JP3012522B2 - River monitoring system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a river monitoring system, and more particularly to a river monitoring system for remotely monitoring changes in water depth and flow velocity of a river.

[0002]

2. Description of the Related Art A conventional river monitoring system is designed to reduce the water depth when a river bottom is dug down due to a rapid current when a river rises due to a typhoon or the like, and when a bridge or a dike over the river is subjected to a large water pressure and is in danger of collapse. It is provided to automatically and continuously monitor a change in the water depth of a river so that a change in the water level can be known from the change in the water level and an alarm can be issued as soon as possible.

[0003] This conventional river monitoring system is disclosed in
As disclosed in Japanese Patent Application Laid-Open No. 1-216909, water depth is measured using ultrasonic waves and radio waves. FIG. 5 is an explanatory diagram showing the configuration of this conventional river monitoring system.

In FIG. 5, a sounding part 73 is fixed below a pier 71 of a bridge 70 or a river surface 83 of a base 72 of the bridge.
Fixed to. Since the downstream of the base 72 is dug by the water flow and is dangerous, it is necessary to monitor. Therefore, the sounding part 73 is installed in the water downstream of the base 72, and the change in the depth of the river bottom 84 with the sounding part 73 as the reference plane. Is monitored by measuring the time and intensity of the echo 85 of the radio wave emitted from the sounding section 73.
Further, in order to monitor the change in the water level on the river surface, the state of the change in the water level on the river surface 83 with the sounding
The time and the intensity of the echo 86 of the ultrasonic wave emitted from are measured and monitored. On the bridge there is a sounding part 73 and a cable 82
Is installed. The control unit 75 controls the operation of the sounding unit 73, and the data transmitting unit 76 controls the sounding unit 7.
The echo signal obtained in the operation 3 is converted into a modulated signal, the transmission frequency is further modulated with the modulated signal, and transmitted to the monitoring station as a transmission radio wave via the transmission antenna 77. The echo detection is repeatedly performed in a time division manner using the ultrasonic waves and the radio waves.
The echo detection time is set to three minutes.

[0005]

The above-mentioned conventional river monitoring system merely measures the water level and the water depth and remotely monitors the water level, and determines when the bridge is in a dangerous state based on the change in the water level and the water depth. However, actually, not only the water level and water depth but also the flow velocity are involved as factors that cause the bridge to collapse, and it is not sufficient to predict the dangerous state of the bridge due to changes in water level and water depth. Had.

An object of the present invention is to provide a river monitoring system capable of measuring not only the water level and depth but also the flow velocity.

[0007]

A river monitoring system according to the present invention comprises a river monitoring system provided with measuring means for measuring a water level under a bridge and a depth of a river bottom under the bridge using radio waves and ultrasonic waves. (A) the first radio wave attached to the bridge and transmitting water under the bridge;
First radio wave emitting means for emitting toward a surface, (B) the first radio wave reflected from the water surface and returned
(C) the first radio wave emitting means emits the first radio wave from the first radio wave receiving means.
The time of the shot and the first power reflected from the water surface.
The time when the reflected wave of the wave is received by the first radio wave receiving means;
First time difference detection for detecting a first time difference which is a time difference of
Detecting means, a first calculating the water level from the first time difference (D)
Calculation means, (E) ultrasonic waves attached to the bridge are applied to the water surface under the bridge
(F) the ultrasonic waves emitted toward the surface of the water reach the bottom of the river, and
Receive the reflected wave of the ultrasonic wave reflected back from the bottom
Ultrasonic receiving means that, the ultrasonic waves emitted from (G) the ultrasound firing unit
Time and the reflected wave of the ultrasonic wave reflected from the water surface
A second time difference from the time received by the ultrasonic receiving means.
Second time difference detecting means for detecting a time difference between 2 to calculate the depth of the river bottom from the second time difference (H)
Second computing means, (I) a second radio wave attached to the bridge and transmitted to the upstream water surface
Second radio wave emitting means, (J) a reflected wave of said second radio wave reflected from the water surface to fire toward
Second radio wave receiving means for receiving, (K) and the frequency of the second radio wave, is reflected from the surface of the water
The difference from the frequency of the reflected wave of the second radio wave
Frequency difference detecting means for detecting a certain frequency difference, (L) the frequency difference and the second radio wave reach the water surface
The flow velocity at the water surface from the value of the incident angle when
Third arithmetic means, (M) the water level values, the depth values of the riverbed, and the
The value the value of the flow rate has been determined, respectively it in advance at the water surface
Control means for issuing an alarm when it exceeds the limit .

