JP2000105892A - System traffic control unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high-precision system traffic control unit which can perform control according to a vehicle traffic. SOLUTION: The vehicle sensor 21 of a traffic signal controller A measures vehicles entering an intersection CR1 through a road 100 as a vehicle group at certain time intervals. A signal controller 1A generates histograms of each vehicle group and its frequency from vehicle group measurement information supplied from the vehicle sensor 21. In the histograms, a vehicle group center value M is found; when the deviation from the center value M is denoted as Δm, a vehicle group entering a range (M±Δm) is extracted, a synchronizing signal is generated according to the extracted information, and the synchronizing signal is supplied to traffic signal controllers B and C installed at other intersections CR2 and CR3 present along the road 100, so that the controllers are placed in synchronous operation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a system traffic control device.

[0002]

2. Description of the Related Art Traffic signal control systems at intersections are roughly classified into point traffic control systems and centralized traffic control systems. As point traffic control systems, there are known a fixed time control system and a point sensitive control system. I have.

[0003] The fixed time control system is mainly used for an independently controlled intersection independently of a traffic control center, and prepares several time tables for setting a signal time based on a local traffic condition survey made in advance. A morning switch, a daytime pattern, a nighttime pattern, and the like are selected by a time switch. The problem with this fixed-time control method is that a time table is created in advance based on a local traffic situation survey conducted by a person, and the control pattern is switched by a time switch. Inability to cope with the situation, inability to follow changes in traffic conditions over time, and the like. As a result, a long green indication time may be given in a direction in which no vehicle arrives, a signal switching cycle may be short in spite of a heavy traffic, or a time ratio of a green indication given between roads in a master-slave relationship may be inappropriate. This causes a drawback that it becomes dull.

In the point-sensitive control system, a vehicle sensor is installed at each inflow channel at an intersection where traffic fluctuations are severe, that is, at an intersection where traffic demand on the main and subordinate roads is unpredictable, and in response to a gap time of the vehicle, It is to extend the blue presentation time. This traffic control method can reflect an actual traffic entity in traffic control.

[0005] However, when the traffic volume increases, both the main and subway roads operate with the extended time limit, so that the operation is the same as that of the fixed time control system, and the problem described in the fixed time control system becomes apparent. . When the fixed-time control method is entered, simple questions such as "If the green time of the subordinate road is extended for 5 seconds, the subordinate road does not have to be crowded difficultly" will be raised on the vehicle driver side. .

In the centralized control system, a signal control device is connected to a traffic control center by using a communication line such as a telephone line, and the signal time is remotely controlled centrally to control a system with an adjacent intersection.
Alternatively, macro control or the like reflecting the traffic situation in the control area is performed. Micro-control at each intersection extends or shortens the blue-indicating time in response to vehicles entering each of the inflows at the intersection. Therefore, in a critical situation that causes traffic congestion, the same problem as in the point-sensitive control method. Produces a point.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a system traffic control device capable of performing highly accurate and reliable signal control at an intersection.

Another object of the present invention is to provide a highly accurate and highly reliable system traffic control device capable of predictive control based on a vehicle traffic condition.

[0009]

In order to solve the above-mentioned problems, a system traffic control device according to the present invention includes a plurality of traffic signal control devices. Each of the traffic signal control devices includes a vehicle sensor, a traffic light, and a traffic light control device, and is provided at a plurality of intersections existing along one road. The vehicle sensor measures vehicles entering the intersection through the road at certain time intervals as a group of vehicles.

The traffic light control device performs the following operation. First, a histogram of each vehicle group and its frequency is created from the vehicle group measurement information supplied from the vehicle sensor. The information of the vehicle group is divided according to the number of vehicles included therein.

Next, in the histogram, a vehicle group median M is obtained, and a deviation from the median M is represented by Δm.
A group of vehicles included within the range of (M ± △ m) is extracted, a synchronization signal is generated based on the extracted information, and the synchronization signal is provided at another intersection existing along the road. The signal is supplied to the traffic signal control device to perform a synchronous operation.

According to the system traffic control device having the above configuration, a stable signal cycle according to the traffic condition of each inflow channel can be realized, and highly accurate and highly reliable signal control can be performed at an intersection.

Other objects, configurations and advantages of the present invention will be described in detail below with reference to the accompanying drawings which are embodiments.

