CN106683449A - Dynamic green-light interval time adjustment method of traffic control system under vehicular access cooperation environment - Google Patents

Abstract

The invention provides a method for dynamically adjusting the green light interval time of a traffic control system in a vehicle-road collaborative environment, which can obtain real-time vehicle running state information in the detection area; yellow light time analysis: when the remaining green light time of the current phase is less than 1s, according to the vehicles in the detection area Running status information, analyze and optimize the next yellow light time; after the green light time ends, the current phase enters the yellow light time; full red time analysis: when the remaining yellow light time of the current phase is less than 1s, according to the vehicle running status in the detection area Information, analyze and optimize the next full red time; after the yellow light time ends, the current phase enters the red light time. This method obtains the real-time position and speed information of each vehicle in a vehicle-road collaborative environment, dynamically optimizes the interval time between green lights, and reduces parking delays for vehicles while ensuring safety, thereby improving road traffic efficiency and reducing environmental pollution.

Description

Dynamic adjustment method of green light interval time in traffic control system under vehicle-road collaborative environment

technical field

The invention belongs to the field of intelligent traffic safety control, and in particular relates to a method for dynamically adjusting the green light interval time of a traffic control system in a vehicle-road collaborative environment.

Background technique

For a motor vehicle at a phase of a signal-controlled intersection, the color of the signal light changes sequentially in the order of green light-yellow light-red light-green light and operates in a cycle. The green light interval time refers to the time interval between two conflicting traffic flows from the end of the green light of the previous traffic flow that lost the right of way to the start of the green light of the next traffic flow that has the right of way. The function is to avoid collision between the leading vehicle with the green light in the next phase and the tail vehicle that did not pass through the intersection in the previous phase at the traffic conflict point within the intersection range. It is composed of the sum of the yellow light time and the full red time between two adjacent phases, namely

T=A+AR

In the formula, T is the interval time of the green light, A is the time of the yellow light, and AR is the time of the full red light. The traditional green light interval is the sum of the yellow light time and the full red time. In order to ensure traffic safety, it is calculated and determined according to the fixed traffic flow. There is a certain waste of time and reduces the traffic efficiency to a certain extent.

In response to the above problems, researchers at home and abroad have proposed a traffic control system in a vehicle-road collaborative environment for signal notification, which has achieved certain results in improving intersection traffic efficiency and reducing intersection traffic accidents, but there are still some shortcomings. Although the current method strengthens the connection between the driver and the traffic signal, it ignores the impact of possible traffic conflicts on traffic safety and traffic efficiency.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for dynamically adjusting the interval time between green lights of a traffic control system in a vehicle-road collaborative environment, so that vehicles can reduce parking delays, improve road traffic efficiency and reduce environmental pollution.

The technical solution adopted by the present invention to solve the above-mentioned technical problems is: a method for dynamically adjusting the interval time between green lights of a traffic control system in a vehicle-road collaborative environment, which is characterized in that it includes the following steps:

S1. Real-time acquisition of vehicle running status information in the detection area; wherein the detection area includes the area from the detection start-stop line located in the entrance lane to the area passing through the intersection;

S2. Analysis of yellow light time: when the remaining green light time of the current phase is less than 1s, analyze and optimize the next yellow light time according to the vehicle running status information in the detection area; after the green light time ends, the current phase enters the yellow light time;

S3. Analysis of full red time: when the remaining yellow light time of the current phase is less than 1s, analyze and optimize the next full red time according to the vehicle running status information in the detection area; after the yellow light time ends, the current phase enters the red light time ;Full red time refers to the time interval from the end of the yellow light of the current phase to the start of the green light of the next phase;

S4, the red light time ends, and the green light time enters;

S5. The current phase ends, and the next phase cycle S1 to S4;

The specific method for analyzing and optimizing the yellow light time in said S2 is:

2.1. Determine whether there are vehicles in the detection area within the system default yellow light time. Vehicles can neither stop safely within the stop line nor pass the stop line before the end of the yellow light. If not, follow the system default yellow light time Set the yellow light time;

2.2. When there are vehicles that can neither stop safely within the stop line nor pass the stop line before the end of the yellow light within the default yellow light time of the system, these vehicles are called vehicles in a dilemma, and the vehicles in a dilemma are calculated according to the following formula Yellow light time:

A is the yellow light time required by the vehicle, the unit is s; _t0 is the reaction time required for the driver to see the yellow light, which is the preset value, the unit is s; v is the real-time speed of the vehicle, which is collected, and the unit is m/s ; a is the real-time acceleration of the vehicle, collected and obtained, and the unit is m/s ² ; g is the slope, which is a preset constant;

