JPH06132907A - Method and device for transmitting intra-duct signal - Google Patents

Abstract

PURPOSE:To provide an intra-duct signal transmission method/device which transmits the signals by using the water flowing in a duct as a transmitting medium and improves the transmitting/receiving precision and reliability regardless of quality of the fluids like the muddy water, etc., flowing in the duct and of the flowing states of those fluids. CONSTITUTION:A fluid 8 supplied always into a duct 7 is used as a transmitting medium and also the ultrasonic waves within a frequency range of several tens through several hundreds of kHz are used. Then the signal transmission data are defined against 2n pieces of digital signals (n>=1) and for each sine pulse of plural wavelengths. These signal transmission data are repetitively transmitted by N times.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used in civil engineering construction work, construction and maintenance of piping, etc., when the water supply and distribution pipes attached to the soil are being maintained, or the water supply and distribution pipes. When excavating while attaching, information such as position, direction and measurement data signal obtained through a sensor etc. at one end of the water supply and distribution pipe, without using a cable for signal transmission,
The present invention relates to a pipe signal transmission method and device for transmitting a signal by ultrasonic waves using a fluid such as water supply and distribution flowing in a pipe as a medium.

[0002]

2. Description of the Related Art Conventionally, as a technique for transmitting a signal in a water distribution pipe of this type of technique, a technique using electromagnetic waves, light, sound waves or the like as a transmission medium is used as a method other than a cable laying cable. It has been.

[0003]

However, when the fluid such as water is filled or flowing in the pipeline, the electromagnetic waves are generated in the following states due to attenuation, scattering, refraction, etc. by the fluid in the pipeline. It was difficult to propagate light and sound waves over long distances.

First, when electromagnetic waves are used, the permittivity of water is about 81, and it is difficult to propagate a distance of several tens of meters or more considering the attenuation characteristics of electromagnetic waves in water. When light is used, it can be sufficiently propagated when transparent water is distributed in the pipe, but in muddy fluid such as muddy water, signal is propagated because of large reflection and scattering. It is difficult.

In the case of using sound waves, if a wavelength larger than the inner diameter of the pipe is used, it becomes difficult to propagate in the longitudinal direction of the pipe, and even if a wavelength smaller than the inner diameter of the pipe is used, the muddy water flowing in the pipe is Since the transmission of sound waves is significantly attenuated by the generated bubbles, mud particles, vortices, etc., the frequency used for transmission, the transmission method, the choice of transmission / reception functions, and devising are required considerably. Is.

In view of the above-mentioned problems of the prior art, the present invention propagates a signal by using the transmission and distribution water in the pipeline as a transmission medium, and affects the water quality and running state of fluid such as muddy water flowing in the pipeline. Therefore, it is an object of the present invention to provide a method and apparatus for transmitting a signal in a pipeline, which has high transmission / reception accuracy and reliability.

[0007]

The above-mentioned problems can be solved by the present invention by adopting the novel characteristic construction methods and means listed below. That is, the first feature of the method of the present invention is to use an ultrasonic wave defined in a frequency range of several tens of kHz to several hundreds of kHz as a transmission medium, using a fluid constantly supplied in the pipeline, and A tube in which sinusoidal pulses for a plurality of wavelengths are set as one unit, the presence or absence thereof is determined as signal transmission data corresponding to 2n (n ≧ 1) digital signals, and the signal transmission data is repeatedly transmitted n times. This is an in-road signal transmission method.

A second feature of the method of the present invention is that immediately before the data transmission in the first feature of the method, a pilot signal is transmitted from the data signal receiving side in advance, and the pilot signal of the pilot signal is transmitted at the data signal transmitting side. This is a signal transmission method in a pipeline, which starts data transmission after confirming reception.

