JPH0443229B2 - - Google Patents

Description

Detailed Description of the Invention [Field of Application of the Invention] The present invention relates to a monitoring device for suspended solids in water, which uses image recognition technology to recognize the formation of suspended solids such as flocs in a water treatment plant, for example. Regarding.

[Background of the invention]

The quality of the formation of substances suspended in water, such as flocs, in water treatment plants is extremely important for water treatment, and has a direct and large impact on subsequent treatment processes. If good floc formation is not carried out, the flocs will not settle in the sedimentation tank and the load on the filter will increase. Furthermore, if the recognition of floc sedimentation is delayed, micro flocs may flow out of the filter basin. Therefore, in order to improve the reliability of water quality management at water treatment plants, it is necessary to quantitatively understand the floc formation status.

An example of the current flow monitoring will be explained with reference to FIGS. 1 to 3. In FIG. 1, a floc formation pond 1 is provided with a paddle 2 for stirring the floc, and the floc 3 is stirred. This flock 3 is visually observed. Monitors are experts, but it is difficult to quantitatively understand the situation visually.

FIG. 2 shows an example in which a monitoring TV camera 4 is installed directly above the floc formation pond 1, and this camera 4 directly images the flocs. The video signal from the camera 4 is taken into the CRT 6 via the controller 5 and displayed. A supervisor visually monitors the display screen of the CRT 6 and judges the floc formation status.

This example is different from the example shown in FIG. 1 in that the flock is imaged by a TV camera 4, but the final judgment is still made by visual inspection.

FIG. 3 shows an example in which the floc formation status is continuously grasped. This embodiment is characterized by the provision of an image recognition device 11 consisting of a computer or the like. The image recognition device 11 takes in a flock image from the TV camera 4 and automatically grasps the flock formation status through image processing. Image processing refers to processing for making two plants, processing for calculating the area of the flock body, and the like. The floc formation status can be determined by the size of the area.

Although this is an improvement over Figures 1 and 2 in terms of automatic recognition, it has the following problems.

In order to accurately and stably recognize images using the image recognition device 11, the key is how to capture image information from the TV camera 4 under certain conditions. This will be explained with reference to FIGS. 4 and 5.

FIGS. 4 and 5 show that the spherical object 12 is irradiated with light,
This is an example in which image information is captured by an industrial TV camera 15. FIG. 4 is a diagram illustrating the influence of a difference in light, and FIG. 5 is a diagram illustrating the influence of a difference in the irradiation position of light on the capture of image information.

FIG. 4 shows a case where a spherical object 12 (which can be thought of as a flock) is irradiated with strong light 13 and weak light 14 from the same direction, and image information is captured from the same direction by an industrial television camera 15. . At this time, the luminance information, which is the image information captured by the industrial television camera 15, is indicated by reference numeral 16 in FIG.
become that way. That is, when the light is strong, the white level 17 occupies a larger proportion of the luminance information.
The information obtained when this luminance information 16 is subjected to binarization processing using the threshold value 18 is binarized information 20. In other words,
Even if the objects have the same shape, the binary information 20 will be different from A and B in Fig. 4 due to the difference in the intensity of light.
It can be seen that there is a difference as shown in the figure.

FIG. 5 shows a case where the spherical object 12 is irradiated with lights 21 and 22 of the same intensity from different positions, and image information is captured from the same direction by an industrial television camera 15. At this time, the luminance information, which is the image information captured by the industrial television camera 15, becomes as shown in 23 in FIG. That is, when light is irradiated from the same direction as the industrial television camera 15, the proportion of the white level 17 in the luminance information becomes larger. Binarized information 24 is information obtained by binarizing this luminance information 23 using the threshold value 18 . In other words, even if the object has the same shape, if the position of the object irradiated with light is different, the binary information 24 will be different from the 5th one.
It can be seen that there are differences as shown in A and B in the figure.

As explained above using FIGS. 4 and 5,
When image processing technology is used, the way in which light is applied to an object to be recognized (light amount, direction of irradiation, etc.) becomes a major issue.

Generally, treatment facilities in water treatment plants are constructed outdoors due to restrictions due to their size.
Therefore, the amount of light incident on the floc formation pond is
As time passes, there are differences between day and night, and even at the same time there are infinite differences due to changes due to the celestial position, changes in the intensity of light due to the change of seasons, etc. Also, as time passes, the angle of incidence of light changes from moment to moment. do.

[Purpose of the invention]

An object of the present invention is to provide a monitoring device that makes it possible to stably and accurately obtain the formation status of suspended substances in water such as flocs.

[Summary of the invention]

An object of the present invention is to provide an imaging means installed under the surface of water containing suspended solids, which images the state of the suspended solids and converts the image information into an electrical signal; and a means for image processing the electric signal and converting it into binary information, and the imaging means is installed above the water flow. This is achieved by a monitoring device for suspended solids in water, which is characterized by:

The present invention is based on the discovery that flocs can be monitored stably and accurately by placing a TV camera under the water and unaffected by agitation.

[Embodiment of the invention] FIG. 6 shows an embodiment of the invention. In the floc formation pond 1, a paddle 2 for stirring the floc was installed. The photographing device 50 is equipped with a floodlight 7 and a TV camera 4 inside. The outside of the photographing device 50 has a box shape with a light shielding member 25, and the surface that comes into contact with the water surface of the floc formation pond 1 has a glass plate 26.

