KR101020650B1 - Non-Contact Open Channel Flow Meter - Google Patents

Abstract

It is an object of the present invention to provide a non-contact open channel flow meter that is accurate in flow rate measurement and low in maintenance costs without accumulating suspended matter.
As a means for achieving this object, the non-contact open channel flow meter according to the present invention is installed spaced apart in the vertical direction from the surface of the fluid flowing in the conduit 300, ultrasonic distance sensor 754 and microwave radar sensor 758 A flow sensor part 200 formed in one housing; And a flow rate calculation unit 100 electrically connected to the flow rate sensor unit 200, wherein the ultrasonic distance sensor 754 is configured to control the flow of fluid flowing in the conduit 300 using ultrasonic waves. The distance from the surface to the flow sensor unit 200 is measured, and the microwave radar sensor 758 measures the surface flow velocity of the fluid flowing in the conduit 300 by using the microwave, and the flow rate calculation unit 100 ) Receives the distance and the surface flow rate from the flow sensor unit 200, obtains the cross-sectional area of the fluid flowing in the conduit 300 based on the distance, multiplies the cross-sectional area by the surface flow rate to increase the flow rate. It is characterized by calculating.

Description

Non-contact open channel flow meter {OPEN CHANNEL FLOWMETER WITHOUT CONTACTING FLUID}

The present invention relates to a non-contact open channel flow meter for measuring instantaneous flow rate and to calculate a flow rate, and more particularly to a non-contact open channel flow meter having a microwave radar sensor for calculating a flow rate.

In recent years, the precise measurement of the flow rate of open channels, such as wastewater treatment systems or rivers, has become increasingly important with increasing interest in wastewater treatment systems or disaster prevention. In order to prevent damage by instantaneous peak flow in these facilities, it is necessary to measure the actual flow rate very precisely and reliably.

Many open channel flowmeters have been developed for this need. One example of calculating the flow rate using a conventional open channel flow meter will be described with reference to FIGS. 1 and 2. In this case, the open channel refers to a state in which a pipe is not shielded and is open, such as a water pipe having a manhole, a pipe, a river, or the like.

1 is an explanatory diagram schematically showing a liquid-contact open channel flowmeter having a conventional ultrasonic water level sensor and an ultrasonic flow rate sensor, and FIG. 2 is an explanatory diagram showing an irradiation range of ultrasonic waves in the ultrasonic flow rate sensor of FIG. 1.

The wetted open channel flow meter of FIG. 1 includes an ultrasonic water level sensor 10, an ultrasonic flow rate sensor 20, and a multiplier 40. The ultrasonic water level sensor 10 is installed at the upper end of the open manhole of the conduit 30, and the ultrasonic flow rate sensor 20 is installed at the bottom surface of the conduit 30. In the wetted flow meter, the ultrasonic level sensor 10 measures the level of the fluid flowing in the space by the number of pipes 300 or rivers, and inputs the result into the multiplier 40, and the ultrasonic flow rate sensor 20 is in the pipeline. Measure the flow rate of the fluid flowing through the and input the result to the multiplier (40). The multiplier 40 calculates the cross-sectional area of the fluid flowing in the conduit based on the water level input from the ultrasonic water level sensor 10, and multiplies the calculated flow cross-sectional area by the flow rate input from the ultrasonic flow rate sensor 20. Output the flow rate.

In FIG. 1, the ultrasonic water level sensor 10 calculates the water level by measuring the time from transmitting the ultrasonic wave to receiving the ultrasonic water level sensor 20, and the ultrasonic flow rate sensor 20 when the ultrasonic wave is scattered by the microparticles in the flow of the fluid. The frequency changes due to the Doppler effect, and the flow rate is measured by using the frequency change proportional to the particle velocity.

The ultrasonic flow rate sensor 20 is mounted on the bottom of the conduit, and emits ultrasonic waves while being always immersed in the fluid. The irradiation range of the ultrasonic wave emitted from the ultrasonic flow rate sensor 20 is a cone shape as shown in FIG. 2, and a large number of particles exist within the cone-shaped irradiation range. Therefore, since the Doppler effect occurs for each of the various particles n widely spread within the irradiation range of the ultrasonic wave, the ultrasonic flow rate sensor 20 changes the flow velocity depending on which particle is measured on the basis of which particle, and the deviation thereof increases. That is, it can be seen that in FIG. 2, the particles n in the θ angle and the particles n in the θ n angle move at different speeds, and the larger the θw angle is, the more the difference in speed increases. Here, Vn is the flow direction of the particle n in the fluid, θ n is the angle formed by the ultrasonic flow rate sensor 20 and the direction of movement of the particle n, θ is an angle formed by the center line of the ultrasonic wave and the estimated flow direction (ultrasonic projection angle) , θw represents the ultrasonic width or spread.

