JPH0660905B2 - Moving direction detector - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving direction detecting device for detecting a moving direction of a moving body such as a person moving in and out, and more particularly to a moving direction detecting device using a video signal. It is about.

(Prior Art) Conventionally, a detection element using light, infrared rays, ultrasonic waves, ultra-short waves, etc. has been used as a device for detecting the movement of a person in and out of passenger monitoring, crime prevention monitoring, etc., and in product management. It is used. Such a detection element is for detecting a one-dimensional physical quantity from a specific position or a specific direction,
When performing direction detection, the detection elements are installed at a plurality of positions.

Further, as a method of analyzing the television image and detecting the moving direction of the object, the moving direction from the first scanning time point to the second scanning time point is used by using the scan line encoded information of the entire screen for the calculation. Method (Japanese Patent Publication No. 43-2487)
No. 5) is also proposed.

(Problems to be Solved) However, according to the above-described conventional direction detection technique, there are the following problems.

In the conventional method using the one-dimensional physical quantity detection element, it is necessary to increase the installation position when the moving body is small or there is a degree of freedom in the movement path. If it fails, it will no longer be detectable. Therefore, it is necessary to thoroughly maintain and manage, and the cost burden is large.

Further, even in the conventionally proposed method of analyzing a TV image, even if the moving direction at that time can be detected when there is a degree of freedom in the moving path, for example, when the vehicle turns back or changes direction. However, it is difficult to determine whether or not the vehicle has finally passed through the entrance and exit, and the number of people entering and exiting may be wrongly counted.

An object of the present invention is to solve the above-mentioned problems, and to provide a highly reliable moving direction detection device which is easy to install and cable installation, has few troubles such as breakdown, and has improved measurement accuracy. To do.

(Means for Solving Problems) In order to solve the above problems, the configuration of the movement direction detection device according to the present invention includes the following four constituent requirements.

(1) There are multiple gate circuits to which the video signals branched corresponding to the divided small screens are respectively input.

(2) There is a gate control means for sequentially selecting and opening / closing the plurality of gate circuits based on a synchronizing signal included in the video signal.

(3) There is a plurality of comparing means for comparing the luminance signal included in the video signal taken in from the corresponding gate circuit with the reference value.

(4) There is a determination means for determining the state transition direction between the presence / absence state of the output pulse from one comparison means and the presence / absence state of the output pulse from the other comparison means.

(Operation of the Present Invention) According to the moving direction detecting device having such a configuration, the plurality of gate circuits are sequentially opened and closed by the control of the gate control means, and the time-divided video signals are input to the corresponding comparison means. This time-divided video signal corresponds to a video signal for scanning on a small screen obtained by dividing the screen into a plurality of parts, and only the video signal on the corresponding small screen is input to each comparison means. The comparison means compares the luminance signal of the video signal on the small screen with a reference value and converts and outputs the two-dimensional luminance change of the small screen as a time series pulse train. Therefore, if there is a change in brightness even in a part of the small screen, a pulse will appear. The determining means determines the change in the presence or absence of the output pulse train from each comparing means, and determines the direction of the luminance change between the small screens. That is, when the output pulse train from both comparison means is present, in the next determination period, the output pulse train from one comparison means disappears, and the output pulse train from the other comparison means is present, The transition of the brightness change from the corresponding one small screen to the other corresponding small screen is confirmed, and the moving direction when crossing the boundary of the small screen is declared.

(Embodiment of the present invention) Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a moving direction detecting device according to the present invention. Reference numerals 1a and 1b denote gate circuits to which the branched video signal from the input terminal 2 is input and which are controlled to be opened / closed by a gate control signal from the gate control circuit 3. The gate control circuit 3 is for alternately selecting and opening / closing the gate circuits 1a and 1b based on the synchronizing signal included in the video signal, and includes a synchronizing circuit 3a and a rectangular pulse generating circuit 3b. The synchronizing circuit 3a separates the synchronizing signal from the video signal, and the rectangular pulse generating circuit 3b outputs a rectangular pulse having a duty ratio of 50% based on the synchronizing signal. The frequency of the square pulse is
It is 15,750 Hz. 4a and 4b are gate circuits 1a and
It is a comparison circuit for comparing the luminance signal included in the video signal captured from 1b with a reference value. In this embodiment, the reference value is set as a predetermined fixed value described later. A determination circuit 5 determines the state transition direction between the presence / absence state of the output pulse from one comparison circuit 4a and the presence / absence state of the output pulse from the other comparison circuit 4b.
As will be described later, the determination signal is output to the output terminal 6a when transitioning from one side to the other, and the determination signal is output to the output terminal 6b when transitioning in the opposite direction.

FIG. 2 is a block diagram showing the notification means connected to the output terminal 6a or the output terminal 6b of the above embodiment.

Reference numeral 7 is a chime that obtains a determination signal and sounds. 8 is
It is a TV monitor that obtains a judgment signal and images a specific place. Reference numeral 9 is a voice synthesizer that obtains a determination signal and sounds a message.

Next, the operation and effect of the above embodiment will be described with reference to FIGS. 3 and 4.

Considering the small screens 10a and 10b obtained by dividing the television screen into the left and right at the center, the scanning lines flow from left to right as shown in FIG. 3, and return to the left by a return line (shown by a broken line). By the way, the square pulse from the square pulse generating circuit 3b has the same H level.
In the present embodiment, the gate circuit 1a is opened and the gate circuit 1b is closed, and the gate circuit 1b is opened and the gate circuit 1b is opened and the gate circuit 1a is closed in the L level period. Therefore, the gate circuit 1a takes in only the video signal on the small screen 10a,
b captures only the video signal on the small screen 10b.

