JPS62245966A - Detecting device for moving direction - Google Patents

Abstract

PURPOSE:To attain great reduction in expense by searching successively for the generation and disappearance of a pulse train obtained by comparing luminance signals in plural divided small screen with a reference value and thus deciding a moving direction. CONSTITUTION:A rectangular pulse from a rectangular pulse generating circuit 3b consists of an H and an L level at the same time; and a gate circuit 1a is opened and a gate circuit 1b is closed in the H-level period, and the circuit 1b is opened and the circuit 1a is closed in the L-level period. Therefore, the circuits 1a and 1b input only video signals of screens 10a and 10b. Then, comparators 4a and 4b compare the luminance signals of video signals of the screens 10a and 10b with the reference value and convert two-dimensional luminance variation of the screens 10a and 10b into time-series pulse trains, which are outputted. A decision circuit 5 decides the transition directions of the generation and disappearance of output pulse trains from the circuits 4a and 4b and outputs a right-direction decision signal to an output terminal when the image of a mobile body 11 moves, for example, from the screen 10a to the screen 10b.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a moving direction detecting device for detecting the moving direction of a moving body, such as when a person enters or exits, and particularly relates to a moving direction detecting device that uses a video signal. It is related to.

(Prior Art) Conventionally, detection elements using light, infrared rays, ultrasonic waves, ultrahigh frequency waves, etc. have been used to detect the entry and exit of people in visitor monitoring, crime prevention monitoring, etc., and the moving direction of conveyed objects in product management, etc.・It is used. Such a detection element detects a one-dimensional physical quantity from a specific position or a specific direction,
When performing direction detection, detection elements are installed at multiple positions.

(Problems to be Solved) However, the above conventional direction detection technology has the following problems.

When the moving object is small or there is a degree of freedom in the movement route, it is necessary to increase the installation position, making the installation work time-consuming and costly.

When detecting the detection directions of moving bodies of various sizes, it is necessary to set the installation position so as to detect the direction of the smallest moving body, but if a failure occurs in one of the moving bodies, detection is no longer possible. Therefore, it is necessary to carry out thorough maintenance and management, and the cost burden is also large.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and to provide a highly reliable moving direction detection device that is easy to install and attach cables to, has fewer troubles such as breakdowns, and is highly reliable.

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

(1) There are a plurality of gate circuits into which the branched video signals are respectively input.

(2) There is a gate control means that sequentially selects and controls opening and closing of the plurality of gate circuits based on a synchronization signal included in the video signal.

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

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

(Effects of the Invention) According to the moving direction detection device having such a configuration, the plurality of gate circuits are sequentially opened and closed under the control of the gate control means, and the time-divided video signals are inputted to the corresponding comparison means. This time-divided video signal corresponds to a video signal operated 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 comparing means. The comparison means compares the luminance signal of the video signal on the small screen with a reference value, and converts and outputs a two-dimensional luminance change on the small screen as a time-series pulse train. Therefore, if there is no brightness change on the small screen, the pulse disappears, and if there is a brightness change in a part of the small screen, the pulse still appears. It is determined whether the output pulse train from each comparison means disappears or not, and the direction of luminance change between each small screen is determined. That is, if output pulse trains from both comparison means exist, and in the next determination period, the output pulse train from one comparison means disappears and the output pulse train from the other comparison means exists, This is to declare the transition of brightness change from one corresponding small screen to the other corresponding small screen.

(Example of the present invention) Next, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a block diagram showing an embodiment of a moving direction detecting device according to the present invention.

Reference numerals la and lb are gate circuits to which the branched video signal from the input terminal 2 is input, and whose opening and closing are controlled by a gate control signal from the gate control circuit 3. The gate control circuit 3 alternately selects and closes the gate circuits 1a and 1b based on a synchronization signal included in the video signal, and is composed of a synchronization circuit 3a and a rectangular pulse generation circuit 3b. The synchronization circuit 3a separates the synchronization signal from the video signal.
The square pulse generating circuit 3b outputs a square pulse with a duty ratio of 50% based on the synchronizing signal. Furthermore, the frequency of the square pulse is 15,? It is 50Hz. 4a and 4b are comparison circuits that compare the luminance signals included in the video signals taken in from the gate circuits 1a and 1b, respectively, with a reference value. In this embodiment, the reference value is set as a predetermined fixed value to be described later. It is set. 5 is a judgment circuit;
It is for determining the state transition direction between the presence/absence state of output pulses from one comparison means 4a, 4b and the presence/absence state of output pulses from the other comparison means 4a, 4b,
As will be described later, when there is a transition from one to the other, a determination signal is output to the output terminal 6a.

If the transition is in the opposite direction, a determination signal is output to the output terminal 6b.

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 indicates a chime that is generated upon receiving a determination signal. 8 is
This is a television monitor that receives judgment signals and images a specific location. Reference numeral 9 denotes a speech synthesizer which obtains a judgment signal and produces a message.

Next, the effects of the above embodiment will be explained with reference to FIGS. 3 and 4.

