not be extended forever. When a preset "limit extension time g0" is reached, the green light will be extended continuously. max ”, the phase is switched even if a vehicle is detected coming from behind.

[0051]

[0052] Among them, g min is the shortest green light time, unit: seconds; gi is the initial green light time, unit: seconds, g0 is the green light extension time, unit: seconds, g max It is the preset maximum green light time, in seconds. min The shortest green light time is the shortest time for a vehicle to pass in any signal phase.

[0053] In order to ensure that vehicles arriving after the initial green light time has ended 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 through the pressure sensor during the extended time, the phase is switched; if a vehicle passes through the pressure sensor from behind, the green light time is extended by one unit. However, it will not be extended forever. When a preset "limit extension time g is reached, max ”, the phase is switched even if a car is detected passing the pressure sensor from behind.

[0054] Step 6: According to the shortest green light time g min and unit extension time g0, draw the traffic induction signal control diagram, such as Figure 2 , Figure 3 As shown, an initial green light g is preset i At the end of the initial green light, if no subsequent vehicle arrives within a preset time, the light will turn red; if a vehicle arrives, it will be extended by one g0 until the preset maximum green light time g is reached. max , the light will turn red regardless of whether there are any vehicles arriving at this time. Adjust g according to the actual situation of each intersection i ,g0,g max The value of can better reduce delays and alleviate traffic jams. Thus, the duration T of the main road induction signal control can be obtained:

[0055]

[0056] Among them, T is the duration of the main road sensing signal control, unit: second; N is the number of vehicles passing through the pressure sensor after the shortest green light time at the intersection (the counting will stop if the front and rear vehicles pass through the pressure sensor for more than 5 seconds), unit: vehicle; t is the average time for the front and rear vehicles to pass through the pressure sensor belt after the shortest green light time, unit: second.

[0057] like Figure 4 As shown in the figure, the pressure sensor is 45m away from the stop line, and the width of the secondary road at the intersection is 25m. The radar speedometer is used to measure the 85% speed of vehicles in the straight lane of the main road passing through the intersection at the 85% speed survey point. The measured data is shown in the figure. The 85% speed V mThe speed is 54 km / h. The average headway of the straight-moving vehicles on the main road measured at the intersection is 2.5s and the limit headway is 2.1s. The number of straight-moving vehicles on the main road at the intersection during peak hours is 350. The number of vehicles that can be parked between the detector and the stop line is 8, and the vehicle loss time is 3s. Substituting the calculation, the initial green light time is 23s and the unit green light time is 9s. Based on the calculated initial green light time, the average interval time between the front and rear vehicles passing the pressure sensor after the initial green light time is 2.8s at the intersection, rounded to 3s. The number of vehicles passing the pressure sensor on the main road after the initial green light is 6.

[0058]

[0059] Substituting the above data into formula (13), we can get that the duration of the green light on the main road is between 32 and 56 seconds.

[0060] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for intelligently adjusting traffic lights based on a traffic sensing signal control diagram, characterized in that: The following steps are involved: (1) Collect traffic data at road intersections and convert the collected traffic volume of each type of vehicle into equivalent car traffic volume; (2) Establish the Greenshields linear model to derive the relationship between the speed V1 before entering the intersection entrance and the green light speed V2 at the intersection entrance; (3) Based on the average headway time h of vehicles on the main road of the intersection t The distance l between the pressure sensor and the stop line, the number of vehicles n that can be parked between the detector and the stop line, and the initial green light time g are obtained. i ; (4) Combining the total width of the motor vehicle road d, the distance l between the pressure sensor and the stop line, and the speed v of vehicles passing through the intersection on the main road, the unit green light extension time g0 is obtained; (5) Combined with the initial green light time g i And the unit green light extension time g0, get the shortest green light time g min ; (6) Based on the shortest green light time g min And the unit green light extension time g0, draw the induction signal control diagram, and then get the duration T of the main road induction signal control.

2. The intelligent traffic light deployment method based on the traffic sensing signal control diagram according to claim 1 is characterized in that: The traffic data in step (1) includes: The total width of the motor vehicle road is d, and the average headway of vehicles on the main road of the intersection is h. t , the number of vehicles that can be parked between the detector and the stop line n, the 85% speed v of vehicles on the main road passing through the intersection, the distance l between the pressure sensor and the stop line, the average time t for the two vehicles to pass through the pressure sensor strip after the shortest green light time, and the number of vehicles N passing through the pressure sensor after the initial green light on the main road lane during peak hours max .

3. The intelligent traffic light deployment method based on the traffic sensing signal control diagram according to claim 1 is characterized in that: The step (2) is implemented by the following formula: Among them, Q m is the maximum traffic flow of the through lane at the intersection entrance, K is the limit headway time of vehicles in the through lane at the intersection entrance, j is the blocking density of the through lane at the intersection entrance, K1 is the traffic density of through vehicles entering the through lane at the intersection entrance, and K m is the density corresponding to the saturated flow of the through lane at the intersection entrance, V f is the smooth traffic speed before entering the intersection entrance, V1 is the actual speed before entering the intersection entrance, V2 is the green light speed at the intersection entrance, Q is the arrival flow of straight vehicles in the right lane of the intersection entrance; K is the traffic density of the right lane of the intersection entrance.

4. The intelligent traffic light deployment method based on traffic sensing signal control diagram according to claim 1 is characterized in that: The initial green light time g in step (3) i This is achieved through the following formula: g i =h t ·n+k (9) Among them, h t is the average headway time 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, and k is the vehicle start time.

5. The intelligent traffic light deployment method based on traffic sensing signal control diagram according to claim 1 is characterized in that: The unit green light extension time g0 in step (4) is achieved by the following formula: Among them, 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 of vehicles on the main road passing through the intersection; if no oncoming vehicle is detected within the unit green light extension time, it is determined that the traffic is interrupted and the green light can be ended; g0 is the unit extension time, and the unit green light extension time is the green light time extended when the subsequent vehicle arrives within a certain time interval after the initial green light time ends; if no oncoming vehicle is detected during this period of time, it is determined that the traffic is interrupted and the green light can be ended; the unit green light extension time plays a decisive role in the efficiency of the induction signal control; the green light limit extension time is the extension limit of the green light time stipulated for each phase in order to maintain the best green-to-signal ratio; when the signal reaches the green light limit extension, the green light is forced to end and the phase is changed.

6. The intelligent traffic light deployment method based on the traffic sensing signal control diagram according to claim 1 is characterized in that: The shortest green light time g in step (5) min This is achieved through the following formula: Among them, h t is the average headway time 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 entrance, and Q is the arrival flow of through vehicles at the intersection entrance.

7. The intelligent traffic light deployment method based on the traffic sensing signal control diagram according to claim 1 is characterized in that: The step (6) is implemented by: Among them, T is the sensing signal control duration of the main road, N is the number of vehicles passing through the pressure sensor after the initial green light time of the intersection, and t is the average time for the front and rear vehicles to pass through the pressure sensor belt after the shortest green light time.

8. The intelligent traffic light deployment method based on the traffic sensing signal control diagram according to claim 2 is characterized in that: The number of vehicles passing through the pressure sensor after the initial green light on the main lane during the peak period is stopped if the front and rear vehicles pass through the pressure sensor for more than 5 seconds.

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