JP7446984B2 - Floating object observation device - Google Patents

Description

The present invention relates to a floating object observation device that images floating objects such as flocs in a liquid.

Conventionally, as shown in FIG. 14, this type of floating object observation device irradiates sheet laser light 103 from the outside of a stirring tank 102 that stores raw water 101, and detects sheet laser light in the raw water 101 in the stirring tank 102. Some devices are configured to photograph the irradiated area irradiated with the light 103 from outside the stirring tank 102.

Here, in the stirring tank 102, an incident area into which the sheet laser beam 103 enters and a visual field area into which photographing is performed are each constituted by transparent glass windows (not shown). Further, the sheet laser beam 103 is emitted from an irradiation unit 104 provided outside the stirring tank 102 in a fan-like manner. Furthermore, a photographing unit 105 is provided outside the stirring tank 102 for photographing an irradiated area within the stirring tank 102 irradiated with the sheet laser beam 103 to generate a photographed image.

According to this, by photographing the irradiation area in the stirring tank 102 with the photographing unit 105, it is possible to obtain a photographed image in which flocs in the raw water 101 within the irradiation area irradiated with the sheet laser beam 103 are photographed. By binarizing this captured image, the shape, size, number, etc. of the flocs can be measured.

Incidentally, a floating object observation device as described above is described, for example, in Patent Document 1 below.

JP2018-4506

However, in the above-mentioned conventional type, there is an entrance glass window for allowing the sheet laser beam 103 to enter the stirring tank 102 from the outside to the inside, and a photographing glass window for allowing the inside of the stirring tank 102 to be photographed from the outside. must be provided in the stirring tank 102, and if such a glass window becomes dirty, there is a risk that the accuracy of the photographed image will decrease, so the glass window must be cleaned frequently, which requires time and effort for maintenance. There's a problem.

SUMMARY OF THE INVENTION An object of the present invention is to provide a floating object observation device that can reduce maintenance effort and obtain clear images of floating objects.

In order to achieve the above object, the first invention is a floating object observation device for observing floating objects in a liquid, comprising:
A laser light source that irradiates the liquid surface with sheet laser light that spreads laterally, and an imaging device that images floating objects irradiated with the sheet laser light that has entered from the liquid surface are provided above the liquid surface,
The point where the sheet laser beam enters the liquid surface from above the liquid surface is defined as the liquid surface incident point,
If the part where the reflected light incident on the imaging device among the reflected light that is reflected by the sheet laser beam hitting the floating object passes through the liquid surface is defined as the liquid surface passage point.
A wave shielding member is provided that surrounds the liquid surface incident point and the liquid surface passing point above and below the liquid surface to block waves on the liquid surface,
The imaging range in which floating objects irradiated with sheet laser light are imaged by an imaging device includes at least an area below the wave shielding member below the liquid surface.

According to this, since the laser light source and the imaging device are installed above the liquid surface, there is no need to provide a glass window for incidence or a glass window for photographing in the tank, and maintenance can be easily performed, reducing maintenance costs. It is possible to reduce the

In addition, since the wave shielding member surrounds the liquid surface incident point and the liquid surface passing point above and below the liquid surface and blocks waves on the liquid surface, the sheet laser beam and reflected light are not affected by the waves on the liquid surface. This can prevent irregular swinging in the liquid. Thereby, it is possible to prevent the captured image from being distorted, and it is possible to obtain a clear image of the floating object.

In addition, since the imaging range includes at least the area below the wave shield member below the liquid surface, even if it is difficult for floating objects to flow inside the wave shield member, the area below the wave shield member The floating object can be reliably imaged by the imaging device, and the accuracy of observing the floating object is improved.

In the floating object observation device according to the second aspect of the present invention, a light shielding member is provided between the laser light source and the imaging device to prevent sheet laser light emitted from the laser light source and reflected on the liquid surface from entering the imaging device. It is something that exists.

According to this, the light shielding member blocks the sheet laser light irradiated from the laser light source and reflected on the liquid surface, thereby preventing the sheet laser light reflected on the liquid surface from entering the imaging device. You can get clear images of objects.

In the floating object observation device according to the third aspect of the present invention, the opaque case that houses the laser light source and the imaging device also serves as a wave shielding member,
There is a liquid level entrance point and a liquid level passage point inside the case.
A lower end opening that opens below the liquid level is formed at the lower end of the case,
The imaging range includes at least an area below the bottom opening,
The sheet laser light reaches the imaging range from inside the case through the bottom opening,
The reflected light enters the case from the imaging range through the lower end opening.

