JPH0589378A - Monitoring device - Google Patents

Abstract

PURPOSE:To stably operate monitoring in a monitoring device which monitors the occurrence of abnormality in a monitored object based on the video signal of a video camera having an automatic iris lens. CONSTITUTION:A brightness detecting means detects the brightness of a brightness detection area set on a display screen, opening and shutting in the diaphragm of the automatic iris lens is controlled and also the opening and shutting control of the diaphragm in the automatic iris lens is interrupted when abnormality occurs in the monitored object (step SP4-SP6-SP3-SP4) so that the quantity of image pickup light passing through the automatic iris lens can be unchanged and, then, a monitoring operation is stabilized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a monitoring device, and is particularly suitable for application to the case of monitoring the presence / absence of an object, the presence / absence of a defect, etc. using a video camera.

[0002]

2. Description of the Related Art As a monitoring device of this type, the presence or absence of an object or a defect is detected by determining a change in brightness of a specific area of a detection image picked up by a video camera as a monitoring area. There has been proposed a device for monitoring the presence or absence of light (Japanese Patent Laid-Open No. 60-39581).
When a surveillance device for security is to be realized by using a detection image obtained from, for example, a video camera installed outdoors using the surveillance device having such a configuration, the brightness of the surveillance target to be captured by the video camera is Since there is a large difference between inside and night, a stable determination operation cannot be performed only by the automatic adjustment operation of the automatic gain adjustment circuit normally provided in the image pickup signal processing circuit of the video camera, so the lens aperture is automatically adjusted. It is necessary to provide so-called auto iris means.

When the auto iris means is not used, the signal level of the image pickup signal becomes higher than the dynamic range of the image pickup signal processing circuit (saturated state) in the daytime, while the image pickup is performed at night. The result is that the signal level of the signal is below the dynamic range, and as a result, the imaging signal does not change based on that change even though there is an actual change in the imaging target, so the occurrence of an abnormality cannot be correctly determined. become. Also, when trying to monitor the presence or absence of abnormality on the mold surface of an injection molding machine using this type of monitoring device, when the mold is in an open state (that is, when the mold is opened) and the mold is closed. The brightness of the mold surface may be extremely different from that when the mold is in a closed state (that is, when the mold is closed). In such a case, the brightness of the mold surface exceeds the dynamic range of the image pickup signal processing circuit in the same manner as in the above case, so that the occurrence of abnormality cannot be correctly determined.

[0004]

As a means for solving such a problem, the conventional auto iris means supplies an image pickup signal to a low-pass filter to respond to a change in the brightness of the entire image picked up at its output end. An automatic iris control signal for controlling the aperture is controlled by the automatic iris control signal. However, when the auto iris unit having such a configuration is used, when an object that covers the entire detection image formed by the image pickup signal enters, the image pickup signal level is extremely changed and the aperture is automatically changed. Due to the extreme opening / closing operation, there is a possibility that it may be determined to be normal even though the occurrence of abnormality should be determined.

The present invention has been made in consideration of the above points, and it is an object of the present invention to propose a surveillance device capable of surely performing a determination operation even when a surveillance object that covers a video camera invades. To do.

[0006]

SUMMARY OF THE INVENTION In the present invention for solving the above-mentioned problems, a detection image of a video signal VD obtained from the video camera 2 when the imaging light of the monitoring target is incident on the video camera 2 through the auto iris lens 30. In a monitoring device that determines whether or not an abnormality has occurred in the monitored object based on the change that has occurred, a brightness detection unit that detects the brightness of the brightness detection region set at a predetermined position on the detected image, A diaphragm control means for opening and closing the diaphragm of the auto iris lens based on the detection output of the brightness detecting means, and an opening and closing control interruption means for interrupting the diaphragm opening and closing control of the diaphragm control means when an abnormality occurs in the monitored object are provided. To

[0007]

When an abnormality occurs in the monitored object, the diaphragm control of the automatic iris diaphragm control means is interrupted by the diaphragm opening / closing control interrupting means. Therefore, after the occurrence of an abnormality, the diaphragm of the auto iris lens holds the value at the time of the abnormality occurrence,
The brightness data of the monitoring area on the detected image is not changed by the auto iris operation, and the abnormality monitoring operation becomes stable accordingly.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the drawings.

