JP2000009507A - River current velocity measuring instrument - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a river current velocity measuring instrument which is complied with changes of water quality. SOLUTION: When a command signal S50a is outputted from a detection arithmetic part 50, a receive signal S62a is detected by the detection arithmetic part 50 through a transmitter/receivers 61, a wave transmitter/receiver 71, a transmitter/receiver 65, a wave transmitter/receiver 75, a wave transmitter/ receiver 72, and a transmitter/receiver 62 in order. In the reverse direction, a receive signal S61b is detected by the detection arithmetic part 50 similarly to calculate a current velocity V1. A signal transmitting and receiving means consisting of the transmitter/receivers 63, 64, and 65 and the wave transmitter/ receivers 73, 74, and 75 calculates a current velocity V2 by the detection arithmetic part 50 as well as the current velocity V1 and a display unit 51 displays it. The mean current velocity Vav of the overall river width is obtained by finding the mean value of the current velocities V1 and V2.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a river flow velocity measuring apparatus for measuring a flow velocity of a river having a sound velocity distribution characteristic whose sound velocity varies depending on the water depth, using an ultrasonic signal.

[0002]

2. Description of the Related Art Conventionally, techniques in such a field include:
For example, there is one described in the following literature. Reference: JP-A-55-20174 FIG. 2 is a configuration diagram showing a conventional river flow velocity measuring device described in the above-mentioned reference. This river flow velocity measuring device outputs command signals S10a and S10b for commanding output of a transmission signal, and receives reception signals S22a and S21b corresponding to these command signals S10a and S10b, respectively, to measure the medium to be measured of the river 1. (I.e., river water) has a detection calculation unit 10 that calculates a flow velocity V of 1 W and outputs a calculation result S10c. A display 11 for displaying the calculation result S10c is connected to the detection calculation unit 10. Further, the detection operation unit 1
0, the command signal S10a is input and the transmission signal S21a
And a transmitter / receiver 21 that receives a given received signal S31b and outputs a received signal S21b, and receives a command signal S10b and outputs a transmitted signal S22b, and outputs a given received signal S32a. A transceiver 22 that receives and outputs a reception signal S22a is connected, and these transceivers 21 and 22 are installed on one shore of the river 1. This river flow velocity measuring device has a transceiver 23 installed on the other shore of the river 1. The transceiver 23 receives the received wave signal S33a1 and transmits the transmission signal S23a, and receives the received wave signal S33b1.
And transmits the transmission signal S23b.

[0003] The transceiver 21 is connected to a transmitter / receiver 31 disposed underwater at a predetermined distance from one shore of the river 1. The transmitter / receiver 31 converts the transmission signal S21a into an ultrasonic signal S31a and transmits it, receives the supplied ultrasonic signal S33b2, converts it into a received signal S31b, and outputs the converted signal. The transceiver 22 includes a transducer 31
The transmitter / receiver 32 arranged at a position separated by a distance d in the direction of the river 1 of the river 1 is connected. The transducer 32 converts the transmission signal S22b into an ultrasonic signal S32b and transmits the signal,
The received ultrasonic signal S33a2 is received and the received signal S33a2 is received.
32a and output. The transmitter / receiver 23 is connected to a transmitter / receiver 33 arranged in water at a predetermined distance from the shore of the river 1 and at a distance r from the transmitter / receivers 31 and 32. The transducer 33 receives the ultrasonic signal S
31a is received and converted into a received signal S33a1 and output, and the ultrasonic signal S32b is received and received signal S33b1.
Is converted and output.

Next, the operation of FIG. 2 will be described. In this river flow velocity measuring device, when the command signal S10a is output from the detection operation unit 10 to the transceiver 21, the transmission signal S21a is output from the transceiver 21 and the transducer 31 is driven. An ultrasonic signal S31a is emitted. The ultrasonic signal S31a is received by the transmitter / receiver 33, converted into a reception signal S33a1, and sent to the transceiver 23. The reception signal S33a1 is amplified to a certain level by the transmitter / receiver 23 and, when detected as a signal, is input to the transmitter / receiver 33 as a transmission signal S23a. And the transducer 33
, An ultrasonic signal S33a2 is emitted. Ultrasonic signal S
33a2 is received by the transmitter / receiver 32, and the received signal S32a
And transmitted to the transceiver 22. Received signal S32
The signal a is amplified to a certain level by the transceiver 22 and sent to the detection operation unit 10 as a received signal S22a to be detected.

