JP2005321314A - Ultrasonic flowmeter, flow measuring method therefor, and flow measuring program therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic flowmeter of simplified instrument structure while maintaining measuring precision in the ultrasonic flow measuring instrument even in a river and a large artificial open channel, a flow measuring method therefor, and a flow measuring program therefor. <P>SOLUTION: This flowmeter is provided with a trigger generating means 60 for receiving a request of starting measurement to generate a trigger, a flow velocity distribution acquiring means 61 for acquiring a flow velocity distribution serving as a fundamental for flow rate measurement, a flow rate calculation means 62 for calculating a flow rate based on the flow velocity distribution acquired by the flow velocity distribution acquiring means, and a flow rate display means 63 for displaying a flow rate calculated by the flow rate calculation means as a flow rate measured value. The flow velocity distribution acquiring means 61 is provided with a water face side flow velocity distribution acquiring means 65 for acquiring a flow velocity distribution from a surface side of a channel (flow passage) 24 through which water (fluid) 21 flows, a water bottom side flow velocity distribution acquiring means 66 for acquiring a flow velocity distribution from a bottom side of the channel 24 through which the water (fluid) 21 flows, and a flow velocity distribution calibration processing means 67 for obtaining a flow velocity distribution along a depth direction of the channel 24, based on the flow velocity distributions acquired respectively by the water face side flow velocity distribution acquiring means 65 and the water bottom side flow velocity distribution acquiring means 66. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an ultrasonic flowmeter that measures the flow velocity distribution and flow rate of a fluid using ultrasonic pulses, and more particularly to an ultrasonic flowmeter in a large artificial open channel (opening) on the order of meters and its flow measurement. The present invention relates to a method and a flow measurement program thereof.

  There are several devices or methods for measuring the flow velocity and flow rate in rivers and large artificial open channels. Broadly speaking, there are an apparatus or method for measuring the flow velocity distribution and flow rate of the fluid by mechanical means using a propeller type flow meter and the like, and an apparatus or method for measuring the flow velocity distribution and flow rate using ultrasonic waves. The latter device or method for measuring flow velocity distribution and flow rate using ultrasonic waves has the following advantages over the former device or method for measuring fluid flow velocity distribution and flow rate by mechanical means, and therefore, convenience of measurement. This is considered advantageous.

(1) The flow velocity distribution is not disturbed (even if disturbed, it is in a range that can be ignored in measurement).
(2) There is linearity from a very low flow rate to a high flow rate.
(3) The flow velocity component is known.
(4) Real-time measurement is possible and continuous automatic observation is possible.
(5) Maintenance is easy because there is no mechanical operating part.

  FIG. 16 shows a schematic configuration diagram of a conventional ultrasonic flow rate measuring apparatus 1 having the above-described advantages installed in an open channel.

  Here, FIG. 16A is a cross-sectional view in a direction perpendicular to the virtual measurement straight line B shown in FIG. 16B, and FIG. 16B is a plan view of FIG. FIG.

  When the ultrasonic flow velocity distribution measuring device or the flow rate measuring device 1 is outlined with reference to FIG. 16, the conventional ultrasonic flow rate measuring device 1 has an end of one virtual measurement straight line B (as shown in FIG. 16A). Transmitting transducer section 2 for transmitting ultrasonic waves to the peripheral edge of the open channel), transducer pair 4 having receiving transducer section 3 for receiving at the other end of the virtual measurement straight line B (peripheral edge of the open channel), and oscillating ultrasonic waves And an ultrasonic oscillating unit 5 to be supplied to the transmitting transducer unit 2.

  A support column 6 is installed on the receiving transducer unit 3 side from the water surface direction toward the water bottom direction. The rack 6 having the receiving transducer unit 3 attached thereto is attached to the column 6 in a state of being freely rotatable in the horizontal direction, and a plurality of racks 7 are attached at predetermined intervals in the depth direction. Further, as shown in FIG. 16B, the receiving transducer section 3 attached to the rack cage 7 is configured such that the receiving transducers 8A and 8B make a pair with a predetermined distance therebetween.

  The ultrasonic flow rate measuring apparatus 1 uses the electric signal corresponding to the received ultrasonic wave from the receiving transducer unit 3 and the electric signal converted into the moving distance from the rotation number of the motor unit 9 for driving the rack cage 7. And a flow rate / flow rate calculation unit 10 for calculating the flow rate, and performs calculation processing based on a signal acquired by the flow rate / flow rate calculation unit 10.

  In the calculation process performed based on the signal acquired by the flow velocity / flow rate calculation unit 10, first, an average flow velocity value at a constant water depth is calculated. After that, the flow rate is calculated by further calculating (integrating) using the calculated average flow velocity value. In the depth direction, the average flow velocity value is measured at multiple locations, and the flow rate distribution and flow rate of the fluid (water) flowing through the water channel are calculated by performing the same calculation process, and the calculation result is used as the measurement result. doing. Therefore, the ultrasonic flow rate measuring device 1 can also be an ultrasonic flow rate distribution measuring device by outputting the calculation result when the flow velocity distribution is calculated.

  In addition, V shown in FIG.16 (b) shows the flow velocity of the fluid which flows through a water channel, and the arrow shows a flow direction. The virtual measurement straight line B is a straight line that is arbitrarily set and has a relationship substantially orthogonal to the fluid flow direction (arrow direction).

  The conventional ultrasonic flow rate measuring apparatus 1 configured as described above measures the flow velocity and flow rate easily and accurately by utilizing a deflection phenomenon that occurs when ultrasonic waves propagate in water. Here, the deflection phenomenon means that when the ultrasonic velocity is transmitted from one end of the virtual measurement line B when the flow velocity V is V ≠ 0, the position reaching the other end side of the virtual measurement line B is shifted downstream with respect to the flow direction. A phenomenon.

  Examples of the above-described ultrasonic flow velocity distribution device and method or ultrasonic flow rate measurement device and method include Japanese Patent Application Laid-Open Nos. 2000-111374 and 2000-258212.

On the other hand, although not applied in rivers and large artificial open channels, unlike the ultrasonic flow measuring device 1, in addition to using a pair of transducers 4 as shown in FIG. There are also ultrasonic flow rate measuring devices that can transmit and receive and measure flow velocity distribution or flow rate. An example of such an ultrasonic flow measuring device is disclosed in, for example, Japanese Patent Application Laid-Open No. 2000-97742.
JP 2000-111374 A Japanese Unexamined Patent Publication No. 2000-258212 (FIGS. 9A and 9B) JP 2000-97742 A

  However, in the conventional ultrasonic flow rate measuring apparatus 1 and the method thereof as described above, a pair of transducers 4 each having the transmission transducer unit 2 for transmitting ultrasonic waves and the transducer unit 3 for receiving ultrasonic waves is indispensable. It is essential that the receiving transducer unit 3 for receiving the ultrasonic wave transmitted from the transmitting transducer unit 2 on one end side of the virtual measurement line B is provided on the other end side of the virtual measurement line B. For this reason, the structure on the receiving transducer section 3 side becomes complicated, and there is a problem that the configuration of the entire apparatus becomes complicated.

  More specifically, the structure on the receiving transducer unit 3 side is complicated in that a support 6 for fixing the receiving transducer unit 3 to the other end side of the virtual measurement straight line B is required. Further, in order to measure the flow rate of a fluid (generally water) flowing through an open channel as shown in FIG. 16, it is essential to obtain a flow velocity distribution. It is completely different from the area near the bottom. For this reason, in order to ensure a certain degree of measurement accuracy, it is necessary to provide the receiving transducer section 3 at a plurality of water depths, and the support column 6 must be configured to have a plurality of rack rods 7 at predetermined intervals. This point complicates the structure on the receiving transducer section 3 side.

  Furthermore, since the ultrasonic wave transmitted under the influence of the flow velocity V of the fluid flowing through the open channel is deflected, in order to receive the transmitted ultrasonic wave, the rack rod 7 attached to the support column 6 is moved in the horizontal direction. It is necessary to make it freely rotatable (in a state where the water depth is constant). In this respect, the structure on the receiving transducer unit 3 side is complicated.

  Also, since the ultrasonic flow rate measuring device 1 cannot obtain a flow velocity distribution, the flow rate measurement error tends to be relatively large. More specifically, in the ultrasonic flow rate measuring apparatus 1, an experiment is performed in a simulated flow channel that simulates an actual flow channel, and the flow rate is determined using a correction coefficient. However, in an actual flow path, deposits are accumulated at the bottom, and there are usually irregularities in an artificial water channel, and the shape of the measurement location and the roughness of the bottom surface vary depending on the location. That is, the simulated channel is often far from the actual channel. Naturally, as the simulated flow channel and the actual flow channel become far apart, the measurement error of the flow rate increases.

  On the other hand, if an ultrasonic flow measuring device capable of transmitting and receiving ultrasonic waves with one transducer and measuring flow velocity distribution or flow rate is used, the transducer has a transmitting transducer section 2 and a receiving transducer section 3. It is considered that the column 6 and the rack 7 for installing the receiving transducer section 3 as shown in FIG. 16 are not necessary, and the problem of the complicated structure can be solved.

  However, it is not possible to simply use an ultrasonic flow measurement device as a flow measurement device or a method thereof in a river or a large artificial open channel. Conventionally, there is no example in which an ultrasonic flow rate device is applied to a flow rate measuring device or a method thereof in a river or a large artificial open channel, because the following problems exist.

  As a problem that occurs when applying an ultrasonic flow measurement device in a river or a large artificial open channel, there is a problem that measurement cannot be performed unless the measurement range in which the flow rate can be measured is at a distance of about 1 to 3 meters from the transducer. That is, even if the flow rate can be measured in a small river or an artificial open channel, for example, the ultrasonic flow rate measuring device cannot be applied in a large artificial open channel having a water depth of 5 m or more.

  As another problem, in the large artificial open channel as described above, there is a problem that the flow rate cannot be measured accurately unless the flow velocity distribution in the vicinity of the bottom of the water can be measured accurately. Even if it is an artificially created water channel, deposits are usually deposited on the bottom of the water and there are irregularities, and the shape of the measurement location and the roughness of the bottom surface vary depending on the location. Even in the case of water depth, it is considered difficult to measure the flow rate with high accuracy by the method of correcting by approximating the flow velocity.

  Therefore, in the present invention, an ultrasonic flow measurement device that can be applied in a river or a large artificial open channel is constructed by solving the problems that occur when the ultrasonic flow measurement device is applied in a river or a large artificial open channel, In addition, the problem of the ultrasonic measuring apparatus 1 is solved.

  That is, the present invention has been made to solve the above-described problem, and in a river or a large artificial open channel, the apparatus structure is further simplified while maintaining the measurement accuracy of the ultrasonic flow measurement device. An object of the present invention is to provide a sonic flow meter, a flow rate measurement method thereof, and a flow rate measurement program thereof.

  In order to solve the above-described problems, an ultrasonic flowmeter according to the present invention is characterized by comprising: Trigger generating means for receiving a measurement start request and generating a trigger, flow velocity distribution acquiring means for acquiring a flow velocity distribution as a basis of flow measurement, and flow rate for calculating a flow rate based on the flow velocity distribution acquired by the flow velocity distribution acquiring means And a flow rate display means for displaying the flow rate calculated by the flow rate calculation means as a flow rate measurement value, wherein the flow velocity distribution acquisition means acquires the flow velocity distribution from the surface side of the flow path through which the fluid flows. Side flow velocity distribution acquisition means, water bottom flow velocity distribution acquisition means for acquiring a flow velocity distribution from the bottom side of the flow path through which the fluid flows, and flow velocity distributions acquired by the water surface side flow velocity distribution acquisition means and the water bottom side flow velocity distribution acquisition means, respectively. And a flow velocity distribution calibration processing means for obtaining a flow velocity distribution in the depth direction of the flow path.

  In order to solve the above-described problem, an ultrasonic flowmeter according to the present invention is characterized in that, as described in claim 2, the water surface side flow velocity distribution acquisition means and the water bottom side flow velocity distribution acquisition means are provided in a fluid whose flow rate is measured. An ultrasonic transmission means for transmitting an ultrasonic pulse; an ultrasonic reception means for outputting an ultrasonic echo signal corresponding to the ultrasonic echo received in the fluid; and a signal processing means for processing the ultrasonic echo signal. A flow velocity distribution calculating means for calculating the flow velocity distribution of the fluid from the ultrasonic echo signal signal-processed by the signal processing means, and the ultrasonic wave transmitting means and the ultrasonic wave receiving means of the water surface side flow velocity distribution acquisition means The ultrasonic wave transmitting means and the ultrasonic wave receiving means of the water bottom side flow velocity distribution acquisition means are provided in a water surface unit that is installed so as to be movable in the flow path width direction across the flow path in which the water flows. Characterized in that provided in the bottom of the water unit to Chakumen.