The first feature of the device of the present invention is that an ultrasonic transducer that oscillates a transmission signal and an A / D that digitizes a data signal are provided in a pipeline in which fluid is constantly supplied to the pipeline.
A D conversion section, a transmission circuit section that modulates a carrier frequency with the digital data signal converted by the A / D conversion section and sends the modulated carrier frequency, and an ultrasonic transducer that amplifies the signal output from the transmission circuit section. A transmitter installed at or at the end of the pipeline, an ultrasonic oscillator, and a pre-amplifier that pre-amplifies a transmission data signal received by the ultrasonic oscillator. A receiver provided with an amplifier at an open end to which the fluid of the pipeline is supplied, and a filtering means for filtering a reception data signal by an ultrasonic wave from the receiver according to a property in the pipeline. An amplifier that amplifies the filtered reception data signal output from the filtering means, a signal processing unit that binarizes the amplified filtered reception data signal from the amplifier, and further performs addition and averaging processing of the binarized data signal N times. And a signal processor having A conduit signal transmission device including a.

A second feature of the device of the present invention is that, in the receiver and the transmitter of the first feature of the device, the power supply for the transmitter for operating the transmitter is turned on / off by an ultrasonic signal. , A pilot signal generating circuit for transmitting a pilot signal by propagating ultrasonic waves to a fluid in a pipeline to the receiver, and a pilot signal receiving circuit for receiving the pilot signal and turning on / off the power It is a signal transmission device in a pipeline provided in each of the vessels.

[0011]

In the present invention, since the above-mentioned method and means are taken, the position, the direction, the inclination, and the depth of ultrasonic waves are utilized by using the fluid in the water pipes laid in the soil. Since information signals and the like are transmitted, information can be easily transmitted.
In addition, information can be efficiently transmitted through pipes where cables cannot be laid.

[0012]

EXAMPLE (Method Example) An example of the present invention will be described. First, the outline of the apparatus configuration used in the method of the present invention will be described with reference to the drawings. FIG. 1 is a schematic explanatory diagram of a device configuration when performing signal transmission by applying this embodiment. A is an in-pipe signal transmission device, 1 is a transmitter, 2 is a receiver, 3 is a signal processor, 4 is a display / storage unit, 5 is a power supply for the transmitter 1, 6 is a receiver 2 and a signal processor 3. A power source for use, 7 is a water transmission and distribution pipeline (hereinafter, simply referred to as a pipeline), and 8 is a transmission medium (hereinafter, simply referred to as a medium) such as muddy water flowing in the pipeline 7.

Next, the characteristics of ultrasonic waves used in this method example will be described. First, the frequency range to be used is set to a range of several tens kHz to several hundreds kHz. The transmission method of ultrasonic waves is a sinusoidal pulse of 100 to 1,000 wavelengths per pulse, and 2n time-sequential pulses of this pulse are transmitted / received as an ultrasonic signal pulse of one data with a repetition number N.

From the transmitted ultrasonic signal pulse, only the data signal within the above frequency range is filtered and extracted at the receiving side, the signal pulse is reproduced again by digitization, and the reproduced N times repeated signal group. Is added and averaged to improve the reception accuracy and reliability of the transmission data signal.

The execution procedure of this method example will be described below. First,
A pilot signal is transmitted from the receiver 2 side. The pilot signal is converted into an ultrasonic signal, and the medium 8 in the conduit 7 is converted.
Through the transmitter 1 side. As a result, the power supply 5 of the transmitter 1 is turned on, and the data transmission signal is transmitted from the transmitter 1 side. The data transmission signal is transmitted to the receiver 2 side through the medium 8 in the conduit 7.

Next, the signal transmission of this method example will be described in detail with reference to the drawings. FIG. 2 is a time chart showing the relationship between the transmission transmission data signal T on the transmitter 1 side and the reception transmission data signal R on the receiver 2 side. In the figure, T1 is a transmission talk start signal on the transmitter 1 side, Δt is a time unit of 1 bit of signal, T
n is a transmission transmission data signal in which 2n sine wave pulses of 100 to 1,000 wavelengths per pulse are combined as a digital signal at 1-bit intervals, and R1 is a receiver 2
Side reception talk start signal, Rn is a reception transmission data signal received by the receiver 2 side.

The delay δ between the transmission talk start signal T1 and the reception talk start signal R1 is given by δ = L / v by the propagation sound velocity v of the medium 8. In the case of this method example, since the minimum signal unit is 2 × Δt, 2 ⁿ types of signals can be transmitted. In order to ensure accuracy and reliability, these T
Data from 1 to Tn is repeatedly transmitted and received N times. Also,
On the receiver 2 side, in synchronization with the reception talk start signal R1,
The reliability of the data signal Rn is improved by performing the averaging process.