[0005] Similarly, the detection operation unit 10 transmits the signal to the transceiver 22.
When the command signal S10b is output to the
The transmission signal S22b is output from 2 and the transducer 32 is driven, and the ultrasonic signal S32b is emitted in the river water 1W. The ultrasonic signal S32b is received by the transmitter / receiver 33, converted into a received signal S33b1, and sent to the transceiver 23. The reception signal S33b1 is amplified to a certain level by the transceiver 23, and when detected as a signal, the transmission signal S33b1 is amplified.
23b is input to the transducer 33. Then, the ultrasonic wave signal S33b2 is emitted from the transducer 33. The ultrasonic signal S33b2 is received by the transmitter / receiver 31, converted into a reception signal S31b, and transmitted to the transceiver 21. The reception signal S31b is amplified to a certain level by the transmitter / receiver 21, sent to the detection operation unit 10 as the reception signal S21b, and detected. The detection operation unit 10 calculates the flow velocity V using, for example, a frequency difference method, a time difference method, an inverse time difference method, or the like, and the flow velocity V is displayed on the display 11.

[0006]

However, the conventional river flow velocity measuring device shown in FIG. 2 has the following problems. Since the temperature and salinity of the river water 1W are different between near the surface and near the water bottom, the river 1 has a sound velocity distribution characteristic (hereinafter, referred to as "vertical sound velocity distribution") in which the sound velocity C varies depending on the water depth. That is, the sound velocity C becomes lower as the water depth becomes deeper. In particular, the gradient of the vertical sound velocity distribution becomes steeper in summer or the like. At this time, the horizontally emitted ultrasonic signals S31a and S33a
2, S32b and S33b2 progress while bending downward according to Snell's law and may hit the water bottom.
Ultrasonic signals S31a, S33a2, S32b, S33b
When 2 hits the water bottom and is reflected, the rise of the waveform becomes ambiguous, and the measurement of the flow velocity V becomes impossible. Therefore, in a river with a steep vertical sound velocity distribution, if the river width is wide,
There has been a problem that the measurement of the flow velocity V may not be possible.

[0007]

In order to solve the above-mentioned problems, a first aspect of the present invention is a river flow velocity measuring apparatus for measuring a flow velocity of a river having a sound velocity distribution characteristic whose sound velocity varies depending on water depth. Has the following means. It is provided for each of a plurality of divided areas where the river width is divided within a range of a distance where an ultrasonic signal directly propagates, and inputs first and second command signals for output command of a transmission signal, and calculates a flow rate. A plurality of signal transmitting / receiving means for outputting the first and second received signals, and a plurality of the first and second command signals, and receiving the plurality of the first and second received signals. Calculating means for calculating the flow velocity of the river by calculation.

Each of the signal transmission / reception means receives the first command signal, transmits a first transmission signal, receives a first reception signal, and outputs the first reception signal. And a transmitter / receiver, which is arranged near one end of the divided area, converts the first transmission signal into a first ultrasonic signal and transmits the same, and delays the second ultrasonic signal by a propagation time t2. A first transmitter / receiver for receiving and transmitting the second command signal, transmitting a second transmission signal by inputting the second command signal, A second transceiver that receives a signal and outputs the second received signal; and a second transceiver that is disposed at a distance d from the first transducer in the direction of the river channel of the river,
The second transmission signal is converted into a third ultrasonic signal and transmitted, the fourth ultrasonic signal is received with a delay of propagation time t4, converted into the second received signal, and output. A second transducer, the first ultrasonic wave being disposed near the other end of the divided area and at a distance r from the first and second transducers and having a propagation time t1; Receiving the signal, converting the signal into a third received signal and outputting the signal, receiving the third ultrasonic signal with a delay of propagation time t3, converting the signal into a fourth received signal, and outputting the signal; A third transmitter / receiver that converts the third transmission signal into the fourth ultrasonic signal and transmits the fourth ultrasonic signal, and converts the fourth transmission signal into the second ultrasonic signal and transmits the third ultrasonic signal; A third transceiver that receives a third received signal, transmits the third transmission signal, receives the fourth received signal, and transmits the fourth transmission signal; It is provided, respectively.

The calculating means calculates the propagation times t1, t
2, t3, and t4, and the flow velocity Vp of each of the divided areas is calculated using the following equation, and the average value of the flow velocities Vp is calculated to calculate the flow velocity Vav of the river. River velocity measuring device. ^{Vp = (r 2 / d)} (ΔTa n + Ta n + 1) / Ta n 2 _{where, ΔTa n = Tb n -Ta n} , ΔTa n + 1 = Ta n -Ta
_{n + 1} Ta = t1 + t4 Tb = t2 + t3 C: Sound velocity when the river water is stationary n: Number of measurements By adopting such a configuration, when the first command signal is output from the arithmetic means, the first command signal is output. , A first transceiver, a third transceiver, a third transceiver, a third transceiver, a second transceiver, and a second transceiver through the second transceiver sequentially. The received signal is detected by the calculating means. Similarly, in the reverse direction, the first received signal is detected by the calculating means, and the flow velocity of each divided area is calculated. The average flow velocity over the entire river width can be obtained by calculating the average value of the flow velocity for each divided area.

In the invention according to claim 2, the following means is provided in a river flow velocity measuring device for measuring the flow velocity of a river 1 having a sound velocity distribution characteristic whose sound velocity varies depending on the water depth. 2. The signal transmission / reception means according to claim 1, wherein the signal transmission / reception means is provided for each of the first and second divided areas in which the river width is divided within a range of a distance in which an ultrasonic signal directly propagates. A third receiving signal which is provided at an intermediate position between the first transducer and the second transducer in the divided area and receives the first ultrasonic signal in the second divided area; The third ultrasonic signal is received and converted to a fourth received signal and output, and the third transmission signal is converted to the fourth ultrasonic signal and transmitted. And a fourth transducer for converting a fourth transmission signal into the second ultrasonic signal and transmitting the fourth ultrasonic signal, and the third transducer in the fourth transducer or the second divided area. Switching means for selectively connecting the third transceiver to the third transceiver. Thereby, when the river width is within the range of the distance where the ultrasonic signal directly propagates, the fourth transducer, the first and second transducers in the second divided region, and the first transducer , The second and third transceivers, and the switching means constitute one signal transceiver, and when the river width is larger than the range, two signal transceivers are provided in the first and second divided areas. Are respectively constituted. Then, the same operation as the invention according to claim 1 is performed in each signal transmitting / receiving unit.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment FIG. 1 is a block diagram of a river flow velocity measuring device showing a first embodiment of the present invention. This river flow velocity measuring device has a calculation means (for example, a detection calculation unit) 50. The detection operation unit 50 includes a command signal S50 for a transmission signal output command.
a, S50b, S50c, and S50d,
These command signals S50a, S50b, S50c, S5
0d, the received signals S62a, S61b,
Receiving S64c and S63d, the divided areas A and B of the river 1
Has the function of calculating the flow velocities V1 and V2 of the river water 1W in the above, and outputting the calculation result S50e. Division areas A and B
Is obtained by dividing the river width within the range where the ultrasonic signal directly propagates. The detection calculation unit 50 includes a calculation result S
A display 51 for displaying 50e is connected. Furthermore,
The detection calculation unit 50 includes transceivers 61, 62, 63, 64
Is connected.

The transceiver 61 receives a command signal S50a and outputs a transmission signal S61a, and receives a given reception signal S71b and outputs a reception signal S61b. A signal S50b is input, a transmission signal S62b is output, and a given reception signal S72a is received and a reception signal S62a is output. The transceiver 63 receives the command signal S50c and outputs the transmission signal S63c, and receives the received reception signal S74d and outputs the reception signal S63d. The transceiver 64 transmits and receives the command signal S50d. It inputs and outputs a transmission signal S64d, and receives a given reception signal S75c and outputs a reception signal S64c. These transceivers 61, 62, 63, 64
Is installed on one shore of the river 1. Further, this river flow velocity measuring device has a transceiver 65 installed on the other shore of the river 1. The transceiver 65 receives the given received signal S73a1, transmits the transmitted signal S65a, receives the given received signal S73b1, transmits the transmitted signal S65b, and receives the given received signal S73c1. Then, the transmission signal S65c is transmitted, and the received reception signal S73d1 is received and the transmission signal S65d is transmitted.

The transmitter / receiver 61 is connected to a transmitter / receiver 71 disposed underwater in a divided area A at a predetermined distance from one shore of the river 1. The transmitter / receiver 71 converts the transmission signal S61a into an ultrasonic signal S71a and transmits it, receives the supplied ultrasonic signal S75b2, and receives the received ultrasonic signal S71b2.
b and output. The transceiver 62 includes:
A transducer 72 arranged at a distance d from the transducer 71 in the direction of the river channel of the river 1 is connected. The transmitter / receiver 72 converts the transmission signal S62b into an ultrasonic signal S72b and transmits it, and receives the supplied ultrasonic signal S75a2, converts it into a received signal S62a, and outputs the converted signal. The transmitter / receiver 63 is connected to a transmitter / receiver 73 arranged in the water in the divided area B at a predetermined distance from the other shore of the river 1. The transmitter / receiver 73 converts the transmission signal S63c into an ultrasonic signal S73c and transmits it, receives the supplied ultrasonic signal S75d2, converts it into a received signal S73d, and outputs it. The transmitter / receiver 64 is connected to a transmitter / receiver 74 arranged at a distance d from the transmitter / receiver 73 in the river direction of the river 1. The transmitter / receiver 74 converts the transmission signal S64d into an ultrasonic signal S74d and transmits it, receives the supplied ultrasonic signal S75c2, and receives the received ultrasonic signal S7.
4c.

The transmitter / receiver 65 is connected to a transmitter / receiver 75 disposed in the water at the boundary between the divided areas A and B and at a distance r from the transmitter / receivers 71, 72, 73 and 74.
The transmitter / receiver 75 receives the ultrasonic signal S71a, converts the received ultrasonic signal S71a into a received signal S75a1, and outputs the received ultrasonic signal S72b, converts the received ultrasonic signal S72b into a received signal S75b1, and outputs the received ultrasonic signal S73c. Is received and converted into a received signal S75c1 and output, and the ultrasonic signal S74d is received and the received signal S75c1 is received.
75d1 and output. Transceiver 6
1, 62, 65 and the transducers 71, 72, 75 constitute one signal transmitting / receiving means. Also, the transceiver 63,
The other signal transmission / reception means is constituted by 64, 65 and the transducers 73, 74, 75.

Next, the operation of FIG. 1 will be described. In this river flow velocity measuring device, the calculation operations (a) and (b) of the flow velocities V1 and V2 of the river water 1W in the divided areas A and B are performed. (A) Calculation operation of flow velocity V1 Command signal S5 from detection calculation unit 50 to transceiver 61
0a is output, the transmission signal S61 is transmitted from the transceiver 61.
is output, the transducer 71 is driven, and an ultrasonic signal S71a is emitted into the river water 1W in the divided area A. The ultrasonic signal S71a is received by the transmitter / receiver 75 at the propagation time t1, converted into a received signal S75a1, and transmitted to the transceiver 65. The reception signal S75a1 is amplified to a certain level by the transmitter / receiver 65 and, when detected as a signal, is input to the transmitter / receiver 75 as a transmission signal S65a. And
An ultrasonic signal S75a2 is emitted from the transducer 75.
The ultrasonic signal S75a2 is received by the transmitter / receiver 72 at the propagation time t4, converted into the received signal S72a, and
Sent to The received signal S72a is amplified to a certain level by the transceiver 62, sent to the detection operation unit 50 as a received signal S62a, and detected.

Similarly, the transmission / reception device 62
When the command signal S50b is output to the
2 outputs the transmission signal S62b, drives the transducer 72, and outputs the ultrasonic signal S72b in the river 1W in the divided area A.
Is fired. The ultrasonic signal S72b is received by the transmitter / receiver 75 at the propagation time t3, converted into a received signal S75b1, and sent to the transceiver 65. The reception signal S75b1 is amplified to a certain level by the transmitter / receiver 65 and, when detected as a signal, is input to the transmitter / receiver 75 as a transmission signal S65b. Then, the ultrasonic signal S75 is transmitted from the transducer 75.
b2 is fired. The ultrasonic signal S75b2 has a propagation time t
The signal is received by the transmitter / receiver 71 at step 2, converted into a received signal S 71 b, and sent to the transceiver 21. The received signal S71b is
The signal is amplified to a certain level by the transceiver 61 and the received signal S6
1b is sent to the detection calculation unit 50 and detected. In the detection calculation unit 50, the flow velocity V1 shown in the following equation (1) is calculated using the inverse time difference method, and the display unit 5 calculates the calculation result S50e.
1 is displayed.

