KR20210147727A - Distribution type Time Domain Reflectometry device and Underground facilities diagnostic visualization system using the same - Google Patents

Abstract

A TDR device that transmits a pulse signal to a TDR measurement line and receives a reflected pulse signal reflected through the TDR measurement line includes: a reference clock signal generation unit for generating a reference clock signal; a clock signal distribution unit for generating a pulse signal to be transmitted to the TDR measurement line using the reference clock signal; a sampling pulse signal generation unit for generating a sampling pulse signal having a higher frequency than the reference clock signal; and a reflected signal sampling unit for sampling the reflected pulse signal reflected through the TDR measurement line in response to the sampling pulse signal. The TDR device according to the present invention can secure operational reliability by sampling the reflected pulse signal in response to a differential signal corresponding to the sampling pulse signal.

Description

Distribution type Time Domain Reflectometry device and Underground facilities diagnostic visualization system using the same}

The present invention relates to a measuring device, and more particularly, to a distributed time domain reflectometry (TDR) measuring device and an underground facility diagnosis visualization system using the same.

1 is an exemplary diagram of a point-type TDR sensor.

In order to prevent embankment collapse due to infiltration or water leakage, it is most important to understand the unsaturated state and behavior of the embankment body. Even if the technique is applied, it is difficult to accurately analyze the actual embankment initial conditions, non-homogeneity, and problems with anisotropy.

Methods such as electrical resistivity survey, natural potential method, and GPR survey method have been suggested as physical probe methods for penetration behavior. pointed out as difficult.

In order to compensate for the shortcomings of such point type sensors, research on distributed time domain reflectometry (TDR) sensors is being actively conducted.

KR 10-2013-0137420 A

The present invention has been proposed to solve the above technical problem, and provides a distributed time domain reflectometry (TDR) measuring apparatus for sampling a reflected pulse signal in response to a differential signal corresponding to the sampling pulse signal.

In addition, it provides a diagnostic visualization system for underground facilities that can convert all underground facilities covered by a plurality of distributed time domain reflectometry (TDR) measurement devices into 3D graphics and transmit them to a user terminal along with diagnostic information.

According to an embodiment of the present invention for solving the above problem, in the TDR measurement device for transmitting a pulse signal to a TDR measurement line and receiving a reflected pulse signal reflected through the TDR measurement line, generating a reference clock signal A reference clock signal generating unit, a clock signal distribution unit generating a pulse signal for transmission to the TDR measurement line using the reference clock signal, and a sampling pulse signal generating unit generating a sampling pulse signal having a higher frequency than the reference clock signal and a distributed time domain reflectometry (TDR) measuring device including a reflected signal sampling unit for sampling a reflected pulse signal reflected through a TDR measurement line in response to the sampling pulse signal.

In addition, the reflected signal sampling unit included in the present invention is characterized in that it samples the reflected pulse signal in response to a differential signal corresponding to the sampling pulse signal.

In addition, the reflected signal sampling unit included in the present invention includes a sampling signal coupled matcher that receives a sampling pulse signal and outputs a first output signal and a second output signal in a differential form corresponding to the sampling pulse signal, and the first output signal and a sampler circuit for sampling the reflected pulse signal in response to the second output signal.

In addition, according to another embodiment of the present invention, a plurality of distributed time domain reflectometry (TDR) measuring devices for diagnosing each allocated underground facility, and all underground devices in charge of a plurality of distributed time domain reflectometry (TDR) measuring devices The facility is 3D graphic, but the location that needs inspection is calculated based on the measurement data transmitted from a plurality of distributed time domain reflectometry (TDR) measurement devices and the location information of the plurality of distributed time domain reflectometry (TDR) measurement devices An underground facility diagnosis visualization system including a management server and a user terminal that receives diagnostic information of an underground facility from the management server and maps and displays the map in a three-dimensional graphic form is provided.

