JP2005114634A - Measuring device for hydraulic information of river or lake - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To measure simply and accurately hydraulic information of rivers or lakes. <P>SOLUTION: This measuring device for the hydraulic information of rivers or lakes is equipped with ultrasonic sensors 503, 504 for irradiating an ultrasonic beam toward the bottom of a river or a lake under a measuring line set in the river or the lake, and detecting a reflected wave of the ultrasonic beam from the bottom, a rotation mechanism 505 for rotating the ultrasonic beam in the measuring line direction, a means for changing an ultrasonic frequency of the ultrasonic beam, corresponding to the time from irradiation of the ultrasonic beam until detection of the reflected wave, a propulsion mechanism 502 for moving the ultrasonic sensors along the measuring line, a position sensor 507 for determining the position on the measuring line of the ultrasonic sensors, and a means for calculating the position of the bottom along the measuring line from the irradiation direction of the ultrasonic beam, the positions of the ultrasonic sensors 503, 504, the time from irradiation of the ultrasonic beam until detection of the reflected waves, and the speed of the ultrasonic beam in the water of the river or in the water of the lake. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a lake bottom or river bottom shape (hereinafter referred to as a river bed shape) along a measurement line set in advance in a river or a lake, and an apparatus for measuring a flow rate as hydraulic information as necessary.

  River flow and riverbed shape are extremely important issues for preventing disasters such as floods caused by heavy rain. The riverbed shape of the river can be observed by continuously obtaining the distance from the water surface to the riverbed, that is, the water depth in the river cross section. The flow rate can be converted into the amount of water from the above-mentioned water depth by detecting the average flow velocity of the riverbed and water surface at a certain position. Ultrasonic waves are often used for these measurements.

  A detection method using an ultrasonic wave is described in, for example, Japanese Patent Application Laid-Open No. 2000-97738 “Water depth / flow velocity / water temperature measuring apparatus”. In this method, a rod-like hanging material is provided in the depth direction, and a plurality of ultrasonic transducers are installed along the hanging material. Ultrasonic waves are emitted from ultrasonic transducers at the bottom of the river, received by the transducers at various locations of the drooping material, and the propagation time is obtained to measure the speed of sound and the depth of water between the transducers. In this method, it is necessary to provide a hanging material in the measurement part of the river, and even if the hanging material is moved, a large amount of labor is required.

  Japanese Patent No. 2955920 “River Flow Rate Measuring Device and Method” includes a moving means for moving an ultrasonic transducer. This method also requires a plurality of ultrasonic transducers to be placed on the surface of the water and in the water. Further, since the ultrasonic reflector is submerged in the vicinity of the riverbed, it may not be a simple measurement method.

  Japanese Patent Laid-Open No. 11-304484 “River State Measuring Method and Apparatus” discloses an apparatus and method for measuring the cross-sectional shape of a river. In this method, the shape of a portion without water is measured with a laser beam measuring device, and ultrasonic waves are used for measuring the shape of a river portion. The ultrasonic wave used for measuring the riverbed shape is 100 kHz to 500 kHz, but there is a decrease in accuracy due to the spread of the ultrasonic beam. In addition, measurement accuracy cannot be secured due to the influence of plants, algae, etc. existing in the riverbed.

  There exists a "bed search tool" described in Unexamined-Japanese-Patent No. 2000-98046 as what calculates | requires a riverbed shape, without using an ultrasonic wave. In this method, a number of probe tools with permanent magnets embedded in riverbed material collected from the riverbed are placed on the riverbed, and the position and movement of the probe are measured from the measurement of the magnetic field. This method has problems such as a limited measurement range and the need for another means for water depth measurement.

Japanese Unexamined Patent Publication No. 2000-97738 Japanese Patent No. 2955920 JP-A-11-304484 JP 2000-98046 A

  Changes in river flow and riverbed hydraulic information are extremely important information for preventing disasters such as floods caused by heavy rain. The riverbed shape of the river can be observed by continuously obtaining the distance from the water surface to the riverbed, that is, the water depth in the river cross section. The flow rate can be converted into the amount of water from the above-mentioned water depth by detecting the average flow velocity of the riverbed and water surface at a certain position. Ultrasonic waves are often used for these measurements.

  There are several methods for detection using ultrasound. A rod-like hanging material is provided in the depth direction, a plurality of ultrasonic transducers are installed along the hanging material, and the speed of sound and water depth between the transducers are measured. In this method, it is necessary to provide a hanging material in the measurement part of the river, and even if the hanging material is moved, a large amount of labor is required.

  In addition, the method with moving means for moving the transducer also requires a plurality of ultrasonic transducers to be placed on the water surface and in the water, and further, the ultrasonic reflector is submerged in the vicinity of the riverbed, which is not a simple measurement method. There is a fear.

  Although there are methods and devices for measuring river conditions, there is a decrease in accuracy due to the spread of the ultrasonic beam, and the measurement accuracy cannot be ensured due to the influence of plants and algae present in the riverbed.

  There is one that obtains the riverbed shape without using ultrasonic waves, and embeds permanent magnets in the riverbed material collected from the riverbed and places them in the riverbed, and measures the position and movement of this probe by measuring the magnetic field. . This method has problems such as a limited measurement range and the need for another means for water depth measurement. As described above, ensuring the accuracy of measurement and simplifying measurement are issues in measuring the riverbed shape and flow rate.

  Accordingly, an object of the present invention is to easily and accurately obtain hydraulic information of rivers and lakes.