V1 = (r ² / d) ｛(1 / Ta _n− 1 / Tb _n ) + (1 / T _{n + 1} −1 / T _n )｝ + (r / 4d) (ΔC _n −ΔC _{n +1} ) (1) where t1 is the propagation time of the ultrasonic signal S71a from the transducer 71 to the transducer 75 t4; the propagation of the ultrasonic signal S75a2 from the transducer 75 to the transducer 72 Time t2: Propagation time of ultrasonic signal S75b2 from transmitter / receiver 75 to transmitter / receiver 71 t3; Propagation time of ultrasonic signal S72b from transmitter / receiver 72 to transmitter / receiver 75 Ta: Transmission / reception from transmitter / receiver 71 Time (= t1 + t4) of the ultrasonic signals S71a and S75a2 transmitted to the transmitter / receiver 72 via the transmitter 75 Tb; The ultrasonic signal S72b transmitted from the transmitter / receiver 72 to the transmitter / receiver 71 via the transmitter / receiver 75 , S75b2 (= t2 + t3) C: Speed of sound in the case where water 1W is stationary n: number of measurements d; distance r between the transducer 31 and 32; distance between transducers 31 and 33, transducer 33 and 32
(ΔC _n −ΔC _{n +} 1) in the equation (1) is a fluctuation amount of the sound speed C for each measurement and can be ignored. ^{Thus, V1 = (r 2 / d} ) × {(1 / Ta n -1 / Tb n) + (1 / T n + 1 -1 / T n)} = (r 2 / d) {ΔTa n / ( _{Ta n · Tb n) + ΔTa} n + 1 / (Ta n + 1 · Tb n)} ··· (2) _{where, ΔTa n = Tb n -Ta n} , ΔTa n + 1 = Ta n -Ta
_{n + 1} Here, the _{ΔTa n = Ta n + 1,} Ta n = Tb n,
Even if the denominator of equation (2) is common, the error is small. Therefore,
The flow velocity V1 is represented by the following equation (3). ^{V1 = (r 2 / d)} (ΔTa n + Ta n + 1) / Ta n 2 ··· (3) (b) flow rate V2 of the arithmetic operation transceivers 63,64,65 and transducer 73,74,7
5, the flow rate V2 is calculated by the detection calculation unit 50 in the same manner as the flow rate V1, and the calculation result S50e
Is displayed on the display 51. The average velocity Vav over the entire river width is represented by the following equation (4). Vav = (1/2) Σ (V1 + V2) = (r 2 / 2d) Σ [{(ΔT (V1) n + ΔT (V1) n + 1) / T n 2} + {(ΔT (V2) n + ΔT ( V2) _{n + 1} ) / T _n ² }] (4) When both the flow velocities V1 and V2 can be measured, the correlation between the average flow velocity Vav and the flow velocity V1, and the average flow velocity Vav and the flow velocity V2 If the correlation function is calculated by calculating the correlation of
For example, even if a failure occurs in the transmitter / receiver 61 or the gradient of the vertical sound velocity distribution becomes steep and either the flow velocity V1 or the flow velocity V2 cannot be measured, the average flow velocity Vav is calculated from the flow velocity V1 or the flow velocity V2 using this correlation function. can do.
When measuring the flow velocity V1 and the flow velocity V2, if sound waves of the same frequency are used, it is difficult to measure them at the same time.

As described above, in the first embodiment,
Since the river width is divided into the divided areas A and B and the flow velocities V1 and V2 are measured, the ultrasonic signals S71a and S75b
2, S72b, S75a2, S73c, S75d2, S
Even if the propagation paths of 74d and S75c2 are shorter than before and the gradient of the vertical sound velocity distribution is steep, these ultrasonic signals S71a, S75b2, S72b, S75a2, and S75a2
73c, S75d2, S74d, and S75c2 do not hit the water bottom. Therefore, stable propagation can be ensured, and stable measurement of the flow velocities V1, V2 and the average flow velocity Vav without erroneous measurement can be performed. Further, when both the flow velocities V1 and V2 can be measured, the average flow velocity Vav, the flow velocity V1, and the average flow velocity V1 are measured.
By calculating the correlation function between the velocity V2 and the flow velocity V2, the gradient of the vertical sound velocity distribution becomes steeper, and even if either the velocity V1 or V2 cannot be measured, the velocity V1 or V2 cannot be measured. If one of them can be measured, the average flow velocity Vav can be calculated from the flow velocity V1 or V2 using this correlation function, so that the frequency of missing measurement is reduced and stable measurement can be performed.

