JPH08221690A - Control method for traffic signal - Google Patents

Abstract

PURPOSE: To efficiently utilize an intersection and make a traffic flow smooth on the whole by performing traffic light control in consideration of intersection passage demands of both a main road side and a subordinate road side. CONSTITUTION: An arithmetic control circuit 3, a signal control circuit 4, etc., which constitute a signal control part 2 are constituted integrally as a microcomputer circuit having a CPU, a memory, a clock circuit, etc., integrated, and a light color switching part 6 turns on or off a specified light with an input signal. It is judged whether or not a vehicle group is made to be stopped at an intersection under blue indication control of a prescribed time and when it is judged that the group is stopped, the delay time (Dm) of a main road side traffic flow in case of the stop of the vehicle group is predicted to find a blue extension time value required to make the main road side vehicle group pass through the intersection, and the delay time (Ds) of a slave road side traffic flow when the blue display is extended by the time value, is predicted, and both the times (Dm and Ds) are compared with each other, thereby setting blue indication extension by the blue extension time value when (Dm)>(Ds).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traffic signal control method for controlling a traffic signal installed at an intersection, and more specifically, a traffic for effectively utilizing the intersection in consideration of a vehicle group of each of a main road and a subordinate road. The present invention relates to a signal control method.

[0002]

2. Description of the Related Art A traffic signal is provided at each intersection C as shown in FIG. 6 for the purpose of smoothly controlling traffic by automobiles and suppressing accidents.
(A1, A1, A2, A2, P1, P1, P2, P2) are installed on both the main road (main road) M and the sub road S. The traffic lights at the intersections are collectively controlled by the central control unit of the central control center to collectively control the lighting of a plurality of traffic lights at the intersections. A group of traffic lights at an intersection
The light color is changed in sequence according to the signal control time table to control the traffic flow on the main road (M) and the traffic flow on the slave road (S). The display time of each light color is not fixed and can be changed as needed. Vehicle group sensitive control (gap sensitive control)
In this case, a vehicle detector (1) is provided at a certain point (separation distance Li) upstream of the intersection to extend or shorten the green signal display time according to the head time or the headway time of the vehicle group. For detecting a vehicle, for example, a loop coil type vehicle detector or an ultrasonic type vehicle detector is used.

In the conventional vehicle group sensitive control, the control is performed by paying attention to the demand of the inflow vehicle traveling on the main road side, and the situation on the intersection side is not taken into consideration at all. Therefore, there is a problem that a vehicle waiting to pass on the side of the crossing secondary road is unreasonably kept waiting for a long time. It is hard to say that this is an efficient operation of intersections even for traffic control as a whole. Further, in the conventional vehicle group sensitive control, the variation of each vehicle is not taken into consideration. For this reason, if there is a gap (gap) in a group of vehicle rows, the extension of the blue display time may be terminated even though there is passing demand, which results in the smooth running of the vehicle on the sensitive side. ing.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in order to improve such an irrational point of the conventional vehicle group sensitive control, and takes into consideration the crossing passage demand on both the main road side and the sub road side. The purpose of the present invention is to propose a traffic signal control method that enables efficient traffic control at intersections and facilitates traffic flow comprehensively.

[0005]

In the traffic signal control method according to the first aspect of the present invention, the passing time and the speed of each vehicle traveling toward the intersection are continuously detected at a predetermined position on the upstream side of each inflow path of the intersection. In parallel with the processing step (S10), the case where a vehicle group is formed for each inflow path by the detected vehicle group is detected (S1), and when the vehicle group exists on the main road side, each vehicle group is detected. Of the vehicle group on the main road side and the predicted arrival time at the intersection of the vehicle group on the main road is obtained (S2), and it is determined whether the vehicle group can be stopped at the intersection by the blue display control for the specified time (S3). ),
If not stopped, the process returns to the processing step (S1), but if it is determined to stop, the delay time (Dm) of the main road side traffic flow when the vehicle group stops is predicted (S4), and the main road The delay time (Ds) of the subway side traffic flow when the blue extension time value required for passing the side vehicle group at the intersection is obtained and the blue indication is extended by this time value is predicted (S5), and both delay times ( Dm, Ds) are compared (S6), and if (Dm)> (Ds), the blue display extension is set by the blue extension time value (S8) and the process returns to step (S1). Do the process.