That is, even though a large number of particles exist within the irradiation range of the ultrasonic wave radiated from the ultrasonic flow rate sensor 20, the various flows are moved at different speeds according to the fluid flow profile in various parts of the region affected by the ultrasonic wave. The errors are severe, and the number of particles causes a high noise generation rate and a discontinuous Doppler signal.

 In addition, since the ultrasonic flow rate sensor 20 of FIG. 2 is mounted on the bottom of the pipeline, deposits accumulate on the main body of the ultrasonic flow rate sensor 20 for a long time, so that the measurement error is increased, maintenance is difficult, and the cycle is accompanied. There is a problem in that the maintenance cost is increased because the cleaning is required.

Accordingly, the present invention has been made in view of the above-described problems of the conventional liquid open channel flow meter, and an object thereof is to provide a non-contact open channel flow meter which is accurate in measuring flow velocity and low in maintenance cost without accumulating suspended matter in the main body.

In order to achieve the above object, the non-contact open channel flow meter according to the first embodiment of the present invention is installed spaced apart in the vertical direction from the surface of the fluid flowing in the pipeline, the ultrasonic distance sensor and the microwave radar sensor is one housing A flow sensor unit formed therein; And a flow rate calculation unit electrically connected to the flow rate sensor unit, wherein the ultrasonic distance sensor measures the distance from the surface of the fluid flowing in the conduit to the flow rate sensor unit using ultrasonic waves. The microwave radar sensor measures the surface flow velocity of the fluid flowing in the conduit using microwaves, and the flow rate calculation unit receives the distance and the surface flow velocity from the flow sensor unit, based on the distance. The cross-sectional area of the fluid flowing inside is calculated, and the flow rate is calculated by multiplying the cross-sectional area by the surface flow rate.

A non-contact open channel flow meter according to a second embodiment of the present invention is a non-contact open channel flow meter according to a second embodiment of the present invention, wherein the flow rate is vertically spaced apart from the surface of the fluid flowing in the conduit. It is characterized in that it further comprises a crest generating device is installed on the upstream side of the fluid flow compared to the sensor portion, and generates crests on the surface of the fluid.

The non-contact open channel flow meter according to the third embodiment of the present invention is a non-contact open channel flow meter according to the first or second embodiment of the present invention, wherein the non-contact open channel flow meter is spaced apart from the surface of the fluid flowing in the pipe in a vertical direction. An image pickup device installed on an upstream side of the fluid flow relative to the flow rate sensor portion, the image pickup device generating image data by imaging the surface of the fluid, wherein the image pickup device is connected to the flow rate calculation unit electrically connected to the image data. And the flow rate calculating unit extracts a feature point from the image data, detects a motion vector of the feature point by digital signal processing, calculates a feature point movement speed based on the detected motion vector, By the difference from the surface flow velocity measured from the microwave radar sensor It is characterized in that for correcting the flow rate.

In the non-contact open channel flow meter according to the third embodiment of the present invention, the feature point indicates position data of bubbles or floats floating on the surface of the fluid flowing in the conduit among the image data captured by the imaging device. It is characterized by.

A non-contact open channel flow meter according to a fourth embodiment of the present invention is a non-contact open channel flow meter according to a first or second embodiment of the present invention, wherein a bar shape is inserted into a fluid flowing in the pipeline to measure a flow rate. And a multi-point flowmeter having a measuring pointer of the multipoint flowmeter, wherein the multi-point flowmeter has a difference between the flow rate measured by the bar-shaped measuring pointer and the surface flow rate measured from the microwave radar sensor. As described above, the flow rate is corrected.

According to the present invention, it is possible to provide a non-contact open channel flowmeter because the sensor is not installed at the bottom of the pipe so that suspended matter does not accumulate, the flow rate measurement is accurate, and the maintenance cost is low.