Next, in the comparison circuit 4a, the luminance signal of the video signal on the small screen 10a is compared with the reference value, and the two-dimensional luminance change of the small screen 10a is converted and output as a pulse train in time series.
In the comparison circuit 4b, the luminance signal of the video signal on the small screen 10b is compared with the reference value, and the two-dimensional luminance change of the small screen 10a is converted and output as a pulse train in time series. In this embodiment, the reference value is fixedly set in advance as the background level of the small screens 10a and 10b. Therefore, if there is no brightness change on the small screens 10a and 10b, ideally no pulse train is output, and if there is a brightness change even on a part of the small screen, the pulse train appears. Becomes The determination circuit 5 determines the change in the presence or absence of the output pulse train from the comparison circuits 4a and 4b, and determines the direction of the brightness change between the small screens 10a and 10b. For example, as shown in FIG. 4 (A), when the image of the moving body 11 is located within the small screen 10a, there is a pulse train from the comparison circuit 4a and no pulse train from the comparison circuit 4b. As shown in FIG. 4B, when a part of the image of the moving body 11 is displayed on the small screen 10b,
The pulse train from the comparison circuit 4b is also present. When the image of the moving body 11 completely moves into the small screen 10b, the pulse train from the comparison circuit 4b exists, but the pulse train from the comparison circuit 4a almost disappears. Judgment circuit 5
Determines the transition direction of the generation and disappearance of such a pulse train,
When the image of the moving body 11 moves from inside the small screen 10a to inside the small screen 10b, the right direction determination signal is output to the output terminal 6a.
On the contrary, the image of the moving body 11 is moved from the inside of the small screen 10b to the small screen 10a.
When it is moved inward, a leftward direction determination signal is output to the output terminal 6b. Based on these determination signals, the chime 7, the television monitor 8 and the voice synthesizer 9 are activated, and the movement of the moving body 11 is notified.

When using the above-mentioned device (shown in FIGS. 1 and 2) for surveying the number of people entering and leaving, by matching the boundaries of the small screens 10a and 10b, which are obtained by dividing the TV screen to the left and right, with the entrance and exit, You can check the entry and exit more accurately. For example, even when a person who enters the small screen 10a and heads for the doorway turns back near the entrance, it can be accurately recognized that the moving body did not cross the boundary of the screen, that is, the person did not cross the doorway. .

In the above embodiment, the static luminance change is detected by setting the reference value of the comparison circuits 4a and 4b as a fixed value. However, temporary storage means is provided to temporarily store the previous luminance signal, Dynamic luminance changes can be detected by comparing the luminance signal of the previous time with the luminance signal of this time as a reference value, and even if the background of the screen is not limited to a specific one, it can be moved under any background. Regardless of the shade of the body,
The moving direction can be detected.

Further, the number of divisions and the direction of division of the television screen may be set as necessary, and thus even if there are two entrances and exits, one video camera can simultaneously investigate.

(Effects of the Invention) As described above, the moving direction detection device according to the present invention sequentially searches for the generation and disappearance of the pulse train obtained by comparing the luminance signal on each of the divided small screens with the reference value. Since it has a feature in determining the moving direction by doing so, the following effects can be obtained.

(1) By increasing the number of screen divisions, it is only necessary to install one video camera around the route of the moving body not only in one place but also in multiple surveys. Need not be installed.

(2) Since only one coaxial cable needs to be laid from the video camera to this device, the installation work is simpler and the cost can be significantly reduced compared to the conventional case.

(3) The moving direction of the moving body can be detected without being affected by the size or the shade of the moving body. This is because it is similar to the case where the detection elements corresponding to the number of picture elements on the television screen are used.

(4) The accuracy of measurement is improved by dividing the screen into small screens and clarifying the parts to be investigated.

(5) With the long life and reliability of the video camera, maintenance and management becomes easy, and the cost can be reduced as compared with the past.

[Brief description of drawings]

FIG. 1 is a block diagram showing a first embodiment of a moving direction detecting device according to the present invention. FIG. 2 is a block diagram showing a notification means connected to the output terminal of the embodiment. FIG. 3 is a schematic diagram showing scanning lines on the left and right small screens obtained by dividing the television screen into two. FIGS. 4 (A), (B), and (C) are schematic diagrams showing a moving body imaged on the left and right small screens. 1a, 1b ... Gate circuit, 2 ... Input terminal, 3 ... Gate control circuit, 3a ... Synchronous circuit, 3b ... Square pulse generation circuit, 4a, 4b ... Comparison circuit, 5 ... Judgment circuit, 6
a, 6b ... Output circuit, 7 ... Chime, 8 ... TV monitor, 9 ... Voice synthesizer, 10a, 10b ... Small screen,
11 …… A moving image.

Claims (1)

[Claims] 1. A plurality of gate circuits to which video signals branched corresponding to divided screens are respectively input, and a plurality of gate circuits are sequentially selected and opened / closed based on a synchronization signal included in the video signals. Gate control means for controlling, a plurality of comparing means for comparing the luminance signal included in the video signal fetched from the corresponding gate circuit with a reference value, the presence or absence state of the output pulse from one comparing means, and the other A moving direction detecting device comprising: a judging means for judging a state transition direction between the presence / absence of an output pulse from the comparing means.