JPH0365075B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a solid-state imaging device (Charge Coupled
The purpose of this paper is to automatically and highly accurately monitor the occurrence of abnormalities such as fires and intruders in buildings using a new abnormality monitoring method using a camera (hereinafter simply referred to as a CCD camera).

(Prior Art) Several systems have been proposed, and some have been put into practice, for monitoring intruders in buildings by processing images from television cameras and detecting moving parts.

However, the development of systems capable of monitoring not only intruders but also fires in buildings has been delayed, and only recently has an invention regarding an abnormality monitoring device been disclosed in Japanese Patent Application Laid-Open No. 61-94665.

This includes a television camera that photographs the monitoring area, a video change identification unit that identifies areas where brightness or hue has changed from the video signal from the television camera, and a radiation temperature detector that measures the temperature of the monitoring area. a fire determination processing section that processes the output of the radiation temperature detector to determine a fire; an intruder determination processing section that determines an intruder; an output of the image change recognition section; a fire determination processing output; and an intruder determination processing section output. and a display section that displays the type and location of the abnormality.

(Problems to be Solved by the Invention) However, in the conventional monitoring device described above, the coordinates of the changing part in the image taken by the television camera and the coordinates of the temperature change taken by the radiation temperature detector are not necessarily the same part. Confirmation was difficult and there were many problems such as misidentification or false alarms regarding intrusions and fires.

In addition, conventional monitoring devices generally often malfunction even when the monitoring area is exposed to the morning sun or the evening setting sun, and there is a need for fundamental improvements in this respect as well.

(Means for Solving the Problems) The present invention was devised after various studies in order to solve the various problems in the conventional devices described above. The coordinates of the changing part and the temperature change of the changing part are centrally determined through the same image sensor,
Moreover, it is completely unaffected by the morning sun and setting sun (westerly sun) within the monitoring area, making it possible to monitor intruders and fires with high precision. It consists of a CCD camera that captures images, a plurality of image memories that memorize the imaging information of the camera, and a control unit that determines abnormalities by processing the plurality of images captured and stored by the CCD camera. An infrared cut filter that sometimes allows only light of a certain wavelength or less to pass through, and an infrared cut filter that allows only light of a certain wavelength or more to pass when there is a luminance change or image difference between multiple images passing through the filter over time, or The present invention relates to an abnormality monitoring system using a CCD camera, which is equipped with a switchable filter that cuts only the light in the band.

(Example) The specific content of the present invention will be explained below based on the illustrated example. In the figure, 1 is a CCD
A camera, 8 an analog/digital converter (hereinafter referred to as A/D converter), 9 an image memory unit, 10
indicates the control section.

The CCD camera 1 uses a known solid-state image element (Charge
Coupled Device).
A disk 3 rotated by a motor 4 is attached to the front side of the CCD camera, and an infrared cut filter 5 and an infrared pass filter 5 are mounted on this disk 3 at positions corresponding to the lens 2 of the CCD camera 1. Furthermore, the sensor 7 constantly confirms the positions of the infrared cut filter 5 and the infrared passing filter 6, which instructs the rotation direction and stop position of the disc 3 as necessary. Therefore, the disc 3 can be rotated arbitrarily.

The filter of the disc 3 normally passes light with a wavelength of 0.75 μm or less, and an infrared cut filter 5 is placed in front of the lens 2 to block light with a wavelength longer than that.

The pattern inside the monitoring section is imaged by a CCD camera,
The images are A/D converted by an A/D converter 8 at regular time intervals and then sequentially stored in an image memory 9.

On the other hand, the control unit 10 extracts the difference between the two images stored in the image memory unit 9 at regular time intervals, and if there is a valid difference, it is recognized as a moving object (intruder) and an alarm is issued. is output to the output terminal 13, the video switch 11 is closed, and the image is displayed on the monitor television 12.

Furthermore, when the above-mentioned effective difference signal contains a high brightness component of a predetermined level or higher, the motor 4 is driven to rotate the disk 3, and light of a specific wavelength of, for example, about 0.9 to 1.5 μm is generated. An infrared passing filter is placed in front of the lens 2 to allow the light to pass therethrough or to cut out only light in a specific wavelength band.

The CCD element of a CCD camera has enough sensitivity to react even at a wavelength of 1.2 μm, and the temperature of the combustion flame is in the range of about 800℃ to 1300℃, which is lower than natural light sources or artificial light sources, and it is not radiated. Infrared rays are also distributed in the long wavelength range.

Therefore, the above-mentioned infrared passing filter reduces the level reduction ratio of the combustion flame image compared to natural light or artificial light.As a result of calculating the level ratio of the above-mentioned high-brightness part, this value is above a certain value. Only in this case, it is possible to determine that the high-luminance part is a flame.

In addition, natural light and artificial light are used at short intervals (for example, 5 seconds), and each time is even shorter (for example, 0.5 seconds).
When comparing the integral images, there are few differences between the images, so the selection can be easily made using this as well.

In this case, an integrating circuit is inserted between the A/D conversion section 8 and the image memory section 9 to integrate the image signal.