1 is an explanatory view schematically showing a liquid-contact open channel flow meter having a conventional ultrasonic sensor and ultrasonic flow rate sensor.
It is explanatory drawing which showed the irradiation range of the ultrasonic wave in the ultrasonic flow velocity sensor of FIG.
3 is a view showing a state in which a non-contact open channel flow meter according to a first embodiment of the present invention is installed.
4 is a block diagram illustrating the internal configuration of the non-contact open channel flow meter of FIG.
5 is a view showing a state in which a non-contact open channel flow meter according to a second embodiment of the present invention is installed.
FIG. 6 is a block diagram illustrating the internal configuration of the non-contact open channel flow meter of FIG.
7 is a view showing a state in which a non-contact open channel flow meter according to a third embodiment of the present invention is installed.
FIG. 8 is a block diagram illustrating the internal configuration of the non-contact open channel flow meter of FIG.
9 is a conceptual diagram illustrating a principle of measuring a flow rate in a non-contact open channel flow meter according to a third embodiment of FIG. 7.
10 is a block diagram showing the internal configuration of a non-contact open channel flow meter according to a fourth embodiment of the present invention by function.

Hereinafter, a non-contact open channel flow meter according to the present invention will be described with reference to the accompanying drawings. In the present invention, in order to measure the surface flow rate, a microwave radar sensor is used instead of the ultrasonic flow rate sensor.

First, a non-contact open channel flow meter according to a first embodiment of the present invention will be described with reference to FIGS. 3 and 4. The distances, surface flow rates, and flow rates mentioned in the following description are electrical signals that can be expressed as physical quantities such as analog values or digital values, which are a kind of data information. Thus, distance, surface flow rate and flow rate are not specifically indicated, such as distance value, surface flow rate value and flow rate value, or distance signal, surface flow rate signal and flow rate signal, or distance data, surface flow rate data and flow rate data, respectively (required It may mean a certain physical quantity that can be obtained as needed by those skilled in the art.

First embodiment

3 is a view showing a state in which a non-contact open channel flow meter is installed according to a first embodiment of the present invention, Figure 4 is a block diagram showing the internal configuration of the non-contact open channel flow meter of Figure 3 by function.

In FIG. 3, the non-contact open channel flowmeter according to the first embodiment of the present invention includes a flow rate calculation unit 100 and a flow rate sensor unit 200, and the flow rate calculation unit 100 and the flow rate sensor unit 200 It is electrically connected to each other by the flow sensor cable 110. The flow rate sensor unit 200 is vertically installed with respect to the surface of the fluid flowing in the space, for example, the pipe line 300 or the river, and at the same time the distance from the surface of the fluid to the flow rate sensor unit 200 and the surface flow velocity of the fluid at the same time. The detected distance and the surface flow velocity are transmitted to the flow rate calculation unit 100 through the flow rate sensor cable 110. The flow rate calculation unit 100 calculates the cross-sectional area of the fluid flowing in the conduit 300 based on the transmitted distance, multiplies the cross-sectional area of the fluid by the surface flow rate, calculates the flow rate, and displays the calculated flow rate on the display unit 700. And output through the output unit 720.

As shown in FIG. 3, since the cross-sectional area of the pipe line 300 is determined from the time of manufacture, the flow rate sensor unit 200 can calculate the level of the fluid and the cross-sectional area of the fluid if only the distance from the fluid surface is known. . The method for calculating the flow rate based on the distance and the surface flow velocity described above is not particularly limited and may be any one that can be selected by a person skilled in the art.

As illustrated in FIG. 4, the flow sensor 200 includes an ultrasonic distance sensor 754 and a microwave radar sensor 758. As shown in FIG. 3, the ultrasonic distance sensor 754 and the microwave radar sensor 758 are integrally installed in one housing.

The ultrasonic distance sensor 754 transmits the ultrasonic waves vertically downward as shown in FIG. 3 toward the surface of the fluid flowing in the conduit 300 and receives the ultrasonic waves reflected by the surface of the fluid. At this time, the frequency range of the ultrasonic wave to be used is not particularly limited and can be selected according to the precision by those skilled in the art.