(1) First Embodiment In FIG. 1, reference numeral 1 denotes a monitoring device as a whole, which receives a video signal VD generated by a video camera 2 in a video data input section 3 and a timing control section 4, and
The monitor unit 5 receives the monitor 7 via the superimposing circuit 6. The timing control unit 4 receives the sync signal SY (which is a horizontal sync signal and a vertical sync signal) included in the video signal VD in the sync separation circuit 11, and the clock signal CL that is synchronized with the horizontal sync signal and the vertical sync signal.
To the timing generation circuit 12.

The timing generation circuit 12 outputs a clock signal C
L is counted to form position data representing the current scan position for each line of the video signal VD, and this position data is given via the bus 14 under the control of the central processing unit (CPU) 13. TD
, The sampling pulse SMP having a pulse width corresponding to the width data of the timing control data TD is generated and supplied to the accumulator 15 of the video data input unit 3 to generate the analog / digital conversion circuit. The image pickup data DIM is fetched by the accumulator 15 through 16, and the marker position signal MKR can be supplied to the CPU 13.

In this embodiment, when the CPU 13 receives the marker position signal MKR, it supplies the display control data DD to the display control circuit 17 via the bus 14,
The display control circuit 17 of the monitor unit 5 supplies the display signal MD to the superimposing circuit 6. Thus, the CPU 13 causes the detected image DPIC formed based on the video signal VD to be displayed on the display screen 7 of the monitor 7.
In the state displayed on A (FIG. 2), the marker position signal M from the timing generation circuit 12 via the bus 14.
When KR is given, the marker MK is displayed on the display screen 7A together with the cursor K0 in a superimposed manner.

The marker MK displayed on the display screen 7A in this manner represents a monitoring area Aj on the detected image DPIC to be monitored which is formed by the video signal VD, and the CPU 13 has this monitoring area Aj. It is determined whether or not an abnormality has occurred in the monitoring target within the field of view of the video camera 2 based on the monitoring data DIN corresponding to. Thus, the accumulator 15 of the video data input unit 3 converts the digital data obtained from the video signal VD for one frame by the sampling pulse SMP supplied from the timing generation circuit 12 through the analog / digital conversion circuit 16 in a non-interlaced manner. An area on the display screen 7A where the marker display signal MKR is obtained (that is, the monitoring area Aj) out of the data of one frame captured by the accumulator 15 is taken in by the CPU 13 as the imaging data.
Monitoring data DIN of the working memory 2 of RAM configuration
It is designed to be included in 2.

The CPU 13 responds to the operation input of the operation input unit 24 by the video data input unit 3, the timing control unit 4, and the monitor unit 5 in accordance with the program data stored in the program memory 25 having the ROM structure. Control is performed using the registers provided in the working memory 22 as necessary. In the case of this embodiment, the working memory 22 is, as shown in FIG. 3, a cursor position register RG1, a monitor area preset register RG2, a video data register RG3, a luminance average value data register RG4, an abnormality rating data register RG5, and a normal / abnormal state. It has a data register RG6 and an auto iris control data register RG7.

The CPU 13 receives the monitoring data DIN acquired based on the position data of the monitoring area Aj preset in the monitoring area preset register RG2.
All pixels included in j are integrated and fetched into the video data register RG3 while being updated from moment to moment, and the deviation between the value of the video data register RG3 and the value of the luminance average value register RG4 is obtained, and the deviation is evaluated as abnormal. When the abnormality evaluation data of the data register RG5 is exceeded, abnormality determination data is formed and written in the normal / abnormal data register RG6.

When the abnormality determination data is written in the normal / abnormal data register RG6 in this way, the CPU 1
After that, 3 supplies the abnormality data SAB to the abnormality signal transmitting circuit 26 via the bus 14 to transmit an abnormality signal notifying the operator that an abnormality has occurred in the monitoring target. In addition to the above configuration, the monitoring device 1 is provided with an auto iris lens 30 in the video camera 2 and controls the aperture thereof by an auto iris control signal AIC sent from an auto iris control circuit 31.

As shown in FIG. 4, the auto-iris control circuit 31 receives the auto-iris drive data DAI supplied from the CPU 13 via the bus 14 in the digital / analog conversion circuit 32 and adds the auto-iris drive signal S1 which is an analog signal. By giving it to 33 as an addition input, the diaphragm adjustment signal S2 obtained from the diaphragm adjuster 35 of the potentiometer configuration is added, and the added output S
3 is supplied to the diaphragm driver 34 as a drive signal. Thus, the auto iris control circuit 31 can manually adjust the aperture of the auto iris lens 30 to the optimum aperture value according to the brightness of the object to be monitored by the operator operating the aperture adjuster 35.