In addition, a plurality of distributed time domain reflectometry (TDR) measurement devices included in the present invention transmit a pulse signal to a TDR measurement line and receive a reflected pulse signal reflected through the TDR measurement line, respectively, to obtain a reference clock signal. A reference clock signal generator for generating, a clock signal distributor for generating a pulse signal for transmission to the TDR measurement line using the reference clock signal, and a sampling pulse signal for generating a sampling pulse signal having a higher frequency than the reference clock signal It characterized in that it comprises a generator and a reflected signal sampling unit for sampling the reflected pulse signal reflected through the TDR measurement line in response to the sampling pulse signal.

In addition, the reflected signal sampling unit included in the present invention includes a sampling signal coupled matcher that receives a sampling pulse signal and outputs a first output signal and a second output signal in a differential form corresponding to the sampling pulse signal, and the first output signal and a sampler circuit for sampling the reflected pulse signal in response to the second output signal.

The distributed time domain reflectometry (TDR) measuring apparatus according to an embodiment of the present invention may secure operational reliability by sampling the reflected pulse signal in response to a differential signal corresponding to the sampling pulse signal.

In addition, the underground facility diagnosis visualization system according to another embodiment of the present invention converts all underground facilities covered by a plurality of distributed time domain reflectometry (TDR) measurement devices into three-dimensional graphics and transmits them to the user terminal along with the diagnostic information. It can provide convenience in management.

1 is an exemplary view of a point-type TDR sensor;
2 is a conceptual diagram of a distributed time domain reflectometry (TDR) sensor;
3 is a diagram illustrating the principle of a distributed time domain reflectometry (TDR) sensor.
4 is a block diagram of a distributed time domain reflectometry (TDR) measuring apparatus 1 according to an embodiment of the present invention.
5 is a circuit diagram of a time domain reflectometry (TDR) measuring device 1 according to a first embodiment.
5A is a circuit diagram of a TDR (Time Domain Reflectometry) measuring device 1 according to a second embodiment;
6 is a block diagram of a distributed time domain reflectometry (TDR) measuring apparatus 2 according to another embodiment of the present invention.
7 is an exemplary operation view of the sampling pulse signal generator 300A of FIG. 6 .
8 is a view showing a pulse signal and a reflected pulse signal output from the TDR measuring device 1 and 2
9 is a block diagram of an underground facility diagnosis visualization system 10
9A is another block diagram of the underground facility diagnosis visualization system 10
10 is an exemplary diagram of a three-dimensional graphic displayed on a user terminal through the underground facility diagnosis visualization system 10

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings in order to describe in detail enough that a person of ordinary skill in the art to which the present invention pertains can easily implement the technical idea of the present invention.

2 is a conceptual diagram of a distributed time domain reflectometry (TDR) sensor, and FIG. 3 is a diagram illustrating the principle of a distributed time domain reflectometry (TDR) sensor.

2 and 3, TDR (Time Domain Reflectometry) is a radar principle that emits electromagnetic waves or electrical signals and measures the location and type of the cause of the reflection using the waveform that has been reflected by the object. it is technology

This is a method to analyze the time domain response of the system. It applies a pulse or step signal to the measurement target system (TDR measurement line) and measures the reflected signal to improve the system (fluid pipeline, underground facility, etc.) status can be analyzed.

TDR (Time Domain Reflectometry) and TDT (Time Domain Transmission) are time domain analyzers that analyze the response of a pulse signal as to how it propagates through an interconnect. That is, the measurement principle for time domain reflectometry is applied to evaluate the frequency-dependent electrical and dielectric properties of various materials and materials.

A portable and miniaturized distributed time domain reflectometry (TDR) measuring device capable of sampling a repetitive square wave used as an output pulse signal and an underground facility diagnosis visualization system using the same will be described.

4 is a block diagram of a distributed time domain reflectometry (TDR) measuring apparatus 1 according to an embodiment of the present invention.

The TDR (Time Domain Reflectometry) measuring apparatus 1 according to the present embodiment includes only a simple configuration to clearly explain the proposed technical idea.