Calculate the yellow light time required by all vehicles in a dilemma and round up to obtain the constraint time, and then select the maximum constraint time that is less than the preset maximum yellow light time A _max as the optimized yellow light time;

The specific method for analyzing and optimizing the full red time in the S3 is:

Let the intersection of the current phase vehicle’s driving route and the next phase’s green light vehicle’s driving route be the conflict point; let a vehicle pass the stop line at the last moment before the current phase’s yellow light goes out, and set this vehicle as the current conflicting vehicle;

Calculate the time t a for the current conflict vehicle to travel to the conflict point, and the time t _b for the first vehicle to travel to the conflict point with the green light in the next phase, both in s; then the full red time is _{t a} -t _b and then taken up all.

According to the above method, the above-mentioned 2.1 is specifically judged according to the following method: when all vehicles in the detection area satisfy the following inequality, set the yellow light time according to the system default yellow light time;

S _n is the distance between the vehicle and the stop line, the unit is m; L _n is the length of the vehicle body, which is a preset value, and the unit is m; _t0 is the reaction time required for the driver to see the yellow light, which is a preset value, and the unit is s; v _n is the real-time speed of the vehicle, collected and obtained, and the unit is m/s; a _n is the real-time acceleration of the vehicle, collected and obtained, and the unit is m/s ^; A is the default yellow light time, which is the preset value and the unit is s;

Vehicles that do not satisfy the above inequality are all dilemma vehicles.

According to the above method, the calculation method of the time t _a when the current conflicting vehicle travels to the conflict point is specifically: t _a = (S _a +L _a )/va _{; S a is} the stop line passed by the current conflicting vehicle to The distance of the conflict point, the unit is m; L _a is the length of the vehicle body, which is a preset value, and the unit is m; v _a is the speed of the current conflicting vehicle, which is collected, and the unit is m/s.

According to the above method, the calculation method of the time t _b for the first vehicle with the green light in the next phase to the conflict point is specifically:

If the first vehicle with the green light in the next phase stops at the stop line and accelerates through the intersection from a standstill, then Wherein S _b is the distance between the stop line where the first vehicle with the green light of the next phase is to the conflict point, unit m; a _b is the real-time acceleration of the first vehicle with the green light of the next phase, collected, and the unit is m/s ² ;

If the first vehicle with a green light in the next phase passes the stop line at a certain speed and drives towards the conflict point, then t _b = S _b /v _b ; where S _b is the distance from the stop line where the first vehicle with a green light in the next phase to the conflict point The distance between them, the unit is m; v _b is the speed of the first vehicle with the green light in the next phase, which is collected, and the unit is m/s.

According to the above method, in S3, if there is more than one conflict point, calculate the all-red time corresponding to each conflict point, and take the maximum value.

According to the above method, in the S3, the default full red time and the maximum full red time are preset, and when the calculated full red time is less than the default full red time, the full red time is set as the default full red time; If the full red time is greater than the maximum full red time, then set the full red time to be the maximum full red time.

According to the above method, the distance between the detection start-stop line and the stop line of the entrance road where it is located is 150m.

The signal auxiliary system for implementing the method for dynamically adjusting the green light interval time of the traffic control system under the vehicle-road coordination environment is characterized in that it includes an intelligent vehicle-mounted device installed in the vehicle, a roadside signal machine located on the roadside, and Traffic lights; the intelligent on-board equipment located in the detection area is used to send the collected vehicle status information of the vehicle to the roadside signal; the roadside signal is used to calculate the phase based on the collected vehicle status information of all vehicles in the detection area The yellow light time and the full red time are sent to the traffic lights for display.

The beneficial effects of the present invention are: the method obtains the real-time position and speed information of each vehicle in the vehicle-road collaborative environment, dynamically optimizes the interval time between green lights, and reduces the parking delay of vehicles under the condition of ensuring safety, thereby improving the traffic efficiency of the road And reduce environmental pollution, and can achieve good results in improving the efficiency of intersection traffic and reducing traffic accidents at intersections.

Description of drawings

Figure 1 is a diagram of the traffic control system setup.

Figure 2 is a schematic diagram of traffic conflict prediction during all red hours.

Fig. 3 is a flowchart of a method according to an embodiment of the present invention.

In the figure: 1-roadside signal machine, 2-detection area, 3-stop line, 4-detection start-stop line, 5-traffic signal light, 6-conflict point, 7-current conflict vehicle, 8-next phase green light first vehicles.

detailed description

The present invention will be further described below in conjunction with specific examples and accompanying drawings.

