JP2000346856A - Method and device for measurement of speed of traveling body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make measurable the moving speed of a travelling body whose images are taken by a plurality of video cameras installed at specified intervals in specified directions by processing signals of the images of the body taken by the cameras. SOLUTION: When a vehicle passes, trigger signals are outputted respectively at the time points at which a tip (front right end) of the vehicle reaches lines a1, b1, and trigger signals are outputted at the time points at which the vehicle advances and the tip thereof reaches lines a2, b2. As a result, the time that the vehicle has passed a distance between the lines a1-a2 and a distance between the lines b1-b2 can be measured. With the installation of two cameras A, B made such that the lines a1, a2 and the lines b1, b2 forming detection angles may cross at the position where the vehicle passes, the distance between cross points P, Q can be calculated from the distance between the cameras A, B, detection angles of the cameras A, B, and an angle between the central direction line of the image angle and the line H. The time that the vehicle has passed the distance can be measured by a timer means to measure the trigger signals, and thereby the speed of the vehicle passing can be measured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for measuring the speed of a moving object that measures the moving speed of a moving object passing through a predetermined position, such as a vehicle traveling in a predetermined traveling lane.

[0002]

2. Description of the Related Art A speed measuring device used for detecting a speeding vehicle uses a radar speed measuring device as disclosed in, for example, Japanese Patent Application No. 8-42195 "speed monitoring recording device". A device that measures the traveling speed by receiving a Doppler frequency from a vehicle to be measured, or a similar device that uses sound waves instead of electromagnetic waves. For example, Japanese Patent Application No. 10-369714
A device that measures a traveling speed based on a change amount of distance data per unit time using an optical range finder, such as a device disclosed in Japanese Patent Application Publication No. 2000-151, “speed measuring device and speeding vehicle control system”. For example, there is an apparatus for detecting the transit time of a vehicle passing a predetermined distance by using an optical transmitter / receiver, such as an apparatus disclosed in Japanese Patent Application No. 11-91847 "Speed Violating Vehicle Detecting Apparatus".

[0003]

As described above, all of the conventional speed measuring devices for moving objects emit light, sound waves, radio waves, and the like from the measuring device to measure the speed. The device becomes more complicated. It is easily affected by installation location restrictions. There are problems such as being easily noticed when used for speed control.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and has been made to solve the above-mentioned problems. In order to photograph a moving object, the moving object is photographed by two video cameras installed at predetermined intervals in a predetermined direction. An object of the present invention is to provide a moving body speed measuring method and a moving body measuring method which measures a moving speed of a moving body taken by performing signal processing on an image signal.

[0005]

A moving object speed measuring method according to the present invention is a moving object speed measuring method for remotely measuring a moving speed of a moving object passing through a predetermined position. In this case, two video cameras each having a means for detecting a change in brightness or (and / or hue) of a video memory and a timer means for measuring the time of each change are used, and a moving object passing through each of the two video cameras is tilted. The mobile body passes by being installed so that it can be captured from the front and both ends of the angle of view of each video camera intersect (cross) at the passing position of the mobile body and at an appropriate distance H. The distance L between the intersections at both ends of the angle of view is defined as the distance H, the direction of the line H (the straight line forming the distance H), the angle of view of each video camera, and the center direction of the angle of view of each video camera. Calculated from the angle between the line H, wherein the distance is mobile by a change in the video memory L
And measuring the speed of the moving object by measuring the time required to pass through.