Second Embodiment FIG. 3 is a block diagram of a river flow velocity measuring apparatus showing a second embodiment of the present invention. Elements common to those in FIG. 1 showing the first embodiment are the same as those shown in FIG. Common symbols are assigned. In this river flow velocity measuring device, a transmitter / receiver 76 is provided at an intermediate position between the transmitters / receivers 73, 74, and the transmitter / receivers 75, 76 are switched between the transmitter / receivers 75, 76 and the transceiver 65. A switching means (for example, a switching device) 80 for use is added. Other configurations are the same as those in FIG.

Next, the operations (a) and (b) of FIG. 3 will be described. (A) Flow velocities V1 and V when the gradient of vertical sound velocity distribution is steep
2. Arithmetic operation The switch 80 is switched to the transducer 73 side. And the first
Similarly to the embodiment, the signal transmission / reception means including the transceivers 61 and 62 and the transmitter / receivers 71, 72, and 75, and the signal transmission / reception means including the transceivers 63 and 64 and the transmitter / receivers 73, 74, and 75, The flow rates V1 and V2 are measured. (B) Flow velocity V1, when the gradient of the vertical sound velocity distribution is small
Operation of V2 The switch 80 is switched to the transducer 76 side. Then, similarly to the prior art, the transceivers 61 and 62 and the transmitter / receiver 71,
The flow velocity V over the entire river width is measured by the signal transmission / reception means 72 and 76.

As described above, in the second embodiment,
When the gradient of the vertical sound velocity distribution is steep, the flow rates V1 and V2 are measured by dividing the area into the areas A and B. Therefore, the ultrasonic signals S71a, S75b2, S72b, S75a2,
The propagation paths of S73c, S75d2, S74d, and S75c2 are shortened, and have the same advantages as in the first embodiment. or,
When the gradient of the vertical sound velocity distribution of the river water 1W is small, the flow velocity V is measured on a long propagation path similar to the conventional one.
Stable measurement is possible. In this case, the ultrasonic signal S71
a, S75b2, S72b, S75a2, S73c, S
Since the propagation distances of 75d2, S74d, and S75c2 are long, a large reverse time difference can be obtained, and the transceivers 61, 62, 6
5 can be less affected by the delay time. Furthermore,
Since the transceivers 63 and 64 are not used, the detection operation unit 50
Is performed at high speed.

The present invention is not limited to the above embodiment,
Various modifications are possible. For example, there are the following modifications. (A) In the first embodiment, the river width is divided into the divided areas A and B. However, a wider river width may be divided into three or more divided areas. (B) In the second embodiment, the transmitter / receiver 76 is disposed at a position intermediate between the transmitters / receivers 73 and 74, but this may be disposed at a position intermediate between the transmitters / receivers 71 and 72. .

[0023]

As described above in detail, according to the first aspect of the present invention, the river width is divided into a plurality of divided areas and the respective flow velocities are measured. Even if the propagation paths of the second, third, and fourth ultrasonic signals are shorter than before and the gradient of the vertical sound velocity distribution is steep, these ultrasonic signals do not hit the water bottom. Therefore, stable propagation can be ensured, and the flow velocity and the average flow velocity in each divided region can be measured without erroneous measurement. Further, when the flow velocity in each divided area can be measured, the gradient of the vertical sound velocity distribution becomes steeper by calculating the correlation function between the average flow velocity and the flow velocity in each divided area and calculating the correlation function. Even if a part of the flow velocity in the divided area cannot be measured, if the flow velocity in the other divided areas can be measured, the average flow velocity can be calculated using this correlation function. it can.

