CN105303849A - Inductive arterial road coordination control method based on electronic tag - Google Patents

Abstract

The invention relates to an inductive arterial road coordination control method based on an electronic tag. An induction phase reads the number of vehicles with electronic license plates in a road section through an RFID reader which is arranged at an intersection. The density of the vehicles in the road section is used as a control index to carry out induction control on the induction phase, so that the inductive coordination control induction phase overcomes failed induction control when traffic flow is supersaturated. The inductive arterial road coordination control coordination phase operates in a fixed timing scheme mode, participates in intersection coordination. A non-coordinated phase operates in an induction control mode to adapt to the randomness of traffic flow reaching under traffic control. Main road green wave control is realized. The green light time of secondary road traffic flow is effectively used. The average delay and the average number of stops of vehicles at the intersection can be effectively reduced.

Description

A Coordinated Control Method for Inductive Arterial Roads Based on Electronic Tags

technical field

The invention relates to a traffic signal control technology, in particular to an inductive arterial coordinated control method based on an electronic tag.

Background technique

At present, most of the intersections in our country still adopt fixed coordinated control, mainly by allocating more green light time to the main road to realize the green wave control of the main road, so as to realize the continuous traffic flow of the main road through multiple intersections without stopping. However, the arrival of the traffic flow is random, and the fixed coordination control will increase the delay at the intersection.

Inductive control coordinated control can adjust the green signal ratio according to real-time traffic flow data. It is more adaptable to the random arrival of vehicles, which can make vehicles stop as little as possible before the stop line, improve the utilization rate of green lights, and achieve smooth traffic. Effect, so induction control is widely used in traffic control. However, there are defects in the coil-based inductive coordinated control strategy: coil-based inductive control generally selects intersections with small traffic flow and large traffic flow fluctuations; Deviations will occur.

In view of this, the present invention uses RFID electronic tags as the information intermediary, utilizes the RFID reader-writer installed at the intersection to read the number of vehicles equipped with electronic license plates in the road section, and realizes inductive coordinated control with the vehicle density in the road section as the control index.

Contents of the invention

The present invention aims at the problem that the traditional vehicle detection technology makes the existing inductive coordinated control invalid when the traffic flow is high and saturated, and proposes an inductive arterial coordinated control method based on electronic tags, using RFID electronic tags as the information intermediary, The transformation of the existing inductive arterial coordination control that will fail when the traffic flow is high and saturated can minimize the average vehicle delay and average parking times of vehicles at the intersection, improve the utilization rate of green light time, design and realize a useful , Practical inductive arterial coordinated control strategy.

The technical solution of the present invention is: an inductive arterial coordinated control method based on electronic tags, which specifically includes the following steps:

1) The arterial road that intersects with the main road is called an inductive arterial road. On the inductive arterial road, an RFID reader is installed 50-100 meters before entering the parking line at the main road crossing, and the electronic tag installed on the vehicle is a vehicle-mounted unit. RFID The reader will transmit the read vehicle data information to the intersection traffic controller through the RS485 bus to realize induction control, and the main road adopts conventional coordinated control;

2) Based on the coordinated control of the main road, the green light is always kept on the coordinated control phase, and the red light is kept on the induction control phase. Only when the vehicle equipped with active electronic tags enters the reading range of the RFID reader, the RFID reader senses When a car arrives, the traffic controller judges: at this time, it is judged whether the minimum green light time of the coordinated control of the main road is over. If it is over, the induction control is performed, and the induction control phase turns green, and the coordination control phase turns red; otherwise, wait for the coordination control phase minimum end of green light time;

3) After entering the induction control, the RFID reader at the intersection reads the vehicle information and records the number of vehicles in the section, and calculates the density of vehicles in the detection section. If the vehicle density in the section of the induction control section is higher than the threshold Δρ, the green light will be extended until The longest set green light time; when the vehicle density of the road section is lower than the threshold Δρ, stop extending the green light and switch the phase.

