JPH03175338A - Apparatus for monitoring substance suspended in water - Google Patents

Abstract

PURPOSE:To quantitatively grasp the formation state of floc by arranging an imaging means below the surface of the water to take in the image data of floc. CONSTITUTION:The industrial TV camera 4 fixed to an airtight container 20 confirms the image of flocs 3 present in a floc forming basin 1c in a magnified state by a close-up lens 31 through an observation window 21 and a wiper driving apparatus 23 drives a wiper 22 to periodically remove the surface contamination of the window 21. A black back screen 24 is arranged in front of the window 21 so as to accurately confirm a floc group and a shield cover 92 is provided to make the circumference dark to set the luminous intensity of a definite condition due to a floodlight projector 7. Further, barrier plates 25A, 25B, 25C are arranged to suppress the movement of water and constituted so that the light from the floodlight projector 7 is incident in a planar state. By this constitution, floc image data is transmitted to an image confirming apparatus 9 from the camera 4 through an ITV taking-in circuit 5 and an image is binarized to calculate a floc particle size and the calculation result is displayed on a monitor.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to the treatment of aggregates of substances suspended in water at water treatment plants.
This invention relates to a monitoring device for substances suspended in water that automatically recognizes the formation status of flocs using image recognition technology.

[Conventional technology]

At water treatment plants, since the suspended particles in raw water are small in size, a process is carried out in which they are coagulated to form flocs, and the flocs are allowed to settle. The success or failure of floc formation is determined by the subsequent treatment process, precipitation.

Directly affects the filtration process. Poor floc formation worsens the floc settling properties in the settling basin. Furthermore, this deterioration of sedimentation leads to an overload phenomenon in the filter basin.

Furthermore, if the recognition of excessive load is delayed, it can lead to serious accidents such as the outflow of minute flocs from the filtration basin.

Therefore, it is necessary to monitor the flocs. Traditionally, flocks have been monitored by lifeguards.

An example is shown in FIG. A paddle 2 for stirring the flocs is provided in the floc formation pond 1 to stir the flocs. A lifeguard visually monitors the flocs in the pond.

However, it is difficult to quantitatively understand the flocs through this visual inspection.

FIG. 2 shows an example in which an industrial television camera 4 and a floodlight 7 are installed in a floc formation pond 1. Inside the building 8^, there is a drive circuit 8. Intake circuit 5. A CRT6 is provided. The drive circuit 8 supplies power supply voltage to the projector 7 . Floodlight 7
The reason for this was that the middle of the floc formation pond 1 was crowded and dark.

This is because the TV camera 4 cannot image the flock using only natural light. The CRT 6 displays an image captured by the TV camera 4, and a monitor monitors the displayed image.

This conventional example uses a system in which the situation inside the floc formation pond 1 is imaged by a TV camera 4, but in the end, CR
The method is to visually observe the T6 screen. For this reason, it is still difficult to grasp the state of floc formation quantitatively.

[Purpose of the invention]

An object of the present invention is to provide a monitoring device that can quantitatively grasp the formation status of flocs, that is, substances suspended in water.

[Summary of the invention]

In order to achieve the above object, the present invention includes an imaging means installed under the water surface that images the state of a substance suspended in the water and captures the image information, and binarizes the image information captured by the imaging means. A binarization means, a calculation means for calculating the particle size of the substance based on the obtained binarization information, and a means for displaying the calculation result of the calculation means are provided.

By calculating the particle size of the floc from the binarized image by the binarizing means and displaying the calculation result on a monitor or the like, it becomes possible to quantitatively understand the floc.

[Example〕 Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 3 is a schematic overall configuration diagram of a monitoring device according to an embodiment of the present invention, in which an image recognition device [9 is provided. This image recognition device 9 captures the image captured by the TV camera 4 as a binarized image, calculates the area for the size of the flocs, calculates the distribution density of the flocs, etc., and quantitatively determines the floc formation status. Understand clearly. CRT6 is
The captured image may be displayed directly, or quantified data may be displayed.

