JP2012202794A - Water level measurement device and water level measurement method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water level measurement device capable of easily measuring the water level of a water surface of fluid with high precision even when the water surface of fluid in a cross section to be measured waves.SOLUTION: A water level measurement device (10) is configured to measure a water level of fluid flowing in a water channel (90) in a cross section to be measured. The water level measurement device includes: a reference scale (11) fixed to the water channel (90) nearby a water surface; an irradiation device (20) which continuously irradiates the water surface in the cross section to be measured with light (32) to be photographed across the water surface; a camera (80) which continuously photographs the water surface so that the light (32) to be photographed which is emitted by the irradiation device (20) and the reference scale (11) are included; and calculation means (72) of calculating a height position of the water surface from photographic image data generated by the camera (80).

Description

  The present invention relates to a water level measuring apparatus and a water level measuring method capable of measuring the water level of the water surface even when the water level of the fluid in the cross section to be measured is undulating.

  Management of the intake flow rate of a hydropower plant is important for the proper operation of the facilities of the power plant. In hydroelectric power generation, the output of the generator changes depending on the flow rate of water, and there is also an influence on the downstream side. Therefore, it is necessary to appropriately control the flow rate. For example, in small hydroelectric power generation, water is taken from a water channel branched from a river and the flow rate of water flowing through the water channel is managed. The water channel branched from the river is called “open channel” or “open channel”.

When the flow rate is measured by opening, the flow velocity distribution of a predetermined section of opening is obtained, and the flow velocity distribution data is multiplied by the opening cross-sectional area. In general, a propeller velocimeter or the like is used for the above flow velocity measurement.
On the other hand, it is easiest to use a design drawing for measuring the dimensions of the opening cross section, but there are cases in which actually measured values are used when water is extracted from the opening, that is, when the water is extracted.

In some cases, a dimension measuring method using ultrasonic waves may be employed. In the dimension measuring method, the distance is calculated from the propagation time of the ultrasonic wave and the underwater sound velocity. In this case, the flow rate measurement uses the function of an ultrasonic flow velocity distribution meter (ADCP).
As an example of a method for measuring the flow rate of a water channel using ultrasonic waves, the ultrasonic flow rate measurement method of Patent Document 1 is disclosed. In Patent Document 1, the water channel is divided into a central portion, a peripheral portion closer to the wall surface or the bottom surface than the central portion, and an outer edge portion close to the wall surface or the bottom surface. Then, the flow velocity distribution around the water channel is measured with ultrasonic waves. The flow velocity distribution in the central portion of the water channel is a technique in which the flow rate of the entire water channel is obtained by interpolation using the measured flow velocity distribution in the peripheral region.

JP 2010-190775 A

Now, the purpose of the technique disclosed in Patent Document 1 is to measure the flow rate of the entire large-scale water channel with simple equipment. That is, the flow rate of water is measured using ultrasonic waves using the Doppler method or the cross-correlation method. Moreover, a flowing water cross-sectional area is calculated from a known water channel shape and size and a water level measured by another means, and a flow rate is calculated from the flowing water cross-sectional area and the measured flow velocity.
Therefore, in order to achieve the purpose of measuring the flow rate of the entire large-scale water channel with simple equipment, it is sufficient to use the known water channel shape and dimensions.

However, when measuring for the purpose of calculating an accurate flow rate, it is necessary to accurately grasp the cross-sectional shape of the flowing water to be measured with an ultrasonic flowmeter. In that case, it is necessary to grasp the cross-sectional shape of running water based on accurate measurement of the dimensions of the open cross-section and the position (water level) where the upper ends of the cross-sectional shape are continuous.
For example, since the flow rate measurement accuracy when performing an efficiency test of a hydroelectric power plant is required to be high accuracy, it is necessary to measure the cross-sectional dimension of the unfolding with high accuracy. This is because, depending on the size of the unfolding, a difference in flow rate of about 1% may occur due to a difference in cross-sectional dimensions of about several centimeters.

In view of the above points, the technique disclosed in Patent Document 1 is insufficient. This is because neither the grasping of the cross-sectional shape of running water based on the accurate measurement of the dimensions of the open cross-section nor the position (water level) where the upper ends of the cross-sectional shape are continued can be performed.
This can be dealt with by measuring changes in the water level over time using a commercially available water level meter and means for continuously recording the water level data. However, unevenness is generated on the water surface at a location where the flow disturbance is large, such as immediately after branching. Therefore, unless the water level in the cross-sectional direction of the culvert is measured, it is impossible to measure the flow cross-sectional area with high accuracy.