The present invention provides a method for dynamically adjusting the green light interval time of a traffic control system in a vehicle-road collaborative environment, as shown in Figure 3, which includes the following steps:

S1. Real-time acquisition of vehicle running status information in the detection area; wherein the detection area includes the area from the detection start-stop line located in the entrance lane to the area passing through the intersection;

S2. Analysis of yellow light time: when the remaining green light time of the current phase is less than 1s, analyze and optimize the next yellow light time according to the vehicle running status information in the detection area; after the green light time ends, the current phase enters the yellow light time;

S3. Analysis of full red time: when the remaining yellow light time of the current phase is less than 1s, analyze and optimize the next full red time according to the vehicle running status information in the detection area; after the yellow light time ends, the current phase enters the red light time ;Full red time refers to the time interval from the end of the yellow light of the current phase to the start of the green light of the next phase;

S4, the red light time ends, and the green light time enters;

S5. The current phase ends, and the next phase cycle S1 to S4.

The specific method for analyzing and optimizing the yellow light time in said S2 is:

2.1. Determine whether there is a vehicle in the detection area 2. During the system default yellow light time, there is a vehicle that can neither stop safely within the stop line 3 nor pass the stop line 3 before the end of the yellow light. If not, follow the system default Yellow light time Set the yellow light time. Specifically judge according to the following method: when all vehicles in the detection area 2 satisfy the following inequality, set the yellow light time according to the system default yellow light time;

S _n is the distance between the vehicle and the stop line 3, the unit is m; L _n is the length of the vehicle body, which is a preset value, and the unit is m, usually 6m; t ₀ is the reaction time required for the driver to see the yellow light, which is the preset value Value, unit s, usually 1s; v _n is the real-time speed of the vehicle, collected, unit m/s; a _n is the real-time acceleration of the vehicle, collected, unit m/s ² ; A is the default yellow light time, which is Default value, unit s, usually 2s;

Vehicles that do not satisfy the above inequality are all dilemma vehicles.

2.2. When there are vehicles that can neither stop safely within the stop line nor pass through the stop line 3 before the end of the yellow light within the default yellow light time of the system, these vehicles are called vehicles in a dilemma, and the vehicles in a dilemma are calculated according to the following formula Yellow light time required:

A is the yellow light time required by the vehicle, the unit is s; _t0 is the reaction time required for the driver to see the yellow light, which is a preset value, the unit is s, usually 1s; v is the real-time speed of the vehicle, which is collected, The unit is m/s; a is the real-time acceleration of the vehicle, collected and obtained, and the unit is m/s2; ^g is the slope, which is a preset constant and expressed in decimals;

Calculate the yellow light time required by all vehicles in a dilemma and round up to obtain the constraint time, and then select the maximum constraint time that is less than the preset maximum yellow light time A _max as the optimized yellow light time.

In order to ensure safety, A _max usually takes the yellow light time corresponding to the 85th percentile vehicle speed v ₈₅ in practical applications, namely

During the yellow light period, some vehicles continue to pass the stop line after the green light signal. In order to prevent the vehicle from colliding with the first vehicle with the green light in the next phase, a certain full red time must be set. The full red time refers to the yellow light of this phase. The time interval from the end to the beginning of the green light of the next phase. The specific method for analyzing and optimizing the full red time in the S3 is:

As shown in Figure 2, the intersection point of the vehicle’s driving route in the current phase and the vehicle’s driving route with the green light in the next phase is the conflict point 6; it is assumed that a vehicle passes the stop line 3 at the last moment before the yellow light of the current phase goes out, and this vehicle is the current conflicting vehicle 7;

Calculate the time t a when the current conflict vehicle 7 travels to the conflict point, and the time t _b for the first vehicle 8 with the green light in the next phase to travel to the conflict point, both in s; then the full red time is after _{t a} -t _b Rounded up.

The calculation method of the time t _a when the current conflict vehicle 7 travels to the conflict point is specifically: t _a =(S _a +L _a )/va _{; S a is} the stop line 3 passed by the current conflict vehicle 7 to the conflict point The distance of the point, the unit is m; L _a is the body length, which is a preset value, and the unit is m; v _a is the speed of the current conflicting vehicle 7, which is collected, and the unit is m/s.