The microwave radar sensor 758 transmits microwaves at an angle of incidence of 30 ° to 50 ° with respect to the surface of the fluid flowing in the conduit 300 and receives microwaves scattered from the surface of the fluid. In this case, the incident angle is a case where 90 ° is defined as the vertical downward with respect to the surface of the fluid. Although the ultrasonic flow rate sensor 20 shown in FIGS. 1 and 2 uses ultrasonic waves, the microwave radar sensor 754 used in the present embodiment uses microwaves, and the frequency range is used within the range of approximately 15 GHz to 30 GHz. Preferably, frequencies in the range of approximately 23 GHz to 25 GHz are used.

The specific configuration of the ultrasonic distance sensor 754 and the microwave radar sensor 758 used in the present invention is not particularly limited as long as the above-described distance and surface flow velocity can be measured, and may be any commercially available material. In this case, one skilled in the art can consider the resolution of how precisely the surface flow velocity can be measured. Since the resolution is determined by the resolution = propagation speed ㅧ pulse width / 2, it can be seen that the smaller the fall width, the better the resolution (the higher the frequency).

In FIG. 4, the flow rate calculation unit 100 includes a display unit 700, a control unit 710, an output unit 720, a storage unit 730, a keypad 740, an operation processor 750, and a distance calculator 752. , And a flow rate calculator 756.

The controller 710 is electrically connected to the display unit 700, the output unit 720, the storage unit 730, the keypad 740, the operation processor 750, the distance calculator 752, and the flow rate calculator 756. Connected to control each directly or indirectly.

The storage unit 730 stores an operating system (OS) program and a flow rate for starting the flow rate calculation unit 100. When power is applied to the flow rate calculation unit 100, the controller 710 reads an OS program stored in the storage unit 730 to display the display unit 700, the output unit 720, the storage unit 730, the keypad 740, The operation processing unit 750, the distance calculating unit 752, and the flow rate calculating unit 756 are controlled to be initialized.

The keypad 740 is a device that allows a user to make various inputs such as a condition or an operation command to the flow rate calculation unit 100. The display unit 700 displays a flow rate, displays an operation state of the flow rate calculation unit 100, and displays a menu for allowing a user to input a condition or an operation command through a keypad. The output unit 720 is connected to an external device (not shown) or an internet network (not shown) and outputs a flow rate as an electric signal.

The distance calculator 752 is electrically connected to the ultrasonic distance sensor 754 of the flow sensor 200 to control the ultrasonic distance sensor 754 of the flow sensor 200. The distance calculator 752 commands the ultrasonic distance sensor 754 to transmit and receive an ultrasonic wave, counts the time from the ultrasonic wave to the reflected light after the ultrasonic wave is transmitted, and multiplies the propagation speed of the ultrasonic wave by the counted time to give the distance. To calculate. The distance calculation method is not limited thereto, and may be any method that can be selected by a person skilled in the art as needed. The calculated distance is transmitted to the calculation processing unit 750.

The flow rate calculator 756 is electrically connected to the microwave radar sensor 758 of the flow sensor 200 to control the microwave radar sensor 758 of the flow sensor 200. The flow rate calculator 756 commands the microwave radar sensor 758 to transmit and receive microwaves, and calculates a surface flow rate due to the Doppler effect. The method for calculating the surface flow rate by the Doppler effect is apparent to those skilled in the art, and thus a detailed description thereof will be omitted. The surface flow rate thus calculated is transmitted to the calculation processing unit 750.

The calculation processing unit 750 calculates a cross-sectional area of the fluid flowing in the conduit 300 based on the transmitted distance, multiplies the calculated surface flow rate by the calculated cross-sectional area, calculates a flow rate, and transmits the flow rate to the control unit 710. At this time, the control unit 710 displays the transmitted flow rate on the display unit 700, stores the stored flow rate in the storage unit 730, and also transmits the same to the output unit 720. This flow rate may be stored in the storage unit 730 by matching the time information. The flow rate stored in accordance with the time information may be displayed on the display unit 700 by the user reading from the storage unit 730 at any time by an operation by the keypad 740.

As described above, the non-contact open channel flowmeter according to the first embodiment of the present invention includes the ultrasonic distance sensor 754, the microwave radar sensor 758, and the flow rate calculation unit 100 of the flow sensor unit 200. The distance calculation unit 752, the flow rate calculation unit 756, and the calculation processing unit 750 calculate the flow rate of the fluid flowing in the conduit 300, display it on the display unit 700, and match the time information. The controller 730 stores the data in the memory 730 and outputs the electrical signal to the external device or the Internet via the output 720.

According to the non-contact open channel flow meter according to the first embodiment of the present invention, since the liquid does not come into contact with the liquid flowing in the conduit 300, no suspended matter accumulates in the flow meter, and the microwave radar sensor 758 is a conventional ultrasonic flow rate sensor. Unlike (20), because microwave is used, the resolution is excellent, which can suppress noise caused by the Doppler effect unintentionally generated by particles widely spread in the fluid, thereby improving accuracy. .

Next, a non-contact open channel flow meter according to a second embodiment of the present invention will be described with reference to FIGS. 5 and 6.

Second embodiment

In the non-contact open channel flow meter according to the first embodiment of the present invention, when the surface velocity of the fluid flowing in the conduit 300 is very slow or when the impurities contain little impurities, the microwave radar sensor 758 Radars transmitted by the device are not scattered at the surface of the fluid, and thus no measurement is made. That is, as shown in FIG. 3, in the flow sensor unit 200, ultrasonic waves are radiated toward the vertical downward of the surface of the fluid, and radar is inclined obliquely with respect to the surface of the fluid. When the inclined radar is not scattered on the surface of the fluid, the radar does not return to the flow sensor 200, and thus there is a problem in that measurement is not often made.

Therefore, the non-contact open channel flowmeter according to the second embodiment of the present invention has been made in view of such a problem.

A non-contact open channel flow meter according to a second embodiment of the present invention will be described with reference to FIGS. 5 and 6.

5 is a view showing a state in which a non-contact open channel flow meter according to a second embodiment of the present invention is installed, Figure 6 is a block diagram showing the internal configuration of the non-contact open channel flow meter of FIG.

5 and 6 have the same reference numerals, and the description thereof will be omitted since the configuration is the same except that the wave height generating apparatus 400 is further included as compared with FIGS. 3 and 4 described above. .

As described above, if the surface velocity of the fluid flowing in the conduit 300 is very slow or if there is almost no impurities in the fluid, the surface velocity of the fluid by the microwave radar sensor 758 is not measured. It is necessary to form ripples in the surface of the fluid.

In order to achieve this, the non-contact open channel flow meter according to the second embodiment of the present invention is further provided with a crest generator 400. The crest generator 400 is provided upstream of the fluid flow than the flow sensor 200. The crest generator 400 is controlled by the controller 710 of the flow rate calculation unit 100. The crest generator 400 and the control unit 710 of the flow rate calculation unit 100 are electrically connected to each other by a crest generator cable 110.

If the flow rate is not transmitted from the calculation processing unit 750, the control unit 710 of the flow rate calculation unit 100 determines that the flow rate flowing through the conduit 300 is very slow or that there is almost no impurities in the fluid. Operate the device 400.

Although not shown in FIG. 5 for the specific configuration of the crest generator 400, the crest generator 400 is configured to launch compressed air towards the surface of the fluid.

In the present embodiment, the configuration of the crest generating device 400 is to use compressed air, but is not limited thereto, and the surface on which the crest is measured at the same time may be generated by applying a physical force to the surface of the fluid. As long as it does not affect a flow velocity, it can be any structure which can be selected by a person skilled in the art. For example, in the present embodiment, the wave height generating device 400 is an active body controlled by the control unit 710, but is a passive body such as a bar shape, which is spaced upstream from the flow sensor unit 200 and contained in the fluid. It may be. In this case, the bar is attached to and fixed to the conduit 300 to form a vortex in the flow of the fluid to serve to create a crest.

5 again, the crest generator 400 according to the present embodiment is spaced apart from the flow rate sensor 200 so that the crest generated by the crest generator 400 does not affect the flow rate, and upstream of the fluid flow. It is formed on the side.

Next, an operation relationship of the crest generating device 400 will be described with reference to FIG. 6.

6 is the same as FIG. 4 except that the crest generating device 400 is further included, and thus redundant description will be omitted. In FIG. 6, the crest generator 400 is electrically connected to the control unit 710 of the flow rate calculation unit 100. When a user inputs an operating condition of the wave height generating apparatus 400 to the flow rate calculation unit 100 using the keypad 740, the input operating condition is stored in the storage unit 730. The operating condition may be, for example, to operate the digging generator 400 if the flow rate value is not transmitted for more than 10 minutes from the calculation processing unit 750. This is one example and can be catered to as needed by those skilled in the art.