  The first means for achieving the object of the present invention includes an ultrasonic sensor that irradiates an ultrasonic beam toward the bottom of a river or a lake and detects a reflected wave of the ultrasonic beam from the bottom, and the ultrasonic sensor includes: A floating body provided on the water surface of the river or lake, means for moving the floating body on the water surface of the river or lake, provided on the floating body, and before and after the movement of the floating body. Means for rotating in the direction, means for changing the ultrasonic frequency of the ultrasonic beam according to the time from irradiation of the ultrasonic beam to detection of the reflected wave, means for determining the moving position of the levitation body, From the irradiation direction of the ultrasonic beam, the position of the ultrasonic sensor, the time from the irradiation of the ultrasonic beam to the detection of the reflected wave, and the velocity of the ultrasonic beam in the river water or the lake water The bottom Position is a measuring device for hydraulic information river or lake and means for calculating a.

  Furthermore, in the second means when it is desired to also measure the flow rate as hydraulic information, in addition to the first means, two ultrasonic transmission / reception sensors arranged apart from each other in the water flow direction of the river or lake, Until one of the two ultrasonic transmission / reception sensors detects a reflected wave scattered from the bottom of the two ultrasonic transmission / reception sensors after the ultrasonic wave is irradiated toward the bottom from one of the two ultrasonic transmission / reception sensors. Means for obtaining the time difference from the irradiation of the ultrasonic wave to the detection obtained by reversing the transmission / reception sides of the two ultrasonic transmission / reception sensors, the time difference between these two ultrasonic sensors, the separation distance between the two ultrasonic sensors, and the river bed A river comprising: means for calculating an average flow velocity of the water at the ultrasonic sensor position from a water depth determined from a shape; and means for calculating a flow rate from the average flow velocity and the water depth Using the measuring apparatus of the hydraulic information.

  In the first means, the riverbed shape is measured by an ultrasonic sensor arranged near the water surface of a river or lake. That is, the levitation body is moved along a measurement line set in advance using ultrasonic waves, and the shape of the bottom of the river or lake along the measurement line is accurately obtained. The shape of the bottom along the measurement line is known in advance as the time from the start of irradiation of the ultrasonic beam until the reflected wave is detected by irradiating the ultrasonic beam from the ultrasonic sensor with reduced directivity toward the bottom. The distance from the ultrasonic sensor to the bottom is calculated from the speed of sound in water. At this time, the ultrasonic sensor is moved along the measurement line while rotating the ultrasonic beam by a certain angle. For this reason, the ultrasonic beam repeatedly irradiates and reflects a point at the bottom of a river or lake, and the influence of algae on the bottom and fluctuates in the water flow can be reduced to accurately detect the riverbed shape. Furthermore, if the round-trip time between the ultrasonic sensor of the ultrasonic beam and the bottom of the river or lake is less than the round-trip time when the water depth is a preset value, the frequency of ultrasonic waves is changed to higher frequencies to improve measurement accuracy. Let On the contrary, when the water depth becomes larger than the round-trip time in the case of a preset value, the use frequency of the ultrasonic wave is changed in the low frequency direction. In this way, the shape of the riverbed and lake bottom is measured.

  Further, in the second means, in addition to the measurement of the shape of the riverbed and the lake bottom by the first means, the flow rate can be detected by measurement as hydraulic information when a flow occurs in the river or lake as follows. . That is, in the detection of the flow rate, first, the flow velocity distribution in the cross section along the measurement line is obtained, and converted into the flow rate from the water depth that is the distance to the lake bottom or river bed. Ultrasonic waves are also used to measure the flow velocity. The difference between the time it takes to emit ultrasonic waves from one of the two ultrasonic transmission / reception sensors arranged in the direction of the flow toward the lake or riverbed and the reception by the other, and the ultrasonic transmission / reception sensor that was used for reception first. Two time differences from the time difference when the sound wave is transmitted and received by the other used as the transmission are detected, and the flow velocity is measured from the difference between the two time differences. From the flow velocity distribution thus obtained, the flow rate of the cross section along the measurement line is obtained in consideration of the water depth.

  In addition, if a display means for displaying the measurement results in the land area away from the river or the upper surface of the lake has been deployed, when measuring the remote lake or river shape / flow rate, There is no need for an operator to be able to measure and monitor the riverbed shape and flow rate safely and accurately.

  The present invention can accurately measure at least the bottom shape of a river or lake as hydraulic information using ultrasonic waves.

  In the embodiment of the present invention, the ultrasonic wave from the ultrasonic sensor with reduced directivity is irradiated toward the river bed, the time from the start of irradiation to the detection of the reflected wave and the previously known underwater sound speed to the river bed. The distance is calculated. At this time, the entire measuring apparatus is moved along the measurement line while rotating the ultrasonic beam by a certain angle. For this reason, the ultrasonic beam irradiates a certain point on the riverbed many times, and the riverbed shape can be detected accurately by reducing the influence of algae on the riverbed and fluctuating in the water flow. Further, when the round-trip time of the ultrasonic wave, that is, the water depth becomes smaller than a preset value, the use frequency of the ultrasonic wave is changed to improve the measurement accuracy. In detecting the flow rate, first, the flow velocity distribution in the cross section along the measurement line is obtained, and the flow rate is converted from the water depth, which is the distance to the river bed. Ultrasonic waves are also used to measure the flow velocity. The ultrasonic wave is emitted from one of the two ultrasonic sensors arranged in the flow direction toward the riverbed and received by the other, and transmitted from the ultrasonic sensor used for reception and received by the other Two time differences are detected, and the flow velocity is measured from the difference between the two time differences. From the flow velocity distribution thus obtained, the flow rate of the cross section along the measurement line is obtained in consideration of the water depth. It is not necessary for an operator to get on the water surface moving device that measures the river shape and flow rate, and the river bed shape and flow rate can be measured easily and accurately.