Further, according to the present invention, there is provided a moving body speed measuring apparatus for remotely measuring a moving speed of a moving body passing through a predetermined position. The brightness or brightness of the video memory corresponding to both ends of the angle of view, which is installed so as to be caught and both ends of each angle of view intersect (cross) at the passing position of the moving object and at an appropriate distance H (And) a video camera 2 having means for detecting a hue change and timer means for measuring the time of each change
The distance L between the table and the intersection of the two ends of the angle of view through which the moving object passes is defined by the distance H, the direction of the line H (refers to a straight line forming the distance H), the angle of view of each video camera, each video camera Calculating means for calculating from the direction of the angle of view center and the angle formed by the line H, and measuring the time required for the moving body to pass the calculated distance L by changing the video memory, and measuring the speed of the moving body. Computing means for performing the operation.
The angle of view is a detection angle of view set within the angle of view of a video camera, and video memories at both ends of the angle of view are two specific columns of video memories forming the detection angle of view. It is characterized by.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram for explaining an embodiment of the present invention. The method for measuring the speed of a moving object according to the present invention is based on the two video cameras A and B separated by an appropriate distance (H) so that the moving object passing through the two video cameras A and B can be captured from obliquely forward. (Or a detection angle of view, as will be described later), such that both ends cross each other at the passing position of the moving object. Therefore, when the moving object passes through the images captured by the video cameras A and B, the passing of the moving object can be similarly captured over time as shown in the lower diagram of FIG.

The video cameras A and B have means (not shown) for detecting a change in a specific video memory (in the embodiment of FIG. 1, a change in a specific column of the video memory). Line a forming the above-mentioned detection angle of view
1, the brightness of line a2 or line b1, line b2 or (and)
When the hue changes, it is detected instantaneously and a trigger signal is output, and this trigger signal is input to timer means (also not shown), and the line a1, line a2, line b1, and line b2 change. Is configured to be recorded.

In other words, when the video cameras A and B are installed on the side of the road as shown in the upper diagram of FIG. 1, if no vehicle passes, the trigger signals are output because both video cameras merely show a still image of the background. However, when the vehicle passes, the leading end (front right end) of the vehicle is drawn on the line a1 and the line b1.
Trigger signals are output at the same time when the vehicle reaches, and at the same time when the vehicle advances and the leading edge of the vehicle reaches the lines a2 and b2, the trigger signal is output.
The time (although the same time) when the vehicle passed between 1-a2 and between lines b1-b2 can be measured.
Therefore, the lines a1 and a2 and the lines b1 and b2 forming the detection angle of view
If two video cameras are installed so that they intersect at the passing position of the vehicle, the distance between the two intersections (indicated by P and Q) is the distance H between the video cameras A and B and the line H can be calculated from the direction of H (refers to a straight line forming the distance H; the same applies hereinafter), the angle of view detected by each video camera, and the angle between the center of the angle of view and the line H, and passes through this distance. The elapsed time can be measured by the timer means for measuring the trigger signal, so that the speed of the passing vehicle can be measured.
Hereinafter, this measuring operation will be described with reference to FIG. 1 and FIGS. 2 to 4 which illustrate a method of obtaining the distance between the points P and Q.

When the video cameras A and B are installed at a distance H, it is assumed that the line H is an XY coordinate with the Y axis as the Y axis. The center position of the lens of the video camera A is A (0, 0), and the center position of the lens of the video camera B is B (0, H). The angle formed between the Y axis and the direction of the center of the angle of view (not shown) of the video camera A can be measured when the camera A is installed.
Since the angle of view (or the detected angle of view) is known in advance, the angle θa1 can be calculated, and the angle θa2 can also be calculated. Similarly, the angle formed by the Y axis and the direction of the center of the angle of view (not shown) of the video camera B can be measured when the camera B is installed, and the angle of view (or the detected angle of view) of the video camera B is determined in advance. Therefore, the angle θb1 can be calculated, and the angle θb2 can also be calculated.

The point P is the intersection of the lines a1 and b1, and the point Q is the intersection of the lines a2 and b2.
According to (4), the coordinates (xp, yp) of the point P and the coordinates (xq, yq) of the point Q are obtained by calculation. The distance P-
Since Q = L can be obtained from the equation (5), the distance P−L in the installation interval and the installation direction of the two video cameras A and B is eventually obtained.
Q can be calculated, and the transit time of a moving object passing therethrough can be measured by detecting a change in a specific video memory, so that the moving speed of the moving object can be measured by calculation.