The problem to be solved by the present invention is to provide a water level measuring device and a water level measuring method capable of measuring the water level on the water surface perpendicular to the flow direction.

(First invention)
A first invention in the present application relates to a water level measuring device for measuring a water level of a cross section to be measured in a fluid flowing through a water channel (90).
That is, a reference scale (11) fixed to the vicinity of the water surface with respect to the water channel (90), and irradiation that continuously irradiates the photographing light (32) so as to cross the flow direction with respect to the water surface in the cross section to be measured A device (20), a camera (80) for continuously photographing the water surface so as to include the light to be photographed (32) irradiated by the irradiation device (20) and the reference scale (11), and the camera (80 ) To a water level measuring device (10) provided with calculation means (72) for calculating the height position of the water surface from the photographed image data.

(Glossary)
The “fluid” is generally river water, but is not limited to “water”.
With regard to the camera (80), “continuous shooting” includes shooting of a large number of still images in addition to shooting as a moving image.
Regarding the calculation means (72), “calculating the height position of the water surface from the photographed image data” is to perform image processing where the position of the photographed light (32) is relative to the reference scale (11). is there.

(Function)
The light to be photographed (32) is continuously irradiated by the irradiation device (20) so as to cross the water surface of the cross section to be measured in the fluid flowing through the water channel (90). The to-be-photographed light (32) is reflected by the water surface and becomes reflected light. The camera (80) continuously photographs the water surface so as to include the reflected light of the light to be photographed (32) on the water surface and the reference scale (11).
The calculating means (72) calculates the height position of the water surface from the photographed image data photographed so as to include the reference scale (11).
For example, the height position in the reflected light of the photographing light (32) irradiated on the water surface in the measurement cross section is calculated.
Thereby, even if the water surface of the cross section to be measured in the fluid flowing through the water channel (90) is undulating, the water level on the water surface can be measured easily and with high accuracy.

(Variation 1 of the first invention)
The first invention can also provide the following variations.
That is, the irradiation device (20) may include a horizontal direction changing means (50) for continuously changing the light to be photographed (32) in a direction parallel to the water channel (90).

(Function)
Although the water surface fluctuates at a certain cycle, the water level may not be measured properly because the fluctuation cycle of the water surface is too long. In that case, when the shooting light (32) is continuously changed with respect to the horizontal direction by the horizontal direction changing means (50), the number of reflected light of the shooting light (32) irradiated on the water surface is acquired. Increase. As a result, the water level can be measured appropriately.

(Variation 2 of the first invention)
The first invention can also provide the following variations.
That is, the camera (80) is a stereo camera that shoots the light to be photographed (32) simultaneously from a plurality of different locations, and the calculation means (72) is synchronized in the plurality of cameras (80). Image processing may be executed using the captured image.

(Function)
If the camera (80) is a stereo camera, it can be displayed as a three-dimensional image. Thereby, detailed data corresponding to the disturbance of the water surface can be obtained, and the water level can be measured with higher accuracy.

(Second invention)
The second invention in the present application is directed to an irradiation procedure for continuously irradiating the light to be photographed (32) so as to cross the flow direction with respect to the water surface of the fluid flowing through the water channel (90), and to the water channel (90). A photographing procedure for continuously photographing the water surface with the camera (80) so as to include the reference scale (11) fixed to the vicinity of the water surface and the light to be photographed (32), and the water surface from the photographed image data by the photographing procedure. The water level measurement method by executing the water level calculation procedure for calculating the height position of the water level.

(Function)
For example, even when the water surface of the cross section to be measured in the fluid flowing through the water channel (90) is undulating, the water level of the water surface can be measured.

According to the present invention, a water level measuring device and a water level measuring method capable of measuring the water level on the water surface perpendicular to the flow direction can be provided.

1 is a schematic perspective view showing an embodiment of the present invention. It is sectional drawing of an opening when measuring a to-be-measured cross section. It is a schematic exploded perspective view of an irradiation apparatus. It is operation | movement explanatory drawing explaining the rocking | fluctuation operation | movement of the laser head part which emits a laser beam in an irradiation apparatus. It is the partial front view seen toward the head nozzle from the shielding board. It is the front view seen toward the head nozzle from the shielding board. It is a functional block diagram of the water level measuring device concerning the embodiment of the present invention. It is a schematic perspective view of embodiment which performs stereo imaging | photography.

Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIGS. 1 and 2, the water level measurement device 10 according to the present embodiment includes a reference scale 11, an irradiation device 20, a camera 80, and a control device 60. In the present embodiment, an example is to measure the water level of the cross section to be measured in the fluid flowing through the opening 90.