Referring to FIG. 4 , a time domain reflectometry (TDR) measuring device 1 includes a reference clock signal generator 100 , a clock signal distribution unit 200 , a sampling pulse signal generator 300 , and a reflected signal sampling unit 400 . ), a logic controller 500 , a line driver 600 , an amplifier 700 , and an analog-to-digital converter 800 .

The TDR (Time Domain Reflectometry) measuring device 1 is an inspection device capable of detecting the presence or absence of abnormality in a pipeline by transmitting a pulse signal to the TDR measuring line and receiving the reflected pulse signal reflected through the TDR measuring line. The TDR measurement line can be installed directly on the soil to detect changes in groundwater level and soil quality (moisture content), and can also be placed along a pipeline that transports fluids and underground facilities.

The TDR (Time Domain Reflectometry) measuring device 1 may be configured with 4 channels suitable for leak inspection of water supply pipes and heat transport pipes. The number of channels may be configured to be expandable from at least one.

That is, one or more channels are connected to one TDR (Time Domain Reflectometry) measuring device 1, and it is configured to connect a TDR sensing line (TDR measuring line) of 4 channels as an embodiment of the present invention, and a BNC connector and a coaxial cable combine as

Summarizing the function and configuration of the proposed TDR (Time Domain Reflectometry) measuring device 1, the TDR (Time Domain Reflectometry) measuring device 1 is a pipe that transports a fluid, that is, as an example, the temperature and It is defined as a sensing system for detecting a change in water leakage (water content), and is configured to measure at least one or more channels, preferably, a sensing line (TDR measurement line) of 4 channels.

In other words, when fluid leakage occurs, the magnitude of the reflected pulse signal changes due to the change in dielectric constant around the TDR measuring line arranged along the pipeline. It can be determined whether an abnormal phenomenon estimated as a leak has occurred.

The TDR (Time Domain Reflectometry) measuring device (1) can measure the water content (%) within 200 m (maximum 1 km) with a distance resolution of 6.7 cm. can be measured

In addition, the TDR (Time Domain Reflectometry) measuring device (1) has a 485 communication port for communication with the management server, RS232 to USB communication is possible, and displays the measured results with a PC (or smart phone) viewer program (serial plotter) It is configured so that it can be displayed as

In addition, the TDR (Time Domain Reflectometry) measuring device 1 may use an SD card (memory card) so that an administrator can directly receive data.

The output waveform of the pulse signal output from the TDR (Time Domain Reflectometry) measuring device (1) is based on a 50% duty ratio, a 25KHz rectangular pulse (2ns rise time), and it is a signal through repeated measurement using an A/D converter. By capturing the waveform of

The effective clock period of the clock of the TDR measuring device according to the embodiment is 250 MHz (4 ns) and the phase angle (0, 60, 120, 180, 240, 300) magnification ratio is max. k = 6, the effective sampling frequency is 1.5 GHz, At this time, the temporal resolution is 4ns/6=0.67ns, and the distance resolution is 6.7cm. The system maintains a 0.67 ns time resolution so that the rising edge can be tracked with a rise time of about 2 ns while maintaining the amplitude resolution at the 10-bit level.

The TDR (Time Domain Reflectometry) measuring device 1 changes the boundary layer with an accuracy of ±10 cm, and can monitor the change in the position of the boundary layer with a resolution of about 6.7 cm. In particular, when measuring a coaxial cable that is 67% of the speed of light, 1 ns time is required to measure the location of the defect with a resolution of 10 cm. The time resolution is 1 ns. Also, in the case of a 200m transmission line, the travel time (T_travel) in one direction is about 1,000 ns. The theoretical limit of the frequency of the measurement signal (50% square wave) should be 1/4T_travel = 1/4000ns (250KHz) or more, and the period of the measurement signal should be greater than 4 times the signal movement time in one direction (line). . In this embodiment, 8 times the signal movement time in one direction.