In the second invention, in the traffic signal control method of the above-mentioned first invention, the above-mentioned processing step (S1) for determining the existence of a vehicle group on each inflow path is carried out by a vehicle whose passing time and speed are detected.
It is judged as a vehicle group candidate vehicle when the vehicle group configuration condition that there is a following vehicle between specified vehicles determined based on speed is satisfied, and the vehicle group configuration is performed when the vehicle group candidate vehicles continue beyond the number of vehicle groups established. The vehicle immediately after the continuous vehicle group that satisfies the condition is determined to be the last vehicle in the vehicle group, and the first vehicle in the continuous vehicle group is determined to be the first vehicle in the vehicle group.

[0007]

In both the inventions of the present application, a vehicle group is detected for each inflow route from the detected vehicle, the vehicle group of the main road is recognized, and the delay time (Dm) when this vehicle group stops at the intersection and the vehicle group Compare the delay time (Ds) of the vehicle group on the secondary road side when the blue display extension of the next cycle is performed so that the group does not stop at the intersection, control with less delay time, that is, the utilization efficiency of the intersection Since good control is selected, effective use of intersections becomes possible. Further, according to the second invention of the present application, it is possible to detect a vehicle group that matches the actual situation.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an apparatus suitable for carrying out the traffic signal control method of the present invention will be briefly described. FIG. 2 is a block diagram showing an example of such a device. This device is composed of vehicle information detecting means and arithmetic control means. The vehicle information detecting means is a loop coil type vehicle detector or an ultrasonic type vehicle detector, etc. installed in the up lane and the down lane of each of the main road and the sub road in order to detect the presence of a vehicle traveling on each inflow road. Vehicle detectors (1Au and 1Ad, and 1Bu and 1B
d) is used, and the speed is calculated from the time from the rise of the detection signal of the vehicle detector to the fall and the average vehicle length. This speed value is used for signal control described later. It should be noted that it is possible to install two sensors that make a pair at one location with a predetermined separation distance, and calculate based on the time difference when the traveling vehicle passes through the two vehicle detectors in order and the separation distance. is there. In addition, a sensor that can directly detect the vehicle speed, such as a microwave speed sensor or an ultrasonic Doppler system device, can be used.

Reference numeral (2) is a signal control unit, and the detection signal from each of the vehicle detectors (1Au, 1Ad, 1Bu, 1Bd) is input to the arithmetic control circuit (3) through the communication line (7). Then, the arithmetic processing described later is performed based on the information of these sensing signals, and a signal for instructing signal lamp switching is output to the subsequent signal control circuit (4). (5) is a control constant storage circuit that stores data such as distance from the intersection and constants for signal control for switching the traffic lights according to a predetermined table, and is composed of ROM and RAM. The stored data is referred to by the arithmetic control circuit (3) as needed.

The signal control circuit (4) receives the control signal from the arithmetic control circuit (3) to drive the lamp color switching section (6), and also checks the input signal to improve the system safety and In response to the failure of, control the signal light to a safe display.

The above-mentioned arithmetic control circuit (3), signal control circuit (4) and the like which compose the signal control unit (2) are generally integrally formed as a microcomputer circuit in which a CPU, a memory, a clock circuit and the like are integrated. To be done. The lamp color switching section (lamp opening / closing section) (6) is a known circuit that includes a semiconductor relay such as a thyristor and turns on or off the lamp designated by the input signal.