(Example of Apparatus) Next, an example of an apparatus used in the method of the present invention will be described in detail with reference to the drawings. 3 is a block diagram showing a configuration example of the transmitter 1, FIG. 4 is a block diagram showing a configuration example of the receiver 2, and FIG. 5 is a block diagram showing a configuration example of the signal processor 3. In addition, in FIGS. 3 to 5, the power supply line to each circuit unit is omitted.

In the figure, 9 is a transmission microphone which is an ultrasonic transducer, 10 is an A / D converter for converting an information signal obtained from the terminal X into a digital signal, and 11 is an A / D converter 10.
Reference numeral 12 denotes a transmission signal amplification circuit portion for mounting a digital signal from the transmission frequency signal on the carrier frequency, and reference numeral 12 denotes a transmission signal amplification circuit portion for amplifying the signal from the transmission circuit portion 11 and transmitting it to the transmission microphone 9 as the transmission data signal T.

Reference numeral 13 denotes a pilot signal receiving circuit section for receiving the pilot signal S transmitted from the receiver 2 side through the transmission microphone 9, and 14 always supplies electric power P to the pilot signal receiving circuit section 13 and pilot signal S. After receiving, the power supply 5 is automatically operated to operate the A / D converter 1
0, the power P to the transmission circuit unit 11 and the transmission signal amplification circuit unit 12
Is a supplementary power source for starting the supply of the signal, and 15 is a horn for increasing the directivity of transmission and reception of the transmission microphone 9 in the axial direction of the conduit 7.

Reference numeral 16 denotes a reception microphone which is an ultrasonic transducer, and 17 denotes a transmission data signal T from the transmitter 1 through the reception microphone 16, which is amplified as it is and an amplified reception data signal Ra as a signal processing unit 3 through a terminal Ya. A preamplifier for sending to 18 and a power source 6 through a terminal Yb.
It is a pilot signal transmission circuit unit that is supplied with electric power P from and transmits a pilot signal S at the start of transmission.

Reference numeral 19 is a band pass filter (hereinafter referred to as BPF) for filtering the amplified reception data signal Ra received from the preamplifier 17 through the terminal Ya, and 20 is BP.
A signal amplifier which amplifies the filtered reception data signal Rb filtered by F19, 21 operates and processes the amplified filtered data signal Rc from the signal amplifier 20 and sends it as a reception data signal R to a terminal Yc to the display / storage unit 4. It is a signal processing unit. The power supply 6 supplies power to the preamplifier 17, the pilot signal transmission circuit unit 18, the BPF 19, the signal amplifier 20, and the signal processing unit 21, and after the power supply 6 is turned on,
The pilot signal transmission circuit section 18 automatically transmits the pilot signal S.

(Example of Operation) The example of the present apparatus exhibits the specific embodiment as described above. Next, the operation will be described with reference to the drawings. FIG. 6 is a flow chart for explaining the operation flow on the transmitter 1 side, and FIG. 7 is a flow chart for explaining the operation flow on the receiver 2 and signal processor 3 side.

Regarding the operation on the transmitter 1 side, first, the receiver 2
The pilot signal S from is received by the pilot signal receiving circuit unit 13 via the transmitting microphone 9 (step I in FIG. 6). Thereafter, the power supply 5 is turned on (step II in FIG. 6), the power is supplied to each part, the transmission data signal T is transmitted (step III in FIG. 6), and this is repeated N times (step IV in FIG. 6). . Pilot signal S in this case
Uses an ultrasonic pulse of the frequency described in the above method example.

In the operation of the receiver 2 and the signal processor 3, first, the power supply 6 is turned on (step I in FIG. 7).
Then, the pilot signal transmission circuit unit 18 of the receiver 2
The pilot signal S is automatically transmitted to the transmitter 1 through the receiving microphone 16 (step I in FIG. 7).
I).

Then, the operation on the transmitter 1 side is performed and the transmission data signal T is transmitted through the medium 8. Therefore, the transmission data signal T is received by the receiving microphone 16
The transmission data signal T is received through (step of FIG. 7).
III).