The photographing device 50 is located between the paddles. By providing the photographing device at this position, it is possible to apply a horizontal water flow close to the imaging section. This makes it possible to prevent the binarized information from being affected by the stirring action of the paddle.

The light blocking member 25 has a role of blocking external light.
The irradiated light from the projector 7 is made to enter the floc formation pond through the glass plate 26. Furthermore, the reflected light from the inside of the flock formation pond provided with the projector 7 is imaged by the TV camera 4 via the glass plate 26. The reflected light is mainly from the flock body 3.

Furthermore, the photographing device 50 includes a protrusion 2 for blocking external light.
Has 5A. It is preferable that the photographing device 50 is equipped with a float to prevent it from being submerged in water due to its overall weight, or is constructed from a lightweight member. The glass plate 26 and the light shielding member 25 are in close contact with each other, so that water from the floc formation pond does not enter into the interior through the glass plate 26.

The image recognition device 11 specifies the amount of light irradiated by the light projector 7 via the controller 8 . Further, the image recognition device 11 receives image information from the TV camera 4 via the controller 5 and performs image recognition.

The operation will be explained below.

Let it be the light projection area 27 of the light projector 7. This light projection area is also the imaging field of view of the TV camera 4. External light, especially natural light, does not enter the light projection area 27 .
This is because the light is blocked by the protrusion 25A.

A certain amount of light from the projector 7 enters the floc formation pond 1 through the glass plate 26. The incident light enters the formation pond, hits the flocs, if any, and is reflected. This reflected light is captured by the TV camera 4.
takes an image, and the image recognition device 11 captures it.

The image recognition device 11 uses two images obtained from the captured image.
Based on the digitized image information, the number of flocs and the area of flocs are calculated to recognize the floc formation status.

According to this embodiment, within the imaging field of view, the projector 7
Only the reflected light from the irradiation light is present. Therefore, the reflected light is constant regardless of the condition of the sunlight or whether it is night, and the influence of variations due to external light is eliminated in understanding the floc formation status. A known example of extracting an electrical signal according to the shape of a flock using a photoelectric conversion device is a patent published in 1983-
There is Publication No. 143296, but it does not disclose any specific details such as how to install the photoelectric conversion device.

FIG. 7 shows another embodiment. The feature is that a light shielding support part 25B having a size that covers the entire surface of the floc formation pond is provided in place of the protrusion part 25A.

According to this embodiment, since the light shielding support part 25B is provided on the entire water surface of the floc formation pond 1, external light can be completely blocked. Therefore, the projector 7 is completely
Line photography is possible only with the amount of light projected.

FIG. 8 shows another embodiment. This embodiment is characterized in that the projector 7 and the TV camera 4 are provided within the space of the photographing device 50, and that their positions are at 90 degrees from each other. Glass plate 26C,
The light will be emitted and received through 26D.

In this embodiment, since the TV camera 4 and the light projector 7 are not configured to project and receive light through the same glass surface, the light reflected by the glass surface during light projection is
This has the advantage of eliminating unnecessary obstacles such as being directly captured by a TV camera. Note that the TV camera 4 and the light projector 7 may be located in opposite positions. There may be cases other than 90°.

Figure 9 shows the floodlight 7 and TV that constitute the photographing device.
This is an example of a configuration in which the camera 4 is separated. It was installed on the side of floodlight 7 and flood pond 1. Furthermore, the photographing section 50C is formed into a box shape with a light shielding member, and there is no inside.
A support section 31 on which a TV camera 4 is installed is provided on the entire surface of the pond. The irradiation light from the floodlight 7 is irradiated into the water through the glass plate 26E, and the TV camera 4
receives the reflected light through the glass plate 26F.

According to the various embodiments described above, since the photographing light is constant, it is possible to accurately grasp the state of floc formation.

In addition, all the light shielding members were fixed, but
A drive mechanism may be used to block light only when photographing. Further, an imaging means other than a TV camera may be used.

FIG. 10 shows a specific example corresponding to FIG. 6. The floc formation pond 1 has a configuration in which three ponds are connected. Each flocculation pond 1 is provided with a stirring paddle 2 for flocculation. A photographing device 50 was installed in the final stage floc formation pond 1. This photographing device 50 is floating on the water surface, and the glass plate 26 (see FIG. 6) is in contact with the water surface.

11 is an enlarged view of a portion where the photographing device 50 is provided. The paddle 2 has a rotary blade 2A and is rotated in the direction of the arrow by a drive system (not shown) to stir the floc. It is also possible to eliminate the drive system and allow natural rotation.

[Effects of the Invention] As described above, image information of suspended solids in water can be stably captured by forming a water flow containing suspended solids close to the imaging section of the imaging means for suspended solids in water. be able to.

[Brief explanation of drawings]

1 to 3 are diagrams of a conventional example, FIGS. 4 and 5 are explanatory diagrams of flock photography, and FIGS. 6 to 11 are schematic diagrams showing embodiments of the present invention. 1...Flock formation pond, 2...Paddle, 3...
Flock, 4...TV camera, 7...Floodlight,
5, 8... Controller, 11... Image recognition device, 50... Photographing device, 25... Light shielding member, 26
...Glass plate.

Claims (1)

[Scope of Claims] 1. Imaging means installed under the surface of water containing suspended solids to image the state of the suspended solids and convert the image information into electrical signals; and close to the imaging section of the imaging means. a means for forming a water stream containing suspended matter in such a way that the electric signal is image-processed and converted into binary information, and the imaging means is installed above the water stream. A monitoring device for suspended solids in water, characterized by: