KR100894977B1 - Hydrograph apparatus in use binocular disparity - Google Patents

Abstract

A hydrograph apparatus is provided to ensure simple installation and easy measurement by using the binocular disparity of a float. A hydrograph apparatus comprises stereo cameras(114) which are installed on the vertical line of measurement water surface, facing the water surface, a rope(122) which hangs down in the center between the stereo cameras, a weight(126) connected to the end of the rope, a float(124) moved up and down along the rope, and a water level output unit which computes the binocular disparity from the right and left images of the float picked up by the stereo cameras and outputs the water level of the measurement water surface.

Description

Level measurement device using binocular disparity {Hydrograph Apparatus in use Binocular Disparity}

The present invention relates to a level measurement device, and more particularly to a level measurement device that can measure the water level using binocular parallax.

In conventional dams and reservoirs, water level measurement is performed using a water level meter for efficient management of low water volume. Conventional water level meters used for water level measurement include a contact level gauge that measures water level by directly contacting water, and an ultrasonic wave from the outside of the water. It is largely divided into a non-contact level gauge which measures the water level using a radar or the like.

A representative water level meter is typically a water level meter, which is the most widely used water level meter using a simple principle of measuring the water level by floating a float having buoyancy on the water surface. This floating water gauge consists of a float floating on the surface of the water, and a pulley body connected to the rich man and a rope to measure and record the water level according to the position of the rich man. It consists of a weight measuring counter (counter-weight), a pen and a magnetic clock to record the water level, and an A / D converter for digital recording or telemeter may be added.

This floating water gauge measures the position of the rich by floating the rich on the surface of the water, and the pulley rotates as the rope linked with the weight is wound on the pulley according to the vertical displacement of the rich according to the water level. Is detected and converted into an electrical signal so that it can be used in various control circuits.

In the case of float (floating) water level gauges, floats that rise and fall in response to changes in the water level on the surface, pulleys that are connected to the float and rotate as the floats rise, and encoders that sense the rotational speed of the pulleys with a constant electrical signal And it is composed of a converter and a display device that receives the signal of the encoder and converts it into an identifiable figure and is configured to measure and observe the reservoir or dam level.

However, in the case of the conventional float level gauge using the encoder, the fluctuation of the level is very large due to the structure of the mechanism directly linked to the pulley axis, despite the precise measurement using the encoder. It is difficult to obtain accurate data of the data, resulting in the effectiveness of the water level data being halved.

On the other hand, the non-contact level gauges typically include an ultrasonic level gauge and a radar level gauge. Among these, the ultrasonic level meter uses the principle of measuring the level by measuring the time when the ultrasonic wave is emitted from the sensor and reflected from the measurement surface, and this ultrasonic receiver is installed vertically above the water surface, when the ultrasonic wave hits the water surface and returns. By measuring the time to sleep and by measuring the distance between the sleeper and the ultrasonic transmitter it is not in contact with the sleep at all.

In addition, the radar level gauge emits several radar pulse signals through the antenna of the radar sensor and receives the signal reflected by the measurement target through the radar echo antenna to measure the distance according to the firing and receiving time of the radar pulse signal. The measurement distance is converted into a level in accordance with the level of the measurement object.

Contact type is widely used because it measures water level directly, but it is complicated in construction and burden of maintenance and inspection. Non-contact type is simple and easy to measure because there is no need for construction, but there is a risk that errors occur depending on the measurement environment.

An object of the present invention for solving the above problems is to provide a water level measuring device that is easy to construct and accurate water level measurement regardless of the measurement environment by measuring the water level non-contact through the image recognition of the float using binocular parallax. .

The water level measuring device for achieving the above object is a water level measuring device is a stereo camera which is installed facing the water on the vertical line of the measurement level, a rope stretched vertically downward on the center line of the stereo camera, the weight connected to the end of the rope Calculate the binocular disparity of the knit image from the zero point by recognizing the weight, a float that can be moved up and down by a rope, and the left and right images picked up from the stereo camera, and calculating the water level of the measured water surface using the calculated binocular disparity. Contains wealth.