(Function) The function of the abnormality monitoring system, which is based on the above-mentioned implementation structure and further includes a two-axis rotary table controlled by the control unit 10, will be explained in detail according to the flowchart in FIG. Then, after the start, the aperture of the lens 2 is determined so that the brightness level at the center of the image becomes a preset value at a predetermined coordinate position.

In this case, if the brightness is insufficient, turn off the lighting.
Turn it on and set the aperture value again.

Next, the primary input image and the secondary input image stored in the image memory section 9 are taken in at regular time intervals, and the brightness of each is converted into a histogram and compared. Abnormality processing is performed when there is a change exceeding a certain error value.

In this abnormality processing, the control unit 10 first determines whether the brightness is high or not, and if the brightness is high, it switches to the infrared passing filter and
The tertiary input image is loaded into the image memory section 9, and its histogram is compared with that of the secondary input image. If the level ratio of the high-luminance component is above a certain value, this part is determined to be a flame. Decide.

In addition, if the brightness is not high, it is determined whether the brightness distribution is uniform or not, and if it is uniform, smoke confirmation processing is performed, and if it is not uniform, the brightness distribution is Performs reflected light processing.

Furthermore, if no change is observed as a result of the comparison of the histograms between the primary input image and the secondary input image, perform the inter-image calculation between the primary input image and the secondary input image. Detect the presence or absence of a difference.

If there is no difference between the two images, the process returns to the start, and if there is a difference, it is further determined whether or not the difference is of high brightness.

If the brightness is high, the flame confirmation process described above is performed after switching to the infrared passing filter.

Based on the various determination results in the various control units 10 described above, the image signal when it is determined to be abnormal after code conversion is transmitted to the monitor television 1 of the monitoring center by operating the video switch 11.
2, and if an object moves (intrudes), it issues an intrusion alarm and automatically tracks the moving object until it is reset.

If there is a fire (flame), a fire alarm is issued until it is reset, and the flame is automatically positioned at the center of the screen.

This is very useful when constructing an automatic or remote extinguishing system, mechanically or electrically integrating the camera and the extinguishing nozzle to ensure accuracy in identifying and extinguishing fires.

Furthermore, if it is smoke, the smoke alarm continues to be emitted until it is reset, and the image check continues at that location.

(Effect of the invention) The present invention images the monitoring unit as described above.
In addition to having a CCD camera, a plurality of image memories that store image information of the camera, and a control unit that determines various abnormalities by processing the plurality of images captured and stored by the CCD camera, the CCD camera described above has a An infrared cut filter that allows only light of a certain wavelength or less to pass during normal monitoring, and an infrared cut filter that allows only light of a certain wavelength or more to pass when a high brightness change or image difference occurs between a plurality of temporal images that have passed through the filter. Alternatively, it is equipped with a switchable filter that cuts only light in a specific wavelength band, so changes in the brightness distribution of the TV camera and height differences between images sampled at regular intervals can be detected. The brightness portion can be reconfirmed using an infrared passing filter.

In other words, in the inter-image difference portion between multiple images passed through an infrared cut filter over time, is there a change in the brightness histogram, especially in the high brightness region?
Or, the brightness of the part that caused the difference due to the calculation between images is above a certain value, or in either case, further
By changing the filter of the CCD camera to an infrared passing filter, we can check for changes in the high brightness area, and if there is a change, we can detect various abnormalities such as an intruder, smoke generation, fire outbreak, etc. Because it uses the same lens on a CCD camera by simply replacing the filter, it is much more accurate than conventional devices of this type, and there is almost no risk of false alarms.

Furthermore, if a reflective optical system is used in the optical system, loss in the infrared region can be reduced and a highly accurate system can be constructed.

Furthermore, it is possible to take countermeasures by checking images depending on the situation, making it possible to configure a simple and highly reliable system.In addition, by combining this system with infrared sensors, gas sensors, smoke sensors, etc. A highly accurate and highly reliable abnormality monitoring system can be constructed.

[Brief explanation of drawings]

Fig. 1 is a block diagram of an abnormality monitoring system that is an embodiment of the present invention, Fig. 2 is a schematic perspective view showing an example of a CCD camera used in the present invention, and Fig. 3 is an example of the configuration of the present invention. This is a flowchart showing the following. 1... CCD camera, 2... Lens, 3... Disc, 4... Motor, 5... Infrared cut filter, 6... Infrared passing filter, 7... Sensor,
8... A/D conversion section, 9... Image memory section, 10
...Control unit, 11...Video switch, 12...
monitor.

Claims (1)

[Claims] 1. Consisting of a CCD camera that images the monitoring unit, a plurality of image memories that memorize the imaging information of the camera, and a control unit that determines an abnormality by processing the images taken by the CCD camera and the plurality of images stored in the memory, The camera is equipped with an infrared cut filter that allows only light of a certain wavelength or less to pass under normal conditions, and an infrared cut filter that allows only light of a certain wavelength or more to pass when there is a change in brightness or a difference between images between multiple images that have passed through the filter over time. An abnormality monitoring method using a CCD camera, which is equipped with a switchable filter that cuts out only light in a specific wavelength band.