In addition, we choose 25 KHz as the fundamental repetition frequency of the TDR signal (pulse signal) as a compromise of acquisition time, time resolution, and transmission line length. The "loop time" in the circuit is a total of 4,000 ns, and the maximum trigger signal frequency can be limited to 1/4000 ns = 25 KHz. At this time, with a fundamental frequency of 25 KHz, it can be designed with a time resolution of 0.67 ns and a distance resolution of 6.7 cm as a compromise between the amplitude resolution and the required acquisition time. The sampling period of the analog-to-digital converter (A/D) is 4,000ns, and it coincides with the period of the output (step wave pulse signal). For reference, the shape and duty ratio of the Hz of the fundamental frequency and the output waveform of the pulse signal may be variously set according to the embodiment.

That is, after synchronizing and sampling the reflected pulse signal to 1.5 GHz in the internal circuit of the TDR (Time Domain Reflectometry) measuring device 1, the signal is output through an analog-to-digital converter (A/D), at this time the analog-to-digital converter ( A/D) outputs an output signal after sampling the signal in response to an internal signal equal to the period of the TDR signal (pulse signal).

That is, the analog-to-digital converter (A/D) samples and outputs the sequentially received reflected pulse signal once in response to an internal signal equal to the period of the TDR signal (pulse signal) during one pulsing period, and then sequentially outputs the internal signal. The reflected pulse signal received next is sampled again during one pulsing period and outputted while delaying.

That is, when the first reflected pulse signal and the second reflected pulse signal are sequentially received, the analog-to-digital converter A/D samples and outputs the first reflected pulse signal once during the pulsing period, and then outputs the second reflected pulse signal Samples once again during the pulsing period of . In this case, the sampling timing of the second reflected pulse signal is delayed by a predetermined time compared to the first reflected pulse signal. In this embodiment, the analog-to-digital converter (A/D) samples and outputs 1000 reflected pulse signals that are sequentially received, and combines them and displays them as an inspection result signal.

The detailed configuration and main operation of the TDR (Time Domain Reflectometry) measuring device 1 proposed as described above will be described as follows.

The reference clock signal generator 100 generates a 250 MHz reference clock signal by multiplying the 125 MHz external clock signal twice.

The clock signal distribution unit 200 divides the reference clock signal of 250 MHz at a predetermined ratio and generates a pulse signal of 25 KHz for transmission to the TDR measurement line. A pulse signal of 25 KHz is transmitted to the TDR measurement line through the line driver 600 .

The sampling pulse signal generating unit 300 generates a sampling pulse signal SYNC having a frequency higher than that of the reference clock signal by dividing the 250 MHz reference clock signal into a plurality of phases.

In this embodiment, the sampling pulse signal generator 300 receives a reference clock signal of 250 MHz and a sampling pulse of 1.5 GHz based on the phases of 0 degrees, 60 degrees, 120 degrees, 180 degrees, 240 degrees, and 300 degrees, respectively. output a signal.

The reflected signal sampling unit 400 samples the transmitted reflected pulse signal reflected through the TDR measurement line in response to the 1.5 GHz sampling pulse signal.

The signal sampled and output by the reflected signal sampling unit 400 is transmitted to the logic control unit 500 through the amplifier 700 and the analog-to-digital converter 800 .

The logic control unit 500 processes the signal output from the analog-to-digital converter 800 and transmits it to the management server or to the user terminal, and controls to display the measured result when the liquid crystal display is provided.

FIG. 5 is a circuit diagram of a time domain reflectometry (TDR) measuring device 1 according to a first embodiment, and FIG. 5A is a circuit diagram of a time domain reflectometry (TDR) measuring device 1 according to a second embodiment.

4, 5 and 5A simultaneously, the clock signal distribution unit 200 divides the reference clock signal of 250 MHz at a predetermined ratio and generates a pulse signal of 25 KHz (T_PULSE) for transmission to the TDR measurement line, , the line driver 600 is composed of a circuit for driving a 25 KHz pulse signal (T_PULSE) with a TDR measurement line.

The reflected signal sampling unit 400 samples the reflected pulse signal R_PULSE in response to the differential signals R_DIFF and F_DIFF corresponding to the sampling pulse signal SYNC.