  The present invention will be described in detail by examples. FIG. 1 is a diagram showing a basic configuration of a river bed shape / flow rate measuring method and apparatus according to the present invention. In FIG. 1, a measurement line 2 in the river 1 is set. The main point of the present invention is to obtain the flow rate through the riverbed shape (river bed shape) 3 and the river cross section 4 along the measurement line 2. To achieve this purpose, there are a mobile measuring device 5 that moves on the water surface along the measurement line 2, and a fixed-side control / processing device 6 that controls the processing of data obtained by the mobile measuring device 5 and the position of the mobile measuring device 5. Prepare.

  First, the configuration of the moving measuring instrument 5 will be described in detail with reference to FIGS.

FIG. 2 mainly shows the configuration for river bed shape measurement. The configuration for measuring the flow velocity will be described separately with reference to FIG. In FIG. 2, the water flow is perpendicular to the figure. In FIG. 2, reference numeral 501 denotes a floating body that loads the device and power source of the mobile measuring instrument 5 and floats on the water surface. The levitation body 501 can move on the water surface by a propulsion mechanism 502 attached to the levitation body 501. The propulsion mechanism 502 may be a known propulsion mechanism such as a propeller propulsion mechanism or a jet ejection mechanism. A low-frequency ultrasonic sensor 503 and a high-frequency ultrasonic sensor 504 are installed on the bottom surface of the levitation body 501. The frequency of the ultrasonic wave generated by each ultrasonic sensor varies depending on the depth of water to be measured and the turbidity of river water. In general, the low-frequency ultrasonic sensor 503 has several tens of kHz to several hundred kHz, and the high-frequency ultrasonic sensor 504 has a high frequency. Several hundred kHz to several MHz are used. The frequency of the ultrasonic wave generated by the low-frequency ultrasonic sensor 503 is lower than the frequency of the ultrasonic wave generated by the high-frequency ultrasonic sensor 504. Both ultrasonic sensors have a small directivity angle of 10 degrees or less, and can be rotated by a rotation mechanism 505 of the ultrasonic sensor, and the direction in which an ultrasonic beam is emitted from each ultrasonic sensor can be controlled. Reference numeral 506 denotes an inclination sensor that detects the inclination of the levitation body 501 attached to the levitation body 501, and reference numeral 507 denotes a position sensor that measures the position of the levitation body 501 attached to the levitation body 501. These detectors are also known. Reference numeral 508 denotes a signal processing / control device, the configuration of which is shown separately. 510 is a vertical movement position sensor for correcting the vertical movement of the levitation body 501 mounted on the levitation body 501, and a known one such as a method of obtaining a displacement by integrating the acceleration measuring device twice can be used.

  FIG. 3 is a diagram illustrating the contents of the low-frequency ultrasonic sensor 503 and the rotation mechanism 505 of the high-frequency ultrasonic sensor 504. In FIG. 3, reference numeral 505a denotes a pulse motor driving power source, which drives the pulse motor 505b. The pulse motor 505b rotates the gear 505c, thereby rotating the gear 505d. The gear 505d is an axis that rotates around a central axis 505e, and a low-frequency ultrasonic sensor 503 and a high-frequency ultrasonic sensor 504 are fixed to the axis and rotated. At the end of the gear 505d, there are limit switches 505f and 505g, and a pulse motor drive power source 505a works so as to reversely rotate when rotating to this switch. The operating state of the pulse motor drive power source 505a is detected via an interface 508a-1 described later.

  FIG. 4 shows a configuration for measuring the flow velocity of a river, and the flow of water is in the direction of the arrow in the drawing parallel to the paper surface. The configuration of the apparatus is almost the same as that shown in FIG. 2, except that an ultrasonic sensor 509 for transmitting ultrasonic waves to the riverbed and receiving scattered waves from the riverbed includes a low-frequency ultrasonic sensor 503 and a high-frequency ultrasonic sensor. It is installed at a position that is a certain distance away from 504 in the flow direction. The frequency characteristics of the ultrasonic sensor 509 have characteristics that cover the frequency bands of the low-frequency ultrasonic sensor 503 and the high-frequency ultrasonic sensor 504.

  FIG. 5 is a diagram showing a detailed configuration and connection state of the mobile measuring instrument 5 shown in FIGS. 2 and 4. In particular, FIG. 5 also shows the internal configuration of the signal processing / control device 508 in detail. The signal processing / control device 508 includes a switching unit 508b that switches a signal connection state by the processing / control units 508a and 508a, and a pulse oscillator 508c that transmits a signal to the ultrasonic sensor, a signal oscillator 508d, and signals from the ultrasonic sensor. It comprises a receiver 508e for receiving. The pulse generator 508c generates a wide-band pulse, and generates a signal in the frequency band of the low-frequency ultrasonic sensor 503 and the high-frequency ultrasonic sensor 504, so that the low-frequency ultrasonic sensor 503 and the high-frequency ultrasonic wave are generated. A signal having a frequency determined by the characteristics of the sensor 504 is output from each sensor. Also, a signal transmitter / receiver 508f is provided for transmitting / receiving data and control signals to / from the fixed-side control / processing device using light or radio waves. An ultrasonic sensor 509 for ultrasonic transmission / reception is used for detecting the flow rate of water, which will be described later.

  FIGS. 6 and 7 each show a switch 508b for switching the signal connection state by the processing / control devices 508a and 508a inside the signal processing / control device 508. FIG. The processing / control device 508a includes a microcomputer including a CPU 508a-1, a RAM 508a-3, a ROM 508a-2, and an interface 508a-4, and a CPU 508a-5, a RAM 508a-7, a ROM 508a-6, and an interface 508a-8. It consists of a similar microcomputer. The former mainly performs control of the detector, driving device, and signal detection for changing the ultrasonic beam irradiation direction of the ultrasonic sensor in addition to the position, vertical movement, and inclination of the floating body 501.