In practice, this adjustment operation is performed by a key operation of the operation input section 24 by the operator so that the CPU 13 outputs a digital value 80 _H as the auto iris drive data DAI to the digital / analog conversion circuit 32 (FIG. 4) of the auto iris control circuit 31. (H represents hexadecimal notation) is supplied, and in this state, the operator adjusts the diaphragm of the auto iris lens 30 as necessary by adjusting the diaphragm adjuster 35. Thus, the light amount of the light currently entering the video camera 2 through the auto iris lens 30 is adjusted to an optimum value.

After making such adjustments, the CPU 13 set to the monitoring operation mode receives the monitoring data DIN from the accumulator 15 and then the monitoring area Aj (FIG. 2).
Integrated values of all the pixels included in (that is, the monitoring area Aj
Brightness of 80 _H or more, the diaphragm driver 34 (FIG. 2) drives the diaphragm of the auto iris lens 30 in the direction of diaphragming. On the other hand, if the brightness of the monitoring area Aj is 80 _H or less, the diaphragm driver 34 is operated by the auto iris lens 3
It drives in the direction of expanding the 0 diaphragm. As a result, CPU13
Can automatically control the aperture of the auto iris lens 30 so that the brightness of the monitoring area Aj is always 80 _H as the auto iris drive data DAI. By adjusting the aperture adjuster 35 with, the standard aperture value of the auto iris lens 30 can be adjusted to the optimum value suitable for the monitoring target.

In the above configuration, the monitoring device 1 executes the process of determining whether or not there is an abnormality in the image of the monitoring target incident on the video camera 2 through the auto iris lens 30 according to the monitoring processing procedure shown in FIG. That is, when the monitoring process is started in step SP0, first, in step SP1, the operator designates the monitoring mark setting mode in the operation input section 24, so that the cursor K0 displayed on the display screen 7A (FIG. 2) of the monitor 7 is displayed.
The monitoring area Aj is set by positioning the marker MK at a predetermined position on the image using.

Subsequently, in step SP2, when the operator uses the operation input section 24 to specify the aperture preset mode, the CPU 13 enters a state of supplying the auto iris drive data DAI having the value of the digital data 80 _H to the auto iris control circuit 31. .. At this time, the auto iris control circuit 31 (FIG. 4) obtains the addition output S3 obtained by adding the aperture adjustment signal S2 of the aperture adjuster 35 to the value corresponding to the numerical value 80 _H and supplies it to the aperture driver 34. By doing so, the aperture of the auto iris lens 30 is changed by adjusting the adjustment position of the aperture adjuster 35, and thus the amount of light of the optimum light amount with respect to the brightness of the monitoring target currently captured by the video camera 2 is obtained. Video camera 2
The auto iris lens 30 can be set in a state in which it can be taken into.

In this state, when the operator designates the monitoring mode via the operation input section 24, the CPU 13 executes the following monitoring processing operation. That is, the CPU 13
First, in step SP3, the monitor data DIN is fetched from the accumulator 15 of the video data input unit 3 into the video data register RG3 of the working memory 22 to form video data obtained by integrating the brightness data of each pixel in the monitor area Aj. To do. Subsequently, the CPU 13 sends the average brightness value data register RG in step SP4.
4 and the data of the abnormality rating data register RG5, it is determined whether or not there is an abnormality in the visual field of the video camera 2 by determining whether or not the brightness of the video data has changed.

If a normal result is obtained, the CPU 13 proceeds to step SP5 and performs aperture adjustment processing. At this time, the working memory 22 corresponds to the brightness of the portion of the monitoring area Aj (FIG. 2) in the image representing the scene in which no abnormality has occurred, based on the incident light that has entered the video camera 2 through the auto iris lens 30. Since the video data to be stored is stored in the video data register RG3 of the working memory 22, the value of the auto iris drive data DAI supplied to the auto iris control circuit 31 by the CPU 13 becomes a value corresponding to the brightness of the monitoring target in the normal state. , The relevant auto iris data DA
The value of I is the value of the auto iris drive data DAI at the time of diaphragm presetting in step SP2, that is, 80
If it is _H , the auto iris control circuit 31 maintains the diaphragm of the auto iris lens 30 as it is.

On the other hand, the auto iris driving data D
If the value of AI exceeds 80 _H , this means that the monitoring area Aj
Means that the brightness of the auto iris has become brighter than the brightness at the time of presetting, and at this time, the auto iris control circuit 31 operates in a direction of narrowing the diaphragm of the auto iris lens 30. On the other hand, the value of the auto iris drive data DAI is 80 _H.
If the following is true, this means that the brightness of the monitoring area Aj is darker than the value at the time of presetting, and at this time, the auto iris control circuit 31 causes the auto iris lens 30 to
Operate in the direction to expand the diaphragm.