According to this, because the case surrounds the liquid surface incident point and the liquid surface passage point and blocks the liquid surface waves, the sheet laser beam and reflected light are affected by the liquid surface waves and become irregular in the liquid. It is possible to prevent it from swinging.

Further, when the floating object observation device is installed outdoors, sunlight is blocked by the case, so sunlight can be prevented from entering the imaging device, and a clear image of the floating object can be obtained.

In the floating object observation device according to the fourth aspect of the present invention, the laser light source and the imaging device are arranged so that the traveling path of the sheet laser beam and the traveling path of the reflected light are orthogonal in the imaging range.

According to this, it is possible to reduce the shift in focus in the imaging range, and it is possible to obtain a clear and focused image of floating objects.

In the floating object observation device according to the fifth aspect of the present invention, the floating objects are flocs generated by adding a flocculant to a liquid.

According to this, a clear image of the flocs can be obtained, and the accuracy of floc observation is improved.

As described above, according to the present invention, it is possible to reduce maintenance effort and obtain clear images of floating objects. Furthermore, the accuracy of observing floating objects is improved.

FIG. 1 is a sectional view of a floating object observation device according to a first embodiment of the present invention. FIG. 2 is a plan view of the floating object observation device. It is a basic conceptual diagram showing the main components of the floating object observation device in three dimensions. FIG. 3 is a sectional view of a floating object observation device according to a second embodiment of the present invention. FIG. 2 is a plan view of the floating object observation device. It is a sectional view of the floating object observation device in a 3rd embodiment of the present invention. It is a partially cutaway bottom view of the floating object observation device in the same. It is a sectional view of the floating object observation device in the 4th embodiment of the present invention. It is a partially cutaway bottom view of the floating object observation device in the same. It is a sectional view of the floating object observation device in the 5th embodiment of the present invention. It is a partially cutaway bottom view of the floating object observation device in the same. It is a sectional view of the floating object observation device in a 6th embodiment of the present invention. 13 is a view taken along the line XX in FIG. 12. FIG. It is a diagram of a conventional floating object observation device.

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

(First embodiment)
In the first embodiment, as shown in FIG. 1, 1 is a floc formation tank installed in a water purification plant, for example. Raw water 2 (an example of a liquid) is stored in the flocculation tank 1, and by adding a flocculant to the raw water 2, a large number of flocs 3 (an example of suspended matter) are generated in the raw water 2.

As shown in FIGS. 1 to 3, the floc formation tank 1 is provided with a floating object observation device 10 for observing flocs 3 in the raw water 2. The floating object observation device 10 includes a laser light source 12 that irradiates a sheet laser beam 11 onto the water surface 4 (liquid surface), and a camera 14 (an imaging device) that images the flocs 3 irradiated with the sheet laser beam 11 incident from the water surface 4. example).

Note that the sheet laser light 11 spreads in a fan shape in the lateral direction from the laser light source 12 in a plan view as shown in FIG. 2, and is substantially linear in a side view as shown in FIG.

These laser light source 12 and camera 14 are provided above the water surface 4 and are supported by a fixed frame (not shown) or the like fixed to the tank wall 1a of the flocculation tank 1.

Note that a location where the sheet laser beam 11 enters the water surface 4 from above the water surface 4 is defined as a water surface incident location 16 (liquid surface incident location). Also, a water surface passing point 18 (liquid surface passing point) is a point where the reflected light 17 of the reflected light that is reflected by the sheet laser beam 11 hitting the flock 3 and entering the lens 15 of the camera 14 passes through the water surface 4 from bottom to top. shall be.
A wave shielding member 20 is provided that surrounds the water surface incident point 16 and the water surface passing point 18 and blocks waves on the water surface 4. The wave shielding member 20 is a cylindrical member supported by a fixed frame (not shown) fixed to the tank wall 1a or bottom of the flocculation tank 1, and its lower end is submerged below the water surface 4. The upper end protrudes above the water surface 4.