The video cameras A and B can be constructed by merely providing a normal video camera with a means for detecting a change in brightness or (and / or hue) of a specific video memory group and a timer means. Also, the moving bodies passing through the two video cameras respectively are captured from diagonally forward, and both ends of the angle of view (or detection angle of view) of the two video cameras intersect (cross) at the passing position of the moving bodies. In this way, it is only necessary to set them at an appropriate distance (H), and unlike a conventional speed measuring device of this type, a light beam, a sound wave, a radio wave, or the like is not emitted from the measuring device, and the passing position of the moving body is not changed. It is possible to measure the moving speed of the moving body without having to install a measuring device in the vehicle or to measure the distance at the passing position of the moving body.

The two video cameras A and B are installed so as to be able to catch a moving object passing obliquely from the front, so that both video cameras can measure the passage of the vehicle at the same position. Out. If the moving object does not pass through the points P and Q accurately, a measurement error will occur. However, since this error is small in actual measurement, there is no particular problem.
In the above-described embodiment, only the speed measuring method is described, and the speed measuring device is not particularly described. However, such two video cameras are installed under the above-described conditions, and the calculating means and the calculating means are used. The operation principle is the same except that the device having the above has the device configuration, and the description thereof is omitted. In the above embodiment, the angle of view of the video camera and the angle of view are different from each other. However, the angle of view of the video camera and the angle of view may be the same (in this case, the line a1) , A2, b1, b2 are located at both ends of the screen, respectively), and lines a1, a2, b1, b
As shown in FIG. 2, the change is detected in the entire specific column of the video memory, but it is needless to say that the change is not necessarily limited to the column.

[0014]

As described above, the method and apparatus for measuring the speed of a moving object according to the present invention require only two video cameras capable of measuring a change in the video memory at a specific position under remote conditions under predetermined conditions. The moving speed of a moving object passing through a predetermined position can be measured, and the apparatus can be simplified and concealed, and the restrictions on the installation location can be greatly eased.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining an embodiment of the present invention.

FIG. 2 is a diagram for explaining a method of obtaining a distance between points PQ.

FIG. 3 is a diagram for explaining a method of obtaining a distance between points PQ.

FIG. 4 is a diagram for explaining a method of obtaining a distance between points P and Q.

[Explanation of symbols]

a1, a2 Specific columns forming the detection angle of view of video camera A b1, b2 Specific columns forming the detection angle of view of video camera B

Claims (3)

[Claims] 1. A method of measuring a moving speed of a moving body, which remotely measures a moving speed of the moving body passing through a predetermined position, comprising: a lightness of a video memory corresponding to both ends of an angle of view;
Using two video cameras each having a means for detecting a hue change and a timer means for measuring the time of each change, so that a moving object passing through each of the two video cameras can be captured from diagonally forward, and The video camera is installed such that both ends of the angle of view of the video camera intersect (cross) at the passing position of the moving body and at an appropriate distance H, so that the intersection between the two ends of the angle of view through which the moving body passes is provided. Distance L,
The video memory is calculated based on the distance H, the direction of the line H (refers to a straight line forming the distance H), the angle of view of each video camera, the center of the angle of view of each video camera, and the angle formed by the line H. And measuring the speed of the moving body by measuring the time required for the moving body to pass through the distance L in accordance with the change in the speed of the moving body. 2. A moving body speed measuring apparatus for remotely measuring a moving speed of a moving body passing through a predetermined position, wherein the moving body passing through the predetermined position is captured from diagonally forward and each angle of view. , So that both ends of the two cross at the passing position of the moving body, and are separated by an appropriate distance H,
Two video cameras having means for detecting changes in brightness or (and / or hue) of the video memory at both ends of the angle of view, and timer means for measuring the time of each change; and The distance L between the intersections at both ends of the angle of view is
Calculating means for calculating from the distance H, the direction of the line H (refer to a straight line forming the distance H), the angle of view of each video camera, the direction of the center of the angle of view of each video camera, and the angle formed by the line H; A speed measuring device for a moving object, comprising: a calculating means for measuring a time required for the moving object to pass through the calculated distance L based on a change in the video memory and measuring a speed of the moving object. 3. The moving object speed measuring apparatus according to claim 2, wherein the angle of view is a detection angle of view set in the angle of view of a video camera, and the video memory corresponding to both ends of the angle of view is stored in the video memory. A moving object speed measuring device comprising two specific columns of video memories forming a detection angle of view.