Next, the data signal T received through the microphone 16 is amplified by the preamplifier 17 and input to the BPF 19, and the BPF 19 lowers the amplified reception data signal Ra to the lower limit frequency (hereinafter referred to as fL) and It filters in the range of the upper limit frequency (hereinafter referred to as fH) (Fig. 7).
Step IV). Next, the filtered filtered reception data signal Rb is amplified by the signal amplifier 20 (step V in FIG. 7) and input to the signal processing unit 21.

The signal processing unit 21 first outputs the amplified filtered data signal Rc output from the signal amplifier 20 to a pulse data signal group with a constant voltage value as a threshold value based on the amplitude envelope of the filtered signal waveform. The value is converted (step VI in FIG. 7).

Then, it is judged whether or not the series of operations described above is repeated N times (step VII in FIG. 7), and N
If repeated, the received and processed binarized data signal is added and averaged (step VIII in FIG. 7).

The data signal R processed by the signal processor 3 as described above is input to the display / storage device 4 through the terminal Yc and displayed so that it can be detected by a human or stored in a magnetic storage medium. To do.

(Measurement Example) Next, the result of transmission of ultrasonic signals when mud is flowed through a steel pipe having a pipe diameter of 80 mmφ and a length of 17.8 m will be described. For ultrasonic wave transmission, the voltage applied to the microphone is a sinusoidal pulse wave with a maximum amplitude of 160.
With Vp-p, the number of pulses Np = 1000 and the water temperature is 32
℃ was made.

FIG. 8 is a graph showing the relationship between the frequency of the ultrasonic wave used for transmission and the gain of the signal amplitude. The signal amplitude gain is based on the reception gain when the transmission / reception microphones 9 and 16 are opposed to each other at a distance of 1 m. The flow rate V of the muddy water flowing in the pipe 7 is 0 to 140 (liter / min.).
I changed it.

From FIG. 8, as the flow rate V increases, f
It can be seen that the signal reception gain is attenuated from about 20 dB to about 60 dB in the range of 100 kHz to 300 kHz. However, at f = 400 kHz, the attenuation of the reception gain is 10 dB or less. Therefore, in this case, BPF19
FL = 300 kHz, fH = 50
When the frequency is set to 0 kHz, the signal gain can be significantly increased.

FIG. 9 shows the flow rate V = 100 (liter / mi).
n. ) Is a graph showing the relationship between the frequency of ultrasonic waves and the gain of signal amplitude due to the difference in the concentration of muddy water. The concentration of muddy water is D1 = 0.4 (vol.%), D2 = 0.8 (vo
l. %). As shown in FIG. 9, the gain of the signal is 100 kHz to 200 kHz when the concentration of the muddy water is doubled.
In the frequency range of about 20 dB. But 200
Above kHz, it is suppressed to fall within 10 dB. Therefore, also in this case, the pass frequency range of the BPF 19 is fL.
= 350 kHz and fH = 450 kHz, it is possible to obtain a large signal gain.

[0035]

As described above, according to the present invention, the pipe laid in the soil or the pipe constructed while excavating the soil is used at both ends of the pipe or in the middle thereof. It becomes possible to transmit a signal of information such as position, direction, inclination, and depth obtained from a sensor or the like at a place to the other end without using a cable.

The liquid flows not only in the soil but also inside,
When signals and information are transmitted at both ends or between two points on the way through a pipe in which a cable cannot be installed, efficient signal transmission can be realized.

Further, in such a technique, the frequency and propagation mode of the ultrasonic wave are appropriately selected depending on the conditions such as the pipe diameter and the water flow, or the apparatus is enlarged or the transmission output is increased according to these conditions. Thus, in oil plants, pipelines, gutters and rivers, it is possible to realize signal transmission over a long distance using a fluid (water, petroleum, etc.) flowing inside as a medium, and exhibits excellent usefulness.

[Brief description of drawings]

FIG. 1 is a schematic explanatory diagram of a device configuration when signal transmission is performed by applying a method example of the present invention.

FIG. 2 is a time chart showing the relationship between the transmission transmission data signal on the transmitter side and the reception transmission data signal on the receiver side.

FIG. 3 is a block diagram showing a configuration example of a transmitter of the device of the present invention.
It is a diagram.

FIG. 4 is a block diagram showing an example of the configuration of the receiver.

FIG. 5 is a block diagram showing an example of the configuration of the signal processor.

