JPH07294431A - Water quality sensor by image processing - Google Patents

Abstract

PURPOSE:To speedily detect the deterioration of water quality, and utilize safe water by providing a water quality sensor by which water quality in a water storage tank is simply inspected. CONSTITUTION:A water quality sensor is composed of a water storage tank 1, a discriminating tool 5 which is arranged under the water surface of this water storage tank and in which an image is drawn on a surface, a camera 6 arranged in a position to photograph an image of this discriminating tool so as to obtain an image signal of the image, a recording means to record image data corresponding to the image of the discriminating tool, an image processing means which converts the image signal of the camera into image data and compares this image data with image data of the recording means and outputs the result and a measuring means to measure water quality of the water storage tank from output of this image processing means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses image processing for water stored in a water tank installed in a building or the like.
The present invention relates to a water quality sensor that measures water quality such as transparency or the degree of turbidity.

[0002]

2. Description of the Related Art Conventionally, there has been no management of water tanks in buildings, condominiums, single-family houses, etc.
Or relied on regular human inspections.

[0003]

According to the conventional management method as described above, even if small animals or the like enter the water tank and the water quality is polluted, the polluted water is used until the inspection work is performed. There was something to continue. An object of the present invention is to provide a water quality sensor capable of easily inspecting the water quality of a water storage tank, and thus to quickly detect deterioration of water quality and use safe water. It is what

[0004]

In order to achieve the above object, the present invention provides a water tank, an identification tool which is arranged below the water surface of the water tank and has an image drawn on the surface, and an image of the identification tool is photographed. A camera for obtaining the image signal of the image, a recording means for recording the image data of the image corresponding to the image of the identification tool, the image signal of the camera is converted into image data, and the image data and the A water quality sensor is constituted by image processing means for comparing the image data of the recording means and outputting the result, and measuring means for measuring the water quality of the water storage tank from the output of the image processing means.

[0005]

For example, an image drawn on the surface of the identification tool is photographed by the camera at a certain time every day. The image processing means converts the image signal obtained by the camera into image data,
This image data is compared with the image data recorded in the recording means, and the degree of coincidence between both images is output. The measuring means obtains a measured value of the degree of transparency or turbidity of the water in the water tank from the degree of coincidence between the two images. Further, the measuring means records the measured value, or when the measured value shows an abnormality in comparison with a predetermined reference value, an alarm is issued to the manager of the building or the water user of the water tank. You can also

Since the water quality inspection by the water quality sensor described above can be easily performed, the water quality inspection of the water storage tank can be performed frequently, for example, once a day. Therefore, when an abnormality occurs in the water in the water storage tank, the abnormality can be detected promptly, and safe water can be supplied to the user.

[0007]

Embodiments of the present invention will be described with reference to the drawings. Figure 1
FIG. 3 is an overall configuration diagram of a water quality sensor. The water quality sensor is composed of a photographing unit 2 arranged around the water storage tank 1 and a measuring unit 4 arranged in another place, for example, a management room 3 of the building.

The photographing section 2 comprises an identification mat 5, an ITV camera 6, and a lighting fixture 7. Below the water surface of the water tank 1, an identification mat 5 is arranged as an identification tool. An image such as a colored pattern or picture is drawn on the surface of the identification mat 5. The identification mat 5 is attached with a weight 8 to reduce the buoyancy, and is fixed in the water tank 1 by a string 9.

An ITV camera 6 and a lighting fixture 7 are attached to a frame 11 and arranged outside the water tank 1. IT
The V camera 6 is arranged at a position where an image drawn on the identification mat 5 is photographed, and the lighting fixture 7 is arranged at a position where the image portion is illuminated. The ITV camera 6 and the lighting fixture 7 may be fixedly arranged at a specific position as described above, or may be movable so that they can be moved to a photographing position at the time of water quality inspection. it can. Furthermore, IT
The V camera 6 and the lighting fixture 7 can also be arranged inside the water tank 2.

Further, the identification mat 5 may be always fixed below the water surface of the water tank 1, or may be arranged below the water surface only at the time of photographing. This identification mat 5
The distance between the water surface and the water surface is preferably constant in order to improve the measurement accuracy. Normally, the water surface in the water tank 1 is kept constant, so that the identification mat 5 is used for the water tank 1.
Can be fixed against. However, in order to obtain a more accurate measurement result, the identification mat 5 is not fixed to the water tank 1, but a means for separately maintaining the distance between the identification mat 5 and the water surface is separately provided. Is also good.

The image signal of the ITV camera 6 is sent to the measuring section 4. Details of the measuring unit 4 are shown in FIG. ITV camera 6
The image captured by the A / D conversion unit 2 of the image processing means 21.
Entered in 2. In the image processing means 21, the color extraction circuit 23, the noise removal circuit 24, the projection calculation circuit 25, and the data processing unit 26 are connected to the subsequent stage of the A / D conversion unit 22.