Small screens 10a and 10 that divide the TV screen into left and right at the center
Considering b, the scanning line flows from left to right as shown in FIG. 3 and returns to the left at the retrace line (indicated by a broken line). by the way,
Since the square pulse from the square pulse generation circuit 3b consists of H level and L level at the same time, in this embodiment, the gate circuit 1a opens and the gate circuit 1b closes during the H level period, and the gate circuit 1b closes during the L level period. The gate circuit 1b opens and the gate circuit 1a closes. Therefore, gate circuit 1a
takes in only the upper video signal of the small screen 10a, and the gate circuit ib takes in 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 lOa is compared with a reference value, and the two-dimensional luminance change of the small screen 10a is converted and output as a time-series pulse train. Further, the comparison circuit 4b compares the luminance signal of the video signal on the small screen 10b with a reference value, and converts and outputs the two-dimensional luminance change of the small screen tOa as a time-series pulse train. In this embodiment, such reference values are set to the small screens 10a, 10.
This is fixedly set in advance to the background level of b. Therefore, if there is no change in brightness on the small screens 10a, 10b, ideally the pulse train disappears. In addition, if there is a change in brightness in a part of the small screen, the pulse train does not disappear and the pulse train still appears.
The determination circuit 5 determines whether or not the output pulse trains from the comparison circuits 4a and 4b disappear, and determines the direction of luminance change between the small screens 10a and 10b.For example, as shown in FIG. 4(A),
When the image of the moving object 11 is located within the small screen 10a, there is a pulse train from the comparison circuit 4a, and the pulse train from the comparison circuit 4b is present.
Although there is no pulse train from
When part of the image of the moving object 11 is projected onto the small screen 10b, the pulse train from the comparator circuit 4b also exists. When the image of the moving object 11 moves completely within the small screen +Ob, the pulse train from the comparison circuit 4b is present, but the pulse train from the comparison circuit 4a is present.
The pulse train from the 0 judgment circuit 5 almost disappears.
determines the transition direction of generation and extinction of such a pulse train,
When the image of the moving object 11 moves from inside the small screen 10a to inside the small screen 10b, a right direction determination signal is output to the output terminal 6a.On the contrary, when the image of the moving object 11 moves from inside the small screen 10b,
When moving into the small screen 10a, a left direction determination signal is output to the output terminal 6b. Based on these judgment signals, chime 7, TV monitor 8, voice synthesis 4I! 9 is activated, and the movement of the mobile object 11 is announced.

The video signal used for direction detection can be obtained by installing one video camera around the moving path of the moving object, so only one coaxial cable needs to be laid, making the installation work extremely simple. , the moving direction can be detected without arranging a large number of detection elements and without being influenced by the size, φ shape, etc. of the moving body.

In the above embodiment, the reference values of the comparison circuits 4a and 4b are fixed values to detect static luminance changes, but a temporary storage means 70 is provided and the previous luminance signal is temporarily stored in this. However, dynamic brightness changes can be detected by using the previous brightness signal as a reference value and comparing it with the current brightness signal. , regardless of the shading of the moving object, etc.
The direction of movement can be detected. Further, the television screen may be divided horizontally, and the number of divisions can be three or more.

(Effects of the Invention) As explained above, the moving direction detecting device according to the present invention sequentially searches for the generation and extinction of a pulse train obtained by comparing the luminance signal on each of the plurality of divided small screens with a reference value. The feature is that the direction of movement can be determined by doing this, so it has the following effects.

(1) Only one video camera needs to be installed around the route of the moving body, and there is no need to install a large number of detection elements with consideration to their relative positions.

(2) Since it is only necessary to install one coaxial cable from the video camera to this device, two cables need to be installed compared to conventional methods.
This makes it possible to significantly reduce costs.

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

(4) Due to the long lifespan and reliability of video cameras, maintenance and
Management is easier and costs can be reduced compared to conventional methods.

[Brief explanation 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 notification means connected to the output terminal of the same embodiment. FIG. 3 is a schematic diagram showing scanning lines on the left and right small screens that divide the television screen into two. FIGS. 4(A), (B), and (C) are schematic diagrams showing moving objects imaged on the left and right small screens. 1a, 1b...gate circuit, 2...input terminal, 3.
...Gate control circuit, 3a...Synchronization circuit, 3b...
Square pulse generation circuit, 4a, 4b...comparison circuit, 5.
... Judgment circuit, 6a, 6b... Output circuit, 7... Chime, 8... Television monitor, 9... Voice synthesizer, 10a, 10b... Small screen, 11... Mobile object Footage of.

Claims (1)

[Claims] A plurality of gate circuits into which branched video signals are respectively input, gate control means for sequentially selecting and controlling opening/closing of the plurality of gate circuits based on a synchronization signal included in the video signals, and the corresponding gates. A plurality of comparison means for comparing a luminance signal included in a video signal taken in from a circuit with a reference value, and a state of presence or absence of an output pulse from one comparison means and a state of presence or absence of an output pulse from the other comparison means. A moving direction detecting device comprising a determining means for determining a direction of state transition between.