The light to be imaged emitted from the irradiation device 20 must be light that can be clearly distinguished from the color of the fluid in addition to the laser light 32.
The reference scale 11 is fixed to the vicinity of the water surface with respect to the opening 90 as shown in FIG. 1, and is a scale for visually measuring the water level.

  The irradiation device 20 includes a laser head unit 30 including a head nozzle 31 that emits a laser beam 32 that is an imaging light, and an imaging target that continuously moves the laser beam 32 so as to cross the water surface in the measurement cross section. And an optical movement device 40.

Furthermore, a horizontal direction changing device 50 that continuously changes the laser beam 32 with respect to the horizontal direction may be provided.
As an example, the irradiation apparatus 20 is provided with a box-shaped apparatus main body 21 on a pedestal 22 on which a tripod 23 can be installed at a desired location, for example, as shown in FIGS.

  The to-be-photographed light moving device 40 is provided in the device main body 21. On one side surface of the apparatus main body 21, an arc-shaped long hole guide hole 41 is formed. Further, the movable support member 42 is guided and moved by the guide hole 41 while being inserted into the guide hole 41. That is, one end side of the movable support member 42 protrudes to the outside of the apparatus main body 21, and the other end side of the movable support member 42 is inserted into the apparatus main body 21.

In addition, a disk-shaped rotating part 45 is provided at the lower part inside the apparatus main body 21 so as to rotate, for example, in one direction by a rotation driving mechanism 44 including a motor and a rotating gear.
In addition, the other end of the movable support member 42 is rotatably connected to a point near the outer peripheral edge of the rotating portion 45 by an interlocking member 43 such as a piston.

  The laser head unit 30 is fixed to one end side of a movable support member 42 that protrudes to the outside of the apparatus main body 21. Further, in addition to the head nozzle 31 being attached to the upper portion of the laser head portion 30, the horizontal direction changing device 50 is provided at the lower portion thereof.

  The horizontal direction changing device 50 includes a rotation driving unit 51 such as a motor fixed to the side surface of the laser head unit 30 on the same side as the head nozzle 31, and a shielding plate 52a fixed to the tip of the rotation shaft of the rotation driving unit 51. And. In the shielding plate 52a, a plurality of laser beam passage holes 53 are provided on a concentric circle of rotation with respect to a position where the laser beam 32 emitted from the head nozzle 31 is blocked.

The laser beam 32 emitted from the head nozzle 31 is shielded by the shielding plate 52a. However, the light passes through the laser beam passage hole 53 as the shielding plate 52a rotates. At this time, since the laser beam 32 has a width and a spread, when the laser beam passage hole 53 moves with respect to the laser beam 32 from left to right, for example, the laser beam 32 is shown in FIGS. Thus, the position of the width through which the laser beam 32 passes changes from left to right.
The laser beam 32 also changes from the left to the right by the subsequent laser beam passage hole 53 as described above. Thereafter, the operation is repeated.
As a result, when the shielding plate 52a is rotated, the laser beam 32 intermittently passes through the laser beam passage hole 53 and changes in the horizontal direction.

As an example different from the above-described shielding plate 52a, the shielding plate 52b shown in FIGS. 6A to 6D has a fan-shaped laser beam passage notch 54 on the outer peripheral side thereof. 6A to 6D are front views as viewed from the shielding plate 52b toward the head nozzle 31. FIG.
When the shielding plate 52b rotates in the direction of the arrow, in FIG. 6A, the laser beam 32 passes through the laser beam passage notch 54 and irradiates with a width and spread.

In FIG. 6B, since the laser beam 32 is shielded from the right side by the right shielding plate 52b of the laser beam passage notch 54, the width of the laser beam 32 moves to the left side and is irradiated.
In FIG. 6C, the laser beam 32 is completely blocked by the shielding plate 52b.

In FIG. 6D, since the laser beam 32 blocked by the shielding plate 52b is released from the right side by the laser beam passage notch 54, the width of the laser beam 32 moves to the right side and is irradiated.
As a result, when the shielding plate 52b is rotated, the laser light 32 is intermittently passed by the laser light passage notch 54 and is changed in the horizontal direction.

The horizontal direction changing device 50 is not limited to the method shown in FIGS. Any configuration of the apparatus that changes the laser beam 32 in the horizontal direction may be used.
Further, the operation of the photographic light moving device 40 is performed, for example, when the disk-like rotating portion 45 makes one rotation in the direction of the arrow as shown in FIGS. 4 (a) to 4 (d), the movable support member 42 moves. It reciprocates once while being guided by the guide hole 41 of the arc-shaped elongated hole through the interlocking member 43.
As a result, the laser head 30 changes its angle so that the laser beam 32 is continuously irradiated across the water surface in the cross section to be measured as shown in FIG.