[0014]

FIG. 1 is a diagram schematically showing a configuration of a system traffic control device according to the present invention. Referring to the drawing, the system traffic control device according to the present invention includes a plurality of traffic signal control devices A to C. Each of the traffic signal control devices A to C includes a vehicle sensitizer 21 to 24 and a traffic light 41 to 44.
And traffic signal control devices 1A to 1C, and are provided at a plurality of intersections CR1 to CR3 existing along one road (hereinafter referred to as a main road) 100. In the example,
Inflow path R1 and inflow path R2 in the opposite direction to inflow path R1
Along the road 100 with three intersections CR1 to CR
R3 exists, and the traffic signal control devices A to C are arranged at each of the intersections CR1 to CR3. Each intersection CR1
In CR3 to CR3, roads 201 and 20 having inflow channels R3 and R4 are compared with a road 100 having inflow channels R1 and R2.
2, 203 intersect.

The vehicle sensors 21 to 24 are connected to the main road 100
Through the intersections CR1 to CR3
Are measured as a group of vehicles at certain time intervals. The embodiment shows an example in which the present invention is applied at cross intersections CR1 to CR3, and vehicle sensitizers 21 to 24 are individually arranged for each of four inflow paths R1 to R4.

A typical example of the vehicle sensors 21 to 24 is a CCD.
Camera. The vehicle sensitizers 21 to 24 are connected to the inflow paths R1
The vehicle 3 is disposed at an appropriate height so as to face the vehicle 3 flowing into the intersections CR1 to CR3 through R4. When a CCD camera is used as the vehicle sensor 21 to 24, the vehicle 3 is detected by comparing the road luminance pattern and the vehicle luminance pattern at daytime, and the vehicle 3 is detected at night by a pair of the headlight luminance pattern of the vehicle 3 can do.
As another means, a light emitting element may be provided. According to such a configuration, the number mi of vehicles 3 can be detected by the vehicle sensation device 21 with a probability of almost 100% as the interruption of the light emitting element. Vehicle sensitive devices 21 to 24 are CCD
In addition to the camera, it may be configured by a point sensor such as an ultrasonic sensor.

The traffic signal control devices 1A to 1C are connected to the vehicle
Based on the signals supplied from 1 to 24, the traffic signals 41 to
44 is controlled. In the embodiment, the traffic signal control devices 1A to 1A
In the description, it is assumed that the traffic signal control device 1A of the intersection CR1 located at the end point of C operates as a master device, and the traffic signal control devices 1B and 1C operate as slave devices. The traffic signal control device 1A generates a synchronization signal from information supplied from the vehicle sensible devices 21 to 24, and outputs the synchronization signal to the traffic signal control device B provided at the other intersections CR2 and CR3 existing on the main road 100. , And C to perform a synchronous operation.

FIG. 2 is a block diagram showing an example of the traffic signal control devices 1A to 1C. As shown in FIG. 2, the traffic signal control devices 1A to 1C have a control unit 1 as a basic configuration.
1, a traffic light drive circuit 12, a traffic light opening / closing circuit 13, a connection portion 14, and the like. The traffic signals 41 to 44 are connected to the traffic signal control devices 1A to 1C via the connection unit 13. FIG.
In the example, the flash unit 15 is further provided. This flash part 15
Detects intersecting traffic indications at the traffic lights 41 to 44 and puts the traffic lights 41 to 44 into a flashing state.

The traffic signal control devices 1A to 1C have the same configuration and are driven according to the signal systems X and Y. Signal system X
Is a system for traffic signals on the main road 100.
Hereinafter, the control operation of the traffic control on the main road 100 will be described by taking the traffic light control device 1A as an example. FIG. 3 is a diagram illustrating a traffic light control operation by the traffic light control device 1A.

In FIG. 3, the signal indications of the traffic lights 41 and 42 become blue (G) at t0. When it is determined that the initial green time Ai1 has elapsed after the signal indications of the traffic signals 41 and 42 have turned blue, the vehicle sensor 2 monitoring the inflow path R1.
It is determined whether or not 1 has a vehicle response. Traffic light 41
When the determination result that the vehicle 3 does not exist in the inflow path R1 controlled by the vehicle is obtained, the signal indications of the traffic signals 41 and 42 change from blue (G) to yellow (Y) after the initial green time Ai1 has elapsed. And further red (R).

In contrast to this, as shown in FIG. 3, when the vehicle sensation device 21 has a vehicle sensitivity when the initial green time Ai1 has elapsed, a unit extension blue time UA1 is added to the initial green time Ai1. , The green times of the traffic lights 41 and 42 are extended from the initial green time Ai1 to the time (Ai1 + UA1).
While the vehicle sensitive device 21 has the vehicle sensitivity, the addition of the unit extended green time UA1 is repeated. If there is no vehicle response during the added unit extended green time UA1, the traffic lights 41 and 42 are terminated at the end of the added unit extended green time UA1.
End of blue time.