The latter microcomputer performs signal detection and transmission control mainly related to transmission and reception of ultrasonic signals. These operations will be described in detail later. As can be seen from FIG. 6, the switch 508b includes two changeover switch elements 508b-1, which can be electronically controlled.
508b-2 is provided. 508b-1 is used to select the ultrasonic sensors 503 and 504, that is, to select high-frequency or low-frequency ultrasonic transmission / reception. The switch element 508b-2 can perform cross-shaped switching, and performs coupling switching between the ultrasonic sensors 509 and 503 or 504, the pulse oscillator 508c, and the signal oscillator 508d. Switching is performed according to riverbed shape measurement and flow velocity measurement, the operation of which will be described later.

  FIG. 8 is a diagram showing an internal configuration of the control / processing device 6 on the fixed side, 601 is a signal transmitter / receiver for wireless communication with the mobile measuring device 5, and 602 is an arithmetic / processing device. Reference numeral 603 denotes a result display device, and reference numeral 604 denotes a storage device. Further, FIG. 9 shows the configuration of the arithmetic / processing device 602 of the fixed-side control / processing device 6. The arithmetic / processing device 602 is a microcomputer including a CPU 602-1, a RAM 602-3, a ROM 602-2, and an interface 602-4.

  Here, in the configuration shown in FIG. 2 to FIG. 9, the method of measuring the riverbed shape and flow rate of the cross section along the measurement line will be described in detail. In this embodiment, the river bed shape is measured by adding a pulse signal from the pulse oscillator 508c to the low-frequency ultrasonic sensor 503 or the high-frequency ultrasonic sensor 504 and measuring the reflection time from the river bed. In order to measure the flow velocity, the time until the ultrasonic sensor 509 receives the intermittent sinusoidal ultrasonic signal transmitted from the low-frequency ultrasonic sensor 503 or the high-frequency ultrasonic sensor 504 and the transmission / reception of the ultrasonic sensor are measured. The flow velocity distribution is obtained from the time measured by switching, and the flow rate is calculated together with the water depth obtained from the riverbed shape.

  FIG. 10 is a diagram showing a schematic flow of processing in the present embodiment. First, measurement conditions are transmitted from the fixed-side control / processing device 6 to the signal processing / control device 508 of the moving-side mobile measuring device 5 by wireless communication. For this purpose, the computation / processing device 602 in FIG. 8 communicates with the signal transceiver 508f in FIG. 5 via the signal transceiver 601 (101). Thereafter, the measurement is started. First, the moving measuring instrument 5 is moved to the measurement position (102), and the river bed reflection time and the flow velocity are measured (103, 104). These data are transmitted to the calculation / processing device 602 to calculate the riverbed shape and flow rate (105), and when the measurement at all the set positions is completed (106), the measurement is completed.

FIG. 11 is a diagram for explaining the operation of moving the movement measuring instrument 5 to the measurement position in the processing step 102 of FIG. The processing flow of FIG. 11 uses a microcomputer comprising the CPU 508a-1, RAM 508a-3, ROM 508a-2 and interface 508a-4 of FIG. 6 in the processing / controller 508a of FIG. A method of controlling the propulsion mechanism 502 from the detection result of the position sensor 507 will be described. In FIG. 11, by detecting the state of the sensor rotation mechanism 505, it is determined whether the ultrasonic sensors 503 and 504 are changing the beam direction (120). If not rotating, the rotating mechanism 505 is operated (121), and the position sensor 507 is used to determine the position of the moving measuring instrument (122). The position data is compared with the position data transmitted from the fixed-side arithmetic / processing device 602 in advance (123), and if it is not within the preset range, the propulsion mechanism 502 is operated to perform detection position alignment (124). When the measurement position matches the set position, the ultrasonic sensor angle is received by the interface 508a-4 from the interface 508a-8 in FIG. 6 (125), and the rotation angle of the ultrasonic sensors 503 and 504 is set by the rotation mechanism 505. (126). Next, the ultrasonic sensor angle, levitation body angle, vertical movement position, and levitation body position data are transmitted from the interface 508a-4 to the interface 602-4 (127). As can be seen from FIG. 10, this series of sequences is repeated until the measurement at the entire set position is completed.

  FIG. 12 is a diagram for explaining a method of measuring the bottom reflection time of an ultrasonic pulse for the riverbed shape measurement 103 in FIG. The processing flow of FIG. 12 uses a microcomputer comprising the CPU 508a-5, RAM 508a-7, ROM 508a-6, and interface 508a-8 of FIG. 6 in the processing / controller 508a of FIG. In FIG. 12, the rotation angle data of the ultrasonic sensors 503 and 504 is transmitted from the interface 508a-8 to the interface 508a-4 in FIG. 6, and the angle of the direction of the ultrasonic beam transmitted from the ultrasonic sensors 503 and 504 is determined. Among the switching elements of the switch 508b of FIG. 5, the switching element 508b-2 of FIG. 7 is set at the time of bed shape measurement (state A) (142, 143). First, in order to obtain the riverbed reflection time by the low-frequency ultrasonic sensor 503, the switching element 508b-1 is set to be connected to the 503 side (144). In this connection state, the pulse oscillator 508c and the low-frequency ultrasonic sensor 503 are connected, and a trigger signal is transmitted from the interface 508a-5 in FIG. 6 to the pulse oscillator 508c to transmit an ultrasonic pulse, and the reception of 508e. Then, the riverbed reflection time transmitted and received by the ultrasonic sensor 503 is measured by the CPU 508a-5 (145).