When the control unit 710 of the flow rate calculation unit 100 reads the OS program from the storage unit 730 and initializes it, it reads the operating condition together and monitors whether the operation processing unit 750 corresponds to this operating condition, If the operating conditions are met, the crest generator 400 is operated to control compressed air to be fired towards the surface of the fluid. Such control is not required when the crest generating device 400 is a passive body such as that described above.

As described above, according to the non-contact open channel flow meter according to the second embodiment of the present invention, like the non-contact open channel flow meter according to the first embodiment, the flow meter is not in contact with the liquid flowing in the conduit 300. Since the float does not accumulate and the microwave radar sensor 758 uses microwaves unlike the existing ultrasonic flow rate sensor 20, the resolution is excellent, and thus the Doppler effect is inadvertently generated by particles spread widely in the fluid. Noise can be suppressed and the accuracy can be improved. In addition, even when the surface velocity of the fluid flowing in the conduit 300 is very slow or there is almost no impurities in the fluid. There is an effect that can measure the flow rate.

Next, a non-contact open channel flow meter according to a third embodiment of the present invention will be described with reference to FIGS.

Third Embodiment

In the non-contact open channel flow meter according to the first embodiment of the present invention, the microwave radar sensor 758 for measuring the surface velocity of the fluid flowing in the conduit 300 is deteriorated over time due to various factors. The precision of the measurement may be inferior. There is a need to calibrate the measurements of the microwave radar sensor 758.

Thus, a non-contact open channel flowmeter according to a third embodiment of the present invention has been made in view of this need.

A non-contact open channel flow meter according to a third embodiment of the present invention will be described with reference to FIGS.

7 is a view showing a state in which a non-contact open channel flow meter is installed according to a third embodiment of the present invention, Figure 8 is a block diagram showing the internal configuration of the non-contact open channel flow meter of Figure 7 by function, Figure 9 The principle of measuring the flow rate in the non-contact open channel flowmeter according to the third embodiment of FIG. 7 is a conceptual diagram shown.

7 and 8 except that the image pickup device 500, the feature point extractor 510, the feature point movement speed calculator 520, and the correction unit 770 are further included in comparison with FIGS. 3 and 4 described above. Since the configuration is the same, the same reference numerals are given and the description thereof will be omitted.

As described above, due to the deterioration of the microwave radar sensor 758 itself, it is necessary to periodically or arbitrarily correct the measured flow rate by the user.

In order to achieve this, the non-contact open channel flow meter according to the third embodiment of the present invention includes an imaging device 500, a feature point extractor 510, a feature point movement speed calculator 520, and a beam as shown in FIG. 7. It further includes a government (770). The correction unit 770 is located between the calculation processing unit 750 and the control unit 710 and is electrically connected, and is also directly connected to the feature point moving speed calculation unit 520. The feature point extractor 510 of the imaging device 500 and the flow rate calculation unit 100 are electrically connected to each other by the imaging device cable 120.

The imaging apparatus 500 continuously photographs the flow of the fluid flowing in the conduit 300 and transmits the image data to the feature point extractor 510. The image data is, for example, a video file of 30 frames or more. Here, 30 frames are defined as 30 still images captured in one second, and one frame is referred to as one frame. The feature point extractor 510 extracts a feature point from the transmitted image data and transmits the feature point to the feature point moving speed calculator 520. The feature point movement speed calculator 520 monitors the movement of the feature points, calculates the speed (that is, the surface movement speed of the fluid), and transmits the calculated speed to the correction unit 770. The correction unit 770 compares the flow rate value transmitted from the calculation processing unit 750 with the surface movement speed value of the fluid transmitted from the feature point movement speed calculation unit 520, and uses the difference as a correction value through the control unit 710. The memory 730 stores the data. The difference can be positive or negative. The correction value stored in this way is always reflected in the flow rate value transmitted from the calculation processing unit 750 even if the correction unit 770 does not capture the image by the imaging device 500.

The correction by the imaging device 500 as described above is not particularly limited, for example, periodically or more once a week or once a month, and can be selected by those skilled in the art.

