JPS6342000A - Traffic signal control system - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of the Invention) The present invention relates to a traffic signal control system that operates a traffic signal controller by determining the traffic flow at an intersection, thereby controlling the operation of a signal lamp.

(Prior art and its problems) When determining traffic flow in this type of system, conventionally, an ultrasonic sensor or a loop coil type sensor is installed at a predetermined location in front of the intersection, and intruders entering the intersection The vehicle's movement status was detected.

However, in the case of a conventional example with such a configuration,
When traffic is heavy and there are no vehicles in the detection area of the sensor, the vehicle is not detected, and even though the traffic is congested, the vehicle is determined to be absent, resulting in poor traffic signal control. There were drawbacks.

(Object of the Invention) The present invention was made in view of the above circumstances, and an object of the present invention is to accurately detect the movement status of vehicles and accurately control traffic signals. do.

(Structure and Effects of the Invention) In order to achieve the above object, the traffic signal control system of the present invention is provided at a number of rings spaced apart in the traveling direction on the plane of an intersection, and is installed on the plane of an intersection at several points spaced apart from each other in the traveling direction. An imaging means for taking an image, an image processing means for processing the images of each of the imaging means and recognizing the vehicle number, and comparing the vehicle numbers recognized by the image processing means to identify vehicles with the same vehicle number. a travel time calculation means for calculating a difference in imaging time of a traveling vehicle and calculating an average (excitation time) of a traveling vehicle; a variable calculation means for calculating a change in signal control based on the calculated average travel time; The present invention also includes a traffic signal controller that outputs a control signal to the signal light device based on variables.

According to this configuration, vehicles are identified based on numbers with the same vehicle number, the travel time of each specific vehicle is determined, the average travel time of the traveling vehicle is calculated, and from the calculated travel time, for example, at an intersection, , the average travel time on one side of the intersecting road is compared with the average travel time on the other side, and control signals are output to the signal lamps to control the lighting time of each signal lamp according to the ratio. can be controlled.

Therefore, the travel time of each specific vehicle is determined, the average travel time is calculated, and the traffic signals are controlled based on the calculated travel time, so regardless of the traffic jam situation, there is no possibility that a vehicle will unexpectedly be present. You can avoid false positives,
Traffic signal control can now be performed accurately based on accurate traffic flow.

(Description of Examples) Hereinafter, the present invention will be described in detail based on examples shown in the drawings. FIG. 1 is a block diagram showing the configuration of a traffic signal control system according to an embodiment of the present invention. In this figure, 1a and 1b are the first imaging means, respectively.
and a second television camera, which is attached to a support etc. erected on the roadside at a predetermined interval in the traveling direction of the vehicle, and is configured to take an image of the license plate R of the vehicle C traveling on the road. It is configured.

Each of the first and second television cameras 1 a and 1 b has a shutter that opens and closes at high speed, and is equipped with a solid-state image sensor (CCD) that converts the image into an electric signal and takes out the image, and is equipped with a solid-state image sensor (CCD) that converts the image into an electric signal and takes out the license plate N of the traveling vehicle C. Set image gloss every set period t (for example, 1/60 sec)
It is configured to take pictures at a speed (for example, 1/1000 sec) and output a still image signal.

2 a and 2 b are image processing devices as image processing means, respectively, and a first and second television camera la
The still image signals from each of , l and b are A/D converted by the A/D converter, the image after the A/D conversion is stored in the image memory section, and the still image captured in the image memory section is sampled. Alternatively, the vehicle number can be extracted and recognized from the image of the license plate N by scanning and image processing, and as shown in the configuration diagram of the memory map M in FIG. 3a
, 3) + is manually memorized.

Although not shown, similar first and second television cameras l a and l b are installed in front of the other intersecting road, and the first and second television cameras l
The image processing devices 2 a, 2 are connected to
2b and memories 3a and 3b, respectively.