An imaging range 21 in which the flock 3 irradiated with the sheet laser beam 11 is imaged by the camera 14 is set below the water surface 4 and below the lower end of the wave shielding member 20. Note that the laser light source 12 and the camera 14 are arranged at a position where the traveling path 23 of the sheet laser beam 11 and the traveling path 24 of the reflected light 17 intersect at right angles in the imaging range 21 . In this arrangement, the incident angle A1 of the sheet laser beam 11 is 54°, and the refraction angle A2 is 37°. Further, the incident angle B1 of the reflected light 17 is 37°, and the refraction angle B2 is 54°. Note that the values of the incident angles A1, B1 and the refraction angles A2, B2 are merely examples, and vary depending on the properties (for example, specific gravity, etc.) of the raw water 2.

In addition, in FIG. 1, the size of the flocculation tank 1 is depicted to be about one size larger than the floating object observation device 10 for convenience, but in reality, the size of the flocculation tank 1 is larger than that of the floating object observation device 10. It is significantly larger.

The operation of the above configuration will be explained below.

A sheet laser beam 11 is irradiated from a laser light source 12, and a camera 14 images the flock 3 within an imaging range 21. At this time, since the wave shielding member 20 surrounds the water surface incident point 16 and the water surface passing point 18 above and below the water surface 4 and blocks waves on the water surface 4, the sheet laser beam 11 and the reflected light 17 are not reflected on the water surface 4. It is possible to prevent irregular shaking in the raw water 2 due to the influence of waves. Thereby, it is possible to prevent the captured image from being distorted, and it is possible to obtain a clear image of the flock 3.

Furthermore, since the imaging range 21 is set in an area below the lower end of the wave shielding member 20, even if the flocs 3 are difficult to flow into the inside of the wave shielding member 20, the area below the wave shielding member 20 is The flocs 3 in the area can be reliably imaged by the camera 14, and the observation accuracy of the flocs 3 is improved.

Furthermore, since the traveling path 23 of the sheet laser beam 11 and the traveling path 24 of the reflected light 17 are perpendicular to each other in the imaging range 21, it is possible to reduce the shift in focus in the imaging range 21, and to obtain clear and focused images. An image of flock 3 can be obtained. By binarizing the image obtained in this manner, the shape, size, number, etc. of the flocs 3 can be measured with high accuracy, and the observation accuracy of the flocs 3 is improved.

In addition, since the laser light source 12 and camera 14 are provided above the water surface 4, there is no need to provide a glass window for incidence or a glass window for photographing in the floc formation tank 1, which facilitates maintenance. It is possible to reduce the effort involved.

Furthermore, since the laser light source 12 and the camera 14 do not come into contact with the raw water 2, it is possible to prevent the laser light source 12 and the camera 14 from becoming dirty or malfunctioning, compared to the case where the laser light source 12 and the camera 14 are installed underwater.

(Second embodiment)
In the second embodiment, as shown in FIGS. 4 and 5, a portion 11a of the sheet laser beam 11 emitted from the laser light source 12 may be reflected on the water surface 4. A light shielding member 30 is provided on the water surface 4 between the laser light source 12 and the camera 14 to prevent part of the sheet laser light 11a reflected on the water surface 4 from entering the camera 14 in this manner. The light shielding member 30 is a flat, opaque member, and is attached to the wave shielding member 20.

According to this, the sheet laser beam 11a reflected on the water surface 4 can be prevented from entering the camera 14 by the light shielding member 30 blocking the sheet laser beam 11a reflected on the water surface 4. Therefore, a clear image of the flock 3 can be obtained.

In the first and second embodiments described above, as shown in FIGS. 1 and 4, the imaging range 21 is set to a region below the lower end of the wave shielding member 20, but the upper part of the imaging range 21 is It may be located somewhat above the lower end of the wave shield member 20.

In the first and second embodiments, the wave shielding member 20 is formed in a cylindrical shape as shown in FIGS. 2 and 5, but it may be formed in a rectangular tube shape.

(Third embodiment)
In the third embodiment, as shown in FIGS. 6 and 7, the laser light source 12 and camera 14 are housed in an opaque case 35. The case 35 also has a function as the wave shielding member 20, and includes one case body 35a and the other case body 35b connected in a V shape when viewed from the side. Note that the lower part of the case 35 is submerged below the water surface 4, and the upper part of the case 35 protrudes above the water surface 4.

Each of the case bodies 35a and 35b is a rectangular cylinder with a closed upper end, and includes an upper plate 60, a lower plate 61, a pair of side plates 62, and an upper end cover plate 63. The lower ends of both case bodies 35a and 35b are connected to each other. Further, a lower end opening 36 that opens below the water surface 4 is formed at the lower end of the case 35 .