  In order to solve the above-described problem, an ultrasonic flowmeter according to the present invention is characterized in that, as described in claims 5 and 6, the water bottom side flow velocity distribution acquisition means includes an ultrasonic pulse in a fluid for measuring a flow rate. , An ultrasonic receiving means for outputting an ultrasonic echo signal corresponding to the ultrasonic echo received in the fluid, a signal processing means for signal processing the ultrasonic echo signal, and this signal A flow velocity distribution calculating means for calculating the flow velocity distribution of the fluid from the ultrasonic echo signal subjected to signal processing by the processing means, and the ultrasonic wave transmitting means and the ultrasonic wave receiving means of the water bottom side flow velocity distribution acquisition means A plurality of and the same number of ultrasonic echo signals are provided at a water bottom unit to be landed on the bottom so as to obtain a plurality of types of ultrasonic echo signals at the same time. Inclination correction calculation processing means for acquiring one flow velocity distribution by performing inclination correction calculation processing for invalidating the influence of the inclination of the bottom unit using a plurality of types of ultrasonic echo signals acquired at the same time by the means. It is characterized by that.

  Furthermore, in order to solve the above-described problem, an ultrasonic flowmeter is characterized in that, as described in claim 7, the water bottom side flow velocity distribution acquisition means transmits ultrasonic pulses into a fluid whose flow rate is measured. Means, an ultrasonic receiving means for outputting an ultrasonic echo signal corresponding to the ultrasonic echo received in the fluid, a signal processing means for processing the ultrasonic echo signal, and the signal processing means The flow velocity distribution calculating means for calculating the flow velocity distribution of the fluid from the ultrasonic echo signal, the ultrasonic transmitting means and the ultrasonic receiving means are provided, and the inclination in the three-axis direction of the water bottom unit which is made to contact the bottom of the flow path is determined. Inclination correction calculation processing for performing the inclination correction calculation processing in consideration of the inclination of the water bottom unit detected by the inclination detection means on the flow velocity distribution calculated by the flow velocity distribution calculation means. Characterized in that it comprises a stage.

  On the other hand, in order to solve the above-described problem, an ultrasonic flowmeter according to the present invention is characterized in that, as described in claim 8, the water surface side flow velocity distribution acquisition means calculates the flow velocity distribution in the water depth direction of the fluid. The water bottom side flow velocity distribution acquisition means acquires the flow velocity distribution in the water depth direction of the fluid, the boundary layer formed by the fluid, and the boundary between the boundary layer and the steady flow region. It is obtained by including the depth of water that becomes a part.

  In order to solve the above-described problem, the flow rate measurement method according to the present invention includes, as described in claim 10, an overall flow velocity distribution acquisition procedure for acquiring a flow velocity distribution serving as a basis for flow rate measurement, and an overall flow velocity distribution acquisition procedure. A flow rate calculation procedure for measuring a flow rate based on the acquired flow velocity distribution, and a flow rate display procedure for displaying the calculated flow rate as a flow rate measurement value, wherein the overall flow velocity distribution acquisition procedure receives a request to start measurement, Measurement preparation completion confirmation process for confirming whether or not measurement can be started, water depth direction flow speed distribution acquisition process for obtaining flow velocity distribution in the depth direction of the flow path, and measurement of flow velocity distribution in the depth direction at other locations And a measurement residual confirmation process for confirming whether or not there is a necessity.

  In order to solve the above-described problem, the flow rate measurement method according to the present invention is, as described in claim 12, the water depth direction flow velocity distribution acquisition process is installed in a trigger generation process for generating a trigger and a water surface unit. Based on the ultrasonic echo signal output from the ultrasonic receiving means, the water surface side flow velocity distribution acquisition process for acquiring the flow velocity distribution on the fluid surface side, and the ultrasonic echo signal output from the ultrasonic receiving means installed in the bottom unit Based on the water bottom side flow velocity distribution acquisition process for acquiring the flow velocity distribution on the channel bottom side based on the flow velocity distribution acquired in the water surface side flow velocity distribution acquisition process and the water bottom side flow velocity distribution acquisition process, necessary data calibration processing is performed. And a flow velocity distribution calibration process for obtaining a flow velocity distribution for flow rate calculation.

  In order to solve the above-described problem, according to the flow rate measurement method of the present invention, as described in claim 13, the water bottom side flow velocity distribution acquisition process includes a plurality of water bottom side flow velocity distribution acquisition means that have a water depth at the same time. The bottom flow velocity distribution acquisition step for acquiring the flow velocity distribution in each direction and the flow velocity distribution in the depth direction at the same time acquired in this bottom flow velocity distribution acquisition process are used to invalidate the influence of the inclination of the bottom unit. A correction calculation processing step for performing a weighted average process.

  Furthermore, in order to solve the above-described problem, the flow rate measuring method according to the present invention is the water bottom side flow velocity distribution acquisition process according to claim 14, wherein the single water bottom side flow velocity distribution acquisition is performed at the same time. The water bottom side flow velocity distribution acquisition step that acquires the flow velocity distribution in each direction, and the water depth direction flow velocity distribution acquired in this water bottom side flow velocity distribution acquisition process, the inclination of the water bottom unit is directly detected, and the detected inclination And a correction calculation processing step for correcting the generated flow velocity measurement error.

  In order to solve the above-mentioned problem, the program according to the present invention (flow velocity distribution acquisition program) receives a measurement start request and confirms whether measurement can be started, as described in claim 15. Acquiring the water surface side flow velocity distribution to acquire the flow velocity distribution on the fluid surface side based on the measurement preparation completion confirmation process, the trigger generation process for generating the trigger, and the ultrasonic echo signal output from the ultrasonic wave receiving means installed in the water surface unit The water bottom side flow velocity distribution acquisition step, the water surface side flow velocity distribution acquisition step, and the water bottom side for acquiring the flow velocity distribution on the flow channel bottom side based on the stroke and the ultrasonic echo signal output from the ultrasonic receiving means installed in the water bottom unit A flow velocity distribution calibration process that obtains a flow velocity distribution for flow rate calculation by performing necessary data calibration processing based on each flow velocity distribution acquired in the flow velocity distribution acquisition process. The flow depth distribution process for acquiring the flow velocity distribution in the depth direction of the water and the remaining measurement confirmation process for checking whether or not there is a need to measure the flow velocity distribution in the depth direction at other locations are provided. Is a program that causes a computer to execute an overall flow velocity distribution acquisition procedure for acquiring a flow velocity distribution that becomes

  In order to solve the above-described problem, a program (flow velocity distribution acquisition program) according to the present invention includes, as described in claim 16, a plurality of water bottom side flow velocity distribution acquisition means at the same time as the water bottom side flow velocity distribution acquisition step. The water bottom side flow velocity distribution acquisition step for acquiring the water flow velocity direction distribution at the water depth and the water flow velocity direction distribution at the same time acquired in this water bottom side flow velocity distribution acquisition process are used to invalidate the influence of the inclination of the water bottom unit. This is a program for causing a computer to execute a correction calculation processing step for performing weighted average processing.

  Furthermore, in order to solve the above-described problem, a program according to the present invention (flow velocity distribution acquisition program), as set forth in claim 17, has a single water bottom side flow velocity distribution acquisition as the water bottom side flow velocity distribution acquisition step. The bottom-side flow velocity distribution acquisition step for acquiring the flow velocity distribution in the water depth direction at the same time, and the inclination of the water bottom unit is directly detected with respect to the flow velocity distribution in the water depth direction acquired in this bottom-side flow velocity distribution acquisition process, This is a program for causing a computer to execute a correction calculation processing step for correcting a flow velocity measurement error caused by a detected inclination.

  According to the ultrasonic flowmeter, the flow measurement method and the flow measurement program according to the present invention, the ultrasonic wave can be transmitted and received by one ultrasonic transducer, and the flow velocity distribution or flow rate can be measured. Can be avoided. In addition, the flow velocity distribution is acquired on the surface side and bottom side of the flow path where the change in flow velocity is large, and data interpolation is performed for points where the change in flow velocity is relatively small. Also, the flow velocity distribution from the surface where the fluid flows to the bottom can be obtained.

  Therefore, it is possible to provide an ultrasonic flowmeter, a flow measurement method thereof, and a flow measurement program therefor which can simplify the structure of the apparatus while maintaining the measurement accuracy of the ultrasonic flow measurement apparatus even in rivers and large artificial open channels. .

  Hereinafter, an ultrasonic flowmeter, a flow measurement method thereof, and a flow measurement program thereof according to the present invention will be described with reference to the accompanying drawings.

[First Embodiment]
FIG. 1 is an explanatory view for explaining an example of an application scene of the first ultrasonic flow meter 20 which is an example of the ultrasonic flow meter according to the first embodiment of the present invention.

  In an example of an application scene of the first ultrasonic flow meter 20 shown in FIG. 1, water 21 flowing through a river is introduced from a water inlet 22 into a water conduit (Yamanote waterway) 23 in a self-flowing (water channel) hydroelectric power plant. In the application scene shown in FIG. 1, the flow rate of water flowing into the river side water channel (Kawate Channel) 24 is measured. Note that an arrow 21 shown in FIG.

  These water channels 23 and 24 are channels whose upper surfaces are free surfaces, that is, open channels, and the first ultrasonic flowmeter 20 measures the flow rate in such open channels. It is. When obtaining the flow rate, first, the flow velocity distribution in the cross section through which the fluid to be measured for flow rate (here, water) passes is obtained. And the flow volume of the fluid which passes a cross section is calculated | required by integrating the calculated | required flow velocity distribution about the cross section.

  Such a method for calculating the flow rate from the flow velocity distribution is adopted in many flow meters, and the first ultrasonic flow meter 20 also calculates the flow rate by performing an arithmetic process on the flow velocity distribution measured using the ultrasonic waves. The calculated flow rate value is used as the measured flow rate.

  The basic principle of flow velocity distribution and flow rate measurement in the ultrasonic flow meter 20 uses the Doppler ultrasonic flow meter disclosed in Japanese Patent Laid-Open No. 2000-97742 and Japanese Patent Laid-Open No. 2003-130699 by the present inventor. It is a thing. Therefore, the description of the basic measurement principle and detailed configuration of flow velocity distribution and flow rate measurement is omitted.

  Moreover, although the target fluid whose flow rate is to be measured is described in the above-mentioned gazette, it can be applied to various fluids other than water, but in the following description, the target whose flow rate is to be measured is simplified. The fluid will be described as water 21 and the flow path through which the fluid flows will be described as water channel 24.

  FIG. 2 is a schematic configuration diagram showing an outline of the overall configuration of the first ultrasonic flowmeter 20.

  2, the axial direction of the water channel 24 through which the water 21 flows is indicated as the x-axis direction, the width direction of the water channel 24 perpendicular to the x-axis direction is indicated as the y-axis direction, and the water depth direction of the water channel 24 is indicated as the z-axis direction. However, these three axial directions are the same in other drawings other than FIG. 2 and in the following description in the text.

  The first ultrasonic flowmeter 20 is based on a flow measurement request from a measurer (user), and particles (hereinafter referred to as reflection) in which ultrasonic waves transmitted in the water 21 to be subjected to flow measurement are constantly mixed in the water. The reflected wave reflected by the body is received, and the reflected wave of the received ultrasonic wave is subjected to signal processing and signal analysis to obtain a flow velocity distribution of the water 21. The flow rate of the water 21 is calculated by integrating the flow velocity distribution of the water 21 in the same manner as other flow meters, and the calculated flow rate is displayed as a flow rate measurement result.

  According to FIG. 2, the first ultrasonic flowmeter 20 includes ultrasonic transmission means for transmitting ultrasonic waves in the water for flow measurement and a large number of reflectors mixed in the water (hereinafter referred to as a reflector group). As ultrasonic wave receiving means for receiving the reflected wave reflected, it is attached to the bottom of the water surface unit 26 for transmitting and receiving ultrasonic waves in the water and in the vicinity of the water surface (the boundary surface of air and water) and the bottom of the flow channel (Kawate waterway) 24. And a bottom unit 27 for transmitting and receiving ultrasonic waves.

  In addition, the first ultrasonic flowmeter 20 is substantially the same as the axial direction (x-axis direction) of the water channel 24 in which the water 21 to be measured by the water surface unit 26 flows and the width direction (y-axis direction) of the water channel 24 that is orthogonal to the water channel. A guide rail 28 is provided to straddle the water channel 24 through which the water 21 to be measured flows so as to be slidable in parallel.

  Further, the first ultrasonic flow meter 20 controls the transmission of ultrasonic waves performed by the water surface unit 26 and the water bottom unit 27 in addition to the water surface unit 26, the water bottom unit 27 and the guide rail 28, and reflects the received ultrasonic waves. An arithmetic processing unit 29 is provided as a trigger generation means, a signal processing means, a signal analysis means, and a flow rate display means for acquiring the flow velocity distribution of the water 21 from the wave and measuring the flow rate. That is, in this embodiment, the arithmetic processing unit 29 receives a measurement start request from a measurer, generates a trigger, or performs signal processing and signal analysis on the received reflected wave of the ultrasonic wave to measure the water to be measured. The flow rate distribution is acquired, the flow rate distribution is calculated by calculating the flow rate distribution of the obtained water, and the calculated flow rate value is displayed as a flow rate measurement value.

  The water surface unit 26 of the first ultrasonic flow meter 20 is attached so as to be movable along the guide rail 28 in the y-axis direction in FIG. Then, the bottom unit 27 is disposed so as to come into contact with the bottom of the water channel 24 for measuring the flow rate from the water surface unit 26 and to face the upstream with respect to the flow direction of the water 21. Further, the water bottom unit 27 and the water surface unit 26 are physically connected by a wire 30 as a unit connection means, and the distance between the two units can be freely adjusted by adjusting the length of the wire 30.

  Further, the arithmetic processing unit 29, the water surface unit 26 and the water bottom unit 27 are electrically connected by a connector cord 31, and the ultrasonic echo signals output from the water surface unit 26 and the water bottom unit 27 are connected to the connector cord 31. And transmitted to the arithmetic processing unit 29.

  FIG. 3 is a schematic configuration diagram showing an outline of the overall configuration of the water surface unit 26 of the first ultrasonic flow meter 20, and FIG. 4 is an overall configuration of the water bottom unit 27 of the first ultrasonic flow meter 20. The structure schematic showing the outline of is shown.

  According to FIG. 3, the water surface unit 26 of the first ultrasonic flowmeter 20 includes a base portion 33 fixed in a slidable manner in a direction along the guide rail 28 (y-axis direction in FIG. 2), and a base A power unit 34 that is installed in the unit 33 and that slidably drives the base unit 33 along the guide rail 28, and a bracket unit 35 that is installed in the base unit 33 and in which a device group used for flow rate measurement is installed.

  A guide 37 for sliding and moving in the direction along the guide rail 28 is fixed to the base portion 33. The guide 37 grips the guide rail 28 a little so that the base portion 33 can slide. Yes. Further, by obtaining power from the power unit 34, the base unit 33 can be slidably moved along the guide rail 28, thereby realizing the sliding movement of the water surface unit 26.

  On the other hand, the bracket portion 35 transmits an ultrasonic wave from the position near the water surface (within 30 cm from the water surface) toward the bottom of the water surface to measure the flow rate, and receives the reflected wave of the ultrasonic wave reflected in the water. A first wire reel 39 and a second wire reel for winding or feeding the acoustic transducer 38 and the first wire 30a and the second wire 30b attached to the water bottom unit 27 for obtaining the flow velocity distribution in the water depth direction on the water bottom side, respectively. 40 is installed.

  The first wire 30 a that is wound or sent out by the first wire reel 39 is a wire whose main purpose is to support the load of the water bottom unit 27. On the other hand, the second wire 30b that the second wire reel 40 takes up or feeds is a wire whose main purpose is to finely adjust the direction of the bottom unit 27, and supports the load of the bottom unit 27. Plays an auxiliary role.

  According to FIG. 4, the water bottom unit 27 of the first ultrasonic flow meter 20 has the front (front) side and the rear (stern) side at the center of the hull in order to maintain the posture in the water 21 as stably as possible. A main body 41 having a shape close to a ship that is thinner than the portion is provided, and a plate 42 that receives the fluid resistance of the water 21 is attached to the center line of the main body 41 and to the stern portion.

  The bottom unit 27 configured as described above is configured such that the plate 42 attached to the stern portion receives the fluid resistance of the water 21 in a state where the bottom unit 27 is suspended in water (a state where the bottom unit 27 is not in contact with the bottom). The bow becomes easier to face the upstream direction with respect to the flow of the water 21. Therefore, it is more effective to measure the flow velocity distribution of the water 21 passing through the plane orthogonal to the flow direction of the water 21.

  Further, the water bottom unit 27 maintains a stable state without being swept away by the flowing water 21 even when the first wire 30a and the second wire 30b are loosened after landing on the water bottom. There is enough weight. Therefore, the bow direction during measurement is stabilized even after the surface is made to land on the bottom of the water.

  The weight of the bottom unit 27 should be as heavy as possible in consideration of the stability of the bottom unit 27. However, considering the strength of the wire 30 that suspends the water bottom unit 27 and the winding ability of the wire reels 39 and 40 that wind the wire, the lighter one is preferable. Therefore, in the first ultrasonic flow meter 20, as a result of comparing and considering the stability of the bottom unit 27, the strength of the wire 30, and the winding ability of the wire reels 39 and 40 for winding the wire, the weight of the bottom unit 27 is about 25kg. did.

  The weight of the water bottom unit 27 is not limited to the above 25 kg, and may be appropriately lighter or heavier than 25 kg depending on the use environment. Further, the bottom unit 27 may be configured such that the weight can be varied by adding and removing weights afterwards.

  The water bottom unit 27 is provided with a wire attachment portion 43 for attaching the first wire 30a and the second wire 30b suspended from the water surface unit 26 installed on the water surface. In the present embodiment, the wire attachment portions 43 are provided on the front, rear, left and right of the water bottom unit 27 so that the water bottom unit 27 can be suspended and pulled up in a balanced manner.

  In the main body portion 41, the wire attachment portion 43 of the water bottom unit 27 is attached to a total of three locations, one each on the front, left, and right sides. Moreover, in the plate 42, it attaches to two places, the front and back. Accordingly, the water bottom unit 27 as a whole is provided with a total of five wire attachment portions 43.

  Of the five wire attachment portions 43 of the water bottom unit 27, the wire attachment portion 43 to which the first wire 30a is attached is the sum of all the wire attachment portions 43 of the main body portion 41 and the wire attachment portion 43 on the front side of the plate 42. The four wire attachment portions 43 to which the second wires 30b are attached serve as the remaining one portion, that is, the wire attachment portions 43 attached to the rear of the plate 42.

  On the other hand, the main body portion 41 of the bottom unit 27 has an internal space, and is configured so that water covering the periphery does not enter the interior even when the bottom unit 27 is submerged. In this internal space, two bottom-side ultrasonic transducers 45 and 46 are installed so that ultrasonic waves can be transmitted in the water surface direction. The water bottom ultrasonic transducers 45 and 46 and the water surface ultrasonic transducer 38 are essentially the same ultrasonic transducers except for the installation location.

  For example, as shown in FIG. 4, the connector cords 31 of the two water bottom ultrasonic transducers 45 and 46 installed in the water bottom unit 27 are guided from the water surface unit 26 side by using the second wire 30b as a guide. After being sunk to the rear of the plate 42, it is guided to a cord introduction hole 47 provided in the vicinity of the center of the upper surface of the main body 41 and connected to each of the bottom-side ultrasonic transducers 45 and 46.

  Also, one of the two transducers 45 and 46 (the ultrasonic transducer 45 in FIG. 4) is parallel to a line L parallel to the water depth direction (z-axis direction) passing through the front and rear and left and right center positions of the bottom unit 27. The other (ultrasonic transducer 46 in FIG. 4) is installed in a state tilted at the same angle θ in the front (head) direction and in the rear (stern) direction.

  FIG. 5 shows a schematic configuration diagram illustrating a schematic configuration of a typical example of the arithmetic processing unit 29.

  The arithmetic processing unit 29 includes a program (hereinafter referred to as a program PG) necessary for causing a so-called electronic computer to function as the ultrasonic flowmeter according to the present invention. Specifically, as shown in FIG. 5, arithmetic processing means 48 such as a CPU (Central Processing Unit) or a microprocessor (MPU) that reads out PG and executes arithmetic processing, and a memory 50 that temporarily stores electronic data. A recording means 51 for recording and storing electronic data, an input means 52 for input by the measurer, a display means 53 for displaying the calculation processing result, and an interface (hereinafter referred to as I / F) with an external device. And I / F means 54 for carrying out the above.

  In the recording means 51, a basic process PG 56 responsible for basic processing operations such as an OS (Operating System) as a PG that can be read and executed by the arithmetic processing means 48, and a flow velocity distribution necessary for flow measurement are calculated and calibrated and acquired. The flow velocity distribution acquisition PG 57 to be performed and the flow rate measurement PG 58 for executing the arithmetic processing necessary for the flow rate measurement are stored. The PG 56, 57, 58 and the arithmetic processing unit 29 cooperate with each other so that the arithmetic processing unit 29 performs signal processing and arithmetic processing on the ultrasonic echo signals acquired from the water surface unit 26 and the water bottom unit 27, and generates ultrasonic waves. Functions as a flow meter.

  In the first ultrasonic flow meter 20 configured as described above, first, the arithmetic processing unit 29 receives a request to start the flow measurement, and triggers as a flow measurement start request to the water surface unit 26 and the water bottom unit 27. Output. Next, when a trigger is input to the water surface unit 26 and the water bottom unit 27, the water surface unit 26 and the water bottom unit 27 transmit ultrasonic waves into the water to be subjected to flow rate measurement. And the reflected wave (ultrasonic echo) of the ultrasonic wave reflected by the reflector group mixed in water is received, and the electrical signal (hereinafter referred to as an ultrasonic echo signal) corresponding to the received ultrasonic echo is the water surface unit 26. And output from the water bottom unit 27 to the arithmetic processing unit 29.

  When the ultrasonic echo signal is received from the water surface unit 26 and the water bottom unit 27, the arithmetic processing unit 29 performs signal processing and arithmetic processing on the received ultrasonic echo signal, and the flow rate of the water 21 obtained as a result of the arithmetic processing Can be displayed on the display means 53 of the arithmetic processing unit 29. The first ultrasonic flowmeter 20 is based on the principle of integrating the flow velocity distribution in a certain cross section to obtain the flow rate of the water 21 passing through the cross section, and once measures the flow velocity distribution. Therefore, the arithmetic processing unit 29 can be configured to display not the flow rate of the water 21 but the flow velocity distribution in time series.

  FIG. 6 is a functional block diagram schematically showing a configuration in which the first ultrasonic flowmeter 20 is functionally captured, that is, functional blocks.

  The first ultrasonic flow meter 20 shown in FIG. 6 includes a trigger generation means 60 that receives a request to start measurement and generates a trigger, a flow velocity distribution acquisition means 61 that acquires a flow velocity distribution that is a basis of flow measurement, and a flow velocity. A flow rate calculation unit 62 that calculates a flow rate based on the flow velocity distribution acquired by the distribution acquisition unit 61 and a flow rate display unit 63 that displays the flow rate calculated by the flow rate calculation unit 62 as a flow rate measurement value are provided.

  Each means constituting the first ultrasonic flow meter 20 is realized by the arithmetic processing means 48 provided in the arithmetic processing unit 29 reading and executing the basic processing PG 56, the flow velocity distribution acquisition PG 57, and the flow rate measurement PG 58. Among the above-mentioned means included in the first ultrasonic flow meter 20, the trigger generating means 60 and the flow velocity distribution obtaining means 61 are configured such that the arithmetic processing means 48 reads and executes the basic process PG 56 and the flow velocity distribution obtaining PG 57, thereby causing the flow rate to flow. The calculation unit 62 and the flow rate display unit 63 are realized by the arithmetic processing unit 48 reading and executing the basic process PG 56 and the flow rate measurement PG 58.

  The trigger generating means 60 in the first ultrasonic flow meter 20 receives a request for measurement start from the measurer and generates a trigger. The generated trigger is used by the flow velocity distribution acquisition means 61 to oscillate an ultrasonic pulse. The generated trigger is also used for synchronization when the flow velocity distribution acquisition means 61 processes the ultrasonic echo signal.

  The flow velocity distribution acquisition unit 61 receives the trigger generated by the trigger generation unit 60 and oscillates an ultrasonic wave transmitted to the water whose flow rate is to be measured. And while transmitting the oscillated ultrasonic wave to water, the reflected wave (ultrasonic echo) from the underwater reflector group is received. When the ultrasonic echo is received, an ultrasonic echo signal is generated, and the flow velocity distribution is acquired by signal processing and analyzing the ultrasonic echo signal.

  The flow rate calculation means 62 calculates the flow rate by performing an integral operation based on the flow velocity distribution output from the flow velocity distribution acquisition means 61. The flow rate display means 63 displays the flow rate calculated by the flow rate calculation means 62 as a measurement value so that the measurer can visually recognize the measurement value of the flow rate.

  If only FIG. 6 is seen, the 1st ultrasonic flowmeter 20 will not differ substantially from the conventional Doppler type ultrasonic flowmeter and its function structure, and it seems that it is not fundamentally different. The principle of flow measurement of the first ultrasonic flow meter 20 is to obtain the flow velocity distribution in a certain cross section by integrating the cross section, and this point is also common to the conventional Doppler type ultrasonic flow meter. ing. However, the configuration of the flow velocity distribution acquisition means 61 that acquires the flow velocity distribution that is the basis of the flow measurement and the method of acquiring the flow velocity distribution are different from the conventional Doppler type ultrasonic flowmeter.

  Such a difference is generated in order to solve a problem caused by a difference in application environment from a conventional Doppler type ultrasonic flowmeter such as a wide range in which a flow velocity distribution is acquired. More specifically, as in the case of the water channel 24 shown in FIG. 1, in general, when the width is in units of m, the flow rate distribution of the water 21 flowing through the water channel 24 is treated as a uniform flow rate distribution because the measurement accuracy of the flow rate measurement is increased. This is because it is difficult to ensure.

  Therefore, in the first ultrasonic flow meter 20, two units of the water surface unit 26 and the water bottom unit 27 are used as the flow velocity distribution acquisition means, and the water velocity near the water bottom, the water surface and the water channel width are greatly different. In the vicinity of the wall surface in the direction, the flow velocity distribution is obtained, and the obtained flow velocity distribution data is calculated to calculate the flow velocity distribution for flow measurement.

  FIG. 7 is a functional block diagram showing a more detailed functional unit of the flow velocity distribution acquisition means 61 of the first ultrasonic flow meter 20.

  The flow velocity distribution acquisition means 61 of the first ultrasonic flow meter 20 is transmitted from the water surface side flow velocity distribution acquisition means 65 that acquires the flow velocity distribution based on the ultrasonic echo signal transmitted from the water surface unit 26 and the water bottom unit 27. Water bottom side flow velocity distribution acquisition means 66 for acquiring the flow velocity distribution based on the ultrasonic echo signal, and necessary data calibration processing based on the respective flow velocity distributions acquired by the water surface side flow velocity distribution acquisition means 65 and the water bottom side flow velocity distribution acquisition means 66. And a flow velocity distribution calibration processing means 67 for obtaining a flow velocity distribution for flow rate calculation.

  The flow velocity distribution acquisition means 61 acquires the flow velocity distribution in the direction (z-axis direction in FIG. 2) from the position of the water surface ultrasonic transducer 38 installed in the water surface unit 26 toward the water bottom. . On the other hand, the water bottom side flow velocity distribution acquisition means 66 acquires the flow velocity distribution in the direction from the position of the water bottom ultrasonic transducers 45 and 46 installed in the water bottom unit 27 toward the water surface (z-axis direction in FIG. 2). Then, the flow velocity distribution in the water depth direction from the water surface to the bottom of the water is acquired by both the flow velocity distribution acquisition means 65 and 66.

  The water surface side flow velocity distribution acquisition means 65 of the flow velocity distribution acquisition means 61 receives an input of a trigger, and when the trigger is input, an ultrasonic wave that oscillates and emits an ultrasonic pulse into the water to be measured for flow rate. A pulse transmitting unit 69; an ultrasonic echo receiving unit 70 that receives an ultrasonic echo reflected in water to be measured for flow rate; and outputs an ultrasonic echo signal corresponding to the received ultrasonic echo; A signal processing unit 71 that performs signal processing on the acoustic echo signal, and a flow velocity distribution calculating unit 72 that calculates the flow velocity distribution of the water 21 that is a flow rate measurement target from the signal-processed ultrasonic echo signal.

  That is, the ultrasonic pulse transmitter 69 serves as an ultrasonic transmitter that transmits ultrasonic pulses into the water 21, and the ultrasonic echo receiver 70 receives an ultrasonic echo signal corresponding to the ultrasonic echo received in water. As an ultrasonic receiving means for outputting, the signal processing section 71 is a signal processing means for signal processing of an ultrasonic echo signal, and a flow velocity distribution calculating section 72 calculates the flow velocity distribution of the water 21 from the ultrasonic echo signal after the signal processing. Functions as a flow velocity distribution calculating means.

  On the other hand, the water bottom side flow velocity distribution acquisition means 66 has substantially the same configuration as the water surface side flow velocity distribution acquisition means 65, but the configuration is slightly different. This difference is due to the fact that the bottom unit 27 faces the bottom to stabilize the posture during measurement. Deposits accumulate on the bottom of the water channel 24 due to the transport / deposition action caused by the flow of the water 21 and are uneven, so that an inclination occurs due to the unevenness of the bottom of the water, and ultrasonic waves are transmitted into the water in a desired direction. It becomes difficult.

  Therefore, in order to nullify the influence of the inclination of the bottom unit 27 caused by the unevenness of the bottom, a plurality of ultrasonic transducers such as two ultrasonic transducers for transmitting and receiving the ultrasonic wave of the bottom unit 27 are installed. For example, in the case of two units, as shown in FIG. 4, the water bottom side ultrasonic transducers 45 and 46 are arranged in front and rear. And the influence of the inclination of the water bottom unit 27 is nullified by performing arithmetic processing using the two flow velocity distributions acquired by the respective water bottom ultrasonic transducers 45 and 46.

  The bottom-side flow velocity distribution acquisition means 66 is based on the ultrasonic echo signal acquired from the first bottom-side ultrasonic transducer 45 because each of the bottom-side ultrasonic transducers 45 and 46 needs to acquire the flow velocity distribution. First water bottom side flow velocity distribution acquisition means 75 for calculating the flow velocity distribution, and second water bottom flow velocity distribution acquisition means for calculating the flow velocity distribution based on the ultrasonic echo signal acquired from the second water bottom ultrasonic transducer 46. 76.

  As can be seen from FIG. 7, each of the first water bottom side flow velocity distribution acquisition means 75 included in the water bottom side flow velocity distribution acquisition means 66 includes an ultrasonic pulse transmitter 69, an ultrasonic echo receiver 70, a signal processor 71, and A flow velocity distribution calculating unit 72, which is essentially the same as the water surface flow velocity distribution obtaining unit 65. Further, the second water bottom side flow velocity distribution acquisition means 76 is the same as the first water bottom side flow velocity distribution acquisition means 75.

  Further, the bottom-side flow velocity distribution acquisition unit 66 further includes an inclination correction calculation processing unit 77 as an inclination correction calculation processing unit that invalidates the influence of the inclination of the water bottom unit 27. The inclination correction calculation processing unit 77 performs weighted average processing using the flow velocity distributions acquired by the first water bottom side flow velocity distribution acquisition means 75 and the second water bottom side flow velocity distribution acquisition means 76, respectively. The influence of the inclination of the bottom unit 27 is canceled and invalidated by the weighted average process performed by the inclination correction calculation processing unit 77.

  FIG. 8 is an explanatory diagram for explaining the principle of the weighted average process performed by the inclination correction calculation processing unit 77 to invalidate the influence of the inclination of the bottom unit 27.

The bottom unit 27 shown in FIG. 8 is not in a state parallel to the x-axis (ideal measurement state) but is inclined by α with respect to the x-axis and is in a state where the tip is raised with respect to the x-axis. In the case shown in FIG. 8, the flow velocity value Vf measured as the flow velocity by the first bottom-bottom ultrasonic transducer 45 attached facing the bow (front) direction is the actual flow direction (x, y, z) = In the case of (U, 0, 0), the actual flow velocity value is U. Using this U,

It can be expressed as

On the other hand, the flow velocity value Vr measured as the flow velocity by the second water bottom ultrasonic transducer 46 attached facing the stern (rear) direction is (x, y, z) = (U, 0, 0). So, using the actual flow velocity value U

It can be expressed as

Based on the flow velocity distribution acquired by the bottom unit 27, the calculated flow velocity is a value obtained by performing a weighted average process on the two equations (1) and (2). The weighted average process is an average process in which each mathematical expression is weighted. Considering the fact that the two transducers 45 and 46 installed in the bottom unit 27 are in a symmetric state, the weighted average flow velocity value V is the actual flow velocity value when the weighted average is calculated with the weight being 1: 1. With U

It can be expressed as

Furthermore, if the expression of Formula (3) is expanded using the trigonometric addition theorem,
[Equation 4]
V = Ucosα (4)
It becomes.

  Therefore, the measurement error rate for the flow velocity caused by the inclination α is 1−cos α when calculated using the above equation (4). When the maximum value of α that can be assumed in the actual measurement environment is 5 ° (gradient rate 8.7%), the error rate of the flow velocity measurement due to the inclination α of the bottom unit 27 is about 0.4%, which is a practical range. The required measurement error (within 3%) can be fully satisfied.

  In an actual measurement environment, the flow direction of the water 21 may have a vector component in the water depth direction. However, when measuring the flow rate or flow velocity distribution, it is sufficiently possible to avoid the point having the vector component in the water depth direction with respect to the flow direction of the water 21, so that the point where the flow direction of the water 21 has the water depth direction component is determined. When measuring the flow velocity distribution avoiding it, it can be considered that the error rate of the flow velocity measurement depends exclusively on the slope α.

  When the flow velocity is measured at a point where the flow direction of the water 21 is inclined by β from the water surface (the flow velocity is U), the first transducer 45 and the second transducer 46 are parallel to the water surface. The flow component Ucosβ is calculated as a flow velocity value.

Therefore, if the above formulas (1) to (3) are calculated in consideration of the fact that the inclination angle of the flow direction of the water 21 from the water surface is β and U is U cos β, the weighted average flow velocity value V is Using actual flow velocity value U

Furthermore, if the expression of Formula (5) is expanded using the addition theorem of trigonometric function,
[Equation 6]
V = Ucosβ (cosα−sinαtanβ) (6)
It becomes.

  Accordingly, the measurement error rate for the flow velocity caused by the inclination α of the bottom unit 27 and the inclination angle β in the flow direction of the water 21 is 1−cos α + sin α tan β when calculated using the above equation (6). Even assuming that β is 5 °, which is the same as α, the measurement error rate is about 1.2% and sufficiently satisfies the measurement error (within 3%) required as a practical range. it can.

  The flow velocity distribution calibration processing unit 67 calibrates the flow velocity distribution in the depth direction used for the flow rate calculation using the flow velocity distribution acquired by the water surface side flow velocity distribution acquisition unit 65 and the flow velocity distribution acquired by the water bottom side flow velocity distribution acquisition unit 66. .

  The flow velocity of the fluid in the depth direction is generally maximum at a portion slightly deeper than the water surface. And it becomes the steady flow area | region where a flow velocity becomes substantially constant in the water bottom side (location which is not a boundary layer) rather than the water depth where the flow velocity becomes the maximum. Furthermore, when it approaches the water bottom which becomes a wall surface from the steady region in the water bottom direction, there is a characteristic that the flow velocity becomes slower as it approaches the water bottom at a certain water depth.

  The reason why the flow velocity decreases as it approaches the bottom of the water is that a boundary layer is formed on the bottom of the water. Here, the boundary layer is a region that is generally 0 to 99% of the flow velocity (main flow velocity) of the water 21 in the steady flow region.

  Utilizing such characteristics of the fluid, the flow velocity distribution on the water surface side adopts the flow velocity distribution acquired by the water surface flow velocity distribution acquisition means 65, and the flow velocity distribution on the water bottom side is acquired by the water bottom side flow velocity distribution acquisition means 66. Calibrate using flow velocity distribution. In other words, the water surface side flow velocity distribution acquisition means 65 is a means for measuring and acquiring the flow velocity distribution including the point (water depth) at which the maximum flow velocity is obtained, and the water bottom side flow velocity distribution acquisition means 66 is the flow velocity distribution in the boundary layer. It is a means for measuring and acquiring.

  FIG. 9 is an explanatory diagram for explaining a place where a flow velocity distribution is measured when the flow rate measurement method of the present invention (hereinafter, referred to as a first flow rate measurement method) performed using the first ultrasonic flowmeter 20 is performed. Show.

  The flow path shown in FIG. 9 corresponds to the application scene of the first ultrasonic flowmeter 20 shown in FIG. In measuring the flow rate of the water 21 flowing through the water channel 24, in the first flow rate measurement method, the flow velocity distribution in the direction of the channel width of the open channel is a center line connecting the centers of the channel widths (one-dot chain line shown in FIG. 9). ), The flow velocity distribution on the other side can be estimated by obtaining one flow velocity distribution.

  Further, in the first flow rate measuring method, the flow velocity distribution is measured at three locations so as to obtain either one of the left and right flow velocity distributions with respect to the center line connecting the centers of the channel widths (in the y-axis direction). Specifically, as shown in FIG. 9, the measurement is performed in (1) a side wall vicinity region, (2) a velocity boundary region, and (3) a flow path center region.

  Here, the side wall vicinity region refers to a region having a large flow rate change rate formed on the wall surface side in a flow velocity distribution in the width direction of a fluid flowing through a generally known opening. The position at which the flow velocity distribution on the water depth side is acquired is the central position with respect to the distance from the side wall that is the side wall vicinity region from the viewpoint of more easily grasping the flow velocity change in the width direction of the water channel 24 in the side wall vicinity region. Specifically, it is 60 cm from the side wall, and a margin is provided for the estimated value (50 cm) of the velocity boundary layer thickness on the side surface.

  When the water surface unit 26 and the water bottom unit 27 move to the side wall side of the water channel 24 in a state where the flow velocity distribution in the depth direction can be measured, the water surface unit 26 and the water bottom unit 27 are positioned in the vicinity of the side wall. Configured to do.

  The velocity boundary region is a boundary between a region formed near the side of the water channel 24 and having almost no change in flow velocity regardless of the position in the width direction of the water channel and a region near the side wall, and allows a range that does not affect the flow rate calculation. This is the area. The flow path center region is substantially the center of the water channel 24 and is a region that allows a range that does not affect the flow rate calculation, in other words, a steady flow region in which the flow velocity of the water 21 is the main flow velocity.

  Note that the range that does not affect the flow rate calculation changes depending on the width of the water channel 24 and the measurement accuracy required at the time of measurement. Therefore, it cannot be uniquely defined, but is considered to be within a range of approximately 50 cm or more.

  As described above, the flow velocity distribution is measured at three locations with respect to the channel width (y-axis direction), and the flow velocity distribution cannot be acquired with accuracy that can be used as basic data for flow measurement only by measuring one location. Because. Therefore, in the first flow rate measurement method, following the flow velocity distribution in the width direction of the fluid flowing through the generally known culvert, the range less than 1 m from the side wall where the flow rate change rate is high is measured finely, and other ranges are measured. The flow velocity distribution in the wide water channel 24 is obtained by interpolation using the flow velocity distributions of (1) to (3).

  In the example shown in FIG. 9, the flow velocity distribution is measured with a time difference using one first ultrasonic flow meter 20, but the measurement order may be arbitrary. Moreover, you may carry out simultaneously using the 1st ultrasonic flowmeter 20 instead of one, and using the three 1st ultrasonic flowmeters 20 in total, one each.

  Next, FIG. 10 shows an explanatory diagram (processing flow diagram) for explaining the first flow rate measurement method performed using the first ultrasonic flowmeter 20 step by step.

  In the first flow rate measuring method, the arithmetic processing means 48 of the arithmetic processing unit 29 reads out the basic process PG 56, the flow velocity distribution acquisition PG 57, and the flow rate measurement PG 58 at each of the locations (1) to (3) shown in FIG. By executing, the arithmetic processing unit 29 functions as each unit shown in FIG. Therefore, each means shown in FIG. 6 measures the flow rate of the water 21 flowing through the water channel 24.

  According to FIG. 10, the first flow rate measurement method is configured to obtain a flow rate based on the flow velocity distribution acquired in the overall flow velocity distribution acquisition procedure (step S <b> 1) that acquires the flow velocity distribution that is the basis of flow rate measurement and the overall flow velocity distribution acquisition procedure. A flow rate calculation procedure for measuring (step S2), and a flow rate display procedure for displaying the calculated flow rate as a flow rate measurement value (step S3).

  In order to start the first flow rate measuring method, first, it is necessary to position the water surface unit 26 and the water bottom unit 27 of the first ultrasonic flowmeter 20 at the measurement location where the flow velocity distribution is acquired. Specifically, positioning is performed in any one of (1) side wall vicinity region, (2) velocity boundary region, and (3) flow path center region. For example, the water surface unit 26 and the water bottom unit 27 are positioned in the above (1).

  The water surface unit 26 can be positioned at a position where the flow velocity distribution is measured by sliding the water surface unit 26 along the guide rail 28. The water surface unit 26 can operate the power unit 34 by remote operation of the measurer, and can move to the position where the flow velocity distribution is measured along the guide rail 28 by operating the power unit 34.

  On the other hand, in order to position the water bottom unit 27, it is necessary to install the water bottom unit 27 in a state where it can be suspended from the water surface unit 26 before the water surface unit 26 is slid (positioned). And after positioning the water surface unit 26, the wire 30 is sent out from the wire reels 39 and 40, and the water bottom unit 27 is submerged in the water bottom from the position where the water surface unit 26 is positioned.

  The operation of the wire reels 39 and 40 to feed and rewind the wire 30 is performed by rotating the wire reels 39 and 40 in the forward direction or the reverse direction by a remote operation of the measurer. When the wire reels 39 and 40 are operated, the length of the wire 30 changes, and the water bottom unit 27 can be submerged from the water surface side to the water bottom side or positioned from the water bottom side.

  When the water bottom unit 27 comes into contact with the water bottom, the first wire 30a and the second wire 30b are loosened. The loosening of the wires 30a and 30b prevents an excessive load from being applied to the wires 30a and 30b, and the wires 30a and 30b are transmitted from the water bottom ultrasonic transducers 45 and 46 to the water. This is to prevent interference with ultrasonic waves.

  Next, when the positioning of the water surface unit 26 and the water bottom unit 27 is completed, it is necessary for the arithmetic processing means 48 to execute the basic processing PG 56 and the flow velocity distribution acquisition PG 57 so that the flow rate measurement can be started anytime (initial state). In the initial state, the arithmetic processing unit 29 enters a measurement start request standby state in which it waits for a measurement start request. Then, when the arithmetic processing means 48 of the arithmetic processing unit 29 recognizes the measurement start request, the process proceeds to step S1, and the entire flow velocity distribution acquisition procedure is performed in step S1.

  FIG. 11 is an explanatory diagram (processing flow diagram) for explaining the processing steps in the overall flow velocity distribution acquisition procedure (step S1) step by step.

  According to FIG. 11, the entire flow velocity distribution acquisition procedure receives a measurement start request and confirms whether or not measurement can be started (step S <b> 11), and in the water depth direction of the flow path. A water depth direction flow rate distribution acquisition step (step S12 to step S18) for acquiring a flow velocity distribution, and a measurement residual confirmation step (step S19) for checking whether or not there is a need to measure the flow rate distribution in the water depth direction at another place. .

  The water depth direction flow velocity distribution acquisition process acquires a water surface flow velocity distribution based on a trigger generation process (step S12) for generating a trigger and an ultrasonic echo signal output from the water surface ultrasonic transducer 38 installed in the water surface unit 26. The flow velocity distribution on the bottom side of the water channel 24 is acquired based on the water surface flow velocity distribution acquisition process (steps S13 to S16) and the ultrasonic echo signals output from the water bottom ultrasonic transducers 45 and 46 installed in the water bottom unit 27. Water bottom side flow velocity distribution acquisition process (step S13 to step S17).

  The depth direction flow velocity distribution acquisition process includes each of the flow velocity distributions acquired in the water surface side flow velocity distribution acquisition process and the water bottom side flow velocity distribution acquisition process in addition to the trigger generation process, the water surface side flow velocity distribution acquisition process, and the water bottom side flow velocity distribution acquisition process. And a flow velocity distribution calibration process (step S18) for performing necessary data calibration processing to obtain a flow velocity distribution for flow rate calculation.

  In the overall flow velocity distribution acquisition procedure, a measurement preparation completion confirmation process is first performed in step S11. A request to start measurement is received, and it is confirmed whether or not a trigger can be generated, that is, whether or not the measurement is ready to start. Whether or not the trigger can be generated is confirmed by the arithmetic processing means 48 of the arithmetic processing unit 29 displaying on the display means 53 and recognizing the confirmation result from the measurer.

  In the measurement preparation completion confirmation process, when the arithmetic processing means 48 of the arithmetic processing unit 29 recognizes the confirmation result from the measurer and recognizes the confirmation result that the trigger may be generated (in the case of YES in step S11), The measurement preparation completion confirmation process is completed, and subsequently, a trigger generation process is performed in step S12.

  In the trigger generation process, the trigger generation means 60 generates a trigger. Then, when the generated trigger is sent to the flow velocity distribution acquisition means 61, the trigger generation process in step S12 is completed. When the trigger generation process is completed, the process proceeds to step S13, where a water surface side flow velocity distribution acquisition process and a water bottom side flow speed distribution acquisition process are performed.

  The water surface side flow velocity distribution acquisition process (step S13 to step S16) of the flow velocity distribution acquisition procedure receives the trigger generated in the trigger generation procedure of step S1, oscillates an ultrasonic pulse, and generates an ultrasonic pulse in the water to be measured for flow rate. The ultrasonic pulse transmission step (step S13) for transmitting the ultrasonic wave, the ultrasonic echo reflected in the water whose flow rate is to be measured, and the ultrasonic echo reception for outputting the ultrasonic echo signal corresponding to the received ultrasonic echo A step (step S14), a signal processing step (step S15) for performing signal processing on the ultrasonic echo signal, and a flow velocity distribution calculating step for calculating a flow velocity distribution of water to be measured for flow rate from the signal processed ultrasonic echo signal ( Step S16).

  On the other hand, in the water bottom side flow velocity distribution acquisition process, the first water bottom side flow velocity distribution acquisition means 75 performs the first water bottom side flow velocity distribution acquisition step (step S13 to step S16) and the second water bottom side flow velocity distribution acquisition means 76. In addition to the second water bottom side flow velocity distribution acquisition step (steps S13 to S16) to be performed, the flow velocity in the depth direction at the same time acquired in the first water bottom side flow velocity distribution acquisition step and the second water bottom side flow velocity distribution acquisition step. An inclination correction calculation processing step (step S17) is further provided that performs a weighted average process that invalidates the influence of the inclination of the bottom unit 27 using each of the distributions.

  In the water surface flow velocity distribution acquisition process, the water surface flow velocity distribution acquisition means 65 acquires the flow velocity distribution in the direction from the position of the water surface ultrasonic transducer 38 installed in the water surface unit 26 toward the water bottom (the z-axis direction in FIG. 2). Is done. Further, the water bottom side flow velocity distribution acquisition process is performed in a direction (the z-axis direction in FIG. 2) in which the water bottom side flow velocity distribution acquisition means 66 moves from the position of the water bottom ultrasonic transducers 45 and 46 installed in the water bottom unit 27 to the water surface. This is done by acquiring the flow velocity distribution.

  Note that the first water bottom side flow velocity distribution acquisition step and the second water bottom side flow velocity distribution acquisition step in the water bottom side flow velocity distribution acquisition step are not essentially different from the water surface side flow velocity distribution acquisition step. That is, the first water bottom side flow velocity distribution acquisition step and the second water bottom side flow velocity distribution acquisition step include an ultrasonic pulse transmission step (step S13), an ultrasonic echo reception step (step S14), and a signal processing step (step). S15) and a flow velocity distribution calculating step (step S16).

  In the following description, in order to clearly distinguish one of the processing steps of the first water bottom side flow velocity distribution acquisition step and the second water bottom side flow velocity distribution acquisition step, hereinafter, the first water bottom side flow velocity distribution acquisition step will be described. The processing steps in are referred to as “first to step”, and the processing steps in the second water bottom side flow velocity distribution acquisition step are referred to as “second to step”.

  In such an overall flow velocity distribution acquisition procedure (step S11 to step S19), the water surface side flow velocity distribution acquisition process (step S13 to step S16) and the water bottom side flow velocity distribution acquisition process (step S13 to step S17) are performed in parallel. . And if the water surface side flow velocity distribution acquisition process and the water bottom side flow velocity distribution acquisition process are completed, the process process after step S18 will be made.

  On the other hand, focusing on the water bottom side flow velocity distribution acquisition process, in the water bottom side flow velocity distribution acquisition process, first, a first water bottom side flow velocity distribution acquisition step (steps S13 to S16) and a second water bottom side flow velocity distribution acquisition step (steps). Steps S13 to S16) are performed in parallel, and when the first water bottom side flow velocity distribution acquisition step (Steps S13 to S16) and the second water bottom side flow velocity distribution acquisition step (Steps S13 to S16) are completed, Step S17 is performed. Then, the inclination correction calculation processing step of step S17 is performed.

  Accordingly, the water surface side flow velocity distribution acquisition process (step S13 to step S16), the first water bottom side flow velocity distribution acquisition step (step S13 to step S16) and the second water bottom side flow velocity distribution acquisition step (step S13 to step S16). The three processing steps from step S13 to step S16) are the same with respect to the processing content. Therefore, the processing steps from step S13 to step S16 will be described by taking the water surface side flow velocity distribution acquisition process as an example.

  In the water surface flow velocity distribution acquisition process, first, an ultrasonic pulse transmission step is performed in step S13. In the ultrasonic pulse transmission step, the ultrasonic transmission unit 69 receives the trigger and oscillates the ultrasonic pulse. The oscillated ultrasonic pulse is transmitted from the ultrasonic transmitter 69 into the water to be measured for flow rate. When the ultrasonic pulse oscillated by the ultrasonic transmitter 69 is transmitted into the water to be measured for flow rate, the ultrasonic pulse transmitting step is completed and the process proceeds to step S14. In step S14, an ultrasonic echo reception step is performed.

  In the ultrasonic echo receiving step, the ultrasonic echo receiving unit 70 receives the ultrasonic echo reflected by the reflector group mixed in the water to be measured for flow rate. When the ultrasonic echo receiving unit 70 receives an ultrasonic echo, the ultrasonic echo receiving unit 70 outputs an ultrasonic echo signal corresponding to the ultrasonic echo. When the ultrasonic echo signal is output, the ultrasonic echo reception step is completed, and the process proceeds to step S15. In step S15, a signal processing step is performed.

  In the signal processing step, the signal processing unit 71 receives the ultrasonic echo signal output from the ultrasonic echo receiving unit 70 and the trigger output from the trigger generating means 60, and performs signal processing of the ultrasonic echo signal. The signal processing unit 71 performs noise reduction processing for the purpose of reducing noise components superimposed on the ultrasonic echo signal as signal processing and analog-digital conversion (hereinafter referred to as AD conversion) for converting an analog signal into a digital signal. .

  The signal processing unit 71 receives a trigger output from the trigger generating means 60, and the trigger is used to take timing (synchronize) for AD conversion of the ultrasonic echo signal. When the received ultrasonic echo signal is converted from an analog signal to a digital signal, the signal processing step is completed and the process proceeds to step S16. In step S16, a flow velocity distribution calculating step is performed.

  In the flow velocity distribution calculation step, the flow velocity distribution calculator 72 receives the ultrasonic echo signal converted into a digital signal, and calculates a flow velocity distribution necessary for calculating the flow rate. The flow velocity distribution calculated in the flow velocity distribution calculation step is a flow velocity distribution in the water depth direction (z-axis direction in FIG. 2). The calculation of the flow velocity distribution is performed by obtaining the position of each reflector in the reflector group mixed in water and the speed of the reflector at that position. This is because the reflector group mixed in the water moves together with the water, so that the speed of the reflector can be regarded as the flow velocity of water at the position of the reflector.

  The speed of the reflector can be obtained by analyzing the ultrasonic echo signal to obtain position information tracking the reflector mixed in the water whose flow rate is to be measured at regular time intervals. The distance the body moves can be determined. After that, the speed can be obtained by converting the distance traveled per unit time. In this way, by acquiring the ultrasonic echoes reflected from the respective reflectors mixed in the water, the position and velocity of the reflector can be obtained, and consequently the flow velocity distribution in the depth direction of the water can be acquired.

  When the flow velocity distribution calculation unit 72 calculates the flow velocity distribution, the flow velocity distribution calculation step is completed, and the water surface flow velocity distribution acquisition process is completed upon completion of the flow velocity distribution calculation step. When the water surface side flow velocity distribution acquisition process is completed, the process proceeds to step S18. In addition, the process step of step S18 is made after the water surface side flow velocity distribution acquisition process (step S13 to step S16) and the water bottom side flow velocity distribution acquisition process (step S13 to step S17) are completed.

  On the other hand, in the water bottom side flow velocity distribution acquisition process, first, the first water bottom side flow velocity distribution acquisition step (steps S13 to S16) and the second water bottom side flow velocity distribution acquisition step (steps S13 to S16) are performed in parallel. The When the first water bottom side flow velocity distribution acquisition step (step S13 to step S16) and the second water bottom side flow velocity distribution acquisition step (step S13 to step S16) are completed, the process proceeds to step S17, and in step S17. The inclination correction calculation processing unit 77 of the water bottom side flow velocity distribution acquisition means 66 executes an inclination correction calculation processing step.

  First, in the inclination correction calculation processing step of step S15, the inclination correction calculation processing unit 77 of the water bottom side flow velocity distribution acquisition means 66 executes the inclination correction calculation processing. The inclination correction calculation process is performed using the flow velocity distributions acquired in the first water bottom side flow velocity distribution acquisition step and the second water bottom side flow velocity distribution acquisition step, respectively.

  The inclination correction calculation processing unit 77 uses the flow velocity distributions acquired in the first water bottom side flow velocity distribution acquisition step and the second water bottom side flow velocity distribution acquisition step, respectively, and uses the first water bottom ultrasonic transducer 45 and the second From the positional relationship of the water bottom ultrasonic transducer 46, a weighted average process is performed to cancel the inclination of the water bottom unit 27.

  When the tilt correction calculation processing unit 77 calculates the tilt correction, the tilt correction calculation processing step is completed, and the process proceeds to step S18. In step S18, a flow rate distribution calibration process is performed.

  In the flow velocity distribution calibration process, the flow velocity distribution calibration processing means 67 calculates the flow velocity distribution in the depth direction from the water surface to the bottom of the water using the flow velocity distribution on the water surface side and the flow velocity distribution on the water bottom side after the inclination correction. Get by. The water surface side flow velocity distribution is acquired by the water surface side flow velocity distribution acquisition unit 65 performing the water surface side flow velocity distribution acquisition process. The water bottom side flow velocity distribution is acquired by the water bottom side flow velocity distribution acquisition unit 66. It is acquired by performing a distribution acquisition process.

  Further, the flow velocity distribution in the depth direction from the water surface to the bottom of the water obtained by the flow velocity distribution calibration processing means 67 is a result of performing a calculation process in consideration of the flow velocity distribution in the depth direction of the water 21 flowing through the open channel guided by hydrodynamics. , What you get. That is, the change in the flow rate of the water 21 is large in the range within 1.5 m from the water surface and the bottom of the water, and there is almost no change in the flow rate of the water 21 in the range of 1.5 m or more from the water surface and the bottom of the water (flow rate Is almost constant).

  More specifically, in the range within 1.5 m from the water surface and the bottom of the water, since the change in the flow velocity is large and accurate estimation of the flow velocity is difficult, the flow velocity distribution on the water surface side and the flow velocity distribution on the water bottom side are separated. The units, that is, the water surface unit 26 and the water bottom unit 27 are acquired. On the other hand, for other water depths, since the flow velocity can be considered to be almost constant, the calculation processing to interpolate the flow velocity data of the water depth for which the flow velocity distribution has not been obtained, using the flow velocity distribution on the water surface side and the flow velocity distribution on the bottom side obtained. The flow velocity distribution in the depth direction from the water surface to the bottom of the water is acquired.

  The range of about 1.5 m from the water surface takes into consideration the point where the flow velocity peak value of water 21 appears relatively close to the water surface (at least 1.5 m or less, which is said to be measurable with a conventional ultrasonic flowmeter). It is a thing. On the other hand, the range of about 1.5 m from the bottom of the water is said to be 1.5 m, which can be measured with a conventional ultrasonic flowmeter, even if the size of the boundary layer formed near the bottom of the water is greatly estimated at a practical level. The following points are taken into consideration.

  On the other hand, even within a range of 1.5 m from the water surface and the water bottom, there is a water depth at which the water surface side ultrasonic transducer 38 and the water surface side ultrasonic transducers 45 and 46 cannot measure the flow velocity of the water 21. For the water depth at which the water surface side ultrasonic transducer 38 and the water surface side ultrasonic transducers 45 and 46 cannot measure the flow velocity of the water 21, the flow velocity data of the water 21 is interpolated even if it is within 1.5 m from the water surface and the water bottom. There is a need to.

  Specifically, positions that should be called blind spots of the water surface side ultrasonic transducer 38 and the water surface side ultrasonic transducers 45, 46, that is, the water depth from the water surface to the tip of the water surface side ultrasonic transducer 38 and the water surface to the water surface side ultrasonic wave. This is the water depth to the tip of the transducers 45 and 46. If the water depth from the water surface to the tip of the water surface side ultrasonic transducer 38 and the water depth from the water bottom to the tip of the water surface side ultrasonic transducers 45 and 46 are small, it can be determined that there is no problem in the flow measurement. You can ignore it without interpolation.

  FIG. 12 is an example of the flow velocity distribution in the depth direction from the water surface to the bottom of the water obtained by the flow velocity distribution calibration processing means 67 executing the flow velocity distribution calibration process.

  When the flow velocity distribution calibration processing unit 67 executes the flow velocity distribution calibration processing step and acquires the flow velocity distribution in the depth direction from the water surface to the bottom of the water as shown in FIG. 12, the flow velocity distribution calibration processing step is completed. Completion of the flow velocity distribution calibration process means that the acquisition of the flow velocity distribution in the water depth direction (from the water surface to the water bottom) at any of the positions (1), (2) or (3) shown in FIG. 9 is completed.

  In the case of the ultrasonic flow meter 20 shown in FIG. 2, the flow velocity distribution in the water depth direction from the water surface to the bottom of the water can be displayed on the display means 53 of the arithmetic processing unit 29. However, the process of displaying the flow velocity distribution in the water depth direction on the display means is omitted from the explanatory diagram of FIG. 11 because it is an arbitrary process that does not necessarily need to be displayed in the process of the overall flow velocity distribution acquisition procedure.

  When the flow velocity distribution calibration process is completed, the process proceeds to step S19, and a measurement remaining confirmation process is performed in step S19. The measurement remaining confirmation process is performed because it is necessary to acquire the flow velocity distribution in the width direction (y-axis direction in FIG. 2) of the water channel 24 necessary for calculating the flow rate of the water 21 flowing through the water channel 24. . That is, in order to obtain the flow velocity distribution in the width direction of the water channel 24 (y-axis direction in FIG. 2), the flow velocity measurement in the water depth direction is performed at each of the locations (1), (2), and (3) shown in FIG. It is necessary to go.

  Therefore, in the measurement remaining confirmation process, it is confirmed whether or not the place where the flow velocity distribution is measured remains, that is, whether or not there is a need to measure the flow velocity distribution at another place. Whether or not the place for measuring the flow velocity distribution remains is confirmed by the arithmetic processing means 48 of the arithmetic processing unit 29 displayed on the display means 53 and recognizing the confirmation result from the measurer.

  When the place where the flow velocity distribution is measured remains (YES in step S19), the water surface unit 26 and the water bottom unit 27 are moved to an unmeasured place, that is, the position (2) or (3) and positioned. After that, the process proceeds to step S11 at the position where the positioning is performed, and the processing steps after step S11 are performed.

  On the other hand, in the measurement preparation completion confirmation process of the overall flow velocity distribution acquisition procedure, when the arithmetic processing unit 48 recognizes a confirmation result that the trigger is not generated, that is, the measurement preparation is not completed (in step S11). In the case of NO), the process proceeds to step S11, and the processing steps after step S11 are repeated.

  Further, in the measurement remaining confirmation process of the overall flow velocity distribution acquisition procedure, the measurement of the flow velocity distribution has been completed at all locations where the flow velocity distribution is measured, that is, the respective positions (1) to (3) shown in FIG. If this is the case (NO in step S19), the entire process of the overall flow velocity distribution acquisition procedure is completed (END).

  When the entire flow velocity distribution acquisition procedure (step S1) is completed, the process proceeds to step S2, and the flow rate calculation procedure is performed in step S2. In the flow rate calculation procedure, the flow rate calculation means 62 calculates the flow rate using the flow velocity distribution in the water channel width direction and the water depth direction of the water 21 flowing in the water channel 24 acquired in the overall flow velocity distribution acquisition procedure. The flow rate can be calculated by integrating the flow velocity distribution for the entire water channel 24 as described above.

  When the flow rate calculation means 62 calculates the flow rate of the water 21 that is the target of flow rate measurement, the flow rate calculation procedure in step S2 is completed. When the flow rate calculation procedure is completed, the process proceeds to step S3, and a flow velocity display procedure is performed in step S3. In the flow rate display procedure, the flow rate display means 63 displays the flow rate calculated in the flow rate calculation procedure on the display means 53 provided in the arithmetic processing unit 29 as a flow rate measurement value. When the flow rate measurement value is displayed on the display means 53, the flow rate display procedure in step S3 is completed, and the first flow rate measurement method is completed.

  According to the first ultrasonic flow meter 20, the first flow measurement method and the PG (flow velocity distribution acquisition PG 57 and flow measurement PG 58) for executing the first flow measurement method, the water surface unit 26, the water bottom unit 27, the guide rail. The flow velocity distribution in the water channel width direction and water depth direction of the water 21 flowing through the water channel 24 can be acquired with a simple apparatus configuration of 28 and the arithmetic processing unit 29. Moreover, a flow rate can be measured by calculating the flow velocity distribution of the acquired water 21 in the channel width direction and the water depth direction.

  Accordingly, an ultrasonic flowmeter, a flow measurement method thereof, and a flow measurement PG thereof are provided in a river or a large artificial open channel, in which the apparatus configuration is simplified from the conventional ultrasonic flowmeter while maintaining the measurement accuracy of flow measurement. be able to.

  In the first ultrasonic flow meter 20, there are two water-bottom-side ultrasonic transducers, but there may be three. When there are three water-bottom-side ultrasonic transducers, the tilt angle parameter is increased by one, but the concept of tilt correction is exactly the same as when there are two.

[Second Embodiment]
An ultrasonic flow meter (hereinafter referred to as a second ultrasonic flow meter) 80 according to the second embodiment of the present invention has a bottom unit in place of the bottom unit 27 as compared with the first ultrasonic flow meter 20. 27A is different from the point that the arithmetic processing unit 29 reads out and executes the flow velocity distribution acquisition PG 57 as the flow velocity distribution acquisition PG 57A, but the other points are not different. Therefore, portions that are not essentially different are denoted by the same reference numerals and description thereof is omitted.

  The application scene of the second ultrasonic flowmeter 80 is applied in the same scene as the application scene of the first ultrasonic flowmeter 20. In other words, if the first ultrasonic flow meter 20 shown in FIG. 1 is replaced with the second ultrasonic flow meter 80, the second ultrasonic flow meter 80 is applied.

  The second ultrasonic flowmeter 80 includes a water surface unit 26, a water bottom unit 27 </ b> A that is attached to the water bottom and transmits and receives ultrasonic waves, a guide rail 28, and an arithmetic processing unit 29. The PG read and executed by the arithmetic processing unit 29 includes a basic process PG 56, a flow velocity distribution acquisition PG 57A, and a flow rate measurement PG 58.

  That is, the configuration schematic diagram of the second ultrasonic flow meter 80 is executed by the arithmetic processing unit 29 reading out the water bottom unit 27 to the water bottom unit 27A in the configuration schematic diagram of the first ultrasonic flow meter 20 shown in FIG. Of the PGs to be processed, this corresponds to the flow rate distribution acquisition PG57 replaced with the flow rate distribution acquisition PG57A. Therefore, the schematic diagram of the second ultrasonic flow meter 80 is omitted, and a water bottom unit 27A flow velocity distribution acquisition PG 57A different from the first ultrasonic flow meter 20 will be described.

  FIG. 13 is a schematic configuration diagram showing an outline of the overall configuration of the water bottom unit 27A of the second ultrasonic flowmeter 80.

  According to FIG. 13, the bottom unit 27A is essentially the same as the bottom unit 27 in that the plate 42 is attached to the main body 41, but the ultrasonic transducer installed in the internal space of the main body 41 is the bottom of the water. Detects a point that is one of the side ultrasonic transducers 45 and the inclination with respect to the flow direction (x-axis direction in FIG. 2), the channel width direction (y-axis direction in FIG. 2), and the water depth direction (z-axis direction in FIG. 2). The difference is that a three-dimensional angle detection device 82 as an inclination detection means is installed in the internal space of the main body 41.

  The three-dimensional angle detection device 82 is installed in the main body 41 of the water bottom unit 27A and directly detects the inclination of the main body 41 in the three-axis directions. The inclination information detected by the three-dimensional angle detection device 82 is received by the arithmetic processing unit 29 via the connector cable 31, and the flow velocity distribution is obtained in consideration of the detected inclination information.

  That is, in the first ultrasonic flow meter 20, when the flow velocity distribution is obtained, the inclination of the bottom unit 27 is invalidated by calculation processing, whereas in the second ultrasonic flow meter 80, the inclination in the three-axis direction is reduced. It is different in that it is directly detected and the flow velocity distribution is obtained in consideration of the detected inclination information. Because of this difference, the function of the second ultrasonic flow meter 80 is different from the function of the first ultrasonic flow meter 20.

  In the second ultrasonic flowmeter 80 in this embodiment, the inclination detecting means is the three-dimensional angle detection device 82, but is not necessarily limited to the three-dimensional angle detection device 82. The tilt detection means is a means for detecting a three-dimensional (x-axis, y-axis, z-axis) angle, and as long as it can detect a three-dimensional angle as a result, it is not necessarily a single device. .

  FIG. 14 is a functional block diagram schematically showing a configuration in which the second ultrasonic flowmeter 80 is functionally captured, that is, functional blocks.

  Each means constituting the second ultrasonic flow meter 80 shown in FIG. 14 is obtained by the arithmetic processing means 48 provided in the arithmetic processing unit 29 reading and executing the basic processing PG 56, the flow velocity distribution acquisition PG 57A, and the flow measurement PG 58. Realized. Note that the difference between the flow velocity distribution acquisition PG 57 and the flow velocity distribution acquisition PG 57 </ b> A is the difference between realizing the flow velocity distribution acquisition means 61 or the flow velocity distribution acquisition means 61 </ b> A, and other points are not essentially different.

  Therefore, the second ultrasonic flow meter 80 realized by the arithmetic processing means 48 of the arithmetic processing unit 29 reading and executing the basic processing PG 56, the flow velocity distribution acquisition PG 57A, and the flow rate measurement PG 58 has the first ultrasonic flow rate. The flow rate distribution acquisition unit 61A is different from the total flow rate 20 in that the flow rate distribution acquisition unit 61A is provided instead of the flow rate distribution acquisition unit 61. On the other hand, a difference is provided in that water bottom side flow velocity distribution acquisition means 66A for acquiring the flow velocity distribution based on the ultrasonic echo signal transmitted from the water bottom unit 27A instead of the water bottom side flow velocity distribution acquisition means 66 is provided.

  According to FIG. 14, the water bottom side flow velocity distribution acquisition means 66A of the flow velocity distribution acquisition means 61A includes an ultrasonic pulse transmitter 69, an ultrasonic echo receiver 70, and a signal processor 71 provided in the water surface flow velocity distribution acquisition means 65. In addition to the flow velocity distribution calculation unit 72, an inclination angle detection unit 84 that detects the inclination angle of the water bottom unit 27A in the three-axis direction, and numerical correction (inclination correction processing) in consideration of the inclination angle information detected by the inclination angle detection unit 84 ) Is further provided with an inclination correction calculation processing unit 77A for the flow velocity distribution calculated by the flow velocity distribution calculating unit 72.

  Similarly to the water bottom side flow velocity distribution acquisition unit 66, the water bottom side flow velocity distribution acquisition unit 66A transmits ultrasonic pulses to the water whose flow rate is to be measured. An ultrasonic echo signal corresponding to the reflected wave received from underwater is transmitted. The signal processing unit 71 receives the ultrasonic echo signal, performs signal processing on the received ultrasonic echo signal, and the flow velocity distribution calculation unit 72 performs the ultrasonic echo signal processed by the signal processing unit 71. The flow rate distribution is obtained by analyzing the signal.

  Since the flow velocity distribution calculation unit 72 does not acquire information on the inclination angles in the three-axis directions, the flow velocity distribution is obtained by performing signal analysis with the inclination being 0 degrees for any axis. That is, the flow velocity distribution calculated by the flow velocity distribution calculation unit 72 is calculated without considering the influence of inclination. Therefore, when the bottom unit 27A is tilted with respect to any axis, the speed component to be obtained is tilted with respect to the speed component to be obtained, and measurement error occurs due to the influence of this slope. .

  Therefore, in the water bottom side flow velocity distribution obtaining unit 66A, the inclination correction calculation processing unit 77A is calculated by the flow velocity distribution calculating unit 72 using the information of the inclination angle in the three-axis direction of the water bottom unit 27A detected by the inclination angle detecting unit 84. Inclination correction calculation processing is performed to numerically correct the flow velocity distribution.

  Regarding the flow rate measurement method of the present invention performed using the second ultrasonic flowmeter 80 (hereinafter referred to as the second flow rate measurement method), the arithmetic processing means 48 of the arithmetic processing unit 29 is configured to acquire the basic processing PG 56 and the flow velocity distribution. By reading and executing the PG 57A and the flow rate measurement PG 58, the arithmetic processing unit 29 functions as each unit shown in FIG. Accordingly, each means shown in FIG. 14 measures the flow rate of the water 21 flowing through the water channel 24.

  By the way, referring to FIG. 6 and FIG. 14, when the means included in the second ultrasonic flowmeter 80 and the means included in the first ultrasonic flowmeter 20 are compared, the difference between the two is that The ultrasonic flowmeter 20 includes flow velocity distribution acquisition means 61 including a water bottom side flow velocity distribution acquisition means 66, whereas the second ultrasonic flow meter 80 acquires flow velocity distribution including a water bottom side flow velocity distribution acquisition means 66A. The point is that the device 61A is provided.

  Therefore, the processing procedure that differs with respect to the processing procedure included in the second flow rate measurement method is different in the means different from the first ultrasonic flowmeter 20, that is, the flow velocity distribution acquisition procedure executed by the flow velocity distribution acquisition means 61A. The other processing procedures are not essentially different. In other words, the second flow rate measurement method includes an overall flow rate distribution acquisition procedure, a flow rate calculation procedure, and a flow rate display procedure, as in the first flow rate measurement method. Is different.

  Therefore, the explanatory diagram (processing flow diagram) for explaining the overall processing procedure for the second flow rate measuring method step by step is omitted as a substitute for the description with the processing flow diagram for the first flow rate measuring method. To do. Hereinafter, the entire flow velocity distribution acquisition procedure with different processing contents will be described in order with reference to the drawings.

  FIG. 15 is an explanatory diagram (process flow diagram) for explaining the process steps in the overall flow velocity distribution acquisition procedure (hereinafter referred to as the second overall flow velocity distribution acquisition procedure) in the second flow rate measurement method.

  In the process flow diagram shown in FIG. 15, the same number is assigned to the process steps that are not essentially different from the overall flow velocity distribution acquisition procedure in the first flow rate measurement method (hereinafter referred to as the first overall flow velocity distribution acquisition procedure). A description thereof will be omitted.

  According to FIG. 15, the second overall flow velocity distribution acquisition procedure includes a measurement preparation completion confirmation step (step S11), a trigger generation step (step S12), and a water surface side flow velocity distribution acquisition step (steps S13 to S16). A second water bottom side flow velocity distribution acquisition step (step S13 to step S16, step S21) for acquiring a flow velocity distribution based on the ultrasonic echo signal transmitted from the water bottom unit 27A, and a flow velocity distribution calibration process (step S18). And a measurement remaining confirmation process (step S19).

  Compared to the first overall flow velocity distribution acquisition procedure, the second difference is that a second water bottom flow velocity distribution acquisition step is provided instead of the water bottom flow velocity distribution acquisition step. More specifically, instead of the slope correction calculation processing step (step S17) of the water bottom side flow velocity distribution acquisition process, a second slope correction calculation processing step (step S21) of the second water bottom side flow velocity distribution acquisition step is provided. It is different in point.

  Even if attention is paid to the execution order of the processing steps of the second overall flow velocity distribution acquisition procedure, the inclination correction calculation processing step of step S17 is changed to the second inclination correction calculation processing step in the first overall flow velocity distribution acquisition procedure. It is different in the point of substitution, and the other points are the same.

  Here, a difference in processing contents between the inclination correction calculation processing step and the second inclination correction calculation processing step will be described. The difference in the processing content between the inclination correction calculation processing step and the second inclination correction calculation processing step is that the first overall flow velocity distribution acquisition procedure uses a plurality of (for example, two) flow velocity distributions to determine the inclination of the bottom unit 27. On the other hand, the second overall flow velocity distribution acquisition procedure directly detects the inclination of the bottom unit 27A, and the flow velocity measurement error caused by the detected inclination is calculated. The difference is that correction calculation processing for correction is performed.

  More specifically, the slope correction calculation processing step of the first overall flow velocity distribution acquisition procedure performs the weighted average process on the two flow velocity distributions acquired using the water bottom ultrasonic transducers 45 and 46, and affects the influence of the gradient. On the other hand, the second inclination correction calculation processing step directly detects the inclination measured by the three-dimensional angle detection device 82, and the single flow velocity distribution obtained in consideration of the influence of the detected inclination. Is different in that correction calculation processing is performed.

  As described above, according to the second ultrasonic flow meter 80, the second flow measurement method, and the PG (flow velocity distribution acquisition PG 57A and flow measurement PG 58) for executing the second flow measurement method, the first ultrasonic flow meter 20 is provided. The same effect as in the case of the PG (flow velocity distribution acquisition PG 57 and flow rate measurement PG 58) that executes the first flow rate measurement method and the first flow rate measurement method is obtained.

  Accordingly, an ultrasonic flowmeter, a flow measurement method thereof, and a flow measurement PG thereof are provided in a river or a large artificial open channel, in which the apparatus configuration is simplified from the conventional ultrasonic flowmeter while maintaining the measurement accuracy of flow measurement. be able to.

  Note that the ultrasonic flowmeter according to the present invention can be configured to display not the flow rate of the water 21 but the flow velocity distribution in time series in the arithmetic processing unit 29. That is, the flow rate display means 63 of the ultrasonic flowmeter according to the present invention can be configured as a flow velocity distribution means for displaying the flow velocity distribution in time series.

  The ultrasonic flowmeter according to the present invention can be configured to display not the flow rate of the water 21 but the flow velocity distribution in time series. The principle of integrating the flow velocity distribution to obtain the flow rate of the water 21 passing through the cross section. This is because the flow velocity distribution is once measured. In this case, the ultrasonic flowmeter according to the present invention functions as an ultrasonic flow velocity distribution meter.

  In addition, it is naturally possible to configure the arithmetic processing unit 29 to display not only the flow rate of the water 21 but also the flow velocity distribution in time series. In this case, the ultrasonic flowmeter according to the present invention can The flowmeter can function not only as a meter but also as a flow velocity distribution meter.

  Further, the program for realizing the function as the ultrasonic flowmeter according to the present invention, that is, the basic processing PG 56, the flow velocity distribution acquisition PG 57, and the flow measurement PG 58 are stored in the arithmetic processing unit 29. If it can be read, it is not necessarily stored in the recording means 51. For example, it may be stored in an external device electrically connected via the I / F means 54 of the arithmetic processing unit 29.

  Furthermore, the display of the flow rate or flow velocity distribution is not necessarily the display means 53 of the arithmetic processing unit 29, and an external device having other display means is electrically connected to the I / F means 54 of the arithmetic processing unit 29. Can be displayed. Moreover, you may display on both the display means 53 of the arithmetic processing unit 29, and the external apparatus which has another display means.

  On the other hand, the water surface unit 26 and the water bottom units 27 and 27A and the arithmetic processing unit 29 are electrically connected by the connector cord 31, but may not necessarily be the connector cord 31. The water surface unit 26 and the bottom units 27 and 27A may be electrically connected to the arithmetic processing unit 29 so that signals can be exchanged between them.

  Further, since the water surface unit 26 is moved by remote operation, the water surface unit 26 is not originally configured on the assumption that a person rides, but may be configured to allow a person to ride. A person who rides on the water surface unit 26 may operate the water surface unit 26 to position the water surface unit 26 and the water bottom units 27 and 27A.

