JPH0670626B2 - Aquatic life monitoring equipment - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to an aquatic organism monitoring apparatus, and in particular, the presence or absence of poisonous substances in raw water of a water purification plant or inflow sewage of a sewage treatment plant is determined by an aquatic organism. The present invention relates to a suitable aquatic organism monitoring device.

[Background of the Invention]

At the water treatment plant, a part of the raw water is guided to a water tank to determine whether toxic substances in the raw water are mixed or not.
It breeds aquatic organisms such as dace, sago, haya and oikawa. That is, when a poisonous substance is mixed in the raw water, the inflow of the poisonous substance into the raw water is monitored by utilizing the phenomenon that the fish behave abnormally or die. In addition, sewage treatment plants need to know whether or not toxic substances prohibited by law have flowed into the inflowing sewage, and rely on manual intermittent water quality analysis.

As such, monitoring poisons in water currently depends on human visual inspection and analysis. For this reason, continuous monitoring and early detection were not possible, and there was a drawback that countermeasures were delayed, such as stopping water distribution to customers.

As a method of monitoring fish, a method of detecting fish in an aquarium with an industrial TV camera (ITV) from the top of the aquarium and processing the image (Reference: 36th National Waterworks Research Conference, Computational Collection p464-46)
6) is known. According to this method, when a fish drifts on the surface of the water with its belly lying, the fish can be recognized as an "independent bright spot of a certain size or more", and the high brightness part of the fish existing near the water surface and the water surface By extracting only the change in light due to unevenness, the background can be arranged and the behavior of the fish can be obtained. However, when this method is put to practical use, it is not possible to recognize fish by binarization with a fixed threshold value when the raw water flowing into the tank is turbid. Therefore, when the raw water becomes muddy, the fish image cannot be recognized.

In addition, there is JP-A-54-143296 as a known example of measuring a suspended matter in water using a photoelectric conversion device.

[Object of the Invention]

It is an object of the present invention to provide an aquatic organism monitoring apparatus capable of objectively and continuously monitoring the movement of an aquatic organism such as fish and its abnormality.

[Outline of Invention]

An object of the present invention is to provide an aquarium for breeding aquatic organisms, an illumination means for illuminating the aquatic organisms in the aquarium with a desired illuminance, and a light scattering plate provided between the aquarium and the illumination means. And an imaging device that images the aquatic organisms in the aquarium from the side and outputs image information of the aquatic organisms, and an image of the aquatic organisms obtained at different imaging times of the image information obtained from the imaging device is image-processed to average the aquatic organisms. And an average moving speed output means for outputting the moving speed.

It is very desirable to provide the lighting means and the image pickup device so as to face each other with the water tank in between, and to provide the light scattering plate between the lighting means and the water tank.

It is also desirable to detect whether the average moving speed of aquatic organisms exceeds a set level and display an abnormal condition or sound an alarm.

Example of Invention

 Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. A water pipe 110 in the aquarium 100
The test water is supplied by the water supply pump 120. The test water is raw water at the water treatment plant, inflow sewage at the sewage treatment plant, and river water when monitoring poisonous substances in the river. The water tank 100 has a rectangular parallelepiped shape with a bottom and an open top. The water introduced into the water tank 100 is drained by the drain pipe 130. Fish 140 are kept in the aquarium 100 as aquatic organisms. In general, a plurality of fishes are bred, but in the present embodiment, for simplicity of explanation, the case of one fish will be described.

As the fish 140, a fish that lives in the test water to be supplied is bred. For example, crucian carp, carp, dace, tanago and oikawa. The lighting devices 150A and 150B are installed above the aquarium 100 and illuminate the fish 140. Since uniform illumination is required, a light scattering plate 160 made of frosted glass or the like is provided between the illumination devices 150A and 150B and the water tank 100. Back screen 170
Is installed to recognize the fish 140 with good contrast. The back screen 170 is preferably white when the color of the back of the fish 140 is black, and conversely, black when the color of the back of the fish 140 is white.

The image pickup device 200 is for picking up an image of the fish 140 in the aquarium 100 and converting it into an electric signal. An industrial television camera (ITV) is desirable, and an output voltage depending on the brightness (luminance) of the pixel to be picked up. Emit different electrical signals. The ITV is located lateral to the aquarium to monitor the sides of the fish. The movement of the fish can be accurately detected by photographing the side surface of the fish. The electric signal output from the imaging device 200 is transmitted to the moving speed detecting means 300. Further, the image pickup apparatus 200 receives the horizontal synchronizing signal and the vertical synchronizing signal from the image pickup control circuit 210, and controls the image pickup timing.