The beneficial effects of the present invention are: the present invention is based on the electronic tag-based inductive arterial coordinated control method, the induction phase passes through the RFID reader set at the intersection, reads the number of vehicles equipped with electronic license plates in the road section, and uses the vehicle density in the road section as the control The index performs induction control on the induction phase, so that the induction coordination control induction phase can overcome the failure of the induction control when the traffic flow is oversaturated; the induction coordination control coordination phase of the induction arterial road operates in the mode of a fixed timing scheme, and participates in intersection coordination, The non-coordinated phase operates in the mode of induction control to adapt to the randomness of the arrival of traffic control traffic, to achieve the purpose of realizing the green wave control of the main road and the effective use of the green light time of the secondary road traffic, so as to effectively reduce the traffic of vehicles at the intersection. Average vehicle delay and average number of stops.

Description of drawings

Fig. 1 is the principle diagram of the coordinated control of the inductive arterial road based on RFID technology in the present invention;

Fig. 2 is a two-phase signal diagram of the present invention;

Fig. 3 is the basic block diagram of inductive signal control of the present invention;

Fig. 4 is the flow chart of coordinated induction control based on RFID induction main road in the present invention;

Fig. 5 is an effect diagram of the coordinated induction control of the RFID-based main road in the present invention.

detailed description

Using RFID electronic tags as the information intermediary, build a two-way communication between the vehicle and the intersection control layer. By using the RFID reader installed at the intersection, read the number of vehicles equipped with electronic license plates in the section of the road section, and use the vehicle density in the section of the road section as the control index Conduct induction control on the induction phase, so that the induction coordination control induction phase can overcome the failure of the induction control when the traffic flow is oversaturated; the coordination phase of the induction arterial road coordination control operates in the mode of a fixed timing scheme, participates in intersection coordination, and non-coordination phase Operate in accordance with the induction control mode to adapt to the randomness of the arrival of traffic control traffic, to achieve the purpose of green wave control on the main road and effective use of the green light time of the traffic flow on the secondary road, so as to effectively reduce the average delay of vehicles at the intersection and the average number of stops.

As shown in Figure 1, a schematic diagram of the coordinated control of inductive arterial roads based on RFID technology, RFID readers are installed 50-100 meters before the parking lines on both sides of the entrance road at the north-south intersection, and the electronic tags are installed on the vehicle as the on-board unit, RFID read and write The vehicle data information read by the controller is transmitted to the intersection traffic controller through the RS485 bus.

The two-phase signal diagram shown in Figure 2, signal phase: At the entrance of the intersection, different flow directions obtain the right of way in a certain order, and each change of the right of way constitutes a signal phase. The order of the right of way constitutes the phase sequence. In one signal cycle, it contains multiple different signal phases. As shown in Figure 1, the phase with the RFID reader installed realizes induction control, which is a non-coordinated phase (north-south direction); not installed The phase of the RFID reader is a coordinated phase (east-west). After setting the phase difference between the three consecutive intersections, the coordinated control of the main road can be realized. This is the current conventional coordinated control method. Conventional coordinated control is adopted on main roads with dense vehicles (large traffic flow) (east-west direction in the diagram), and RFID readers are installed on arterial roads intersecting with main roads to realize induction control assistance and make control more reasonable.

The basic block diagram of inductive signal control is shown in Figure 3. According to the real-time dynamic traffic situation, based on the traffic volume detected by the actual sensor, the microprocessor in the traffic controller uses the control algorithm flexibly according to the traffic needs of each phase. The traffic light time is allocated, and the microprocessor outputs the control signal to the signal light control to control the change of the signal light color. Essentially, this kind of control is to introduce "feedback" into traffic control, which can realize the change of output parameters tracking input parameters. Here, the change of traffic flow can be regarded as an input parameter, and the light color change control of the signal control output can be regarded as an output parameter. This kind of control is traffic induction control.