A laser light source 12 is provided in one case body 35a, a camera 14 is provided in the other case body 35b, and a lower end opening 36 communicates with both case bodies 35a and 35b. Further, the water surface incident point 16 is located within one case body 35a, and the water surface passing location 18 is located within the other case body 35b. Further, the imaging range 21 is set in an area below the lower end opening 36.

Note that the distance between the laser light source 12 and the camera 14 in the horizontal direction at this time is C1, and the imaging depth from the water surface 4 to the imaging range 21 is D1.

The operation of the above configuration will be explained below.

The sheet laser light 11 irradiated from the laser light source 12 passes through one case body 35a and reaches the imaging range 21 from the lower end opening 36. Further, the reflected light 17 passes through the lower end opening 36 from the imaging range 21, enters the other case body 35b, and enters the camera 14.

At this time, one case body 35a surrounds the water surface incident point 16 and blocks the waves on the water surface 4, and the other case body 35b surrounds the water surface passage point 18 and blocks the waves on the water surface 4, so that the sheet laser beam It is possible to prevent the reflected light 11 and the reflected light 17 from swinging irregularly in the raw water 2 due to the influence of waves on the water surface 4.

Further, when the floating object observation device 10 is installed outdoors, sunlight is blocked by the case 35, so sunlight can be prevented from entering the camera 14, and a clear image of the flocs 3 can be obtained. can.

(Fourth embodiment)
In the fourth embodiment, as shown in FIGS. 8 and 9, the case 35 is formed into a U shape when viewed from the side, so that the distance C2 between the laser light source 12 and the camera 14 in the horizontal direction is adjusted to the third value. The interval C1 (see FIG. 6) shown in the embodiment is expanded, and the imaging depth D2 is made larger than the imaging depth D1 (see FIG. 6) shown in the third embodiment.

The case 35 has one case body 35a, the other case body 35b, and an intermediate case body 35c connected between the lower part of the one case body 35a and the lower part of the other case body 35b. .

The intermediate case body 35c has an intermediate upper plate 66 and a pair of intermediate side plates 67. The intermediate upper plate 66 is provided between the lower end portions of the upper plate 60 of both case bodies 35a and 35b. Moreover, the intermediate side plate 67 is provided between the lower ends of the side plates 62 of both case bodies 35a and 35b.
The intermediate case body 35c is submerged below the water surface 4. Further, the lower end opening 36 communicates with the interior of the intermediate case body 35c, and is formed below the intermediate upper plate 66 and between the lower ends of the pair of intermediate side plates 67. One end in the intermediate case body 35c and a lower end in one case body 35a are in communication, and the other end in the intermediate case body 35c and a lower end in the other case body 35b are in communication. There is.

According to this, as shown in FIGS. 6 and 8, by enlarging or reducing the horizontal distances C1 and C2 between the laser light source 12 and the camera 14, the imaging depth can be easily adjusted to the optimal imaging depth D1, It can be changed to D2.

Further, by preparing a plurality of types of intermediate case bodies 35c having different lengths and exchanging these intermediate case bodies 35c, the imaging depth can be changed to the optimal imaging depth.

(Fifth embodiment)
In the fourth embodiment described above, as shown in FIG. 8, the intermediate case body 35c is submerged below the water surface 4, but in the fifth embodiment described below, as shown in FIGS. As shown, the lower part of the intermediate case body 35c is submerged below the water surface 4, and the upper part of the intermediate case body 35c protrudes above the water surface 4.

Inside the intermediate case body 35c, there are a water surface 4 and a space 40 formed on the water surface 4 and communicating with the internal spaces 38, 39 of both case bodies 35a, 35b.

According to this, the same operation and effect as the fourth embodiment described above can be obtained.

In the third to fifth embodiments described above, both case bodies 35a and 35b are each formed into a rectangular tube shape, but they may also be formed into a cylindrical shape.

(Sixth embodiment)
In the third to fifth embodiments described above, the case 35 was shown to be V-shaped or U-shaped in side view, but in the sixth embodiment described below, the case 35 is shown in FIGS. 12 and 13. As shown, the laser light source 12 and camera 14 are housed in a square box-shaped case 45.

The case 45 also has a function as a wave shielding member 20, and has a rectangular square tube-shaped body wall part 46 and a ceiling part 47 provided at the upper end of the body wall part 46. Note that the lower part of the case 45 is submerged below the water surface 4, and the upper part of the case 45 protrudes above the water surface 4. Further, a lower end opening 36 that opens below the water surface 4 is formed at the lower end of the case 45 . Further, the water surface incident point 16 and the water surface passing point 18 are located inside the case 45. Further, the imaging range 21 is set in an area below the lower end opening 36.