The moving speed detecting means 300 detects the moving speed Vw of the fish 140 based on the image of the fish 140 obtained by the imaging device 200.

As the moving speed V, an average moving speed is used to reduce noise due to an instantaneous disturbance. Moving speed detection means
The detailed configuration and operation of 300 will be described later. The signal V of the average moving speed of the fish 1401 obtained by the moving speed detecting means 300 is
It is transmitted to the moving speed determiner 500. On the other hand, the moving speed determiner 500 includes a first moving speed setter 510 and a second moving speed setter.
From 520, the first and second moving speeds Vmax and Vmin are input. It goes without saying that the setting of the value Vmax and the value Vmin in the first moving speed setting device 510 and the second moving speed setting device 520 can be changed according to environmental conditions such as the type of fish and the water temperature.

This changing operation is performed manually or automatically. For example, when the first moving speed Vmax and the second moving speed Vmin are automatically changed with respect to the change in the water temperature, first, the water temperature in the water tank is measured by the water thermometer 102. This measured value is sent to the set value changing circuit 103, and the first
The moving speed Vmax and the second moving speed Vmin are changed.

The first moving speed Vmax is set to a moving speed at which the movement of the fish 140 can be considered to be abnormally active, and a value larger than Vmax indicates abnormal behavior due to inflow of poison. Second moving speed Vmin
Is set to a moving speed at which it can be considered that the movement of the fish 140 is abnormally small, and a value smaller than Vmin indicates that the movement of the fish 140 is extremely small due to the inflow of poison.

The moving speed determining device 500 compares the average moving speed V of the fish 140 obtained by the moving speed detecting means 300 with the first moving speed setting device 510 and the second moving speed setting device 520, respectively. That is, the moving speed determiner 500 determines that the movement of the fish 140 is abnormal when the average moving speed V of the fish 140 is higher than the first moving speed Vmax or lower than the second moving speed Vmin. The determination result is output as an ON / OFF signal.

Although not shown, if the abnormal state is turned on, an alarm is sounded at this time, or a message for prompting the water quality survey to the monitor is output by voice.

FIG. 2 shows the configuration of the moving speed detecting means 300, and its configuration and operation will be described. An image processing device is used as the moving speed detecting means.

The moving speed detecting means 300 detects the average moving speed V of the fish 140 from the image of the fish 140 obtained by the imaging device 200. The image pickup apparatus 200 internally has M vertical rows and N horizontal rows of image pickup elements as shown in FIG. 3, and i rows j corresponding to the respective image pickup elements at time t.
The density G (i, j, t) of the brightness of the pixels in the row is output.

Various images in the image memory 310, specifically, the imaging device 200
The density signal G (i, j, t) from is stored. The image processor 320 is a feature amount processor, a labeling processor,
It consists of a histogram processor and a composition processor. The address processor 360 reads / writes an image memory, captures an image from the imaging device 200, and controls the display of the monitor 370. The system processor 380 manages and controls the image memory 310, the address processor 360, and the image processor 320. The console display 390 is used to input and display management control information of the system processor 380. Frotpi disk 400
The image information and the image processing program are stored in.

In FIG. 2, the image memory 310A first stores the grayscale image G (i, j, t) of the image pickup apparatus 200 at time t. Next, the address processor 360 is controlled by the system processor 380 to take in the grayscale image G (i, j, t + h) after the time h into another image memory 310B. The time h is about 0.1 to 10 seconds.

Image density information G captured in the image memories 310A and 310B
(I, j, t) and G (i, j, t + h) are processed by the image processor 320, and finally the average moving speed V of the fish 140 is calculated. The details of the information processing flow in the image processor 320 are shown in FIG.

In FIG. 4, the image difference circuit 340 includes image memories 310A and 3A.
Image brightness information G (i, j, t) and G (i, j,
The difference is calculated from (t + h). That is, the difference image S (i, j, t) is calculated by the equation (1) for all the pixels.

S (i, j, t) = G (i, j, t + h) -G (i, j, t) (1) The moving object is extracted from the difference image. A high brightness value represents a bright object and a low brightness value represents a dark object, but consider the case where the fish is black and the water background is white. FIG. 5 shows time t
6 represents the image of the fish, FIG. 6 represents the image of the fish at time t + h, and FIG. 7 represents the difference image between them. In FIG.
A represents the water part, B represents the image of the fish before moving, and C
Represents the image of the fish after moving. Although the brightness is not shown, each brightness has a value of 0 near A, a negative value of B, and a positive value of C. The reason for this will be described below.