The traffic signal control method of the present invention can be implemented mainly as a function of the arithmetic control circuit by using the above-mentioned device, for example. An embodiment of the method of the present invention will be described below. 2 shows a flowchart corresponding to FIG. 1. In the embodiment, a total of four vehicles are provided at predetermined positions (distance: Li) of the inflow lane upstream of the main road (M) and the subordinate road (S) at the intersection with a traffic light to be controlled. The sensor group detects the passage time and the traveling speed of each vehicle traveling toward the intersection for each inflow path (S10). When one sensor is used at one detection point, the traveling speed can be obtained from the vehicle detection period (time) and the average vehicle length value.
Further, an ultrasonic Doppler sensor or the like can directly obtain a velocity value. When two vehicle detectors are used at one detection point, it is calculated from the difference in detection time of each vehicle detector. This vehicle detection processing step (S10) is continuously performed in parallel with each processing step described below. It should be noted that even one CPU can realize the time-division processing. The passing time and speed of each vehicle are sequentially stored as a pair of data for each inflow path.

By the processing (S10), based on the individual data of the detected vehicle group obtained one after another, the arithmetic control circuit (3) forms a vehicle group on the main road side by the detected vehicle group for each inflow path. If it occurs, it is detected (S1). At the same time, the vehicle group is detected in other inflow directions as a time division process. In order to determine the vehicle group, it is verified whether each vehicle can form a vehicle group from the relationship between the traveling speed and the preceding vehicle of the detection time. That is, all vehicles detected by the vehicle detector are selected by the following equation group.

[0014]

[Equation 1]

Whether or not both of the above expressions are satisfied at the same time is tested, and a vehicle satisfying the conditions is determined to be a vehicle group configuration candidate vehicle. When n or more (for example, 10) such vehicle group configuration candidate vehicles are consecutive, all the vehicles are combined and detected as one vehicle group.
(S1). An example of this vehicle group detection process part is shown. First, based on the passing time and speed of each vehicle traveling toward the intersection at a predetermined position on the upstream side of each inflow path of the intersection, which is continuously obtained in the above-described processing step (S10), a certain vehicle determines the speed. A vehicle group candidate vehicle is determined when a vehicle group configuration condition that a succeeding vehicle between the prescribed vehicles determined based on the vehicle continues is satisfied. Then, when the number of vehicle group candidate vehicles continues in excess of the number of vehicle groups established, the vehicle immediately after the continuous vehicle group that satisfies the vehicle group configuration condition is determined to be the vehicle group tail vehicle. Further, the first vehicle of the continuous vehicle group is determined to be the vehicle head vehicle, and the following process (FIG. 1: S2) is performed. When the vehicle group is detected in this way, the following parameters are obtained for the vehicle group (S2).

[0016]

[Equation 2]

Then, as the intersection arrival time of the vehicle group,
The arrival time (Ts) and the arrival time (Te) of the leading vehicle to the stop line of the controlled intersection are obtained (S2). Both arrival times can be calculated by the following equations. Note that FIG. 3 is a diagram illustrating the relationship between the values.

Arrival time of the first vehicle in the vehicle group: Tsj = t + Lj / Vj (3) Arrival time of the last vehicle in the vehicle group: Tej = Tsj + Sj (4) where Lj is the distance between the stop line and the vehicle detector , Vj: average speed of the vehicle group, Sj: time required for passage of the vehicle group (corresponding to vehicle group length), t: current time. Through the above processing steps, the vehicle group is recognized and the intersection arrival time is obtained for each of the four inflow paths.

Next, it is determined whether the rearmost vehicle of the vehicle group for each of the up and down lines on the main road (M) side cannot pass through the intersection at the specified green light indication time (S
3). In other words, it is determined whether or not the rearmost vehicle is in a state of being stopped by the start of the next (scheduled) red signal indicating cycle (S3). The determination is performed as follows (see FIG. 4). Let Ri be the start time of the scheduled red traffic light display cycle and Te be the arrival time of the last vehicle in the vehicle group. If the following equation is satisfied, the vehicle in the front of the vehicle group will stop at the red traffic light (in the next cycle) under the prescribed control. Will be done. Ri <Te ... (5)

When it is determined that the operation is not stopped, the signal control is continued for the specified display time, and the first processing step is performed.
Return to (S1). On the other hand, when it is determined to stop, the influence on the traffic flow on the main road side when the red traffic light is started at a specified time without extending the green traffic light is influenced by the main delay time (D
m) is predicted (S4). The calculation process will be described later.