Explanatory drawing explaining an example of an application scene about the ultrasonic flowmeter which concerns on the 1st Embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS The structure schematic which represented the outline of the whole structure of the ultrasonic flowmeter which concerns on the 1st Embodiment of this invention. The structure schematic showing the outline of the whole structure about the water surface unit of the ultrasonic flowmeter which concerns on this invention. BRIEF DESCRIPTION OF THE DRAWINGS The structure schematic which represented the whole structure outline about the water bottom unit of the ultrasonic flowmeter which concerns on the 1st Embodiment of this invention. BRIEF DESCRIPTION OF THE DRAWINGS The structure schematic which represented the structure outline about the typical example of the arithmetic processing unit in the ultrasonic flowmeter which concerns on this invention. The functional block diagram of the ultrasonic flowmeter which concerns on the 1st Embodiment of this invention. The functional block diagram explaining in more detail the flow velocity distribution acquisition means of the ultrasonic flowmeter which concerns on the 1st Embodiment of this invention. Explanatory drawing explaining the principle of the weighted average process which the inclination correction calculating process part in the water bottom unit of the ultrasonic flowmeter which concerns on the 1st Embodiment of this invention performs. Explanatory drawing explaining the place which measures the flow-velocity distribution when performing the 1st flow measuring method which concerns on this invention. Explanatory drawing explaining the procedure about the 1st flow measuring method concerning this invention later on. Explanatory drawing explaining the process process in the whole flow-velocity distribution acquisition procedure of the 1st flow measuring method which concerns on this invention later on. Explanatory drawing explaining the flow velocity distribution of the depth direction from the water surface to the water bottom which the flow velocity distribution calibration process means of the ultrasonic flowmeter which concerns on this invention acquired by performing the flow velocity distribution calibration process process. The structure schematic showing the whole structure outline about the bottom unit of the ultrasonic flowmeter which concerns on the 2nd Embodiment of this invention. The functional block diagram of the ultrasonic flowmeter which concerns on the 2nd Embodiment of this invention. Explanatory drawing explaining the process process of the whole flow velocity distribution acquisition procedure in order in the 2nd flow measuring method which concerns on this invention later on. It is the structure schematic of the conventional ultrasonic flow measuring device installed in the open channel, (a) is sectional drawing of the orthogonal | vertical direction with respect to the virtual measurement straight line B shown in the figure (b), (b) is a top view (above sky) Front view when seeing an open channel from the top).

Explanation of symbols

20 First ultrasonic flow meter 21 Water (fluid)
22 Intake 23 Waterway (Yamanote Channel: Channel)
24 River side channel (Kawate Channel: channel)
26 Water surface unit 27, 27A Water bottom unit 28 Guide rail 29 Arithmetic processing unit 30 Wire (unit connection means)
30a First wire 30b Second wire 31 Connector cord 33 Base portion 34 Power portion 35 Bracket portion 37 Guide 38 Water surface side ultrasonic transducer 39 First wire reel 40 Second wire reel 41 Main body portion 42 Plate 43 Wire attachment Units 45, 46 Water bottom ultrasonic transducer 47 Code introduction hole 48 Arithmetic processing means 50 Memory 51 Recording means 52 Input means 53 Display means 54 I / F means 56 Basic processing PG
57 Flow velocity distribution acquisition PG
58 Flow measurement PG
60 trigger generation means 61 flow velocity distribution acquisition means 62 flow rate calculation means 63 flow rate display means 65 water surface side flow velocity distribution acquisition means 66 water bottom side flow velocity distribution acquisition means 67 flow velocity distribution calibration processing means 69 ultrasonic pulse transmitter 70 ultrasonic echo receiver 71 Signal processing unit 72 Flow velocity distribution calculating unit 75 First water bottom side flow velocity distribution acquiring unit 76 Second water bottom side flow rate distribution acquiring unit 77, 77A Inclination correction calculation processing unit (tilt correction calculation processing unit)
80 Second ultrasonic flow meter 82 Three-dimensional angle detector 84 Inclination angle detector

Claims (17)

Trigger generating means for receiving a measurement start request and generating a trigger, flow velocity distribution acquiring means for acquiring a flow velocity distribution as a basis of flow measurement, and flow rate for calculating a flow rate based on the flow velocity distribution acquired by the flow velocity distribution acquiring means A calculation means, and a flow rate display means for displaying the flow rate calculated by the flow rate calculation means as a flow rate measurement value,
The flow velocity distribution acquisition means includes a water surface side flow velocity distribution acquisition means for acquiring a flow velocity distribution from the surface side of the flow path through which the fluid flows, and
Water bottom side flow velocity distribution acquisition means for acquiring the flow velocity distribution from the bottom side of the flow path through which the fluid flows;
An ultrasonic flow rate comprising: a flow rate distribution calibration processing unit that obtains a flow rate distribution in the depth direction of the flow path based on the flow rate distributions acquired by the water surface side flow rate distribution acquisition unit and the water bottom side flow rate distribution acquisition unit, respectively. Total. The water surface side flow velocity distribution acquisition unit and the water bottom side flow velocity distribution acquisition unit include an ultrasonic wave transmission unit that transmits an ultrasonic pulse in a fluid for measuring a flow rate, and an ultrasonic echo corresponding to the ultrasonic echo received in the fluid. Ultrasonic receiving means for outputting a signal, signal processing means for signal processing of the ultrasonic echo signal, flow velocity distribution calculating means for calculating the flow velocity distribution of the fluid from the ultrasonic echo signal signal-processed by the signal processing means, With
The ultrasonic wave transmitting means and the ultrasonic wave receiving means of the water surface side flow velocity distribution acquiring means are provided in a water surface unit that is movably installed in a flow path width direction across a flow path in which a fluid flows,
The ultrasonic flowmeter according to claim 1, wherein the ultrasonic wave transmitting means and the ultrasonic wave receiving means of the water bottom side flow velocity distribution acquisition means are provided in a water bottom unit that contacts the bottom of the flow path. The water surface unit is configured to be connected to the water bottom unit by unit connection means, and the water surface unit varies the length of the unit connection means so that the fluid flows from the position of the water surface unit to the fluid. The ultrasonic flowmeter according to claim 2, wherein the ultrasonic flowmeter is configured to be movable to the bottom of the flow path. 3. The super-bottom unit according to claim 2, wherein the submarine unit has a main body having a shape close to a ship, and a plate that receives fluid resistance is attached to a center line of the main body and to the stern part. Sonic flow meter. The water bottom side flow velocity distribution acquisition means includes an ultrasonic transmission means for transmitting an ultrasonic pulse in a fluid for measuring a flow rate, and an ultrasonic reception for outputting an ultrasonic echo signal corresponding to the ultrasonic echo received in the fluid. Means, signal processing means for signal processing the ultrasonic echo signal, and flow velocity distribution calculating means for calculating the flow velocity distribution of the fluid from the ultrasonic echo signal signal-processed by the signal processing means,
The ultrasonic wave transmitting means and the ultrasonic wave receiving means of the water bottom side flow velocity distribution acquiring means are provided in a water bottom unit to be landed on the bottom of the flow path, and a plurality of ultrasonic echo signals are acquired to acquire a plurality of types of ultrasonic echo signals at the same time. The ultrasonic flowmeter according to claim 1, wherein the ultrasonic flowmeter is configured in the same number. The water bottom side flow velocity distribution acquisition means performs an inclination correction calculation process for invalidating the influence of the inclination of the water bottom unit using a plurality of types of ultrasonic echo signals acquired at the same time by the ultrasonic receiving means in the fluid. 6. The ultrasonic flowmeter according to claim 5, further comprising inclination correction calculation processing means for acquiring one flow velocity distribution. The water bottom side flow velocity distribution acquisition means includes an ultrasonic transmission means for transmitting an ultrasonic pulse in a fluid for measuring a flow rate, and an ultrasonic reception for outputting an ultrasonic echo signal corresponding to the ultrasonic echo received in the fluid. Means, signal processing means for processing the ultrasonic echo signal, flow velocity distribution calculating means for calculating the flow velocity distribution of the fluid from the ultrasonic echo signal signal-processed by the signal processing means, the ultrasonic transmission means, Inclination detecting means for detecting an inclination in the three-axis direction of the water bottom unit that is provided with the ultrasonic wave receiving means and contacts the bottom of the flow path, and an inclination correction calculation process in consideration of the inclination of the water bottom unit detected by the inclination detecting means The ultrasonic flowmeter according to claim 1, further comprising: an inclination correction calculation processing unit that performs the correction on the flow velocity distribution calculated by the flow velocity distribution calculating unit. The water surface side flow velocity distribution acquisition means acquires the flow velocity distribution in the water depth direction of the fluid including the water depth at which the flow velocity of the fluid becomes the maximum value,
The water bottom side flow velocity distribution acquisition means acquires the flow velocity distribution in the depth direction of the fluid including a boundary layer formed by the fluid and a water depth that is a boundary portion between the boundary layer and the steady flow region. The ultrasonic flowmeter according to claim 1. The ultrasonic flowmeter according to claim 1, wherein the flow rate display unit is configured to function as a flow rate distribution display unit that displays the flow rate distribution acquired by the flow rate distribution acquisition unit. Flow rate acquisition procedure for acquiring the flow velocity distribution that is the basis of flow rate measurement, flow rate calculation procedure for measuring the flow rate based on the flow velocity distribution acquired in the overall flow velocity distribution acquisition procedure, and displaying the calculated flow rate as a flow measurement value A flow rate display procedure,
The overall flow velocity distribution acquisition procedure is a measurement preparation completion confirmation process for accepting a request for measurement start and confirming whether measurement can be started,
The depth direction flow velocity distribution acquisition process for acquiring the flow velocity distribution in the depth direction of the flow path,
A flow rate measurement method comprising: a measurement remaining confirmation process for confirming whether or not there is a need to measure a flow velocity distribution in a depth direction in another place. The overall flow velocity distribution acquisition procedure is performed by performing the water depth direction flow velocity distribution acquisition step in a side wall vicinity region, a velocity boundary region, and a flow channel center region in the width direction of the flow channel. The flow rate measuring method according to 10. The depth direction flow velocity distribution acquisition process includes a trigger generation process for generating a trigger,
A water surface side flow velocity distribution acquisition step of acquiring a flow velocity distribution on the fluid surface side based on an ultrasonic echo signal output from an ultrasonic wave receiving means installed in the water surface unit;
A water bottom side flow velocity distribution acquisition step of acquiring a flow velocity distribution on the channel bottom side based on an ultrasonic echo signal output from an ultrasonic receiving means installed in the water bottom unit;
A flow velocity distribution calibration processing step for obtaining a flow velocity distribution for calculating a flow rate by performing necessary data calibration processing based on each flow velocity distribution acquired in the water surface side flow velocity distribution acquisition step and the water bottom side flow velocity distribution acquisition step. The flow rate measuring method according to claim 10. The water bottom side flow velocity distribution acquisition step includes a water bottom side flow velocity distribution acquisition step in which a plurality of water bottom side flow velocity distribution acquisition means respectively acquire flow velocity distributions in the depth direction at the same time, and
A correction operation processing step for performing a weighted average process for invalidating the influence of the inclination of the bottom unit using each of the flow velocity distributions in the depth direction at the same time acquired in the bottom flow velocity distribution acquisition process. The flow rate measuring method according to claim 10. The water bottom side flow velocity distribution acquisition step is a water bottom side flow velocity distribution acquisition step in which a single water bottom side flow velocity distribution acquisition acquires the flow velocity distribution in the depth direction at the same time, and
A correction calculation processing step for directly detecting the inclination of the water bottom unit with respect to the flow velocity distribution in the depth direction acquired in the bottom flow velocity distribution acquisition process and correcting a flow velocity measurement error caused by the detected inclination; The flow rate measuring method according to claim 10. A measurement preparation completion confirmation process for accepting a measurement start request and confirming whether or not measurement can be started;
Trigger generation process for generating a trigger, water surface side flow velocity distribution acquisition process for acquiring the flow velocity distribution on the fluid surface side based on the ultrasonic echo signal output from the ultrasonic receiving means installed in the water surface unit, and the water bottom unit Acquired in the water bottom side flow velocity distribution acquisition process for acquiring the flow velocity distribution on the channel bottom side, the water surface side flow velocity distribution acquisition process, and the water bottom side flow velocity distribution acquisition process based on the ultrasonic echo signal output from the ultrasonic receiving means. A flow velocity distribution calibration process for obtaining a flow velocity distribution for calculating a flow rate by performing necessary data calibration processing based on each flow velocity distribution, and a water depth direction flow velocity distribution obtaining step for obtaining a flow velocity distribution in the water depth direction of the flow path; ,
It has a measurement remaining confirmation process to confirm whether or not it is necessary to measure the flow velocity distribution in the depth direction at other locations, and causes the computer to execute the entire flow velocity distribution acquisition procedure to acquire the flow velocity distribution that is the basis of flow measurement program. As the bottom flow rate distribution acquisition process,
A water bottom side flow velocity distribution acquisition means in which a plurality of water bottom side flow velocity distribution acquisition means respectively acquire flow velocity distributions in the depth direction at the same time,
Claims that cause the computer to execute a correction calculation processing step for performing a weighted average processing for invalidating the influence of the inclination of the bottom unit using each of the flow velocity distributions in the depth direction at the same time acquired in the bottom flow velocity distribution acquisition process. Item 15. The program according to Item 15. As the bottom flow rate distribution acquisition process,
A bottom-side flow velocity distribution acquisition step in which a single bottom-side flow velocity distribution acquisition acquires a flow velocity distribution in the depth direction at the same time, and
A correction calculation processing step for directly detecting the inclination of the bottom unit with respect to the flow velocity distribution in the depth direction acquired in the bottom flow velocity distribution acquisition process, and correcting a flow velocity measurement error caused by the detected inclination is stored in the computer. The program according to claim 15 to be executed.

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