[0008]

[0009]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a river monitoring system according to the present invention. FIG. 2 is a block diagram showing a configuration of the measuring device 3 shown in FIG. FIG. 3 is a block diagram showing a configuration of the control device 2 shown in FIG. Also,
FIG. 4 is a block diagram of the data receiving device 40 connected to the control device 2 shown in FIG.

The river monitoring system of the present embodiment shown in FIG. 1 is installed on a bridge girder or a railing of a bridge, emits a radio wave to a river surface immediately below, receives a reflected wave reflected from the river surface and returns,
Detects the delay of the received reflected wave and measures the delay time, and also measures the delay time by detecting the delay of the reflected wave returning from the bottom of the river by emitting an ultrasonic wave to the river surface directly below, A measuring device 3 that emits radio waves toward the upstream river surface, detects a shift due to the Doppler effect of the frequency of the reflected wave that is reflected back from the river surface, measures the frequency of the shift, and outputs respective data; The respective measuring operations of the measuring device 3 are controlled, and the data output from the measuring device 3 are processed to calculate the distance from the bridge to the river surface, ie, the water level and the distance from the bridge to the river bottom, ie, the water depth and the flow velocity at the river surface. The control device 2 issues an alarm when those values approach an abnormal value, and the data receiving device 40 wirelessly receives data from the control device 2 and displays the data on a monitor display panel.

The measuring device 3 shown in FIG. 2 transmits a radio wave transmitter 28 for outputting a high-frequency signal, a high-frequency signal from the radio wave transmitter 28 to the river surface as a radio wave 14, and transmits a radio wave (reflected wave) 15. A transmitting / receiving antenna 34 for receiving and transmitting / receiving a radio wave (reflected wave) 17 from a radio transmitter 28 as a radio wave 16 toward the river surface.
5, a radio receiver 29 that receives a radio wave (reflected wave) 15 and a radio wave (reflected wave) 17 via a transmitting / receiving antenna 34 and a transmitting / receiving antenna 35 and outputs a high-frequency signal, an output of a radio transmitter 28, and a radio receiver 29, the delay time of the radio wave (reflected wave) 15 is detected, and the radio wave (reflected wave) 1 is detected.
7, a radio wave delay time / frequency deviation detector 37 for detecting a frequency deviation, and an ultrasonic transmitter 26 for outputting an ultrasonic signal.
And an ultrasonic transmitting / receiving antenna 36 which transmits an ultrasonic signal from the ultrasonic transmitter 26 as an ultrasonic wave 18 toward the river surface and receives an ultrasonic wave (reflected wave) 19, and an ultrasonic transmitting / receiving antenna 3
An ultrasonic wave (reflected wave) 19 receives an ultrasonic wave (reflected wave) 19 and outputs an ultrasonic signal, and outputs an ultrasonic wave (reflected wave) from the output of the ultrasonic transmitter 26 and the output of the ultrasonic receiver 27. ) 1
And an ultrasonic delay time detector 38 for detecting the delay time of N.9.

The control device 2 shown in FIG. 3 controls each measuring operation of the measuring device 3 via a control / power supply cable 5, and issues an alarm when those values approach abnormal values. A control unit 21 for displaying a warning on the warning display plate 7,
An arithmetic processing unit 22 that processes data output by the measuring device 3 to calculate a water level, a water depth, and a flow velocity at a river surface; a synchronization processing unit 23 that controls timing of each measuring operation of the measuring device 3; A transmitter 24 wirelessly transmits the measured water level, water depth, and flow velocity data to a remote data receiving device 40 via the antenna 11.

A data receiving device 40 shown in FIG. 4 receives, via an antenna 43, water level, water depth and flow velocity data wirelessly transmitted from the control device 2, and processes the received data. And a data processing unit 42 for displaying the data on the monitor display panel 45.

Next, the operation will be described.

First, the operation of measuring the distance from the measuring device 3 to the river surface 9 using radio waves will be described.

The synchronization processing unit 23 of the control device 2 shown in FIG.
Sends a measurement start instruction signal instructing to start measurement at a set time to the control unit 21 and the arithmetic processing unit 22. The control unit 21 sends a measurement start signal to the radio wave transmitter 28 of the measuring device 3 shown in FIG. 2 via the control and power supply cable 5 at the instructed time. Upon receiving the measurement start signal, the radio wave transmitter 28 of the measuring device 3 generates a high-frequency pulse signal, sends it to the radio wave delay time / frequency shift detector 37, and directs it to the river surface 9 as the radio wave 14 via the transmission / reception antenna 34. Fire into space. The radio wave 14 emitted toward the river surface is a radio wave (reflected wave) 15 reflected on the river surface 9.
Is received by the radio wave receiver 29 via the transmission / reception antenna 34 of the measuring device 3, and the radio wave receiver 29 outputs a high-frequency pulse signal. This high-frequency pulse signal is used as an echo signal for the high-frequency pulse signal transmitted from the radio transmitter 28 to the radio delay time / frequency deviation detector 37 when the measurement is started.
7 is sent. Radio wave delay time / frequency shift detector 37
From the timing of receiving the high-frequency pulse signal output from the radio wave transmitter 28 and the frequency of the high-frequency pulse signal output from the radio wave receiver 29 when the measurement is started, from the time when the radio wave is emitted to the time when the reflected wave is received A delay time obtained as a time difference is detected, and the data of the delay time is returned to the control unit 21 via the control / power supply cable 5, and further transmitted from the control unit 21 to the arithmetic processing unit 22. The arithmetic processing unit 22 determines the measurement device 3 and the river surface 9 from the delay time data transmitted from the radio wave delay time / frequency shift detector 37.
Is calculated.

Next, the operation of measuring the distance from the measuring device 3 to the river surface 9 using ultrasonic waves will be described.

In the case of ultrasonic waves, the same operation as in the case of radio waves is performed. First, the synchronization processing unit 23 of the control device 2 sends a measurement start instruction signal for instructing to start the measurement at a set time to the control unit 21 and the arithmetic processing unit 22. The control unit 21 sends a measurement start signal to the ultrasonic transmitter 26 of the measuring device 3 shown in FIG. 2 via the control / power supply cable 5 at the instructed time. Upon receiving the measurement start signal, the ultrasonic transmitter 26 of the measuring device 3 generates an ultrasonic pulse signal and sends it to the ultrasonic delay time detector 38,
The ultrasonic waves 18 are emitted as ultrasonic waves 18 toward the river surface 9 via an ultrasonic transmitting / receiving antenna 36. A part of the ultrasonic wave reaching the river surface 9 is reflected by the river surface 9 and returns to the measuring device 3 as an ultrasonic wave (reflected wave: not shown), and the remaining ultrasonic waves are further transmitted as ultrasonic waves 18 in the water 10 And returns to the measuring device 3 as ultrasonic waves (reflected waves) 19 reflected on the riverbed 10. The ultrasonic wave reflected on the river surface 9 and the ultrasonic wave (reflected wave) 19 reflected on the river bottom 10 are received by the measuring device 3 via the ultrasonic transmitting / receiving antenna 36 to the ultrasonic receiver 27, and from the ultrasonic receiver 27. An ultrasonic pulse signal is output. This ultrasonic pulse signal is transmitted to the ultrasonic delay time detector 38 as an echo signal for the ultrasonic pulse signal transmitted from the ultrasonic transmitter 26 to the ultrasonic delay time detector 38 when the measurement is started. . The ultrasonic delay time detector 38
The echo signal due to the reflected wave from the river surface 9 is distinguished from the echo signal due to the ultrasonic wave (reflected wave) 19 from the river bottom 10, and the time difference from the point at which the ultrasonic wave is emitted to the point at which the reflected wave from the river bottom 10 is received. Is detected and returned to the control unit 21 via the control / power supply cable 5.
The delay time returned to the control unit 21 is further processed by the arithmetic processing unit 2
2 is sent. The arithmetic processing unit 22 calculates the distance between the measuring device 3 and the riverbed 10 from the delay time data transmitted from the ultrasonic delay time detector 38. The above-mentioned ultrasonic wave is measured by emitting a pulse wave using a frequency of about 20 kHz that can be used in both the medium in space and in water. In addition, since the bridge and the river surface are close to each other, it is desirable that the pulse wave be set to an extremely small value in consideration of the short distance.

Next, the operation of measuring the flow velocity of a river using radio waves will be described.

In this case as well, a measurement start instruction signal for starting the measurement is sent from the synchronization processing unit 23 of the control device 2 to the control unit 21 and the arithmetic processing unit 22, and the control unit 21 transmits the measurement start signal via the cable 5 at the instructed time. To start the measurement by controlling the radio transmitter 28 of the measuring device 3. The radio wave transmitter 28 controlled by the control unit 21 outputs a continuous wave high frequency signal. This high-frequency signal is transmitted to a radio wave delay time / frequency shift detector 37 and is transmitted through a transmitting / receiving antenna 35 to the radio wave 16.
It is launched into the space toward the river surface 9 slightly upstream. Among the radio waves reflected on the river surface 9, a radio wave (reflected wave) 17 reflected so as to travel in the same route as the emission wave in the reverse direction is received by the radio wave receiver 29 via the transmission / reception antenna 35,
From the radio wave receiver 29, a high frequency signal is transmitted to a radio wave delay time / frequency shift detector 37. The radio wave delay time / frequency shift detector 37 compares the frequency of the high-frequency signal output from the radio transmitter 28 with the frequency of the high-frequency signal output from the radio receiver 29, and detects the radio wave ( A frequency shift due to the Doppler effect of the reflected wave (17), that is, a frequency difference between a transmitted high-frequency signal and a high-frequency signal generated from the reflected wave is detected. Data of the detected frequency difference is sent to the control unit 21 via the cable 5,
The data is further transmitted from the control unit 21 to the arithmetic processing unit 22. In the arithmetic processing unit 22, the data of the frequency difference between the transmitted high-frequency signal and the high-frequency signal generated from the reflected wave, and the incident angle 20 when the radio wave emitted from the transmitting / receiving antenna 35 to the river surface 9 reaches the water surface From the value γ of the river surface 9
Is calculated. Here, fd in the following equation indicates a frequency difference between the high-frequency signal and the high-frequency signal generated from the reflected wave.

[0022] The above-described water level measurement and flow velocity measurement are sequentially measured at arbitrary measurement intervals, and the control unit 21 controls the synchronization processing unit 23 so as to repeat cyclically at predetermined time intervals. Further, the data indicating the water level, the water depth, and the flow velocity of the river are transmitted to the data receiving device 40 shown in FIG. 4 by the transmitter 24 of the control device 2. The transmitted data is received by the receiver 41 via the antenna 43 and the data processing unit 4
In step 2, data processing such as calculating the flow rate from the water level data and the flow velocity data received periodically is performed and recorded. The processed data is transmitted to the monitor display panel 45 via the cable 44 and displayed. In the arithmetic processing unit 23 of the control device 2, regarding the result obtained by the above measurement, each data or a part of the data is obtained from the viewpoint of flood control measures in consideration of the correlation between the water level, the water depth and the flow velocity. To determine whether or not a predetermined value has been reached,
When it is determined that the dangerous state has been reached, a message such as "no traffic" is displayed on the warning display panel 7 installed under the bridge via the control unit 21. If necessary, an audible alarm will sound.

The above-mentioned measurement is set to be performed at a predetermined time, but can be adjusted by the control device 2 so that the measurement interval is automatically set when the water level and the flow velocity change significantly or in the event of a disaster. It can be changed to increase the number of measurements.