Subsequently, a green light extension time (a) for passing the intersection without stopping the rearmost vehicle in the vehicle group
´) The green light extension time (a ') for passing the intersection without stopping the vehicle at the end of the vehicle group is
It can be obtained as a '= (Te-Ri). With respect to the traffic flow on the sub-road side when the green signal display is extended by this value (a), a long value is set as the extension candidate value (a) within the green signal display extension time (a ') of each of the vertical lines thus obtained. The influence is predicted as the slave delay time (Ds) (S5). The calculation process will be described later.

Then, the master side delay time (Dm) and the slave side delay time (Ds) are compared, and when (Dm)> (Ds) ... (6) is satisfied, only the time (Tgi) is actually reached. Extend the green light display (S8).

The process of determining whether to extend the above-mentioned green signal display will be described in detail below. First, the main-side delay time (Dm) of the vehicle group of interest (longer one) on the main road side is calculated by the following formula. FIG. 4 is an explanatory diagram corresponding to the calculation principle.

[0024]

(Equation 3)

On the other hand, regarding the delay time (Ds) of the vehicle group (longer one) on the secondary road side when the green signal display time is extended by the extension time (a), the explanation between FIG. Because of the relationship shown in the figure, the slave side delay time (Ds) is calculated by the following equation.

[0026]

[Equation 4]

Then, the above-mentioned main road side delay time (Dm)
And the expected delay time on the secondary road (Ds) are compared, and if (Dm)> (Ds) ... (9), the control table is extended so that the green signal display time is extended by the time (a). Set.

Even if a vehicle is detected on the main road, the process
When it is determined in (S1) that the vehicle group is not configured, the conventional gap sensitive control (S9) is performed, and the process returns to step (S1).

As described in the above embodiments, the traffic signal control method of the first invention of the present application determines the passing time and speed of each vehicle traveling toward the intersection at a predetermined position on the upstream side of each inflow path of the intersection. In parallel with the continuous detection process (S10), a case where a vehicle group is formed for each inflow path by the detected vehicle group is detected (S1), and a vehicle group exists on the main road side. , Calculate the vehicle group parameter of each vehicle group and obtain the predicted arrival time at the intersection of the main road side vehicle group (S2), and determine whether the vehicle group can be stopped at the intersection by the blue display control for the specified time. It is determined (S3), and if it is not stopped, the process returns to the processing step (S1), but if it is determined to be stopped, the delay time (Dm) of the main road side traffic flow when the vehicle group is stopped is calculated ( S4),
The blue extension time value required for passing through the intersection of the main road side vehicle group is calculated, and the delay time (Ds) of the sub road side traffic flow when the blue indication is extended by this time value is calculated (S5). The delay times (Dm, Ds) are compared (S6), and if (Dm)> (Ds), the blue display extension is set by the blue extension time value (S8).
Then, the process is returned to the processing step (S1).
As described above, since the control is performed by paying attention to the vehicle group and considering the utilization efficiency of the intersection as a whole, the effective use of the intersection can be measured and the smoothing of the traffic flow is promoted.

The second aspect of the present invention is a process of determining the presence of a vehicle group on each inflow route in the above traffic signal control method.
(S1) is determined to be a vehicle group candidate vehicle when the vehicle that has detected the passing time and the speed satisfies the vehicle group configuration condition that there is a following vehicle between specified vehicles that is determined based on the speed, and the vehicle group candidate vehicle is When the number of vehicles in a row exceeds the number of vehicles in a row, the vehicle immediately after the group of vehicles that meet the vehicle group configuration conditions is determined to be the last vehicle in the group,
Each process of determining the first vehicle of the continuous vehicle group as the vehicle head vehicle is sequentially performed, and an appropriate vehicle group can be determined by this.