  When the measurement reflection time is smaller than the preset time (145), this is a case where the ultrasonic beam propagation distance is short, so that the switch 508b-1 is connected to the high frequency ultrasonic sensor 504 in order to use high frequency ultrasonic waves. Set (147) and measure the same river bottom reflection time (148). The measurement riverbed reflection time, which is the measurement result, is transmitted from the interface 508a-8 in FIG. 5 to the interface 602-4 of the fixed-side arithmetic / processing device in FIG. 8 (149).

FIG. 13 is a diagram illustrating a method for measuring the bottom scattering time of an ultrasonic pulse in order to measure the flow velocity of the river necessary for the flow measurement 104 in FIG. The processing flow of FIG. 13 is the interface with the CPU 508a-5, RAM 508a-7, ROM 508a-6 of FIG. 6 in the processing / controller 508a of FIG. A microcomputer composed of 508a-8 is used. In FIG. 13, the rotation angle (ultrasonic sensor angle) data of the ultrasonic sensors 503 and 504 is transmitted from the interface 508a-8 of FIG. 5 to the interface 508a-4 to determine the angle of the ultrasonic beam direction (161). The specific angle in this case is a direction perpendicular to the water surface, and may be either after the riverbed shape measurement at a certain position is completed or before the ultrasonic beam is in the riverbed direction. The water depth data is received from the interface 602-4 by the interface 508a-8 (162), and it is determined whether the water depth at the position is equal to or less than the set value (163). If the water depth is deep, the low frequency ultrasonic sensor 503 is used, and if it is shallow, the high frequency ultrasonic sensor 504 is used. In FIG. 13, the case where the water depth is deep and the low-frequency ultrasonic sensor 503 is used is described. However, in the case where the water depth is shallow, the measurement method is simply switched to the switching element 508b-1 in FIG. 7 so that the high-frequency ultrasonic sensor 504 is used. Are the same.

First, the switching element 508b-2 of FIG. 7 is set to the state A (164, 165). Since the water depth is deeper than the set value, the switch element 508b-1 is set to be connected to the low frequency ultrasonic sensor 503 (166). The trigger signal is transmitted from the interface 508a-5 to the oscillator 508d, the ultrasonic beam is transmitted from the low-frequency ultrasonic sensor 503, the reflected wave of the ultrasonic beam at the riverbed is detected by the ultrasonic sensor 509, and the reflection is detected. The waveform is stored in the RAM 508a-7 in the processor / controller 508a (167). In order to exchange the ultrasonic transmission / reception relationship between the ultrasonic sensor 503 and the ultrasonic sensor 509 so as to be reversed, the switch element 508b-2 is set to the state B (168), and the riverbed reflection waveform is similarly detected and processed. The data is stored in the RAM 508a-7 in the controller 508a (169). At this stage, two time waveform data in the forward direction and the reverse direction with respect to the river flow are obtained and transmitted to the fixed-side arithmetic / processing device 602 in FIG.

The riverbed shape and flow rate are calculated from the above measurement data, and this is performed by the fixed-side arithmetic / processing device 602. Hereinafter, the operation of the fixed-side arithmetic / processing device 602 will be described. As can be seen from FIG. 14, reference numerals 181 to 184 relate to data transmission / reception, and are the paired items already described in the description of each processing. Data necessary for river bed shape measurement and flow rate measurement is being accumulated at the stage of finishing 184, and these calculation methods (185) will be described in detail below.

First, river shape measurement is described. As mentioned above, the river shape measurement is calculated from the propagation time of the reflected wave bottom of the pulsed ultrasound. The specific signal timing will be described. A pulse signal is output from the pulse oscillator 508c by a pulse signal generation trigger from the processing / control device 508a in FIG. This signal is guided to the low frequency ultrasonic sensor 503 or the high frequency ultrasonic sensor 504 through the switch 508b. Which of the two sensors is selected by the switch 508b is determined by the processing / control unit 508a by looking at the time of the reflected signal from the riverbed. Pulsed ultrasonic waves emitted from the low-frequency ultrasonic sensor 503 or the high-frequency ultrasonic sensor 504 are reflected by the riverbed, detected by the same ultrasonic sensor, received by the signal transmitter / receiver 508f through the switch 508b, and then processed. The time from transmission to reception sent to the controller 508a is calculated. Since the sound speed of water is known, the round-trip propagation distance of a certain ultrasonic transmission beam can be easily calculated. In this process, the pulsed ultrasonic waves emitted from the low-frequency ultrasonic sensor 503 or the high-frequency ultrasonic sensor 504 are rotated in the beam emission direction by the sensor rotation mechanism 505. In addition, the radiation direction of the ultrasonic beam is always corrected and calculated from the data detected by the tilt sensor 506, such as the wave of the floating body 501. Furthermore, the position in the depth direction is also corrected by the vertical movement position sensor 510 for vertical movement. The levitation body 501 moves on the water surface by the propulsion mechanism 502. The position of the levitation body 501 is detected by a known position sensor 507 such as GPS or position detection of a rope stretched from both banks. As described above, the pulsed ultrasonic wave from the ultrasonic sensor repeats two ultrasonic beam radiations of rotation and translation, which move along the measurement line while swinging the direction of the ultrasonic beam. As shown in FIG. 17, in such control of the ultrasonic beam, for example, when observing the A point at the bottom of the river shown in FIG. 17, the position is obtained with a large number of ultrasonic beams composed of translation and rotation (FIG. 17). Then, the example of three beams of ○, △, ▽ is shown). For this reason, it has the feature that accuracy can be improved more than one measurement, and the influence of water-swinging objects such as algae that inhabit the riverbed can be reduced. In addition, there is an advantage that measurement can be performed without observing that the measuring apparatus moves to a position directly above point A to observe point A. In FIG. 17, where the water depth becomes shallow, such as a portion near the riverbank, the detection time of the reflected wave is equal to or less than a preset time. Therefore, the switching unit 508 b is controlled by the processing / control unit 508 a and the high-frequency ultrasonic sensor 504 is set. use. By using a high frequency, the ultrasonic wavelength in water is shortened, and it becomes possible to measure accurately with a short round-trip reflection time of the ultrasonic pulse.