Assuming that the brightness of the fish is f and the brightness of water is w, the water part having the same brightness w is subtracted in the difference image, and w−w = 0. Therefore, the water whose brightness is close to 0 is muddy. Even so, the brightness w becomes w−w = 0, so the water part is 0
Get closer to. Since the fish image portion at time t + h was exposed to water at a large time (FIG. 5), the bright brightness w of the water is subtracted from the dark brightness f of the fish, so that fw <0 and a negative value is obtained. On the other hand, in the image of the fish before moving at the time t, conversely, the dark brightness f of the fish at the time t is subtracted from the bright brightness w of the water at the time t + h, so that w−f> 0.
Next takes a positive value. Even if the water is cloudy, if there is a difference between the brightness w of the water and the brightness f of the fish, the fish portion becomes positive or negative.

The image difference circuit 340 outputs a fish image at time t (FIG. 5), a fish image at time t + h (FIG. 6), and a difference image between them (FIG. 7).

Subsequently, in the moving object ternarization step 342, the difference image is ternarized according to the following formula for all pixels. The threshold Ls for ternarization is set.

S (i, j, t) <-Ls; S (i, j, t) = 1 (2) S (i, j, t)>Ls; S (i, j, t) = 1 (3) ) -Ls <S (i, j, t) <Ls; S (i, j, t) = 0 (4) The threshold Ls is set by the difference w−f between the brightness w of water and the brightness f of fish.
Select above. If the threshold value Ls is close to 0, noise is easily picked up, so that the brightness level is set to, for example, 3 brightness levels or more.

The moving object ternarization circuit 342 ternarizes the image output from the image partial circuit 340. That is, equations (2), (3),
According to the calculation of (4), the fish 140 at time t has a luminance of -1.
, The fish 140 at time t + h has a value of brightness “1”, and the water part has a value of brightness “0”. The results are shown in FIG. FIG. 9 shows a diagram in which the luminance “−1” and “1” are shown in black and the luminance “0” is shown in white. The numbers in the figure are luminance values.

The center of gravity calculation circuit 344 calculates the center of gravity of each of the images having the values “−1” and “1”. G- (i, j, t),
G + (i, j, t) is set, and this value is input to the moving speed calculation circuit 346. The moving speed calculation circuit 346 calculates the moving speed of the fish 140 by the following equation.

Vw (t) = 1G + (i, j, t) -G- (i, j, t) 1 / h ...
(9) In this way, the center-of-gravity moving velocities Vw (t), Vw (t + h), Vw (t + 2) at times t, t + h, t + 2h, ...
h), ... Vw (t + Kh) are calculated one after another.

The center-of-gravity moving speed memory 334 stores the values of the center-of-gravity moving speed Vw (t), Vw.
(T + h), Vw (t + 2h), ... Vw (t + kh) are stored.

The average moving speed calculation circuit 336 calculates the average moving speed V of the barycentric coordinates from these values by the following equation.

Here, K + 1 is the average number of times, which is about 3 to 1000 times. The average moving speed V obtained by the average moving speed calculation circuit 336 is output from the image processor 320.

In this way, the moving speed V of the fish 140 obtained by the moving speed detecting means 300 is the moving speed judging device 500 as shown in FIG.
Sent to. In the moving speed judging device 400, the average moving speed V of the fish 140 obtained by the moving speed detecting means 300 and the first moving speed setting device 510 and the second moving speed setting device 520 are transmitted.
Compare Vmax and Vmin respectively. That is, when the moving speed V of the fish 140 is greater than the first moving speed Vmax or less than the second moving speed Vmin, the moving speed determiner 500 determines that the fish 14
It is determined that the movement of 0 is abnormal.

As described above, in the embodiment shown in FIG. 1, the movement of the fish is recognized based on the difference between the images, so that the fish can be recognized even when the water is muddy. As a result, the moving speed of the fish can always be detected stably.

Another example of the water tank of the present invention is shown in FIG. FIG. 10 can more effectively perform image extraction of fish. FIG. 10 shows the ITV of the water tank 100 against the background of the back screens 170, 170A and 170B.
Monitor at 200.

In this embodiment, the background has a constant brightness. That is,
First, in addition to the back screen 170, back screens 170A and 170B are arranged on the side surfaces, and the frame 105 of the water tank 100 is painted with a brightness close to that of the back screen (the same brightness as possible). As a result, the fish and the background can always be separated with good contrast.