After the extension time limit EA1 has passed, the unit extension green time UA1 is not added and the traffic light 4
The blue time of 1, 42 ends.

It is desirable that the initial green time Ai1 be made variable depending on the traffic volume or occupancy of the inflow path R1. That is,
As the traffic condition of the inflow channel R1 becomes denser, the traffic light 41,
The initial green time Ai1 of 42 is lengthened.

If the difference (EA1-Ai1) between the extension limit time EA1 and the initial green time Ai1 is large, the signal cycle changes drastically in response to a sudden change in traffic volume. Cannot be set, and a self-contained traffic control device cannot be configured.
As a means to deal with such a problem, the initial green time Ai
It is preferable to set the lock-in time TLi and the lock-out time TLo so that the vehicle 1 does not follow a rapid change in traffic volume but follows only a gradual change in traffic conditions. That is, when the traffic conditions such as the traffic volume and the occupancy rate continue for a certain specified time, the initial green time Ai1 is changed to a value corresponding to the traffic condition for the first time. The lock-in time TLi is a time required to change the initial green time Ai1.

Next, once the initial green time Ai1 is changed to a new value, the initial green time Ai1 is maintained regardless of changes in traffic conditions such as traffic volume and occupancy. This time is the lockout time TLo.

As shown in FIG. 3, the traffic lights 43 and 44 provided for the traffic control of the inflow paths R3 and R4 also have an initial green time A2i, a unit extension time UA2, and an extension limit time EA.
2 and are controlled in the same manner as the traffic signals 41 and 42.

[0027] Further, the system traffic control device according to the present invention includes:
Each of the traffic signal control devices A to C performs system operation in cooperation. Next, the system operation will be described. FIG. 4 is a diagram for explaining a basic system operation. When the system signal X relating to the main road 100 is supplied to the traffic signal control devices A to C, the traffic signals 41 and 42 of the traffic signal control device A at t0.
Of the traffic lights 43 and 44 become red (R).

The signal condition of the traffic signal controller A is supplied to the traffic signal controllers B and C. In the traffic signal control device B, the signal indication of the traffic lights 41 and 42 becomes blue (G) at the time t1 when the offset time (delay time) △ OB has elapsed from the start of the blue time of the traffic signal control device A t0, Traffic light 4
3, 44 become red (R). In the traffic signal control device C,
At the time t2 when the offset time 経 過 OC has elapsed from the start of the green time t0 of the traffic signal control device A at t2, the signal indications of the traffic lights 41 and 42 become blue (G) and the traffic lights 43 and 44 become red (R). .

As described above, the traffic signal control device A located at the end point is used as the master unit, and the traffic signal control devices B and C located downstream are positioned as the slave units. The phase is synchronized with the phase of the signal timing of the traffic signal control device A with offset times △ OB and △ OC.

Also in the traffic signal control devices B and C, the vehicle sensor 21 detects the vehicle 3 flowing through the inflow path R1 of the main road 100, so that the traffic signal control devices 1B and C
In 1C, the own offset time 信号 OB, △ OC can be corrected based on the sensing signal of the vehicle sensor 21.

As described with reference to FIG. 3, when the traffic volume changes, the signal timing of the traffic signal control device A changes. Therefore, in the traffic signal control devices B and C which are synchronized with the change, the synchronization phase cannot be corrected. Will be needed. In this case, according to the signal timing of the traffic signal control device A, even if the traffic signal control devices B and C need to sharply correct the phase, the offset times △ OB and △ OC may be rapidly changed. Instead, the phase adjustment for correcting the offset times △ OB and △ OC is performed in each signal cycle, for example, within a range of about 10%.

FIG. 5 is a diagram for explaining the offset time extension correction processing. Traffic lights 41 and 42 of traffic signal control device A
T1 with offset time △ OB from blue start time t0 at
At times, the traffic lights 41 and 42 of the traffic signal control device B are blue.

In the next signal cycle in which the traffic lights 41 and 42 of the traffic signal control device A show blue, the offset time (時間 OB + 0.1 × △ OB) from the time t2 when blue starts is set to t.
At 3 o'clock, the traffic lights 41 and 42 of the traffic signal control device B become blue.

In the next signal cycle in which the traffic lights 41 and 42 of the traffic signal control device A show blue, the start time of blue t4
At time t5 after the offset time (△ OB + 0.2 × △ OB), the traffic signals 41 and 42 of the traffic signal control device B become blue.