FIG. 4 shows a monitoring device according to an embodiment of the present invention. 1 is a cross-sectional view of a floc formation pond 1. Flock formation pond 1
There are three floc-forming ponds IA and IB.

Consists of IC. The flocculation ponds IA, IB, and IC are connected in cascade via a flow path 13. Furthermore, the floc ponds LA, -IB, and IC are equipped with floc stirring paddles 2A,
28.2C was installed to stir the flocs. Each paddle 2A, 2B, 2C has a wing 60, 61.6 in a cruciform configuration.
2, and the blades have the role of stirring the flocs. Channel 13
has the function of a rectifying wall. Although the flow path 13 is a flow hole extending from the upper surface of the floc pond to the bottom, it may be a part of the flow path.

FIG. 5 is an overall perspective view of the floc formation pond 1. Paddles 2A, 2B, and 2C are in the floc formation pond IA.

1B, stir the inside of the IC along its length.

A rapid mixing pond (not shown) is provided upstream of the flocculation pond 1, and raw water and a group of minute flocs mixed therein flow into the flocculation pond 1. The paddle stirs the micro flocs, causes the flocs to collide with each other, and gradually aggregates the flocs. This agglomeration increases the particle size of the flocs. The particle size of the flocs in the floc formation pond IB is larger than that in the floc formation pond IA, and the particle size of the flocs in the floc formation pond IC is larger than that in the flocculation pond IB. That is, the particle size increases each time the particles pass through one floc formation pond.

Therefore, a floc monitoring device was installed at the last floc pond IC. This is because the purpose is also to monitor the final degree of floc formation. This flock pond IC is also a pond before the settling pond. That is, when the purpose is to monitor the final degree of floc formation, the floc image recognition device with this configuration is placed at the front stage of the settling tank, that is, near the exit of the third pond of floc formation pond 1. . On the other hand, when monitoring the process of floc formation,
Of course, it may be installed in the second or second pond.

This will be discussed in FIGS. 15, 16, and 17, which will be described later. An example in this case is shown in FIG.

In the figure, 20 is an airtight container, 21 is an observation window (usually
glass plate), 22 is a wiper, 23 is a wiper drive device, 24 is a back screen, 25A, 25B, 25
C is each baffle board, 4 is industrial television camera (ITV)
, 31 is a close-up lens, 7 is a light projector, 5 is an ITV image capture circuit, 8 is a light projector drive circuit, 42 is a light-shielding cover 9 is an image recognition device, and 60 is a control device.

Wiper? -22 has a function of moving the surface of the glass surface (observation window) 21 from side to side and wiping off dirt when viewed from the front.

The operation of this embodiment is as follows. The ITV 30 fixed in the airtight container 20 uses a close-up lens 31 to observe the flocs 1 in the floc formation pond 10 through the observation window 21.
Enlarge and recognize image 2. Wiper drive device! The wiper 22 driven by the wiper 23 operates periodically to remove dirt from the surface of the wt inspection window 21.

Further, a back screen 24 is installed in front of the observation window 21 in order to accurately recognize the flock group with high contrast. Considering that the color of the flocks 3 is white, the back screen 24 is desirably black in order to accurately recognize the flock with high contrast.

Incidentally, the floc-forming pond 1 is opened to the atmosphere for the purpose of constantly monitoring flocs. Therefore, the amount of light incident on the flocculation pond IC changes over time and is strongly influenced by the weather.

A floodlight 7 is usually installed as a means for constantly monitoring the flocs. If the purpose is simply monitoring that relies on the eyesight of a maintenance manager, installation of the floodlight 7 is sufficient.

However, changes in ambient illumination strongly affect the accuracy of image recognition of flocks. For example, if the illuminance is low, the flocs will be perceived as small, and conversely, if the illuminance is high, the flocs will be perceived as large.

In order to eliminate this influence, it is necessary to avoid being influenced by changes in illuminance as a natural phenomenon. In this embodiment, a light-shielding cover 42 is provided to darken the surrounding area, and the illuminance provided only by the projector 7 is set under a certain condition. Note that if the light-shielding cover 42 is not provided, the illumination conditions may be controlled at appropriate times using the floodlight drive circuit 8. Furthermore, if circumstances permit, it is better to install a plurality of floodlights 7 to irradiate the flock from multiple directions.