The calculation method of the time t _b for the first vehicle 8 with the green light of the next phase to the conflict point 6 is specifically:

If the first vehicle 8 of the next phase green light stops at the stop line 3 and accelerates through the intersection by starting from a standstill, then Among them, S _b is the distance between the stop line 3 where the first vehicle 8 with the green light of the next phase is located and the conflict point 6, the unit is m; a _b is the real-time acceleration of the first vehicle 8 with the green light of the next phase, which is collected, and the unit is m /s ² ;

If the first vehicle 8 with the green light in the next phase passes the stop line 3 at a certain speed and drives to the conflict point 6, then t _b = S _b /v _b ; where S _b is the stop line where the first vehicle 8 with the green light in the next phase is located 3 to the conflict point 6, the unit is m; v _b is the speed of the first vehicle 8 with the green light in the next phase, which is collected, and the unit is m/s.

Since there may be multiple entrances at the intersection, when a vehicle passes through the intersection, multiple conflicts may occur with different vehicles, and the vehicle needs to pass through all conflict points 6 before the first vehicle with the green light in the next phase. In the above S3, if there is more than one conflict point 6, calculate the all-red time corresponding to each conflict point 6, and take the maximum value.

In the described S3, the default full red time and the maximum full red time are preset. When the calculated full red time is less than the default full red time, the full red time is set as the default full red time. In this embodiment, the full red time is defaulted. The time is taken as 0s; when the calculated full red time is greater than the maximum full red time, set the full red time as the maximum full red time. The maximum full red time is to avoid excessive full red time due to system failure or calculation reasons And setting, take 10s in this embodiment.

In this embodiment, the distance between the detection start-stop line 4 and the stop line 3 of the entrance road is 150m.

The signal auxiliary system used to implement the method for dynamically adjusting the green light interval time of the traffic control system under the vehicle-road coordination environment, as shown in Figure 1, includes an intelligent vehicle-mounted device installed in the vehicle, and a roadside signal machine located on the roadside 1, and traffic lights 5; the intelligent on-board equipment located in the detection area 2 is used to send the collected vehicle status information to the roadside signal machine 1; the roadside signal machine 1 is used to The vehicle state information of all vehicles calculates the yellow light time and the full red time of the phase, and sends it to the traffic signal light 5 for display.

In this embodiment, the intelligent vehicle-mounted device includes: an information collection module, which is used to collect and process real-time vehicle state information of the vehicle through GPS (Global Positioning System) technology, and the vehicle state information includes vehicle position information, vehicle lane information, Vehicle speed and acceleration information; the vehicle wireless communication module adopts DSRC technology (dedicated short-range communication technology), and sends the collected information to the roadside signal machine.

The roadside signal machine includes: an information communication module, which uses DSRC communication to receive traffic flow information on the road; an intelligent analysis module, which calculates the real-time green light interval timing scheme according to the real-time vehicle status information and body length information of vehicles in the detection area , including the current optimization of yellow light time and full red time, and dynamically adjust the timing scheme of traffic lights.

The above embodiments are only used to illustrate the design concept and characteristics of the present invention, and its purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. The protection scope of the present invention is not limited to the above embodiments. Therefore, all equivalent changes or modifications based on the principles and design ideas disclosed in the present invention are within the protection scope of the present invention.

Claims (8)

1. traffic control system copper sulfate basic dynamic adjusting method under a kind of bus or train route cooperative surroundings, it is characterised in that：It is wrapped Include following steps：

Travel condition of vehicle information in S1, in real time acquisition detection zone；Wherein detection zone is included from the inspection positioned at import track Survey start-finish line to start to by the region at crossing；

S2, yellow time analysis：When current phase place residue green time is less than 1s, according to the travel condition of vehicle in detection zone Information, is analyzed and optimizes to ensuing yellow time；After green time terminates, current phase place enters yellow time；

S3, complete red time analysis：When current phase place residue yellow time is less than 1s, according to the travel condition of vehicle in detection zone Information, is analyzed and optimizes to ensuing complete red time；After yellow time terminates, current phase place enters red time；Entirely The red time refers to that current phase place amber light terminates the time interval started to next phase place green light；

S4, red time terminate, into green time；

S5, current phase place terminate, next phase loop S1 to S4；

The concrete grammar for being analyzed to yellow time in the S2 and optimizing is：

2.1st, judge that vehicle is whether there is in detection zone has vehicle to pacify in stop line within system default yellow time Under full cut-off, stop line can not be passed through before amber light terminates, if not having, is set by system default yellow time yellow time；

2.2nd, when there is vehicle can neither to terminate in amber light under safe stopping in stop line within system default yellow time It is front by stop line when, these vehicles be called face a difficult choice vehicle, to face a difficult choice vehicle calculate required yellow time as follows：

$A=t_0+\frac{v}{2a+19.6g}$

Yellow time of the A for needed for vehicle, unit s；t₀In response time for needed for driver sees amber light, be preset value, unit s；V is the real-time speed of vehicle, collects, unit m/s；A is the real time acceleration of vehicle, collects, unit m/s²；g It is preset constant for the gradient；