FIG. 6 is a diagram for explaining the offset time shortening correction processing. Traffic lights 41 and 42 of traffic signal control device A
T1 with offset time △ OB from blue start time t0 at
At times, the traffic lights 41 and 42 of the traffic signal control device B are blue.

In the next signal cycle in which the traffic lights 41 and 42 of the traffic signal control device A show a blue color, an offset time (△ OB-0.1 × △ OB) from the start time t2 of blue is set to t.
At 3 o'clock, the traffic lights 41 and 42 of the traffic signal control device B become blue.

In the next signal cycle in which the traffic lights 41 and 42 of the traffic signal control device A become blue, t is an offset time (△ OB−0.2 × △ OB) from the start time t4 of blue.
At 5 o'clock, the traffic lights 41 and 42 of the traffic signal control device B become blue.

Although the description is omitted, the traffic signal control device C performs the same phase correction processing as that of the traffic signal control device B.

By performing the gradual phase correction processing as described above, a stable signal cycle can be set. When the synchronization signal can be obtained only intermittently, the phase correction is performed only when the synchronization signal is obtained in accordance with the operations shown in FIGS. When the synchronization signal is lost, the operation is performed with the offset time in the previous signal cycle.

In the case of the synchronizing operation described above, as the number of synchronizing signals extracted increases, the offset times △ OB and △ OC of the traffic signal control devices B and C follow the traffic signal control device A more frequently. Will be. From traffic signal control device A,
When the synchronization signal is transmitted in each signal cycle, the traffic signal controllers B and C approach the operation of the normal wired system signal following the traffic signal controller A in both the signal cycle and the offset time.

The operation of the above-described traffic signal control device 1A as a master unit and the operation of the traffic signal control devices 1B and 1C as slave units are those known in current fixed-cycle traffic signal control devices. There is a track record of operation, and there is no problem in implementing.

The system traffic control device according to the present invention differs from the fixed-cycle traffic signal control device in that the vehicle sensible devices 21 to 2
The vehicle group is detected by 4 and a synchronization signal is generated based on the detected vehicle group. In that sense,
The system traffic control device according to the present invention is a self-contained type, and it is extremely important to generate a correct synchronization signal in its operation. Next, creation of a synchronization signal will be described.

The traffic light control devices 1A to 1C operate as masters for the traffic light control devices located downstream of themselves, but in the following description, as shown in FIG. In the following, an example will be described in which the traffic light control devices 1B and 1C operate as slaves and operate as slaves. When the traffic signal control devices 1B and 1C operate as master devices, the operation of the traffic signal control device 1A as the master device is applied as it is. Also, the vehicle sensible devices 21 to 24
Perform the same operation, but assume that the traffic signal control for the vehicle 3 passing through the inflow path R1 of the main road 100 is described with reference to FIG. explain.

FIG. 7 is a diagram showing a vehicle group measurement when the vehicle sensation device 21 is constituted by a surface imaging sensor such as a CCD camera. In this case, for vehicles passing through the inflow path R1, the inter-vehicle gaps G1, G2,. . . A series of m vehicles 30 to 3 m having Gm is treated as one vehicle group. If the inter-vehicle gap Gn is larger than the space gap Gs, it is treated as another vehicle group.

FIG. 8 is a diagram showing a vehicle group measurement when the vehicle sensible devices 21 to 24 are constituted by point sensors such as ultrasonic sensors. In this case, with respect to the vehicle 3 (see FIG. 1) traveling on the inflow path R1, consecutive vehicles having an inter-vehicle time Δt shorter than the gap time Gt are treated as one vehicle group.

FIG. 9 is a diagram showing the time-vehicle group distribution characteristics obtained according to FIG. 7 or FIG. In FIG. 9, the horizontal axis represents time, and the vertical axis represents the number of vehicles. As shown in FIG. 7 or FIG. 8, the vehicle is sensed by the vehicle sensor 21 and the vehicle group is measured. In the vehicle group measurement, the number of vehicles in each vehicle group is measured together with the vehicle group measurement. These measurement processes are performed by the traffic light control device 1A based on the vehicle group measurement information supplied from the vehicle sensor 21. Specifically, the vehicle group measurement information supplied from the vehicle sensor 21 is sampled at a certain time interval in the traffic light control device 1A,
And memorize. FIG. 9 shows the number of vehicles included in the vehicle groups m1 to m6 that are sampled at certain time intervals and stored in the traffic light control device 1A.

As shown in FIG. 10, the traffic signal control device 1A uses the vehicle group measurement information supplied from the vehicle sensitive device 21 as shown in FIG.
A histogram of each vehicle group m1 to m7 and its frequency is created. In the present invention, creating a histogram means not generating an actual histogram as a table, but generating data corresponding to the histogram.