  When the operation of the horizontal direction changing device 50 is further added, the laser light 32 irradiated to the water surface is intermittently changed in the horizontal direction as shown in FIGS. That is, the laser beam 32 is reflected on the water surface and becomes reflected light 33.

The camera 80 continuously photographs the water surface so as to include the reflected light 33 of the laser light 32 irradiated by the irradiation device 20 and the reference scale 11.
Further, the camera 80 can be a stereo camera that simultaneously captures the laser light 32 from a plurality of different locations as shown in FIG. The stereo camera can be displayed as a three-dimensional image. As a result, detailed data according to the disturbance of the water surface can be acquired, and the water level can be measured with higher accuracy.

The control device 60 uses a measurement terminal such as a personal computer. The measurement terminal includes a control unit 70, a storage unit 61, a display unit 62, and an operation unit 63.
The control unit 70 manages and controls the measurement terminal using a semiconductor integrated circuit including a central processing unit (CPU). The storage unit 61 includes a ROM, a RAM, an EEPROM, a nonvolatile RAM, a flash memory, an HDD (Hard Disk Drive), and the like, and stores a program processed by the control unit 70, acquired data, and the like.

  The display unit 62 includes a liquid crystal display, EL (Electro Luminescence), PDP (Plasma Display Panel), and the like, and displays a GUI (Graphical User Interface) of an application stored in the storage unit 61. The operation unit 63 includes a plurality of keys (switches) such as a keyboard, a cross key, and a joystick, and a mouse, and is used to input a user operation.

Further, the control unit 70 includes an image processing device 71, a calculation unit 72 (calculation means), and a command unit 73.
The image processing device 71 converts an image taken by the camera 80 into a digital signal. In the present embodiment, an image photographed so as to include the reflected light 33 of the laser light 32 on the water surface irradiated by the irradiation device 20 and the reference scale 11 is converted into a digital signal.

  The calculation unit 72 compares the reference scale 11 with each laser beam 32 intermittently irradiated across the water surface in the cross section to be measured from the captured image data obtained from the camera 80 through the image processing device 71. Thus, the height position of the reflected light 33 in each laser beam 32 is calculated. The average value of the height positions of the reflected lights 33 is calculated as the water level.

  The command unit 73 gives a command to emit laser light 32 from the head nozzle 31 to the laser head unit 30 in the irradiation apparatus 20 via a cable. At the same time, a command for moving the laser beam 32 so as to cross the water surface of the fluid flow in the cross section to be measured is given to the object light moving device 40. Further, a command for continuously changing the laser beam 32 in the horizontal direction is given to the horizontal direction changing device 50.

Next, the operation of the water level measuring device 10 described above, that is, the water level measuring method according to the present invention will be described.
For example, the case where the water level in the measurement cross section of the eyelid 90 is measured is described. First, as shown in FIG. 1, the irradiation device 20 is installed so as to continuously move the laser beam 32 across the water surface of the fluid flow in the cross section to be measured of the eyelid 90.

  Laser light 32 is emitted from a head nozzle 31 in the laser head unit 30 of the irradiation device 20. At that time, the laser beam 32 is emitted by the imaging light moving device 40 so as to cross the water surface in the measurement cross section of the eyelid 90. In addition, the laser beam 32 irradiated to the water surface by the horizontal direction changing device 50 changes intermittently and horizontally as shown in FIGS.

  The reflected light 33 of the laser light 32 irradiated onto the water surface as described above is continuously photographed by the camera 80 so as to include the reference scale 11.

  In the control device 60, the reflected light 33 of each laser beam 32 intermittently irradiated across the water surface in the cross section to be measured from the captured image data obtained from the camera 80 through the image processing device 71, the reference scale 11, and the like. , And the height position of each reflected light 33 is calculated by the calculation unit 72. The average value of the height positions of the reflected lights 33 is calculated as the water level.

  As described above, the laser light 32 is continuously irradiated so as to cross the water surface of the fluid flow in the cross section to be measured of the opening 90, and the reflected light 33 of the laser light 32 on the water surface and the reference scale 11 are used. Is taken by the camera 80 so as to include. From the obtained image data information, the entire water level of the water surface in the cross section to be measured can be measured. Therefore, even if the water surface of the cross section to be measured in the fluid flowing through the opening 90 is undulating, the water level on the water surface can be measured.