Incidentally, the flock group is in a fluid state, and its moving speed is about 5 to 50 cm/sec. For this reason, it is necessary to perform image recognition of the flock group at high speed. but,
In the case of 512×480 pixels, even if a high-speed image recognition device is applied, it takes 11 milliseconds to recognize the pixels. Therefore, in order to accurately recognize images at the speed of current image recognition devices, it is important to reduce the moving speed of the flock group as much as possible. In this case, it is considered that water is moving in a fixed direction in the flocculation pond IC due to stirring by the stirring paddle 2C.

That is, in order to suppress the movement of water as much as possible within the floc formation pond IC, a baffle plate is arranged so as to block the movement direction. FIG. 7 is a three-dimensional view of FIG. 6, showing the baffle plate 25A when water is moving from the top to the bottom as shown by the white arrow.
258.25C arrangement is shown. At this time, the baffle plates 25B and 25C are configured so as not to interfere with the light rays from the projector 7 and to allow the light rays to enter in a planar manner.

FIG. 8 shows the baffle plates 25A, 258.25G, 25D, and 25H when water is moving laterally parallel to the back screen 24 as indicated by the white arrows.
Figure 9 shows the arrangement of the ITV4 in the floc formation pond I.
Baffle plate 2 when placed across wall 10A of C
The arrangement of 5A and 25B is shown. Further, FIG. 1O is a three-dimensional view thereof.

FIG. 17, which will be described later, shows a situation in which flock formation is actually recognized by ITV4, taking into consideration the points to be noted in image recognition of flocks as explained above.

Here, the background of the flock 3 is black because the back screen 24 is arranged. Further, although the floodlight 7 is not shown, illumination is emitted from two locations on both sides in the horizontal direction.

In this way, the flock image information captured by the ITV 4 is transmitted to the image recognition device 9 via the ITV capture circuit 5.

The image recognition device W9 performs various calculations such as the particle size and distribution of floc groups in order to extract information useful for water quality management at the water purification plant from the obtained image information. Although the specific method will be described later, for example, the grain size of each floc in the floc group is calculated by binarization processing, and the representative grain size of the floc group is determined.

The image recognition control bag Wi9 controls this time sequence. That is, the image recognition control device 9 adjusts the recognition time and number of times of recognition of flock image information by the single image recognition device i9 and ITV4, details of which will be described later. in general,
Since the state of floc formation rarely changes rapidly in a short period of time, it is sufficient to perform the series of floc monitoring operations described above once every 10 minutes to once an hour.

In the apparatus configured in this way, after the image information of the flock group has been captured by the ITV4.

A specific process of signal processing within the image recognition device i9 is shown in FIG. 11 and will be described in detail below.

Here, 100 is a recognition timing control circuit, 101 is A
/D conversion circuit, 102 is a threshold input circuit, 103 is a binarization circuit, 104 is a labeling circuit, 105 is a particle size calculation mode designation circuit, 106 is a particle size measurement circuit, 107 is a particle size comparison circuit, 108A, 108B, 108C,...1
08Z is a number storage circuit, 109 is a recognition number control circuit, and 110 is a particle size distribution calculation display circuit.

Moreover, FIG. 12 shows an image plane of a flock group recognized by ITV4. Since the floc group is a grayscale image, the boundary between the floc 3 and the water is not actually clear, but for the sake of simplicity, only the outline of the floc group is illustrated. The luminance level of the flock is high and white, while the luminance level of the water is low and black because the back screen 24 is placed in the background.

In FIG. 11, the recognition timing control circuit 100
The flock image obtained through the I'TV 4 and ITV controller 5 shown in FIG. 6 is recognized, and the time interval (frequency) at which image information is captured is controlled.