4 is a control device consisting of a CPU 5 and a memory 6;
As shown in FIG. 3, this control device 4 is equipped with the memory 5, travel time calculation means 7, and variable calculation means 8.

The travel time calculation means 7 is an image processing device 2a.

Based on the image processed in step 2b, the image processing device 2b on the rear side in the traveling direction of the vehicle C processes the image processing device 2a on the front side.
When it recognizes an image with the same vehicle number as the one in
Based on these images, the travel time of the vehicle C is calculated based on the photographing time difference, and the travel time calculated for each unit time is averaged.

Based on the average travel time calculated by the travel time calculation means 7, the change/failure calculation means 8 reads from the memory 6 the signal control variable corresponding to [F] or the signal 5h control variable close to it, and calculates the signal control variable based on the average travel time. A signal control variable corresponding to the calculated travel time is calculated, and an fco signal is output to the traffic signal controller 9 in accordance with the calculated signal control variable.

The traffic signal controller 9 determines variables such as the optimum cycle and split based on the signal control variables from the two intersecting points, and outputs a control signal to the signal lamp IO according to the variables. There is.

Note that, for example, on a road where only crosswalks cross without roadways, the configuration may be such that the control signal is output from the traffic signal controller 9 to the signal light device 10 based only on the signal control variables. good.

Next, the operation of the above embodiment will be explained using the flowchart shown in FIG.

First, an image of the license plate N of the traveling vehicle C is taken by the first television camera Ia (Sl), and the vehicle number of the vehicle C is recognized by the image processing device 2a based on the image (S2). The vehicle number and imaging time are stored in the memory 3a (S3).

Next, in the same manner as described above, an image of the number plate (N) of the traveling vehicle C is taken by the second television camera lb (S4), and the vehicle number of the vehicle C is recognized by the image processing device 2b based on the image. S5), store the recognized vehicle number and imaging time in the memory 3b (
S6).

After that, if the images recognized by both image processing devices 2 a and 2 b have the same vehicle number, the travel time of the vehicle C is calculated from the difference in their photographing times, and the average per unit time is calculated. The travel time is calculated (S7).

Thereafter, the variable calculating means 8 calculates and determines a variable corresponding to the average travel time (S8), and outputs a control signal corresponding to the variable to the signal lamp device 10 (S9), and the signal lamp is set at a predetermined period and a predetermined split. Controls the operation of the device lO...

In the above embodiment, the television cameras 1a, 1b are always configured to take pictures at a set shutter speed every set period and output a still image signal. A vehicle sensor for detecting the presence of a running vehicle is provided in front of the installation position of the TV camera la on the front side in the direction, and after sensing the running vehicle, the TV camera la is installed.

It may be configured to release the shutter at the timing when the vehicle is likely to travel within the field of view of lb.

The present invention provides that the first and second television cameras l
It may also be configured such that a vehicle traveling in a right turn lane is photographed using a, 1b, and a right turn signal lamp is controlled.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a traffic signal control system according to an embodiment of the present invention, FIG. 2 is a configuration diagram of a memory map, FIG. 3 is a block diagram showing the configuration of a control device, and FIG. The figure is a flowchart explaining the operation of the embodiment of the present invention. I a, l b...TV camera as an imaging means,
2 a, 2 b... Image processing device as image processing means, 7... Travel time calculation means, 8... Variable calculation means, 9... Traffic signal controller, lO... Signal lamp device, C. - Running vehicle.

Claims (1)

[Claims] (1) Imaging means installed at multiple locations spaced apart in the direction of travel before an intersection to take images of license plates of traveling vehicles, and recognizing vehicle numbers by processing the images from each of the imaging means. an image processing means; a travel time calculation means that compares vehicle numbers recognized by the image processing means and calculates a difference in imaging time of vehicles with the same vehicle number, and calculates an average travel time of the traveling vehicle; A traffic signal control system comprising: a variable calculation means that calculates a signal control variable based on an average travel time; and a traffic signal controller that outputs a control signal to a signal lamp device based on the signal control variable.