[0031]

As described above, in both inventions of the present application, the vehicle groups of the respective inflow paths are detected from the detected vehicle groups of each inflow path in short, and the blue indication of the specified time is shown. The main side delay time of the main road side vehicle group and the subordinate side delay of the sub road side vehicle group when the blue extension is performed for a time such that the main road vehicle group does not stop at the intersection Since the process of performing blue indication extension control is performed only when the delay time is reduced by comparing with the time, control will be performed in consideration of the utilization efficiency of the intersection as a whole, and effective use of the intersection can be measured. Facilitation can be promoted. Dissatisfaction that vehicles waiting for passage on the secondary road will be unreasonably kept waiting for a long time is also resolved. In addition, according to the second invention of the present application, it is possible to detect an appropriate vehicle group according to the actual condition by using a simple vehicle detector, and there is an effect that the above-described effect is further improved in accuracy.

[Brief description of drawings]

FIG. 1 is a flowchart showing an embodiment of a traffic signal control method of the present invention.

FIG. 2 is a block diagram showing an example of a traffic signal control device according to the present invention.

FIG. 3 is a relationship diagram illustrating arrival times and the like of a vehicle group at an intersection.

FIG. 4 is a diagram illustrating a method of calculating a main-side delay time.

FIG. 5 is a diagram illustrating a method of calculating a slave delay time.

FIG. 6 is an external view showing an example of an intersection with a traffic light according to the present invention.

[Explanation of symbols]

 (1Au, 1Ad, 1Bu, 1Bd) ... Vehicle detector (2) ... Signal control unit (3) ... Calculation control circuit (4) ... Signal control circuit (5) ... Control constant memory circuit (6) ... Light color switching unit (C)… Intersection with traffic light (A1, A2, P1, P2)… Signal (M)… Main road (S)… Sub road

Claims (2)

[Claims] 1. The detected vehicle group in parallel with a process step (S10) of continuously detecting the passing time and speed of each vehicle traveling toward the intersection at a predetermined position on the upstream side of each inflow path of the intersection. Detects the case where a vehicle group is formed for each inflow route (S1), calculates the vehicle group parameters of each vehicle group when there is a vehicle group on the main road side, and at the intersection of the vehicle group on the main road side The estimated arrival time to the vehicle is calculated (S2), and it is determined whether the vehicle group can be stopped at the intersection by the blue display control for the specified time (S3) .If it is not stopped, the process returns to the processing step (S1). When it is determined to stop, the delay time (Dm) of the main road side traffic flow when the vehicle group stops is predicted (S4), and the blue extension time value required for passing through the intersection of the main road side vehicle group Then, the delay time (Ds) of the secondary road side traffic flow when the blue indication is extended by this time value is predicted (S5), and The delay times (Dm, Ds) are compared (S6), and if (Dm)> (Ds), the blue display extension is set by the blue extension time value (S8) and the process returns to the processing step (S1). Traffic signal control method to perform each process. 2. The traffic signal control method according to claim 1, wherein the processing step (S) for determining the existence of a vehicle group on each inflow path is performed.
1) determines that a vehicle group candidate vehicle is a vehicle group candidate vehicle if the vehicle whose passing time and speed are detected satisfies the vehicle group configuration condition that there is a following vehicle between specified vehicles that is determined based on the speed. When the number of vehicles in a row exceeds the number of vehicles in a row, the vehicle immediately after the vehicle group that satisfies the vehicle group configuration conditions is determined to be the last vehicle in the vehicle group, and the first vehicle in the vehicle group is determined to be the first vehicle in the vehicle group. Then, the traffic signal control method consisting of each process.