  The method and apparatus for accurately obtaining the riverbed shape by translating and rotating the ultrasonic beam have been described above. Next, a calculation method for obtaining the average flow velocity from the water surface to the river bed along the measurement line will be described. If the average flow velocity distribution is obtained, the flow rate can be converted from the above river bed shape, that is, the water depth at each position.

  The measurement situation of the average flow velocity measurement is shown in FIG. In FIG. 4, the flow of water is in the direction of the arrow shown. In the case of the average flow velocity measurement, the signal from the modulation signal oscillator 508d is guided to the low frequency ultrasonic sensor 503 or the high frequency ultrasonic sensor 504 through the switch 508b. At this time, since the flow velocity distribution in the vertical direction is obtained from the water surface, when the ultrasonic beam becomes vertical, the switch 508b is used so that the amplitude modulation signal is used instead of the pulse signal used before and after that. Switch temporarily. Since the riverbed is not a perfect plane, ultrasound is scattered. The scattered ultrasonic waves are detected by an ultrasonic sensor 509 for transmitting and receiving an amplitude-modulated signal. At this time, since the ultrasonic scattering position of the riverbed is unknown, the ultrasonic sensor 509 having a large directivity angle is used to widen the detection angle range.

The method for measuring the flow velocity distribution is described below. In this embodiment, transmission is first performed by the low-frequency ultrasonic sensor 503 or the high-frequency ultrasonic sensor 504 and received by the ultrasonic sensor 509. Next, it is transmitted by the ultrasonic sensor 509 and received by the low frequency ultrasonic sensor 503 or the high frequency ultrasonic sensor 504. The ultrasonic signal transmitted by the first low-frequency ultrasonic sensor 503 or the high-frequency ultrasonic sensor 504 is an amplitude modulation signal that becomes a sine wave for a set time width, as shown in FIG. The low-frequency ultrasonic sensor 503 and the high-frequency ultrasonic sensor 504 have the same change form, although the size, amplitude, and duration of the operating frequency are different. The signal received by the ultrasonic sensor 509 has a waveform in which the transmission waveform is added with the propagation time of the ultrasonic wave and the change in the propagation speed due to the flow rate described later, as shown in FIG. In FIG. 4, the ultrasonic wave propagates almost perpendicular to the flow between the ultrasonic sensor 503 or 504 and the riverbed, so that it is less affected by the flow velocity. On the other hand, there is a sound speed change component due to the flow in the path where the scattered wave from the riverbed reaches the ultrasonic sensor 509, which apparently changes the sound speed. Now, let θ be the angle formed by a line segment connecting the ultrasonic sensor 503 or 504 and the riverbed and a line segment connecting the riverbed and the ultrasonic sensor 509. The contribution of the flow velocity on the line segment connecting the river bed and the ultrasonic sensor 509, where V is the flow velocity, is V · sin (θ). As a result, when the sound speed in water is Vw, the apparent sound speed Ve is Ve = Vw + V · sin (θ).

  Conversely, the transmission wave of the ultrasonic sensor 509, the reception wave of the low frequency ultrasonic sensor 503, or the high frequency ultrasonic sensor 504 are as shown in FIG. The apparent sound velocity Vf at this time is Vf = Vw−V · sin (θ). Since the distance D to the riverbed and the distance L from the low-frequency ultrasonic sensor 503 or the high-frequency ultrasonic sensor 504 to the ultrasonic sensor 509 are known, θ can be calculated. Since the distance R from the ultrasonic irradiation position of the riverbed to the ultrasonic sensor 509 is R = L / sin (θ), the detection time difference ΔT of the reflected wave obtained by changing the transmission / reception sensor is ΔT = R · (1 / Vf−1 / Ve) = 2 · V · R / (Vw · Vw + V · V · sin (θ) · sin (θ)). Conversely, the average flow velocity V is calculated from the detected time difference ΔT.

  FIG. 18C) is a diagram showing two received signal waveforms. The received wave is captured with the transmission time of the ultrasonic wave as the origin. The time difference between the two received waves is ΔT. Although there is a method of directly measuring ΔT at the rising edge of the signal, there is also a method of detecting the phase difference between two received sine waves in this embodiment. Since this phase difference is 2 · π · f · ΔT, where f is the operating frequency, ΔT is obtained by detecting the phase difference, and the average flow velocity V is calculated therefrom. The method for obtaining the phase difference can be obtained by mixing (multiplying) two received waves and using a DC component obtained from the result.

  A two-dimensional memory is prepared in the display device 603 in the control / processing device 6 on the fixed side. Although the riverbed shape measurement has already been described, a certain point on the riverbed along the measurement line is calculated from the ultrasonic beam direction and the round-trip time from ultrasonic transmission to reception. This is the reflection intensity data at one point in the memory of the display device 603. In this embodiment, the movement measuring instrument 5 moves while changing the ultrasonic beam direction. A point on the riverbed is determined from this position and the beam direction. Since the movement of the movement measuring instrument 5 and the direction of the ultrasonic beam change, a large number of riverbed points are accumulated as data on the memory of the display device 603. The intensity data of the same point on the memory of the display device 603 is added at that point. As a result of such processing, the riverbed shape is accumulated on the memory of the display device 603 and displayed on the display device 603.