According to this, the sheet laser light 11 irradiated from the laser light source 12 reaches the imaging range 21 from inside the case 45 through the lower end opening 36. Further, the reflected light 17 enters the case 45 from the imaging range 21 through the lower end opening 36 and enters the camera 14 .

At this time, since the body wall portion 46 of the case 45 surrounds the water surface incident point 16 and the water surface passing point 18 and blocks the waves on the water surface 4, the sheet laser beam 11 and the reflected light 17 are not affected by the waves on the water surface 4. Therefore, it is possible to prevent irregular shaking in the raw water 2.

Further, when the floating object observation device 10 is installed outdoors, sunlight is blocked by the case 45, so sunlight can be prevented from entering the camera 14, and a clear image of the floc 3 can be obtained. can.

Furthermore, as shown by virtual lines in FIGS. 12 and 13, the wave shielding member 20 shown in the first embodiment may be provided inside the case 45. As a result, the waves on the water surface 4 are blocked in two stages by the case 45 and the wave shielding member 20, so that the sheet laser beam 11 and the reflected light 17 are affected by the waves on the water surface 4 and oscillate irregularly in the raw water 2. movement can be more reliably prevented.

In the sixth embodiment, the body wall portion 46 of the case 45 is formed into a rectangular tube shape, but it may also be formed into a cylindrical shape.

In each of the embodiments described above, the imaging range 21 is set to the lower end of the cases 35, 45, that is, the area below the lower end opening 36, but the upper part of the imaging range 21 is set to be slightly higher than the lower end opening 36. It's okay to be in it.

In each of the embodiments described above, the floating object observation device 10 is provided in the flocculation tank 1, but it may be provided in a tank other than the flocculation tank 1, for example, a sedimentation tank. Further, although the floc 3, which is an example of a floating object, is observed by the floating object observation device 10, particles other than the floc 3 may be observed.

2 Raw water (liquid)
3 Flock (floating matter)
4 Water surface 10 Floating object observation device 11 Sheet laser beam 12 Laser light source 14 Camera (imaging device)
16 Water surface incident point (liquid surface incident point)
17 Reflected light 18 Water surface passing point (liquid surface passing point)
20 Wave shield member 21 Imaging range 23, 24 Travel path 30 Light shielding member 35 Case 36 Lower end opening 45 Case C1, C2 Distance between laser light source and camera D1, D2 Imaging depth

Claims (5)

A floating object observation device for observing floating objects in a liquid,
A laser light source that irradiates the liquid surface with sheet laser light that spreads laterally, and an imaging device that images floating objects irradiated with the sheet laser light that has entered from the liquid surface are provided above the liquid surface,
The point where the sheet laser beam enters the liquid surface from above the liquid surface is defined as the liquid surface incident point,
If the part where the reflected light that is incident on the imaging device among the reflected light that is reflected by the sheet laser beam hitting the floating object passes through the liquid surface is defined as the liquid surface passage point.
A wave shielding member is provided that surrounds the liquid surface incident point and the liquid surface passing point above and below the liquid surface to block waves on the liquid surface,
A floating object observation device characterized in that an imaging range for imaging floating objects irradiated with a sheet laser beam by an imaging device includes at least an area below a wave shielding member below the liquid surface. 2. A light shielding member that prevents sheet laser light emitted from the laser light source and reflected on the liquid surface from entering the imaging device is provided between the laser light source and the imaging device. floating object observation device. The opaque case that houses the laser light source and imaging device doubles as a wave shield,
There is a liquid level entrance point and a liquid level passage point inside the case.
A lower end opening that opens below the liquid level is formed at the lower end of the case,
The imaging range includes at least an area below the bottom opening,
The sheet laser light reaches the imaging range from inside the case through the bottom opening,
3. The floating object observation device according to claim 1, wherein the reflected light enters the case from the imaging range through a lower end opening. Any one of claims 1 to 3, wherein the laser light source and the imaging device are arranged so that the traveling path of the sheet laser light and the traveling path of the reflected light are orthogonal in the imaging range. Floating object observation device described in . 5. The floating object observation device according to claim 1, wherein the floating objects are flocs generated by adding a flocculant to the liquid.

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