With reference to FIG. 9, the surface movement velocity method of the fluid by feature point extraction is demonstrated. As described above, it is assumed that the imaging device 500 of FIG. 8 picks up a still image of 30 frames in one second. A still image of one frame is defined to be 30 cm x 30 cm. It is assumed that the still image of one frame has feature points A and B as shown in FIG. The feature points A and B represent, for example, the positions of bubbles or floats floating on the surface of the fluid flowing in the conduit 300, and are extracted by the feature point extractor 510. The method of extracting the feature point by the feature point extractor 510 is not particularly limited, and an image processing method that can be selected by those skilled in the art may be used, and in particular, may be implemented by a digital signal processor (DSP).

Therefore, as shown in Fig. 9, feature points A and B are extracted in each of 30 frames. It can be seen that the feature points A and B move downward from the ground as the frame progresses from one frame to 30 frames. This can calculate the motion vector values of the feature points by correlating 1 to 30 frames, thereby calculating the movement speeds of the feature points A and B. FIG. As shown in the right side of the arrow in Figure 9 as a result it can be seen that the feature points A and B moved 20 cm in one second down the ground. Therefore, 20cm / sec is calculated by speed V = distance S / time T. This speed calculation is implemented by the feature point moving speed calculator 520 of FIG. 8.

 The method for calculating the feature point moving speed by the feature point moving speed calculating unit 520 is not particularly limited, and an image processing method that can be selected by those skilled in the art may be used, and in particular, may be implemented by a digital signal processor (DSP). Can be.

According to the non-contact open channel flow meter according to the third embodiment of the present invention, like the non-contact open channel flow meter according to the first embodiment, since the liquid does not come into contact with the liquid flowing in the conduit 300, no float is accumulated in the flow meter. In addition, the microwave radar sensor 758 has a high resolution because the microwave radar sensor 758 uses microwaves to suppress noise due to the Doppler effect unintentionally generated by particles spread widely in the fluid. In addition, there is an effect of improving the accuracy, and in addition, various factors such as the microwave radar sensor 758 for measuring the surface velocity of the fluid flowing in the conduit 300 deteriorates over time. When the flow velocity measurement value becomes inaccurate, the correction can be corrected to increase the accuracy.

Next, a non-contact open channel flow meter according to a fourth embodiment of the present invention will be described with reference to FIG.

Fourth embodiment

The non-contact open channel flowmeter according to the fourth embodiment of the present invention also relates to a configuration for correcting the measured value of the microwave radar sensor 758, as in the third embodiment of the present invention.

A non-contact open channel flow meter according to a fourth embodiment of the present invention will be described with reference to FIG.

10 is a block diagram illustrating the internal configuration of a non-contact open channel flow meter according to a fourth embodiment of the present invention for each function.

FIG. 10 has the same reference numerals and is assigned the same reference number because the configuration is the same except that the multi-point flowmeter 600, the driver 610, and the correction unit 770 are further included as compared to FIG. 3 described above. The description is omitted.

As described above, due to the deterioration of the microwave radar sensor 758 itself, it is necessary to periodically or arbitrarily correct the measured flow rate by the user.

In order to achieve this, the non-contact open channel flowmeter according to the fourth embodiment of the present invention further includes a multi-point flowmeter 600, a driver 610, and a compensator 770 as shown in FIG. 10. The correction unit 770 is located between the calculation processing unit 750 and the control unit 710 and is electrically connected to the multi-point flowmeter 600.

The multi point flow meter 600 is a wetted open channel flow meter. The multi-point flowmeter 600 is configured to insert the bar-shaped measurement pointer provided in the multi-point flow meter 600 into the fluid flowing in the conduit 300. The bar-shaped measuring pointer inserted in the fluid is formed at a position where a plurality of measuring points are spaced apart according to the depth of the fluid. Apply. The multi-point flowmeter 600 measures the flow rates according to the depths extracted from the plurality of measurement points and transmits their average values as the flow rate values to the correction unit 770.

The correction unit 770 compares the flow rate value transmitted from the arithmetic processing unit 750 with the flow rate value transmitted from the multi-point flowmeter 600, and uses the difference as a correction value to the storage unit 730 through the control unit 710. Save it. The difference can be positive or negative. The correction value thus stored is always reflected in the flow rate value transmitted from the calculation processing unit 750 even if there is no flow rate measurement by the multi-point flowmeter 600. In addition, when the microwave laser sensor 758 does not operate normally, the multi-point flowmeter 600 may include a switching measurement function for measuring the surface flow velocity.