FIG. 6 is a flow chart for explaining the flow of operation on the transmitter side in the above.

FIG. 7 is a flow chart explaining the flow of operations on the side of the receiver and the side of the signal processor.

FIG. 8 is a graph showing an experiment of an example of the present invention and is a graph showing a relationship between a frequency of an ultrasonic wave used for transmission and a gain of a signal amplitude.

FIG. 9 is a graph showing the relationship between the frequency of ultrasonic waves and the gain of signal amplitude depending on the difference in the concentration of muddy water.

[Explanation of symbols]

 A ... In-pipe signal transmission device 1 ... Transmitter 2 ... Receiver 3 ... Signal processor 4 ... Display / storage unit 5 ... Transmitter power supply 6 ... Receiver and signal processor power supply 7 ... Water distribution pipe 8 ... Fluid 9 ... Transmission microphone 10 ... A / D conversion unit 11 ... Transmission circuit unit 12 ... Transmission signal amplification circuit unit 13 ... Pilot signal reception circuit unit 14 ... Auxiliary power supply 15 ... Horn 16 ... Reception microphone 17 ... Pre-stage amplifier 18 ... Pilot Signal transmission circuit unit 19 ... Band pass filter 20 ... Signal amplifier 21 ... Signal processing unit S ... Pilot signal T ... Transmission data signal

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[Procedure amendment]

[Submission date] December 1, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 1

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

[0007]

The above-mentioned problems can be solved by the present invention by adopting the novel characteristic construction methods and means listed below. That is, the first feature of the method of the present invention is to use an ultrasonic wave defined in a frequency range of several tens of kHz to several hundreds of kHz as a transmission medium, using a fluid constantly supplied in the pipeline, and A tube in which sinusoidal pulses for a plurality of wavelengths are set as one unit, the presence or absence thereof is determined as signal transmission data corresponding to 2n (n ≧ 1) digital signals, and the signal transmission data is repeatedly transmitted N times. This is an in-road signal transmission method.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Hiroki Kuwano 1-1-6 Uchisaiwaicho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation

Claims (4)

[Claims] 1. An ultrasonic wave set in a frequency range of several tens of kHz to several hundreds of kHz is used as a transmission medium, which is a fluid constantly supplied in a pipe, and sinusoidal pulses of a plurality of wavelengths per pulse are used. 1 unit,
An in-pipe signal transmission method, characterized in that the presence or absence thereof is determined as signal transmission data corresponding to 2n (n ≧ 1) digital signals, and the signal transmission data is repeatedly transmitted n times. 2. The data transmission is characterized in that a pilot signal is transmitted from the data signal receiving side in advance immediately before the data transmission, and the data transmission is started after the reception of the pilot signal is confirmed on the data signal transmitting side. The method for transmitting an in-pipe signal according to claim 1, wherein 3. An ultrasonic transducer that oscillates a transmission signal, an A / D conversion unit that digitizes a data signal, and an A / D conversion unit in a pipe in which a fluid is constantly supplied to the pipe. A transmission circuit section that modulates the carrier frequency with the digital data signal converted in step 1 and sends it out; and an amplification circuit section that amplifies the modulated data signal output from the transmission circuit section and outputs it to the ultrasonic transducer. , A transmitter installed at the end of the pipeline or in the middle of the pipeline, an ultrasonic transducer, and a preamplifier that amplifies a transmission data signal received by the ultrasonic transducer in advance, A receiver installed at an open end to which a fluid is supplied, a filtering means for filtering a reception data signal by an ultrasonic wave from the receiver according to a property in the conduit, and a filtering output from the filtering means. Amplifies the received data signal And a signal processor that binarizes the amplified and filtered received data signal from the amplifier and that further performs a averaging process on the binarized data signal N times. Characteristic signal transmission device in pipeline. 4. In the receiver and the transmitter, the power source for the transmitter for operating the transmitter is turned on / off by the ultrasonic pilot signal, so that the ultrasonic wave is propagated to the fluid in the pipeline and the pilot signal is transmitted. 4. The pipeline according to claim 3, wherein the receiver is provided with a pilot signal generating circuit for transmitting the pilot signal, and the transmitter is provided with a pilot signal receiving circuit for receiving the pilot signal and turning on / off the power. Signal transmission equipment.