Thus, the CPU 13 automatically executes the aperture adjustment operation so that the brightness of the monitoring area Aj is always equal to the aperture preset value. When the aperture adjustment process in step SP5 is completed, the CPU 13 returns to step SP3 described above to enter the new data from the accumulator 15 of the video data input unit 3 into the video data register RG3 of the working memory 22, and so on. Steps SP3-SP4-SP5-SP3 are executed.

Similarly, the CPU 13 causes the step S to proceed.
While the result of the determination that no abnormality has occurred in the abnormality determination operation in P4, the monitoring area A is monitored at a predetermined cycle.
Based on the brightness of j, the automatic diaphragm adjustment operation is repeated so that the brightness becomes the brightness at the time of diaphragm presetting. On the other hand, if the CPU 13 obtains the determination result that the abnormality has occurred in the step SP4 during the automatic aperture adjustment operation, the CPU 13 proceeds to the step SP6 and gives the abnormality signal SAB to the abnormality signal sending circuit 26. Causes an abnormality signal to be sent, thereby notifying the operator that an abnormality has occurred in the monitoring target.

At this time, the CPU 13 starts a new judgment operation by shifting from step SP6 to step SP3 described above, and thus the aperture adjustment in step SP5 is not performed, and thus the auto iris lens 30 is set.
Therefore, it is possible to determine the aperture based on the brightness of the monitoring target in a state where no abnormality has always occurred.
Therefore, when an object that covers the video camera 2, for example, comes in as a monitoring target, the CPU 13 determines that an abnormality has occurred in step SP4,
In this case, the processing for adjusting the aperture of the auto iris lens 30 via the auto iris control circuit 31 is not performed.

Accordingly, at this time, the auto iris lens 30
Since the brightness of the monitoring target image light incident on the video camera 2 through the video camera 2 is not changed, the signal level of the video signal VD that is subsequently taken into the accumulator 15 of the video data input unit 3 is controlled by the automatic diaphragm control while the abnormality occurs. The change will follow the change of the monitoring target without being affected. Therefore, when an abnormality occurs in the monitoring target C
Since the data taken into the working memory 22 by the PU 13 remains in the condition at the time of occurrence of the abnormality, the abnormal state can be surely dealt with, and thus the monitoring device 1 can be stably operated for monitoring.

(2) Second Embodiment FIG. 6 shows a second embodiment of the present invention. In the case of FIG. 4, the same parts as those in FIGS. Has provided the diaphragm adjuster 35 in the auto iris control circuit 31, but in the case of FIG. 6, instead of this, the diaphragm adjuster 35 is omitted from the auto iris control circuit 31 and its function is
Let PU13 execute it. In this case CPU13
When the monitoring process of FIG. 5 is executed, the CPU 13 inputs the aperture adjustment signal for the aperture preset process of step SP2 based on the input operation of the operation input unit 24.

That is, when the operator inputs the aperture adjustment value by operating the operation input unit 24 in step SP2, the CPU 13 stores it in the working memory 2.
Auto iris control data register RG provided in 2
After being loaded into 7, the data is added to the adjustment monitoring data (having a digital value of 80 _H ), and the addition result is supplied to the digital / analog conversion circuit 32 of the auto iris control circuit as the auto iris drive data DAI.

At this time, since the auto iris lens 30 of the video camera 2 opens to the aperture value corresponding to the auto iris control signal AIC, the aperture of the auto iris lens 30 is eventually the value of the auto iris control data supplied from the CPU 13 and the operation input section 24. The value corresponds to the sum of the value of the aperture adjustment signal input by the operator. According to the configuration of FIG. 6, compared with the configuration of the auto iris control circuit 31 of FIG. 4, the aperture adjuster 35 is omitted, so that the overall configuration can be further simplified.

(3) Other Embodiments (3-1) In the above-mentioned embodiment, each pixel data included in the monitoring area Aj (FIG. 2) is used as the auto iris drive data DAI supplied from the CPU 13 to the auto iris control circuit 31. Although the value obtained by integrating is directly used, a value obtained by calculation based on the brightness data used in the plurality of abnormality determination cycles in the past, for example, an average value may be used instead. In this way, if the average value of the brightness data of a plurality of times in the past is used, it is inevitable that the brightness data that can be obtained from the monitoring area Aj for each abnormality determination cycle actually varies. By using the average value, the diaphragm of the auto iris lens 30 can be stably controlled.