That is, the reflected signal sampling unit 400 is synchronized with the rising section of the first differential signal R_DIFF corresponding to the sampling pulse signal SYNC and the falling section of the second differential signal F_DIFF and reflected from the TDR measurement line. After sampling the transmitted reflected pulse signal R_PULSE, the sampling output signal R_SYNC is output.

The reflected signal sampling unit 400 includes a sampling signal coupled matching unit 410 and a sampler circuit 420 .

The sampling signal coupled matcher 410 receives the sampling pulse signal SYNC, and a first output signal (first differential signal R_DIFF) of a differential type corresponding to the sampling pulse signal SYNC and a second output signal ( A second differential signal F_DIFF) is output. Since the sampling signal coupled matcher 410 of FIG. 5 and the sampling signal coupled matcher 410A of FIG. 5A perform the same function, hereinafter, the circuit diagram according to the first embodiment of FIG. 5 will be mainly described.

The sampler circuit 420 samples the reflected pulse signal R_PULSE in response to the first output signal (the first differential signal R_DIFF) and the second output signal (the second differential signal F_DIFF) to generate the sampling output signal R_SYNC ) as output.

For reference, a rising section of the first output signal (first differential signal R_DIFF) output from the sampling signal coupled matcher 410 and a falling section of the second output signal (second differential signal F_DIFF) Since precise matching is made, the operational reliability of the sampler circuit 420 is secured.

In this embodiment, the sampler circuit 420 includes a first resistor R57 connected between a first differential signal R_DIFF input node and a ground voltage terminal VSS, a second differential signal F_DIFF input node and a ground voltage terminal. A second resistor R72 connected between VSS, an anode connected to a first differential signal R_DIFF input node, and a cathode connected to a sampling output signal R_SYNC output node, a first diode connected (D1), the anode is connected to the first differential signal (R_DIFF) input node and the cathode is connected to the reflected pulse signal (R_PULSE) input node, the second diode (D2), the anode is sampling The third diode D3 connected to the output node of the output signal R_SYNC and the cathode connected to the input node of the second differential signal F_DIFF, the anode connected to the input node of the reflected pulse signal R_PULSE and a fourth diode (D4) whose cathode is connected to the second differential signal (F_DIFF) input node, and a capacitor (C95) connected between the sampling output signal (R_SYNC) output node and the ground voltage terminal (VSS) do.

The sampling output signal R_SYNC sampled and output by the reflected signal sampling unit 400 is transmitted to the logic control unit 500 through the amplifier 700 and the analog-to-digital converter 800 .

The analog-to-digital converter 800 samples the sampling output signal R_SYNC in response to an internal signal equal to the cycle of the TDR signal (pulse signal T_PULSE) and outputs the output signal.

That is, the analog-to-digital converter (A/D) samples the sequentially received sampling output signal (R_SYNC) once in response to the same internal signal as the cycle of the TDR signal (pulse signal (T_PULSE)) during one pulse period and outputs it. Thereafter, while sequentially delaying the internal signal, the next received sampling output signal R_SYNC is sampled again during one pulsing period and output.

That is, when the first sampling output signal R_SYNC and the second sampling output signal R_SYNC are sequentially received, the analog-to-digital converter 800 samples and outputs the first sampling output signal R_SYNC once during the pulsing period. Thereafter, the second sampling output signal R_SYNC is sampled once again during the pulsing period and output. In this case, the sampling timing of the second sampling output signal R_SYNC is delayed compared to the first sampling output signal R_SYNC by a predetermined time. In this embodiment, the analog-to-digital converter 800 samples and outputs 1000 sampling output signals (R_SYNC) that are sequentially received, and the logic controller 500 analyzes the waveform based on this and determines the leak (abnormality) and the leak location. to determine

6 is a block diagram of a distributed time domain reflectometry (TDR) measuring apparatus 2 according to another embodiment of the present invention, and FIG. 7 is an exemplary operation diagram of the sampling pulse signal generator 300A of FIG. 6 .