The water level measuring device according to an embodiment of the present invention recognizes the image of a float using a stereo camera and calculates the recognized binocular parallax so that the water level is measured, so that a more accurate level measurement is possible, installation and construction are simple, and maintenance is possible. Is easy.

Hereinafter, the water level measuring apparatus according to the embodiments of the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited to the following embodiments, and those skilled in the art The present invention may be embodied in various other forms without departing from the spirit of the invention.

1 is an external perspective view of one embodiment of the water level measuring device according to the present invention.

Referring to FIG. 1, the water level measuring apparatus 100 according to the present invention has a rectangular box shape having a storage space therein by a combination of a main body 102 and a cover 104. On the upper surface of the cover 104, solar cells 106 are installed to obtain power, and a display window 108 for displaying the measured water level is formed on the inclined surface. The water level measuring apparatus 100 of the present invention is positioned on the slab of the dam floor so that the through hole 101 protrudes, and then anchors the anchor bolt to the coupling hole 110 protruding from the side of the main body with a nut.

Therefore, it is easy to install the measuring equipment simply by installing anchor bolts without additional construction on dams or bridges, and it is easy to move and transport.

2 is a longitudinal cross-sectional view of the water level measuring device according to the present invention.

Referring to the drawings, the water level measurement apparatus 100 is provided with a circuit board 112 in the upper upper portion of the storage space, the solar cell 106 is received between the circuit board 112 and the top surface of the cover 104 The top region of the cover 104 installed and corresponding to the solar cell 106 is formed of a transparent plate so that solar light is supplied to the solar cell 106 and protects the solar cell 106 from outside air. The space in which the solar cell 106 is accommodated is sealed with a transparent silicone adhesive to block the penetration of moisture.

The liquid crystal panel 116 is coupled to the display window 108 to display the measured water level.

A through hole 101 is formed downward in front of the device 100, and a stereo camera 114 is installed on a circuit board 114 vertically above the through hole 101. The charging battery 118 is installed below the inclined surface of the cover 104 to charge the electric energy generated by the solar cell 106.

The winch 120 is installed at the center of the main body 102, and the weight 126 is suspended at the end of the wire rope 122 wound on the winch 120, and the wire rope 124 is movable along the rope. 124).

The knitting 124 has a through hole 124a formed at the center thereof, and the wire rope 122 penetrates the through hole 124a and the weight 126 is suspended at the rope end. Therefore, by the weight 126 having a diameter larger than the inner diameter of the through hole 124a, the knit 124 is lifted together when the wire rope 122 is wound and is seated at the inlet of the through hole 101.

The through hole 124a of the knitting 124 has an inner diameter smaller than the diameter of the weight 126 and the lower portion is formed in a vial shape formed to have an inner diameter larger than the diameter of the weight 126. The storage space 124b is provided to accommodate the 126.

3 is a cross-sectional view of a portion of the through hole 101 of the water level measuring device according to the present invention.

Referring to the drawings, the left camera 114L and the right camera 114R of the stereo camera 114 are arranged side by side with a gap C ₀ and an illumination lamp 115 is installed at the center thereof. When the winch 120 is released and the weight 126 is positioned below the minimum water level below the water surface, the knitting 124 floats on the water surface and moves up and down along the rope 122 according to the water level fluctuation. The rope 122 is stretched vertically downward from the center of the stereo camera 144.

4 shows a control circuit configuration of the water level measuring device according to the present invention.

Referring to the drawing, the control circuit unit included in the circuit board 112 includes a left image pickup unit 202, a right image pickup unit 204, a lighting driver 206, a central control unit 208, a display unit 210, and a command input unit. 212, the day and night identification unit 214, the charging circuit unit 216, the winch driving unit 218, and the wireless transmission and reception unit 220.