Next, the A/D conversion circuit 101 receives the obtained analog signal of the brightness information, for example, the screen signal shown in FIG. 12, and converts the signal into a digital signal one by one. The converted digital signal is passed to a binarization circuit 103 based on a threshold specified by a threshold input circuit 102.

Binarization processing is performed.

For example, FIG. 13 shows a case where the screen of FIG. 12 is scanned along the AA' line to display the luminance level distribution. Here, the brightness level is displayed in 8 bits (256 levels), and the brightness is low toward the top of the vertical axis, while the brightness is high toward the bottom. Since the flock 12 is white, the luminance is high. That is, the portion that becomes a valley in the downward direction represents the floc.

In this brightness distribution, each pixel is binarized by a binarization circuit 103 based on a threshold specified by a threshold input circuit 102, for example, the brightness specified by the BB' line. Threshold value I' specified by threshold value input circuit 102! .

It remains constant under constant illuminance, but can also be operated by an operator.

In the binarization circuit 103, a pixel at a brightness level higher than the threshold value is set as 1", and a pixel at a brightness level below the threshold value is set as II OII. Then, as shown in FIG. The part corresponding to water becomes "1", and the part corresponding to water becomes "0".

Examples of the results of floc recognition performed in this manner are shown in FIGS. 15, 16, and 17. Figure 15 is a diagram showing the recognition and binarization of floc groups in the first pond IA of the floc-forming pond 1, and Figure 16 is a diagram of the second pond I of the floc-forming pond 1.
Figure 17 shows the recognition and binarization of floc groups in B.
The figure is a diagram in which floc groups in the third pond IC of the floc formation pond 1 are recognized and binarized. From these figures, it can be seen that the process of increasing the floc particle size can be clearly determined.

Once the flocs are recognized, the representative grain size of the flocs is calculated, but before that a number is assigned to each floc. That is, the labeling circuit 104 independently recognizes each flock and assigns a number to each flock. Then, the particle size measuring circuit 106 analyzes each floc in the order of its number.
Calculate the representative particle size.

As shown in Fig. 18, the typical particle size is 6.
, maximum diameter, ax, minimum diameter D1. In1 area circle equivalent diameter. lr and isolateral circle peripheral major axis Del. here,
The fixed diameter DC indicates a certain diameter in the horizontal direction.

Area circle equivalent diameter DcIr and equilateral circle peripheral major axis. I is defined by the following formula.

0.5 D, ir= (4S/π) ---
--------・(1) Del = L/2/π
(2) Here, S is the area of the floc, and L is the peripheral length of the floc.

The particle size calculation mode designating circuit 105 specifies a representative particle size to be adopted from among these representative particle sizes. In this way, the grain size of each floc is calculated in accordance with the specified standard of representative grain size.

The particle size comparison circuit 107 compares the particle sizes of each floc and stores the number of flocs having each particle size in a corresponding storage location, that is, a number storage circuit 108A.

The numbers are stored in 108B, 108C, . . . 1082.

Since the image of the floc is binarized, the minimum unit for measuring one particle size is one pixel. Therefore, if the number of flocs corresponding to each particle size is N, then, for example, the number storage circuit 108A stores the number N1 of floes whose particle size corresponds to one pixel, and the number storage circuit 108B stores the number N1 of floes whose particle size corresponds to one pixel. The number NZ of flocs corresponding to two pixels is stored, and the number storage circuit 108C stores the number N3 of floes whose grain size corresponds to three pixels. The results are shown in FIG.

By the way, in order to accurately determine the particle size distribution of flocs,
It is necessary to sample a wide area within the floc formation pond. The particle size of the flocs is approximately 0.01 to 0.1 m in one floc formation pond. On the other hand, Pond 3 contains many small ifrocks, but
The floc grows to i tm fR61. The growth process of this floc is shown in Figure 15.

As shown in Figures 16 and 17. In order to recognize minute flocs of about 0.01 mm, it is necessary to use a microscope, and in fact, it is difficult to recognize them with a close-up lens.