FIG. 11 is a view of the water tank 100 seen from the horizontal direction, and the inner area shown by the dotted line is imaged by the ITV 200. The ITV200 is located on the side of the aquarium so that the fish can be imaged from the side. Although not shown in FIG. 11, the fish 140 is captured in the imaged area.
The other parts have the same brightness. That is, the aquarium frame
105, the back surface 100C of the aquarium, the side surface 100A and 100B has a constant brightness, and since the brightness of the fish and the brightness of the background always have a constant brightness difference, the fish can be accurately extracted by the difference between the fish and the background. . Using the water tanks shown in Fig. 10 and Fig. 11, fish can be accurately distinguished from the background for recognition.

FIG. 12 shows another configuration of the water tank. The illumination devices 150A and 150B are arranged behind the water tank 100 when viewed from the imaging device 200. A light scattering plate 160 is arranged between the lighting devices 150A and 150B and the water tank 100. With this arrangement, the aquarium 100 can be evenly illuminated and the fish 140
Illuminated from behind, the fish 140 blocks the light and looks black. Therefore, even when the water flowing into the aquarium 100 becomes cloudy, the fish 140 can be distinguished from the background and can be distinguished with good contrast.

Another embodiment of the present invention is shown in FIG.

In this embodiment, the setting of the value Vmax and the value Vmin in the first moving speed setting device 510 and the second moving speed setting device 520 can be changed according to the water temperature. First, the water temperature in 100 is measured by the water temperature gauge 102, and this measured value is sent to the set value change circuit 103. If the water temperature is high, the set value change circuit 103 will set the maximum value Vmax and the minimum value Vmax.
min is set to be high, and conversely, when the water temperature is low, the value Vmax and the value Vmin are set to be low.

When the water temperature is high, the movement of the fish is active. On the contrary, when the water temperature is low, the fish move slowly. Therefore, in this embodiment, it is possible to monitor the presence or absence of poisons in the raw water from the movement of the fish throughout the year in consideration of the influence of the water temperature.

In the above embodiment, the fish is recognized from the difference between the images, so that the fish can be recognized even when the water becomes muddy. For example, the brightness (luminance) of the water part changes when it becomes cloudy during precipitation. Since the image difference interval h is 0.1 second, if there is no change in the brightness of water within this time, it is possible to sufficiently distinguish between fish and water.

〔The invention's effect〕

As described above, according to the present invention, it is possible to objectively and continuously monitor the movement of an aquatic organism such as a fish and its abnormality, and output the state quantity such as the moving speed. In addition, since a light scattering plate is provided between the lighting device and the water tank to perform imaging under uniform illumination,
The reliability of image processing is also high. As a result, it is possible to accurately monitor the inflow water for poisons at the water purification plant and the sewage treatment plant, and it is possible to ensure the safety of water.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIG.
Detailed configuration diagram showing an example of the moving speed detection means in the figure,
FIG. 3 is an array diagram of image pickup elements in the image pickup apparatus, FIG. 4 is an information processing flow chart, FIGS.
10 and 11 are configuration diagrams of another water tank, FIG. 12 is another configuration diagram of the water tank, and FIG. 13 is a configuration diagram showing another embodiment of the present invention. 100 …… Aquarium, 140 …… Fish, 150A, B …… Lighting device, 160…
... light scattering plate, 200 ... imaging device, 300 ... moving speed detecting means, 500 ... moving speed judging device, 510 ... first moving speed judging device, 520 ... second moving speed judging device.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naoki Hara 5-2-1 Omika-cho, Hitachi-shi, Ibaraki Inside the Omika factory of Hitachi, Ltd. (56) References: 56-42077 (JP, U) Japanese Patent Publication 5-31941 (JP, B2)

Claims (2)

[Claims] 1. An aquarium for breeding aquatic organisms, an illumination means for illuminating the aquatic organisms in the aquarium with a desired illuminance, and a light scattering plate provided between the aquarium and the illumination means. An image pickup device that photographs the aquatic organisms in the aquarium from the side and outputs image information of the aquatic organisms; and an average movement of the aquatic organisms by performing image processing on images obtained from the image pickup device at different imaging times. An average aquatic velocity output means for outputting a velocity, and a monitoring device for aquatic organisms, comprising: 2. The light emitting device according to claim 1, wherein the lighting means and the image pickup device are opposed to each other with the water tank interposed therebetween, and the light scattering plate is provided between the lighting means and the water tank. An aquatic organism monitoring device characterized in that