The left image pickup unit 202 and the right image pickup unit 204 input image signals from the image sensors of the left camera 114L and the right camera 114R, respectively, and convert the image signals into digital image signals. Use only to extract the knitting image and calculate the center point of the extracted wild animal image. Therefore, the left knit image data is output from the left image pickup unit 202 and the right knit image data is output from the right image pickup unit 204. The lighting driver 206 turns on the lighting lamp 115 in response to the night identification signal of the central controller 208, and turns off the lighting lamp 115 in response to the day identification signal. Therefore, the water level can be measured at night.

The central control unit 208 includes a knitting image left parallax calculating module 208a, a knitting image right parallax calculating module 208b, a knitting image parallax calculating module 208c, and a water level calculating module 208d.

The knit image left parallax calculation module 208a and the knit image right parallax calculation module 208b calculate the horizontal left or right parallax value from the zero parallax point using the picked-up knit image data, respectively. The knit image parallax calculation module 208c calculates the binocular parallax value of the knit image by summing the calculated left and right parallax values.

The water level calculation module 208d calculates a corresponding water level value in every frame unit by using the calculated binocular disparity value of the knitted image, and outputs the average value of the calculated water level values as the water level value of the corresponding time in every second or every minute. do.

The central control unit 208 displays the calculated water level value on the display unit 210 or wirelessly transmits to the water level control center through the wireless transceiver 220.

In addition, the central control unit 208 receives data or commands such as power operation, winch operation, and setting value input through the command input unit 212.

The central controller 208 detects a change in ambient illumination through the day and night identification unit 214, and identifies the day and night in response to the detected ambient illumination to control the lighting driver 2060.

The central control unit 208 protects the battery 118 from overcharge and overdischarge by controlling the charging circuit unit 216 that charges the battery 118 with electrical energy generated from the solar cell 106 through the charging circuit unit 216. do.

The central control unit 208 rotates the winch 120 through the winch driving unit 218 to release the weight and stretch or roll it up.

5 shows an optical geometric relationship between the left and right cameras 114R and 114L and the knitting according to the present invention. In FIG. 5, each symbol is as follows.

AX _L : Optical axis of the left lens

AX _R : Optical axis of the right lens

Z ₀ : Linear distance (zero parallax distance) from the lens center to the gaze point (O _Z )

Z _W : Straight line distance from the lens center to the water surface (O _W )

Z _S : Straight line distance from the lens center to the image sensors S _L and S _R

f: Lens focal length

C _o : Distance between left and right lens (L _L , L _R ) centers (left and right camera gap)

C _Z : Distance between the zero parallax left and right image centers of the left and right image sensors S _L and S _R

C _W : Distance between the knitting left and right image centers captured by the image sensors S _L and S _R (distance between the knitting left and right image centers)

P _L : Left parallax

P _R : Right parallax

Accordingly, since Z ₀ : C _0/2 = Z _S : (C _Z -C ₀ ) / 2 in the similar-shaped areas A ₁ and A ₂ of FIG. 5, it is summarized as Equation 1 below.

[Equation 1]

C _Z = (Z _S / Z ₀ ) C _o + C _o

Similarly, in the similarly shaped regions A ₃ and A ₄ , Z _F : C _c / 2 = Z _S : (C _W -C _o ) / 2, which is thus summarized as Equation 2 below.

[Equation 2]

C _W = (Z _S / Z _W ) C _o + C _o

The parallax of the left and right images corresponding to the knitting is summarized by the following equation (3).

[Equation 3]

P _W = P _L + P _R

= C _Z -C _W

= (Z _S / Z ₀ ) C _o + C _o -{(Z _S / Z _W ) C _o + C _o }

= Z _S C _o (1 / Z _0-1 / Z _W )

Therefore, the equation (4) can be obtained by arranging the equation (3).

[Equation 4]

Z _W = Z _S Z ₀ C ₀ / (Z _S C ₀ -Z ₀ P _W )

6 shows a left and right image state obtained through the left and right cameras.

The contours of the knitting 124 are extracted from the images of FIG. 6, the left and right center points C _L and C _R of the extracted knitting image are calculated, and P _L and P _R are finally obtained to obtain P _W = P _L + P _R.

After calculating and substituting into Equation 4, Z _W can be obtained.