The radio wave used has a frequency band of several tens of GHz. For the measurement of the water level, a pulse radar using a pulse wave is used, and for the measurement of the flow velocity, a CW (Continuous Wave) radar using a continuous wave is used.

According to the configuration described as the embodiment of the present invention, the measuring device for measuring the water depth and the flow velocity can be attached to a pier or a girder above the river surface, not below the water surface.
Installation work and maintenance work can be performed easily. Also,
Since the installation location of the measuring device is not underwater, the waterproofness of the device can be reduced and the manufacturing cost can be reduced.

[0026]

As described above, the river monitoring system of the present invention emits a radio wave to the upstream river surface, and detects that the frequency of the radio wave reflected and returned from the river surface is shifted by the Doppler effect, By providing a means to measure the flow velocity at the river surface from the frequency shift, it is possible to measure not only the water depth but also the flow velocity, which is necessary to more accurately predict when the bridge will approach a dangerous state This has the effect of obtaining accurate data.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing one embodiment of a river monitoring system of the present invention.

FIG. 2 is a block diagram showing a configuration of the measuring device 3 shown in FIG.

FIG. 3 is a block diagram showing a configuration of a control device 2 shown in FIG.

4 is a block diagram of a data receiving device 40 connected to the control device 2 shown in FIG.

FIG. 5 is a configuration diagram showing a configuration of a conventional river monitoring system.

[Explanation of symbols]

 2 control device 3 measuring device 5 cable 7 warning display board 8 pier 9 river surface 10 river bottom 11 transmission antenna 12 guard 14 radio wave 15 radio wave (reflected wave) 16 radio wave 17 radio wave (reflected wave) 18 ultrasonic wave 19 ultrasonic wave (reflected wave) 20 Incident angle 21 Control unit 22 Operation processing unit 23 Synchronization processing unit 24 Transmitter 26 Ultrasonic transmitter 27 Ultrasonic receiver 28 Radio transmitter 29 Radio receiver 34 Transmitting and receiving antenna 35 Transmitting and receiving antenna 36 Ultrasonic transmitting and receiving antenna 37 Radio wave delay time Frequency shift detector 38 Ultrasonic delay time detector

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01F 23/284 G01C 13/00 G01F 1/52 G01F 1/66 103 G01F 23/28

Claims (1)

(57) [Claims] 1. A river monitoring system comprising a measuring means for measuring a water level under a bridge and a depth of a riverbed under the bridge using radio waves and ultrasonic waves, wherein: (A) a first radio wave attached to the bridge; (B) first radio wave receiving means for receiving a reflected wave of the first radio wave reflected and returned from the water surface, (C) It is a time difference between the time when the first radio wave is emitted from the first radio wave emitting means and the time when the first radio wave receiving means receives the reflected wave of the first radio wave reflected from the water surface. First time difference detecting means for detecting a first time difference, (D) first calculating means for calculating the water level from the first time difference, (E) ultrasonic waves attached to the bridge and transmitting ultrasonic waves to a water surface under the bridge. (F) toward the water surface Ultrasonic receiving means for receiving a reflected wave of the ultrasonic wave that has been emitted and has returned from the river bottom after reaching the river bottom; (G) a time at which the ultrasonic wave was emitted from the ultrasonic emitting means; (H) second time difference detection means for detecting a second time difference which is a time difference between the time at which the ultrasonic wave reflected from the water surface is received by the ultrasonic wave reception means, and (H) the second time difference. Second arithmetic means for calculating the depth of the riverbed; (I) second radio wave emitting means attached to the bridge for emitting a second radio wave toward an upstream water surface; (J) reflected from the water surface (K) a second radio wave receiving means for receiving a reflected wave of the second radio wave, wherein (K) a frequency of the second radio wave and a frequency of a reflected wave of the second radio wave reflected and returned from the water surface. Frequency difference detecting means for detecting a frequency difference which is a difference, (L Third calculating means for calculating the flow velocity at the water surface from the frequency difference and the value of the angle of incidence when the second radio wave reaches the water surface; (M) the value of the water level, the depth of the riverbed And a control means for issuing an alarm when the value of the water flow rate and the value of the flow velocity at the water surface each exceed a predetermined value.