  The method of measuring the average flow velocity has already been described using mathematical formulas. The arithmetic / processing device 602 can obtain the average flow velocity of the vertical line from the measurement line toward the riverbed by the arithmetic expression already described from the phase difference corresponding to the time difference of the received signal. The distance to the riverbed at this position, that is, the water depth, can be converted to a flow rate that passes through a certain width of the vertical line using the data already obtained. By integrating this over the entire river width along the measurement line by the arithmetic / processing device 602, the flow rate passing through the cross section of the measurement line can be detected.

  Next, the measured river shape, flow rate, and measurement position data are transmitted from the fixed control / processing device to the data management department and used to update hazard map data for disaster prevention. Further, previous data can be called by the control / processing device 6 and compared with the measurement result.

  The second embodiment of the present invention is characterized in that an ultrasonic array sensor is used as the low-frequency ultrasonic sensor 503 or the high-frequency ultrasonic sensor 504 in the first embodiment described. As is well known, the ultrasonic array sensor has a sensor structure in which a large number of subdivided ultrasonic transducers are arranged in a certain direction. In this embodiment, the sensor is arranged in a one-dimensional manner along the measurement line. When applying a pulse voltage to each transducer with a delay of a preset delay time, the directivity angle of the ultrasonic beam and the irradiation direction of the ultrasonic beam can be controlled by controlling the delay amount. Since this control method is known in the fields of ultrasonic inspection and radar, the control method will not be described here. By controlling the delay amount not only at the time of transmission but also at the time of reception, the same effect as the first embodiment of the present invention can be obtained. In the present embodiment, as a matter of course, the mechanical rotation drive mechanism of the ultrasonic sensor is unnecessary, so that there is an advantage that the apparatus can be simplified. Other configurations and operations are the same as those of the first embodiment.

  The third embodiment of the present invention is characterized by an ultrasonic transmission / reception method when measuring the flow velocity of a river. In this embodiment, signals are simultaneously transmitted from the low-frequency ultrasonic sensor 503 or the high-frequency ultrasonic sensor 504 and the ultrasonic sensor 509, and these sensors are respectively connected to the receiver 505e while the ultrasonic wave propagates through the water. -1, connect to 505e-2. For this reason, two receivers 508e are prepared as shown in FIG. A part of the switch 508b is also changed like a switch element 508b-3 in FIG. At the time of transmission of ultrasonic waves, it is in the state shown in the upper diagram of FIG. 16, and the low-frequency ultrasonic sensor 503 or the high-frequency ultrasonic sensor 504 and the ultrasonic sensor 509 are coupled to a signal oscillator, and at the same time, an ultrasonic beam is brought to the riverbed. Sent to. At the time of reception, the switching state shown in the lower diagram of FIG. 16 is entered, and the reception signals of the electrical signals generated by receiving the ultrasonic beams reflected on the riverbed are guided to the two receivers 505e-1 and 505e-2, respectively. The process of collecting the received waveform in the received signal and measuring the time difference is the same as that in the first embodiment, so that the description thereof is omitted. According to the present embodiment, the influence of the propagation distance can be eliminated by subtracting two time differences. In this embodiment, the process for obtaining the time difference is divided into two stages as in the previous embodiment.

  The present invention has been described in detail above. In each of the above embodiments, when the mobile measuring device 5 is moved, the floating body 501 loaded with the mobile measuring device 5 is moved along the measurement line using the propulsion mechanism 502. A known method such as position control by GPS or laser guidance, or towing from a fixed object such as a bridge by a rope can be used. When moving the mobile measuring instrument 5, instead of using the propulsion mechanism 502, a leash is hung on the levitated body 501 from both banks in the river width direction of the river, and the leash is moved by dragging and feeding the leash from both banks. May be. In addition, when there is no flow velocity, that is, when measuring the shape of the bottom of a lake or dam lake, it goes without saying that the portion for measuring the flow velocity can be removed and only the shape measurement portion can be used.

  According to an embodiment of the present invention, an ultrasonic beam is applied to an apparatus for obtaining a flow rate when there is a shape and flow of a riverbed or lake bottom along a measurement line set in a river or lake using ultrasonic waves. The shape is measured by irradiating the bottom or the lake bottom. The ultrasonic beam is rotated by a set angle, and the entire apparatus is moved along the measurement line. For this reason, a point on the riverbed or lake bottom can be measured many times by changing the irradiation angle of the ultrasonic beam, and the measurement accuracy can be improved by reducing the influence of algae near the riverbed or lake bottom. . In addition, since the same measurement system as the shape measurement is used for detecting the flow velocity for measuring the flow rate, it is effective in simplifying the measuring device and reducing the number of operators for measurement.

  INDUSTRIAL APPLICABILITY The present invention has applications in a riverbed shape (bedbed shape) at a position along a measurement line set in advance in a river, a lake, or the like using ultrasonic waves, or a device that measures the flow rate when there is a flow. In particular, to prevent disasters such as floods, the riverbed shape (riverbed shape) and the riverbed shape to provide data that can be measured quickly and measured when there is a flow, and can be reflected in disaster prediction. -Uses can be found in flow measurement devices.