(3-2) In the above embodiment, when the brightness data of the monitoring area Aj or the sum of the brightness data of the monitoring area Aj and the aperture adjustment data is used as the auto iris driving data DAI However, instead of this, a value (brightness data of the monitoring area Aj ± Δ) corrected by a predetermined correction value ± Δ may be used for the brightness data of the monitoring area Aj.

(3-3) In the above embodiment, the brightness information obtained from the monitoring area Aj for determining whether the monitoring target is normal is used to obtain the auto iris driving data DAI. Instead of this, a brightness detection area for automatic diaphragm adjustment is provided on the display screen 7A separately from the monitoring area Aj, and the auto iris drive data DAI is used by using the brightness data obtained from the brightness detection area for automatic diaphragm adjustment. Even if the above is created, the same effect as the above case can be obtained.

(3-4) In the above embodiment, as described above with reference to FIG. 2, the brightness data of the display screen 7A is created from one brightness detection area (one monitoring area Aj in FIG. 2). However, the number of brightness detection areas is not limited to one, and a plurality of brightness detection areas may be provided. When the auto iris drive data DAI is obtained based on the brightness data obtained from the plurality of brightness detection areas in this way,
The following method may be adopted.

First, of the brightness data created from a plurality of brightness detection areas, the brightness data having the largest value may be used as the auto iris drive data DAI. In this case, in particular, an abnormality determination condition is displayed. Screen 7
It is useful when the particularly bright part of A has an important meaning.

Secondly, the brightness data having the smallest value among the brightness data created from a plurality of brightness detection areas may be used as the auto iris drive data DAI. This method uses the display screen 7 as an abnormality monitoring condition.
It is suitable for use when a particularly dark portion of A has an important meaning.

Thirdly, the average value of the brightness data created from a plurality of brightness detection areas is used as the auto iris drive data DAI. This method is suitable for application to the case where the auto iris lens 30 is controlled to the aperture value corresponding to the average brightness of the display screen 7A because the average value of the change occurring on the display screen 7A can be taken. ..

(3-5) In the above embodiment, the integrated value of the pixel data included in the brightness detection area (monitoring area Aj in FIG. 2) is used as the brightness data of the brightness detection area. However, the same effect as in the above case can be obtained even if a predetermined weight is added to each pixel as necessary when performing the integration.

(3-6) In the above embodiment, the DC voltage varying in the range of DC voltage 0 to +1 [V] is used as the auto iris control signal AIC output from the diaphragm driver 34 (FIGS. 4 and 6). The case of continuous transmission is described, but instead of continuous transmission, an aperture control pulse is generated at a timing superimposed on the synchronization signal of the video signal VD transmitted from the video camera 2, and Even if the peak value of the aperture control pulse is used as the aperture control information, the same effect as the above case can be obtained. When the pulse signal is used as the aperture control information in this way, pulse width modulation may be performed instead of using the pulse crest value as the aperture control information.

[0040]

As described above, according to the present invention, when the aperture of the auto iris lens mounted on the video camera is controlled, the aperture control is interrupted when an abnormality occurs in the monitored object. The aperture of the auto iris lens can be controlled more stably.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of a monitoring device according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a display mode on a display screen 7A.

FIG. 3 is a schematic diagram showing a configuration of a working memory 22 of FIG.

4 is a block diagram showing a detailed configuration of an auto iris control circuit 31 of FIG.

5 is a flow chart showing the monitoring processing procedure of FIG. 1. FIG.

FIG. 6 is a block diagram showing another embodiment of the auto iris control circuit.

[Explanation of symbols]

1 ... Monitoring device, 2 ... Video camera, 3 ... Video data input section, 4 ... Timing control section, 5 ... Monitor section, 13 ... CPU, 22 ... Working memory, 24
...... Operation input section, 26 ...... Abnormal signal transmission circuit, 31 ......
Auto iris control circuit.

Claims (1)

[Claims] 1. An imaging light for a subject to be monitored is incident on a video camera through an auto iris lens, and whether or not an abnormality has occurred in the subject to be monitored based on a change in a detected image of a video signal obtained from the video camera. In the determination monitoring device, the brightness detection means for detecting the brightness of the brightness detection area set at a predetermined position on the detected image, and the aperture of the auto iris lens based on the detection output of the brightness detection means. A monitoring device comprising: an aperture control means for controlling opening and closing; and an aperture opening and closing control interruption means for interrupting the aperture opening and closing control of the aperture control means when an abnormality occurs in the monitored object.