In one pond, the flock forming pond 1, the particle size of the flocs is small, so the number of flocs is sufficiently large. However, in the third pond of the flocculation pond 1, the particle size of the flocs is large, so the number of flocs is small. In order to accurately determine the particle size distribution of flocs when the number of flocs is small, it is necessary to recognize as many flocs as possible. The number of flocs is preferably several hundred or more. Therefore, it is possible to enlarge the recognition screen, but if this is done, it becomes difficult to recognize small flocks.

Therefore, balance both small and large flocs <V! , the size of the screen that can be recognized.

Naturally, there is a limit to its size. In this way, in the case of clean water flocs, when determining the particle size distribution with high accuracy, 1
It can be seen that the information on the floc images obtained by screen image recognition is insufficient due to large variations in particle size distribution.

For these reasons, it is necessary to temporarily store the information on the floc images obtained by image recognition, capture the images multiple times, and determine the particle size distribution based on this stored information. Furthermore, in the case of the flocculation pond 1, since the water is stirred by the stirring paddle 11, it is considered that water containing new flocs is constantly flowing in front of the ITV 4.

That is, a floc image is captured at regular time intervals, this is performed multiple times, and the particle size distribution of the floc is determined based on this information.

The number of times a flock image is recognized is specified in the recognition number control circuit 109 in FIG. 11, and if the number is less than this number, the process returns to the recognition timing control circuit 100. The recognition timing control circuit 100 captures an image at a specified timing, repeats the operations described above, calculates the particle size of the flocs, and stores the number of each floc in the number storage circuits 108A and 108B.

108C, . . . 108z.

On the other hand, when the number of recognition times has been specified by the recognition number control circuit 109, the particle size distribution calculation and display circuit 110 performs the number storage circuits 108A, 108B, 108C, -1082(7).
), calculate the number concentration distribution for each particle size. That is, the number concentration M of particle size i is calculated by the following equation.

Mi=Ni/V/Nr −−−−−−−・
(3) Here, V is the observation space volume by the ITV 4, and N is the number of recognitions specified by the recognition number control circuit 109.

Note that in the number concentration distribution, since the number of flocs with a small particle size increases, it goes without saying that a method of illustrating the flocs as a volume concentration distribution may be adopted, assuming that the flocs are spheres. Further, the number of recognitions in the recognition number control circuit 109 and the recognition timing in the recognition timing control circuit 100 are as follows:
All are operated as appropriate from a single image recognition control device.

Next, an operation is performed to determine whether or not the grain size of the flocs is normal. As shown in FIG. 20, the grain size of the floc serving as a reference is determined and is defined as this grain size DS.

The number concentration ratio of flocs having a particle size larger than this Ds is calculated. A diagram for this calculation process is shown in FIG.

Among the signals output by the particle size distribution calculation display circuit 110,
Reference particle size setting circuit 1 targets the signal portion corresponding to the particle size.
6. The particle size comparison circuit 112 compares the magnitude relationship with the reference particle size DS set in step 11.

The number of flocs with a particle size larger than the standard particle size DS is
The number of growing flocs is stored in the concentration storage circuit 113. Let this number concentration be Mg. On the other hand, the number of flocs having a particle size smaller than the reference particle size DS is stored in the micro floc number concentration storage circuit 114.

Let this number concentration be M.

Next, the sum Mt of Mg and Ml is calculated and stored in the total flock number density storage circuit 115. Particle size comparison circuit 116
Now, a comparison is made to see if the ratio of the growing floc number concentration M to the total floc number concentration Mt is greater than a predetermined value r.

Me/Mt≧r ・・・・・・・・・・(
4) That is, when Mg/Mt is larger than the predetermined value r, it indicates that there are many growing flocs, and therefore the flocs are considered to be well formed. On the other hand, when Mg/Mt is smaller than the predetermined value r, it means that there are many minute flocs, and therefore the floc formation condition is considered to be poor.

Based on these determination results, if the floc formation is defective, an alarm output signal may be issued. Similarly, it is possible to control the amount of flocculant injected, the amount of alkali agent injected, and the rotation speed of the stirring paddle 2 based on the determination result of equation (4).