As shown in FIG. 10, the multi-point flowmeter 600 is electrically / mechanically connected to the driver 610, and the driver 610 is electrically connected to the controller 710. Although not specifically illustrated in the drawings, the multi-point flow meter 600 is mechanically lifted and lowered by the driving unit 610 so that the bar-shaped measuring pointer of the multi-point flow meter 600 can be inserted into or detached from the fluid. have. The control unit 710 activates the driving unit 610 by a command by a user through the keypad 740 or by a preset automatic program, thereby electrically supplying power to the multi-point flowmeter 600 and mechanically. Is controlled to rise and fall as described above. The automatic program is usually stored in the storage unit 730, and the control unit 710 reads and executes the same, and a specific implementation program (usually an embedded program) or a mechanical configuration thereof is not particularly limited. Any may be selected by an experienced person.

The correction by the multi-point flow meter 500 as described above is not particularly limited, for example, intermittently or at least once a week or once a month, and is selected by a person skilled in the art. Can be.

According to the non-contact open channel flow meter according to the fourth embodiment of the present invention, like the non-contact open channel flow meter according to the first embodiment, the non-contact open channel flow meter is installed on the side of the channel in the conduit 300 and is not installed on the floor. The sediment does not accumulate, and because the microwave radar sensor 758 uses microwaves unlike the existing ultrasonic flow rate sensor 20, the resolution is excellent, and due to the Doppler effect unintentionally generated by particles spread widely in the fluid. There is an effect of suppressing the noise and thereby improving the accuracy, and in addition, the microwave radar sensor 758 which measures the surface velocity of the fluid flowing in the conduit 300 deteriorates over time. When the flow rate measurement value becomes inaccurate due to various factors, such as, the accuracy can be improved by correcting it.

100: flow rate calculation unit
200: flow sensor unit
700: display unit
710: control unit
720: output unit
730 memory
740: keypad
750: arithmetic processing unit
752: distance calculator
754: ultrasonic distance sensor
756: flow rate calculator
758: microwave radar sensor

Claims (5)

A flow sensor unit 200 spaced apart from the surface of the fluid flowing in the conduit 300 in a vertical direction and having an ultrasonic distance sensor 754 and a microwave radar sensor 758 formed in one housing; And a flow rate calculation unit 100 electrically connected to the flow rate sensor unit 200.
The ultrasonic distance sensor 754 measures the distance from the surface of the fluid flowing in the conduit 300 to the flow rate sensor unit 200 using ultrasonic waves, and the microwave radar sensor 758 uses microwaves. Measure the surface flow rate of the fluid flowing in the conduit 300,
The flow rate calculation unit 100 receives the distance and the surface flow rate from the flow rate sensor unit 200 to obtain a cross-sectional area of the fluid flowing in the conduit 300 based on the distance, and calculates the surface area at the cross-sectional area. Multiply the flow rate to calculate the flow rate,
Crest generator 400 is spaced in the vertical direction from the surface of the fluid flowing in the pipeline 300 and installed on the upstream side of the fluid flow relative to the flow sensor 200, generating a crest on the surface of the fluid (400) Non-contact open channel flow meter further comprises a). delete The method of claim 1.
An imaging device spaced apart from the surface of the fluid flowing in the conduit 300 in a vertical direction and installed upstream of the fluid flow relative to the flow sensor 200 to generate image data by imaging the surface of the fluid Further includes 500,
The imaging device 500 transmits the image data to the flow rate calculation unit 100 electrically connected, the flow rate calculation unit 100 extracts a feature point from the image data, and the digital signal processing of the feature point. Detect a motion vector, calculate a feature point movement speed based on the detected motion vector, and correct the flow rate by a difference between the feature point movement speed and the surface flow velocity measured from the microwave radar sensor 758 Non-contact open channel flow meter. The method of claim 3.
And the feature point represents positional data of bubbles or suspended matter floating on the surface of the fluid flowing in the conduit 300 among the image data captured by the imaging device. The method of claim 1.
And a multi-point flowmeter 600 having a bar-shaped measuring pointer inserted into the fluid flowing in the conduit 300 to measure the flow velocity.
The multi-point flowmeter 600 corrects the flow rate by the difference between the average flow rate measured by the bar-shaped measuring pointer and the surface flow rate measured by the microwave radar sensor 758,
The non-contact open channel flowmeter according to claim 1, wherein the multi-point flowmeter includes a switching measurement function for measuring the surface flow rate when the microwave laser sensor 758 does not operate normally.

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