JPS6190300A - Traffic flow measuring apparatus - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical Field The present invention relates to a traffic flow metering device for vehicles running on roads, and particularly for capturing images of vehicles running at night, in tunnels, or during strong earthquakes. So-called traffic flow parameters such as vehicle speed and traffic volume in the road environment where it is difficult to capture
Suitable for accurately measuring

(2) Prior Art Loop-type or ultrasonic-type devices are known as traffic flow measurement devices that detect vehicles traveling on the road and measure parameters necessary for traffic control such as vehicle speed, traffic volume, and vehicle spacing. There is. In addition, devices have been developed in recent years that capture traffic images on a camera and measure traffic control parameters from the imaging location and time. (IEICE Space and Navigation Electronics Study Group 5ANE83-28 'Traffic flow measurement using monitoring ITV in tunnels' Kanazaki et al. 1
983.10.19 ) (3) Problems with the prior art In the prior art described above, for example, the loop type requires a loop antenna to be installed on the road surface, and the ultrasonic sensing type requires a loop antenna to be installed on the road surface. This is greatly affected by the wind.

Furthermore, equipment that captures images of moving vehicles from the roadside can be used at night.
This method has the disadvantage that it is no longer possible to obtain a vehicle image when environmental conditions change, such as inside a tunnel or in dense fog, and the practical environmental conditions are often limited.

(4) Means for Solving the Problems The present invention relates to a traffic measurement device that solves the problems of the prior art described above. The presence of a vehicle is determined for each measurement line by setting a measurement line, extracting the brightness data of vehicles on this line, and evaluating changes in the brightness data value and changes in the brightness pattern appearing in the direction of the measurement line.

As a result, during the day when vehicle images can be obtained, traffic parameters for each vehicle type can be obtained by measuring the width of the vehicle, and at night or in dense fog, it is possible to obtain traffic parameters by measuring the width of headlights, tail lights, etc. This makes it possible to obtain target traffic parameters using the same processing method as during the daytime.

(5) Function Figure 1 shows an image capture screen on the driving path (2) of the vehicle (1), which is arranged parallel to the vehicle traveling direction on the screen and is proportional to the width of the vehicle on the screen. A plurality of measurement lines (3) having small intervals are also set. Here, n measurement lines 31 , 32 , . . . 31 . ...3n are points a1 to bl and a2 to t on line segments a and b perpendicular to the measurement line, respectively.2. @@* , 31 to i
) A straight line connecting i, . . . an to bn, and its length may be longer or shorter than the vehicle length.

If an image is extracted along this measurement line (3) and the luminance data on each measurement line on the same screen is drawn in a graph, Figure 2 (
a) and FIG. 2(b). Figure 2 (a)
) is a schematic diagram when a vehicle is present, and FIG. 2(b) is a schematic diagram when a vehicle is not present. By comparing the brightness levels obtained in this manner, it is possible to detect on which measurement line and at what timing the vehicle was present, and also to determine the width of the vehicle, that is, the type of vehicle.

Also, this measurement line (3) and the measurement line downstream of this (4)
Measure the speed of the vehicle.

(6) Embodiment FIG. 3 is a diagram showing the configuration of the image processing traffic flow measurement device of the present invention, in which an image of a vehicle is captured by a camera (4), and this video signal is sent to an A/D converter (5). After converting it into a digital signal using

Next, the contents are sent to the image processing measurement unit (8) through the interface (7), and the amount of change in the brightness data value for each measurement line is compared and evaluated to determine whether or not the vehicle (1) was present. If it is detected, the width of the vehicle is calculated. The data obtained in (8) may be printed out as a list of measurement results on a printer via the interface (9), or may be transmitted to another control system.

Next, the data flow in the apparatus of the present invention is shown in FIG. Image data of the vehicle (1) is digitized and stored, and the amount of change in luminance data value for each measurement line (31 to 3n) is evaluated. When the presence of a vehicle is determined, the vehicle width is determined, the traffic volume by vehicle type is calculated, and the vehicle speed is calculated from the amount of change in brightness data value, the amount of movement of the pattern, the image data processing cycle, etc.0 (7) Invention As mentioned above, the width of the vehicle is determined by using the results of determining the vehicle image on multiple parallel measurement lines based on changes in the brightness data value and pattern tracking. .

- medium-sized, small-sized, etc.), it is possible to calculate the traffic volume by vehicle type. In addition, the vehicle speed is measured from the moving distance of the brightness pattern obtained by plotting the brightness level on each measurement line and the processing cycle of the image data, and in conjunction with the following distance, the driver is given caution when driving to ensure safe driving. It can be useful for air traffic control. It is clear that such special effects of the present invention are remarkable in measuring the traffic flow of vehicles traveling at night or in tunnels.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a vehicle image and a luminance data measurement line according to the present invention. FIG. 2 is a diagram for showing the brightness levels on a plurality of measurement lines.
) is applicable when there is no vehicle. FIG. 3 is a configuration diagram showing an embodiment of the present invention. FIG. 4 is a diagram showing the flow of data processing by the apparatus of the present invention. 1 Vehicle 2 Travel path 3 Measurement line 31...31@...3n: Individual measurement line a: Measurement section fj; al, Fist@@ai, @@@an: Intersection with measurement line b = Measurement section line ;bl,...bi,...bn: Intersection with measurement line 4, camera 5 A/D converter 6 video memory 7 interface 8 image measurement unit 9 interface

Claims (3)

[Claims] (1) In a traffic flow measuring device using an image processing method that converts the image signal of a traveling vehicle into a digital signal and processes the brightness data to measure traffic flow, multiple measurement lines are installed on the traveling road of the image of the vehicle to be measured. , means for determining the presence of a vehicle by extracting brightness data on each of the measurement lines and evaluating changes in brightness levels and brightness patterns;
A traffic flow measurement device characterized by having means for detecting a vehicle or a distance between vehicle lights from the brightness pattern and determining the vehicle type, and measuring traffic flow parameters such as traffic volume and vehicle speed for each vehicle type. (2) The vehicle type is determined by calculating the width of the vehicle based on the brightness level data obtained from each of a plurality of measurement lines provided in parallel with the running direction on the running road of the vehicle image to be measured. A traffic flow measuring device according to claim 1. (3) A brightness pattern is determined from the brightness level obtained for each of a plurality of measurement lines provided in parallel with the running direction on the running road of the measurement target vehicle image, and the amount of movement thereof is determined.
The traffic flow measuring device according to claim 1, wherein the traveling speed of the vehicle is calculated from the imaging processing cycle.