Calculating yellow time needed for all awkward vehicles carries out rounding up and obtains confinement time, then choose less than it is default most Big yellow time A_maxThe maximum constrained time, as the yellow time after optimization；

The concrete grammar for being analyzed to complete red time in the S3 and optimizing is：

If current phase place route or travel by vehicle is conflict point with the intersection point of next phase place green light route or travel by vehicle；If current phase place Last is carved with a vehicle by stop line before amber light extinguishes, if the vehicle is current conflict vehicle；

Calculate current conflict vehicle respectively to travel to the time t of conflict point_a, and next phase place green light first car travelled to punching The time t of bump_b, unit is s；So complete red time is t_a-t_bAfter round up.

2. traffic control system copper sulfate basic dynamic adjusting method under bus or train route cooperative surroundings according to claim 1, It is characterized in that：Described 2.1 specifically judge by the following method：When all vehicles in the detection zone be satisfied by it is following not During equation, is set by system default yellow time yellow time；

$\left\{\begin{array}{c}{S}_n>v_n{t}_0+\frac{{v_n}^2}{2a_n}\\ S_n+L_n<v_n{A}_0+\frac{1}{2}{a}_n{(A_0-t_0)}^2\end{array}\right.$

S_nFor the distance of vehicle distances stop line, unit m；L_nIt is preset value for length of wagon, unit m；t₀See for driver In response time needed for amber light, be preset value, unit s；v_nFor the real-time speed of vehicle, collect, unit m/s；a_nFor vehicle Real time acceleration, collect, unit m/s²；A is acquiescence yellow time, is preset value, unit s；

The vehicle for being unsatisfactory for above-mentioned inequality is awkward vehicle.

3. traffic control system copper sulfate basic dynamic adjusting method under bus or train route cooperative surroundings according to claim 1, It is characterized in that：Described current conflict vehicle is travelled to the time t of conflict point_aComputational methods be specially：t_a=(S_a+L_a)/ v_a；S_aThe stop line passed through by current conflict vehicle to conflict point distance, unit m；L_aIt is preset value for length of wagon, it is single Position m；v_aFor the speed of current conflict vehicle, collect, unit m/s.

4. traffic control system copper sulfate basic dynamic adjusting method under bus or train route cooperative surroundings according to claim 1, It is characterized in that：Described next phase place green light first car is travelled to the time t of conflict point_bComputational methods be specially：

If next phase place green light first car is parked at stop line, accelerate to pass through crossing by static starting, thenWherein S_bIt is next phase place green light first car place stop line to the distance between conflict point, unit m； a_bFor the real time acceleration of next phase place green light first car, collect, unit m/s²；

If next phase place green light first car keeps certain speed by stop line, conflict point is driven towards, then t_b=S_b/v_b；Wherein S_bIt is next phase place green light first car place stop line to the distance between conflict point, unit m；v_bFor next phase place green light The speed of first car, collects, unit m/s.

5. under the bus or train route cooperative surroundings according to claim 1 or 4 traffic control system copper sulfate basic dynamic adjustment side Method, it is characterised in that：In described S3, if conflict point is more than 1, the corresponding complete red time of each conflict point is calculated, taken Maximum.

6. under the bus or train route cooperative surroundings according to claim 1 or 4 traffic control system copper sulfate basic dynamic adjustment side Method, it is characterised in that：In described S3, preset acquiescence complete red time and maximum complete red time, when the complete red time for calculating it is little In acquiescence complete red time, then complete red time is set to give tacit consent to complete red time；When the complete red time for calculating more than it is most complete works of red when Between, then complete red time is set as maximum complete red time.

7. traffic control system copper sulfate basic under bus or train route cooperative surroundings as claimed in any of claims 1 to 4 Dynamic adjusting method, it is characterised in that：The distance between described stop line for detecting start-finish line and place entrance driveway is 150m.

8. it is used to realize traffic control system copper sulfate basic dynamic adjustment side under the bus or train route cooperative surroundings described in claim 1 The signal aid system of method, it is characterised in that：It includes that the intelligent vehicle-carried equipment being arranged in vehicle, the trackside positioned at trackside are believed Number machine and traffic light；Intelligent vehicle-carried equipment in detection zone is used for this car vehicle-state letter that will be collected Breath is sent to trackside semaphore；Trackside semaphore is used for the car status information according to all vehicles in the detection zone for collecting Yellow time and the complete red time of phase place are calculated, and is sent to traffic light and shown.