The vehicle group information is classified according to the number of vehicles included therein. The histogram shows each car group m1 to m7
Is measured, for example, over 10 signal cycles.

The traffic signal controller 1A finds the vehicle group median M in the histogram and calculates the deviation from the median M by Δm
Then, the vehicle group included in the range of (M ± △ m) is extracted. In the case of FIG. 10, the vehicle groups m1, m2, m4 and m
6 are extracted as a group of vehicles falling within the range of (M ± △ m).

The traffic signal control device 1A outputs the extracted vehicle group m
A synchronization signal is generated based on information of 1, m2, m4, and m6. FIG. 11 is a diagram illustrating generation of a synchronization signal.
Time intervals of the extracted vehicle groups m1, m2, m4 and m6６
From t1, Δt2, and Δt3, an average value Δta is obtained. Then, a synchronization signal is generated except for a group of vehicles whose time interval does not fall within the range of the time interval (△ ta ± △ t). In the case shown, the time interval Δt3 of the vehicle group m6 is the time interval (Δta
Since the vehicle group m6 does not fall within the range of ± 車 t), the vehicle group m6 is excluded from the target of the synchronization signal generation. After all, vehicle groups m1, m2 and m
4 will be generated at t1, t2, and t3.

The traffic signal control device 1A supplies the synchronization signal obtained as described above to the traffic signal control devices B and C provided at the other intersections on the main road 100 to perform the synchronization operation. Is as described above.

In the above description, the measurement judgment of the vehicle group information is 1
The case where the determination is made by accumulating 0 signal cycles has been described as an example. However, the determination may be made for each signal cycle, or the signal cycle up to the previous time (eg, 9 cycles)
To the vehicle group measurement information of the current signal cycle
The signal cycle may be used, and the moving average may be determined in real time operation for each signal cycle.

[0053]

As described above, according to the present invention, the following effects can be obtained. (A) It is possible to provide a system traffic control device capable of performing highly accurate signal control at an intersection. (B) It is possible to provide a high-precision system traffic control device capable of performing predictive control based on vehicle traffic conditions.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing a configuration of a system traffic control device according to the present invention.

FIG. 2 is a block diagram illustrating an example of a traffic light control device included in the system traffic control device according to the present invention.

FIG. 3 is a diagram illustrating a traffic light control operation by a traffic light control device included in the system traffic control device according to the present invention.

FIG. 4 is a diagram illustrating a basic system operation of the system traffic control device according to the present invention.

FIG. 5 is a diagram illustrating an offset time extension correction process in the system traffic control device according to the present invention.

FIG. 6 is a diagram illustrating offset time shortening correction processing in the system traffic control device according to the present invention.

FIG. 7 is a diagram illustrating vehicle group measurement when the vehicle sensation device is configured by a surface imaging sensor.

FIG. 8 is a diagram illustrating vehicle group measurement when the vehicle sensation device is configured by a point sensor.

FIG. 9 is a diagram showing the number of vehicles included in a group of vehicles sampled at certain time intervals and stored in the traffic light control device.

FIG. 10 is a histogram of each vehicle group and its frequency in the system traffic control device according to the present invention.

FIG. 11 is a diagram illustrating generation of a synchronization signal in the system traffic control device according to the present invention.

[Explanation of symbols]

 A, B, C Traffic signal control devices 1A, 1B, 1C Traffic signal control devices 21-24 Vehicle sensitizers 41-44 Traffic signals 3 Vehicles

Claims (2)

[Claims] 1. A system traffic control device including a plurality of traffic signal control devices, wherein each of the traffic signal control devices includes a vehicle sensitive device, a traffic light, and a traffic light control device, and is provided along one road. The vehicle sensor is provided at a plurality of existing intersections, and the vehicle sensor measures vehicles entering the intersection through the road at a certain time interval as a group of vehicles, and the traffic light control device includes: From the vehicle group measurement information supplied from the vehicle sensor, a histogram of each vehicle group and its frequency is created, and the vehicle group is divided according to the number of vehicles included therein. When a value M is obtained and a deviation from the median M is △ m, a group of vehicles falling within the range of (M ± △ m) is extracted, and a synchronization signal is generated based on the extracted information. Along the road To another of the provided at the intersection traffic signal controller system traffic controller for supplying the synchronous operation. 2. The system traffic control device according to claim 1, wherein the traffic light control device performs phase adjustment on a synchronization signal every synchronization signal transmission cycle.