An inductive arterial coordinated control method based on RFID vehicle-mounted electronic tags, specifically comprising the following steps:

1) The arterial road that intersects with the main road is called an inductive arterial road. On the inductive arterial road, an RFID reader is installed 50-100 meters before entering the parking line at the main road crossing, and the electronic tag installed on the vehicle is a vehicle-mounted unit. The reader data is sent to the traffic controller to realize induction control, and the main road adopts conventional coordinated control;

2) Based on the coordinated control of the main road, the coordinated control phase keeps the green light, and the induction control phase keeps the red light. When the vehicle equipped with active electronic tags enters the reading range of the RFID reader, it senses the arrival of a vehicle , the traffic controller judges: at this time, whether the minimum green light time of the coordinated control phase of the main road is over, if it is over, the induction control is performed, the induction control phase turns green, and the coordinated control phase turns red; otherwise, wait for the end of the minimum green light time of the coordinated control phase;

3) After entering the induction control, the RFID reader at the intersection reads the vehicle information and records the number of vehicles in the road section. If the vehicle density in the induction control road section is higher than the threshold Δρ, the green light will be extended until the set maximum green light time; When the vehicle density of the road section is lower than the threshold Δρ, stop extending the green light and switch the phase; the reader will read the vehicle data information and transmit the data to the traffic controller through the RS485 bus. The traffic controller uses the data obtained by the reader to calculate the density of vehicles in the detection area, changing the traditional induction control theory to take the time interval between vehicles as the evaluation standard, and proposes to use the electronic license plate to use the vehicle density as the evaluation standard for the extension of the induction control green light. Generate an induction signal scheme; the traffic controller uses the generated induction signal control scheme to control the signal lights at the intersection in real time.

Coordinated control of arterial roads based on electronic license plate is to use the reader installed at the intersection to read the number of vehicles within the range of the road section, and calculate the density of vehicles within the range of the road section. It changes the traditional induction control theory and takes the time interval between vehicles as the evaluation standard. The electronic license plate uses the vehicle density as the evaluation standard for the extension of the induction control green light.

RFID-based inductive coordinated control control strategy: in the inductive arterial coordinated control, the main road adopts coordinated control, and the arterial road intersecting with the main road adopts induction control. Normally, the coordinated control phase keeps green light, and the induction control phase keeps red light. Only when the induction control phase detects the arrival of a vehicle, its light color changes to green light. If the vehicle density in the sensing control road section is higher than the threshold Δρ, the green light will be extended until the maximum green light time (that is, the longest green light time set); when the vehicle density of the road section is lower than the threshold Δρ, stop extending the green light and switch to the next phase. In practical applications, in order to avoid traffic accidents, when the induction phase detects the arrival of a vehicle, it must wait until the minimum green light set on the main road ends before transferring the green light signal to the secondary road. That is, the induction control phase will obtain the right of way only if the two conditions of the induction control phase having a car arriving and the coordination phase green light ending are met at the same time.

Figure 4 is an effect diagram of coordinated induction control based on RFID inductive arterial roads. Comparing the average delay of vehicles at intersections based on RFID-based coordinated control of arterial roads, coil-based induction-based coordinated control of arterial roads, and fixed-type coordinated control at different traffic flows shows that the effect of coordinated control based on RFID-based induction-based arterial roads is optimal, and Coordinated control of arterial roads based on RFID induction can overcome the failure of induction control when the traffic flow is oversaturated.

Claims (1)

1., based on an induction type arterial road coordinate control method for electronic tag, it is characterized in that, specifically comprise the steps:

1) arterial highway crossing with major trunk roads is claimed to be induction type arterial highway, on induction type arterial highway, 50-100 meter ampere dress rfid interrogator before the stop line entering trunk road junction place, vehicle being installed electronic tag is board units, the vehicle data information of reading is sent data to crossing traffic controller by RS485 bus by rfid interrogator, realize induction to control, major trunk roads adopt conventional cooperation control;

2) based on major trunk roads cooperation control, cooperation control phase place keeps green light always, induction control phase keeps red light, only have the vehicle when installation active electronic label to sail the read range of RFID reader into, RFID reader has sensed that car arrives, and traffic controller judges: now judge whether the minimum green time of major trunk roads cooperation control terminates, if terminate, then carry out induction to control, induction control phase becomes green light, and cooperation control phase place reddens lamp; Otherwise wait for that the minimum green time of cooperation control phase place terminates;

3) after entering induction control, the RFID reader at crossing reads information of vehicles and records the interval vehicle fleet size in section, calculates the density of vehicle in detection zone, if traffic density is higher than threshold value Δ ρ in induction control interval, section, then extend green light, until the maximum green perild of setting; When section traffic density is lower than threshold value Δ ρ, then stop extending green light, switch phase place.