The data processing unit 26 includes a database 31,
The measuring means 32 is connected. The database 31 stores image data that serves as a criterion for water quality. The image data of this determination standard is the same image as the image of the identification mat 5 converted into image data. The measuring means 32 includes
A monitor device 33 and a printer 35 are connected, and a VTR 34 is connected to the monitor device 33. Further measuring means 32
Outputs an alarm to another organization such as a management room (not shown).

Next, the operation of the water quality sensor configured as described above will be described with reference to the flowchart of FIG. (Step S1) The water quality is measured at an appropriate preset cycle. If the setting is made to perform the measurement once a day at midnight, the water quality sensor waits until the measurement time comes, and when the midnight measurement time comes, the process proceeds to step S2.

(Step S2) Preparation for photographing is performed.
In the above example, the lid of the water tank 1 is opened, and the lighting fixture 7 is turned on for the image of the identification mat 5. If the identification mat 5 is not fixed to the water tank 1,
The identification mat 5 is arranged so as to be located at a certain place from the water surface. Further, when the ITV camera 6 or the like is movably installed, the ITV camera 6 or the like is moved to the photographing position.

(Step S3) When the preparation for photographing is completed, the ITV camera 6 photographs the image of the identification mat 5 and outputs the image signal to the measuring section 4. (Step S4) After photographing, restoration work such as closing the lid of the water storage tank 1 is performed. The preparation work and the recovery work in steps S1 and S4 may be partially or entirely automatically performed, or may be manually performed.

(Step S5) In the measuring section 4, the sent image signal is converted into an A / D conversion section 2 of the image processing means 21.
2. Image data is obtained by passing through the color extraction circuit 23, the noise removal circuit 24, and the projection calculation circuit 25. The data processing unit 26 compares the image data obtained from the ITV camera 6 with the image data of the determination standard stored in the database 31. Although any method can be adopted as this comparison method, for example, by comparing both data for each pixel,
The number of matching pixels and the number of non-matching pixels are counted. At this time,
When the transparency of water is high, the number of matching pixels is large and the number of non-matching pixels is small. Conversely, if water pollution progresses, ITV
The image captured by the camera 6 differs from the image of the identification mat 5, and the number of mismatched pixels increases. The comparison result is output to the measuring means 32.

The measuring means 32 measures the water quality based on the output from the data processing section 26. As a method of this measurement, any method can be adopted. For example, 10
When 0% of the pixels match, the stain degree is 0%, and when 100% of the pixels do not match, the stain degree is 100%, and the ratio of the number of matching pixels to the number of non-matching pixels can be directly used as the measurement data. As another method, the above ratio can be converted into measurement data by using an appropriate conversion formula or table.

(Step S6) Further, the measuring means 32
Compares the obtained measurement data with a preset reference value to determine whether or not the measurement data is abnormal. If the measurement data is abnormal, the process proceeds to step S7, and if there is no abnormality, the process proceeds to step S8. The reference value can be obtained by experiments or the like, or can be set according to the customer's request.

(Step S7) If there is no abnormality in the measurement data, the measurement data is output and the process is terminated. As shown in FIG. 2, the measurement data is displayed on the monitor device 33 and is printed out by the printer 35. Further, the display of the monitor device 33 is recorded in the VTR 34. (Step S8) When there is an abnormality in the measurement data, the measuring means 32 issues an alarm and ends the process. This alarm can be issued not only to the administrator but also to the user at the same time to immediately stop the use of the contaminated water. Further, the abnormal data may be displayed and recorded by proceeding to step S7 described above after the alarm.

[0020]

According to the present invention, the water quality of the water storage tank can be easily inspected. Therefore, by using the water quality sensor of the present invention, it is possible to quickly detect a decrease in water quality and use safe water.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an embodiment of a water quality sensor of the present invention.

FIG. 2 is a diagram showing details of a measurement unit in FIG.

3 is a flowchart for explaining the operation of the water quality sensor of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Water tank 2 ... Imaging part 3 ... Management room 4 ... Measuring part 5 ... Identification mat 6 ... ITV camera 7 ... Lighting device 21 ... Image processing means 22 ... A / D conversion part 23 ... Color extraction circuit 24 ... Noise removal Circuit 25 ... Projection calculation circuit 31 ... Database 32 ... Measuring means 33 ... Monitor device 34 ... VTR 35 ... Printer

Claims (1)

[Claims] 1. A water tank, an identification tool arranged below the water surface of the water tank and having an image drawn on the surface thereof, a camera arranged at a position for photographing an image of the identification tool, and obtaining an image signal of the image, Recording means for recording image data of an image corresponding to the image of the identification tool, converting the image signal of the camera into image data, comparing the image data with the image data of the recording means, and outputting the result. A water quality sensor for image processing, comprising: an image processing means; and a measuring means for measuring the water quality of the water storage tank from the output of the image processing means.