It is a schematic diagram for demonstrating the basic concept of the riverbed shape and flow measuring device by this invention. It is a figure explaining the outline | summary of the apparatus structure and measuring method of a moving measuring device among the riverbed shape and flow volume measuring apparatuses by this invention. It is a figure which shows an example of the rotation mechanism of the ultrasonic sensor of the riverbed shape and flow volume measuring apparatus by this invention. It is a figure explaining the content of the measuring method of the flow velocity by the river-bed shape and flow measuring device by this invention, and the apparatus to be used. It is a figure explaining the detail of the apparatus structure regarding the movement measuring device of the riverbed shape and flow measurement apparatus by this invention. It is a figure explaining the structure of the process and the controller 508a regarding the river bed shape and flow volume measuring apparatus by this invention. It is a figure explaining the structure of a switch regarding the river bed shape and flow volume measuring apparatus by this invention. It is a figure explaining the structure of the control / processing apparatus of the fixed side regarding the riverbed shape and flow measurement apparatus by this invention. It is a figure explaining the structure of the arithmetic and processing apparatus 602 regarding the riverbed shape and flow measurement apparatus by this invention. It is a figure explaining the process outline | summary of this apparatus regarding the river bed shape and flow volume measuring apparatus by this invention. It is a figure explaining the processing content and apparatus control of the microcomputer which uses CPU508a-1 as a central processing part regarding the river bed shape and flow measurement apparatus by this invention. It is a figure explaining the processing content and apparatus control which perform time measurement for a riverbed shape measurement with the microcomputer which uses CPU508a-5 as a central processing part regarding the riverbed shape and flow volume measuring apparatus by this invention. It is a figure explaining the processing content and apparatus control which perform time measurement for flow velocity measurement with the microcomputer which uses CPU508a-5 as a central processing part regarding the river bed shape and flow volume measuring apparatus by this invention. It is a figure explaining the processing content and apparatus control for river bed shape measurement and flow measurement by the microcomputer which uses CPU602-1 as a central processing part regarding the river bed shape and flow measurement apparatus by this invention. It is a figure explaining the detail of the apparatus structure of a 3rd Example regarding the movement measuring device of the riverbed shape and flow volume measuring apparatus by this invention. It is a figure explaining the structure of the process / controller 508a of 3rd Example regarding the riverbed shape and flow volume measuring apparatus by this invention. It is a figure explaining the content of the scanning method of an ultrasonic beam, and riverbed shape drawing regarding the riverbed shape and flow measurement apparatus by this invention. It is a figure explaining the transmission-and-reception waveform in the measurement of a flow velocity regarding the riverbed shape and flow measurement apparatus by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... River, 2 ... Measurement line, 3 ... River bed shape (bed bed shape) along 4 measurement line, 4 ... River cross section, 5 ... Moving measuring device, 6 ... Control and processing device, 501 ... Floating body, 502 ... Propulsion mechanism, 503 ... Low frequency ultrasonic sensor, 504 ... High frequency ultrasonic sensor, 505 ... Rotation mechanism of sensor,
505a: Pulse motor drive power supply, 505b: Pulse motor, 505c, 505d ... Gear, 505e ... Shaft, 505f, 505g ... Limit switch, 506 ... Tilt sensor, 507 ... Position sensor, 508 ... Signal processing / control device, 508a ... Processing Controller, 508b ... Switch, 508c ... Pulse oscillator, 508d ... Signal oscillator, 508e-1, 2, Receiver, 508f, 601 ... Signal transmitter / receiver, 509 ... Ultrasonic sensor for transmission / reception, 510 ... Vertical movement position Sensor, 602... Arithmetic / processing device, 603... Display device, 604.

Claims (4)

An ultrasonic sensor for irradiating an ultrasonic beam toward the bottom of a river or lake and detecting a reflected wave of the ultrasonic beam from the bottom;
The ultrasonic sensor is provided, and a floating body floating on the water surface of the river or lake,
Means provided on the levitation body for moving the levitation body on the surface of the river or lake;
Means for rotating the ultrasonic beam in the longitudinal direction of movement of the levitation body, provided on the levitation body;
Means for changing the ultrasonic frequency of the ultrasonic beam according to the time from irradiation of the ultrasonic beam to detection of the reflected wave;
Means for determining a moving position of the floating body;
From the irradiation direction of the ultrasonic beam, the position of the ultrasonic sensor, the time from the irradiation of the ultrasonic beam to the detection of the reflected wave, and the velocity of the ultrasonic beam in the river water or the lake water Means for calculating the position of the bottom;
Hydrological information measuring device for rivers or lakes equipped with. In Claim 1, two ultrasonic transmission / reception sensors spaced apart in the flow direction of the water of the river or lake,
Until one of the two ultrasonic transmission / reception sensors detects a reflected wave scattered from the bottom of the two ultrasonic transmission / reception sensors after the ultrasonic wave is irradiated toward the bottom from one of the two ultrasonic transmission / reception sensors. And a means for obtaining a time difference from irradiation to detection of the ultrasonic wave obtained by reversing the transmission / reception side of the two ultrasonic transmission / reception sensors,
Means for calculating the average flow velocity of the water at the position of the ultrasonic sensor from these time differences, the distance between the two ultrasonic sensors and the water depth determined from the river bed shape;
Means for obtaining a flow rate from the average flow velocity and water depth;
An apparatus for measuring hydraulic information of a river or lake characterized by comprising:   In claim 2, to the floating body floating on the water surface of the river or lake, at least the ultrasonic sensor, the ultrasonic transmission / reception sensor, among the components constituting the hydraulic information measuring device of the river or lake, An apparatus for measuring hydraulic information of a river or lake, comprising: means for rotating an ultrasonic beam in the direction of the measurement line; and means for changing the ultrasonic frequency. In Claim 3, a part of the parts constituting the river or lake hydraulic information measuring device is mounted on the front levitation body, the other component parts are mounted on land, the part component part and the other structure A river comprising means for wirelessly or wiredly communicating a signal with a component, and a display means for displaying a measurement result of hydraulic information of the river or lake as the other component Or a measuring device for hydraulic information of the lake.

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