According to the second aspect of the present invention, when the river width is within the range of the direct propagation of the ultrasonic signal, the switching means switches the fourth transducer and the second divided area. , The first, second and third transducers, the first, second and third transceivers, and the switching means constitute one signal transmitting and receiving means, so that the first, second, third and fourth The propagation distance of the ultrasonic signal becomes longer. Therefore, a large inverse time difference can be obtained, and the influence of the delay time of each transceiver can be reduced. Furthermore, since the first and second transceivers in the first divided area are not used, the operation of the operation means is performed at high speed. or,
When the river width is larger than the range, by the switching means,
Since two signal transmission / reception units are respectively formed in the first and second divided areas, the same effect as the invention according to claim 1 can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a river flow velocity measuring device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a conventional river flow velocity measuring device.

FIG. 3 is a configuration diagram of a river flow velocity measuring device according to a second embodiment of the present invention.

[Explanation of symbols]

 50 Detection calculation unit 61, 62, 63, 64, 65 Transceiver 71, 72, 73, 74, 75, 76 Transceiver 80 Switch A, B Division area V1, V2 Flow rate

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hideyuki Takahashi 1-7-12 Toranomon, Minato-ku, Tokyo Oki Electric Industry Co., Ltd. F-term (reference) 2F035 AA03 DA04 DA07 DA21

Claims (2)

[Claims] 1. A river flow velocity measuring device for measuring a flow velocity of a river having a sound velocity distribution characteristic in which a sound velocity varies depending on a water depth, wherein the river width is divided within a range where an ultrasonic signal directly propagates. A plurality of signal transmission / reception means provided respectively for inputting first and second command signals for transmission command output commands and outputting first and second reception signals for flow velocity calculation; Outputting the first and second command signals,
Calculating means for receiving the plurality of first and second received signals and calculating the flow velocity of the river by calculation, wherein each of the signal transmitting and receiving means receives the first command signal and performs a first transmission A first transceiver that transmits a signal, receives a first received signal, and outputs the first received signal; and a first transceiver that is disposed near one end of the divided area, Is converted into a first ultrasonic signal and transmitted.
A first transducer that receives the second ultrasonic signal with a delay of a propagation time t2, converts the received signal into the first received signal, and outputs the first received signal; A second transmitter / receiver that transmits a transmission signal, receives a second reception signal, and outputs the second reception signal, and is separated by a distance d from the first transmission / reception device in a river channel direction of the river. The second transmission signal is converted into a third ultrasonic signal and transmitted, and the fourth ultrasonic signal is received with a delay of a propagation time t4. A second transducer for converting and outputting, the second transducer being disposed near the other end of the divided area and at a distance r from the first and second transducers and having a propagation time t1. The first ultrasonic signal is received, converted to a third received signal and output, and the third ultrasonic signal is received with a propagation time t3 delay. A fourth received signal is converted and output, a third transmitted signal is converted to the fourth ultrasonic signal and transmitted, and a fourth transmitted signal is converted to the second ultrasonic signal. A third transmitter / receiver that transmits and transmits the third received signal, transmits the third transmitted signal, receives the fourth received signal, and transmits the fourth transmitted signal. A third transmitter / receiver for transmitting a signal, wherein the calculating means detects the propagation times t1, t2, t3, and t4, and obtains a flow velocity Vp for each of the divided areas using the following equation, A river flow velocity measuring device, wherein an average value of the respective flow velocities Vp is obtained to calculate the flow velocity Vav of the river. ^{Vp = (r 2 / d)} (ΔTa n + Ta n + 1) / Ta n 2 _{where, ΔTa n = Tb n -Ta n} , ΔTa n + 1 = Ta n -Ta
_{n + 1} Ta = t1 + t4 Tb = t2 + t3 C: Sound velocity when the river is stationary n: Number of measurements 2. A river flow velocity measuring apparatus for measuring a flow velocity of a river having a sound velocity distribution characteristic in which a sound velocity varies depending on a water depth, wherein the first and second river widths are divided within a range where an ultrasonic signal directly propagates. 2 provided for each divided area
2. The signal transmission / reception means according to claim 1, wherein the signal transmission / reception means is provided at an intermediate position between the first transducer and the second transducer in the first division area, and the first transmission means in the second division area The third ultrasonic signal is received and converted to a third received signal and output. The third ultrasonic signal is received and converted to a fourth received signal and output. A fourth transducer that converts a transmission signal into the fourth ultrasonic signal and transmits the same, and converts a fourth transmission signal into the second ultrasonic signal and transmits the fourth ultrasonic signal; A switching means for selectively connecting the third transceiver to the third transceiver in the second divided region or the third transceiver in the second divided region.