Therefore, by subtracting the distance (Z _W ) from the height of the dam floor (D _H ) to the knitting, the water level (W _H ) can be obtained by the following equation (5).

[Equation 5]

W _H = D _H -Z _W

The water level data thus obtained can be obtained 30 times per second by 30 frames per second video processing.

Normally, since waves exist on the surface due to wind or the like, the water level obtained by the image processing includes variations due to the waves. Therefore, in order to obtain an accurate water level, the water level data obtained 30 times per second is calculated as an average value according to [Equation 6] in unit time, for example, in minutes, and the average value is finally determined as the water level value of the corresponding time.

[Equation 6]

W _{H AV} = ∑ W _H / N

According to the present invention, the stereoscopic image obtained by using a stereo camera is analyzed to detect the water level, so that accurate water level detection is possible without the influence of fluctuations or movement of the float on the water surface, and it is convenient without additional construction on dams and bridges. Can be installed. In addition, it is possible to pick up knitting images at night by night light using solar energy, so it is possible to measure day and night.

Although described with reference to the embodiments above, those skilled in the art can variously modify and change the present invention without departing from the spirit and scope of the invention described in the claims below. You will understand.

1 is an external perspective view of one embodiment of the water level measuring device according to the present invention.

2 is a longitudinal cross-sectional view of the water level measuring device according to the present invention.

3 is a cross-sectional view of a portion of the through hole 101 of the water level measuring device according to the present invention.

4 shows a control circuit configuration of the water level measuring device according to the present invention.

5 shows an optical geometric relationship between the left and right cameras 114R and 114L and the knitting according to the present invention.

6 shows a left and right image state obtained through the left and right cameras.

Claims (1)

A rectangular box-shaped body having a cover and a first hole facing the water surface and a coupling hole protruding from the side surface; A stereo camera installed inside the main body at an upper portion of the first through hole to face water on a vertical line at a measurement level; An illumination lamp installed at the center of the stereo camera; A rope extending vertically downward through the first aperture on the centerline of the stereo camera; A calabash-type weight connected to the end of the rope; A winch installed inside the main body, the other end of the rope being wound to wind up or unwind the rope; A storage space having a size accommodated in the first through-hole of the main body, the second through-hole having an inner diameter smaller than the diameter of the weight, is formed in the center, and accommodates the bottle-shaped weight below the second through-hole. Is formed, the one end of the rope penetrates through the second through hole and installed so as to move freely up and down along the rope; A solar cell installed inside the main body under the transparent plate of the cover; A battery installed inside the main body and configured to store electrical energy generated from the solar cell; It is installed inside the main body, the winch is driven by hanging the rope to float the float on the measurement surface, the left and right images of the float floated on the surface picked up from the stereo camera to recognize the knitting image from the zero point Comprising a binocular parallax of the calculated and calculates the water level of the measurement sleep using the calculated binocular parallax, and a circuit board with a control circuit unit for lighting the illumination lamp at night in response to the day and night detection, The control circuit unit, Day and night identification unit for detecting day and night from the output voltage of the solar cell; An illumination driver for driving the illumination lamp at night in response to the detected day and night detection; A left image pickup unit which inputs an image signal from a left camera of the stereo camera and outputs left center point image data of a knit image; A right image pickup unit which inputs an image signal from a left camera of the stereo camera and outputs right center point image data of a knitted image; A wireless transceiver for transmitting the calculated water level value wirelessly to the water level control center; And It includes a central control unit for controlling each of these parts, The central control unit A crochet image left parallax calculation module and a crochet image right parallax calculation module for calculating horizontal left and right parallax values from a zero parallax point respectively using the crochet image data picked up from the left image pickup section and the right image pickup section, respectively; A knitting image disparity calculating module configured to calculate the binocular disparity value of the knitting image by adding the calculated left and right parallax values; And Comprising a calculated water level value for each frame unit using the calculated binocular parallax value of the knitting image, and the output level calculation module including the average value of the calculated water level values to the water level value of the corresponding time in the unit of second or every minute Water level measurement device using binocular parallax, characterized in that.

Images