When there is a single irradiation device 20, the laser light 32 may be traversed along the cross section to be measured in the eyelid 90 to be measured.
On the other hand, when a plurality of irradiation devices 20 can be used, for example, a plurality of laser beams 32 are irradiated on the water surface in a fan shape from the vicinity of the side wall 91 of the open eyelid 90, and the reflected light 33 of the many laser beams 32 is irradiated. What is necessary is just to acquire an image.

  Since the water surface changes every moment, the reflected light 33 from the water surface cannot always be acquired constantly. However, since the water surface fluctuates at a certain cycle, if the image measurement time is set so as to sufficiently cover the cycle, the reflected light 33 from the water surface can be acquired.

  When the water level cannot be measured properly because the fluctuation cycle of the water surface is too long, the number of images of the reflected light 33 obtained by finely vibrating the laser light 32 in the direction of fluid flow in the opening 90 is calculated. Can be increased. That is, the laser beam 32 can be finely oscillated in the fluid flow direction by using the horizontal direction changing device 50 to change the laser beam 32 in the horizontal direction of the fluid flow direction.

  With respect to acquiring an image of the reflected light 33 from the water surface, various cameras 80 such as a video camera and a high-speed camera can be selected according to the measurement period of the reflected light 33. At that time, in order to selectively acquire only the laser beam 32, it is desirable to use a frequency band filter of the laser beam 32 to be used.

  Since the water level may be obtained as an average value for a certain period of time, image acquisition by a digital camera is possible instead of image acquisition by a video camera. For example, the shutter of the digital camera is opened during the shooting time, and the reflected light 33 is continuously shot. By processing the image thus measured, the average value of the water level of the reflected light 33 can be obtained.

  From the above, in the water level measurement device and the water level measurement method according to the present embodiment, the fluid flowing through the opening 90 is obtained by combining irradiation with light to be imaged such as the laser light 32 and image measurement using the camera 80. Even when the water surface of the cross-section to be measured was undulating, the water level could be measured.

  If the ultrasonic flowmeter has a cross-sectional shape that includes the water level using the measurement result of the water level, the flow rate of the fluid flowing through the opening 90 is smaller than when the fluid flow rate is measured ignoring the change in the water level. It becomes possible to measure with high accuracy.

The present invention relates to the manufacturing of ultrasonic flowmeters, the surveying service industry for measuring the amount of water in rivers, etc., the information for performing data measurement and data collection for judging the necessity of river dredging work and repair of river opening It has applicability in the service industry.

DESCRIPTION OF SYMBOLS 10 Water level measuring apparatus 11 Reference | standard scale 20 Irradiation apparatus 21 Apparatus main body 22 Base 23 Tripod 30 Laser head part 31 Head nozzle 32 Laser light (light to be imaged) 33 Reflected light 40 Imaged light moving apparatus 41 Guide hole part 42 Movable support member 43 Interlocking member 44 Rotation drive mechanism 45 Rotating unit 50 Horizontal direction change device (horizontal direction change means)
DESCRIPTION OF SYMBOLS 51 Rotation drive part 52a Shielding plate 52b Shielding plate 53 Laser beam passage hole 54 Laser beam passage notch unit 60 Controller 61 Storage unit 62 Display unit 63 Operation unit 70 Controller 71 Image processing unit 72 Calculation unit (calculation means) 73 Command Part 80 Camera 90 Opening (water channel; cross section to be measured) 91 Side wall

Claims (4)

A water level measuring device for measuring the water level of a cross section to be measured in a fluid flowing in a water channel,
A reference scale fixed near the surface of the waterway,
An irradiation device for continuously irradiating the imaging light so as to cross the flow direction with respect to the water surface in the cross section to be measured;
A camera that continuously shoots the water surface so as to include the light to be imaged irradiated by the irradiation device and the reference scale;
A water level measuring device comprising: a calculating means for calculating a height position of a water surface from image data taken by the camera.   The water level measuring device according to claim 1, wherein the irradiation device includes a horizontal direction changing unit that continuously changes the light to be photographed in a direction parallel to the water channel. The camera is a stereo camera that photographs the light to be photographed simultaneously from a plurality of different locations,
The water level measurement device according to claim 1, wherein the calculation unit executes image processing using synchronized captured image data of a plurality of cameras. An irradiation procedure for continuously irradiating the light to be photographed so as to cross the flow direction with respect to the water surface of the fluid flowing through the water channel,
A photographing procedure for continuously photographing the water surface with a camera so as to include a reference scale fixed near the water surface with respect to the water channel and the light to be photographed,
A water level calculation procedure for calculating a water surface height position from photographed image data according to the imaging procedure, and a water level measurement method that executes the following.

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