FIGS. 22(a) and 22(b) show an example of a time chart of the floc recognition process. vIaII/sec, and assuming that the size of the area where the image of the flock is recognized is 1 square, the time T required for the flock to pass through the area where the image is recognized is T 1 = Q 1 / v 1...
......(5). That is, the time interval for capturing the flock images of the recognition timing control circuit 100 shown in FIG. 11 is T.

With the above settings, it is possible to always import new flock information. Of course, it is obvious that the flock images may be captured at the T1 time interval or less.

In addition, a series of processes (hereinafter, this series of processes) of repeating the recognition operation for the number of recognition times N set in the recognition number control circuit 109 shown in FIG. The process is called the flock recognition step) is completed. These processes are performed at high speed by the image recognition device 9, and the time required for them (T++T2) is very short, on the order of several seconds.

Therefore, after the flock recognition step at a certain time is completed,
Although it is possible to repeat the floc recognition step one after another in succession, in general, the responsiveness in process control of a water treatment plant (for example, the time from immediately after chemical injection until the reaction caused by that chemical spreads throughout the treatment process) is several tens of minutes~
It is characterized by being long, on the order of several hours. Therefore, there is little need to constantly repeat the flock recognition step, and the flock recognition step is performed Ns times at every arbitrary time interval T3 (requires (T+ + T2) x N5 seconds), and the free time T4 is used. Then, the image recognition device 9 performs other processing (for example, fish tracking processing for monitoring the inflow of poisonous substances).
This also improves the usage efficiency of the image recognition device 9,
It is highly effective in terms of multipurpose and effective use.

〔Effect of the invention〕

According to the present invention, the floc particle size distribution in the water floc formation process can be changed from micro flocs to grown flocs.
Objective, quantitative, and highly accurate online measurement is possible. This makes it possible to save labor and improve reliability in water treatment plant maintenance and management, and even to apply it to control systems.

[Brief explanation of drawings]

Figures 1 and 2 are conventional examples, Figure 3 is a schematic overall configuration diagram of a monitoring device according to an embodiment of the present invention, Figure 4 is a cross-sectional view of a floc formation pond, and Figure 5 is a water treatment plant. FIG. 6 is a perspective view of the floc formation pond, FIG. 6 is a diagram showing an embodiment of the present invention, FIG. 7 and FIG.
9 and 10 are diagrams showing details of an embodiment of the present invention, FIG. 11 is a diagram showing a signal band process in the embodiment, and FIGS. 12, 13, and 14 are a signal processing process. FIGS. 15, 16, and 17 are diagrams showing binarized images obtained by implementing the present invention, and FIGS. 18 and 1 are diagrams specifically showing the
9 and 20 are diagrams showing details of an embodiment of the present invention, FIG. 21 is a diagram specifically showing a signal processing process, and FIG. 22 is a diagram showing a processing time chart. 1, LA, IB, IC...floc formation pond, 2...
Paddle, 3...Flock, 4...TV camera, 7.
... Light projector, 9 ... Image recognition device, 60 ... Control circuit, 101 ... AD converter, 103 ... Binarization circuit, 104 ... Labeling circuit, 105 ... Particle size measurement Circuit, 107...Particle size comparison circuit, 108A-108
Z...Memory.

Claims (1)

[Claims] 1. Imaging means installed under the water surface that images the state of substances suspended in the water and captures the image information, and binarization that binarizes the image information captured by the imaging means Monitoring of substances suspended in water, comprising: means for calculating the particle size of the substance based on the obtained binary information; and means for displaying the calculation results of the calculation means. Device. 2. An imaging means installed under the water surface that images the state of a substance suspended in the water and captures the image information; and a binarization means that binarizes the image information captured by the imaging means; 1. A monitoring device for substances suspended in water, comprising a calculation means for calculating the particle size distribution of the substance based on binarized information, and a means for displaying the calculation results of the calculation means. 3. A monitoring device for substances suspended in water according to claim 2, wherein the calculation means assigns a number to each image of each substance and calculates the particle size in the order of the numbers.