The TDR (Time Domain Reflectometry) measuring device 2 according to another embodiment has the same basic operation as the TDR (Time Domain Reflectometry) measuring device 1 according to the embodiment, and the sampling pulse signal generating unit 300A The detailed configuration was constructed using an analog circuit. Therefore, descriptions of overlapping functions will be omitted.

6 and 7, the TDR (Time Domain Reflectometry) measuring device 2 includes a reference clock signal generator 100, a clock signal distribution unit 200, a sampling pulse signal generator 300A, and a reflected signal sampling unit. It is configured to include a unit 400 , a logic controller 500 , a line driver 600 , an amplifier 700 , and an analog-to-digital converter 800 .

The TDR (Time Domain Reflectometry) measuring device 2 is an inspection device capable of detecting the presence or absence of abnormality in the pipeline by transmitting a pulse signal to the TDR measuring line and receiving the reflected pulse signal reflected through the TDR measuring line. The TDR measurement line can be installed directly on the soil to detect changes in groundwater level and soil quality (moisture content), and can also be placed along a pipeline that transports fluids and underground facilities.

7, the sampling pulse signal generating unit 300A includes a programmable delay generator, and when the input signal goes from a low level (LOW) to a high level (HIGH) state, the voltage U _C of the output is the supply voltage is exponentially approximated to A digital-to-analog converter (DAC) is used to set the comparator level, so the output signal is delayed according to this level.

That is, the sampling pulse signal generator 300A may generate the sampling pulse signal SYNC having a higher frequency than the reference clock signal by delaying the reference clock signal of 250 MHz.

8 is a diagram illustrating a pulse signal and a reflected pulse signal output from the TDR measuring device 1 .

Referring to FIG. 8 , when a fluid leak occurs, the magnitude of the reflected pulse signal R_PULSE is changed due to a change in the dielectric constant around the TDR measurement line disposed along the pipeline, so the waveform change of the reflected pulse signal R_PULSE And by analyzing the time, it is possible to determine at which point in the pipeline an abnormal phenomenon estimated as a leak has occurred.

9 is a block diagram of the underground facility diagnosis visualization system 10, FIG. 9a is another block diagram of the underground facility diagnosis visualization system 10, and FIG. 10 is displayed on the user terminal through the underground facility diagnosis visualization system 10 It is an example diagram of a 3D graphic that becomes

9 to 10 , the underground facility diagnosis visualization system 10 includes a plurality of distributed Time Domain Reflectometry (TDR) measuring devices 1-1, 1-2, 1-3, 1-4, and management It is configured to include a server (2) and a user terminal (3).

A plurality of distributed Time Domain Reflectometry (TDR) measuring devices 1-1, 1-2, 1-3, 1-4 diagnose each assigned underground facility, and each TDR (Time Domain Reflectometry) measuring device is It is assumed that the TDR (Time Domain Reflectometry) measurement device described above with reference to FIGS. 2 to 8 is configured.

The management server 2 converts all underground facilities in charge of a plurality of distributed Time Domain Reflectometry (TDR) measuring devices (1-1, 1-2, 1-3, 1-4) into 3D graphics. Measurement data transmitted from a distributed Time Domain Reflectometry (TDR) measurement device (1-1, 1-2, 1-3, 1-4) and a plurality of distributed Time Domain Reflectometry (TDR) measurement devices (1-1, Based on each satellite location information of 1-2, 1-3, 1-4), the location that needs to be checked is calculated.

The user terminal 3 receives the diagnosis information of the underground facility from the management server 2, maps it to a three-dimensional graphic form, and displays it. In this embodiment, a user terminal is a generic term for devices that a user can carry and use, such as a mobile phone, a smart phone, a smart pad, etc., and in this embodiment, it is assumed that the user terminal is composed of a smart phone.

That is, since the user terminal 3 registered in advance in the management server 2 maps and displays the diagnostic information of the underground facility provided from the management server 2 in a three-dimensional graphic form, the on-site inspector can check the water supply pipe buried underground. You can check the leak location more conveniently.

At this time, when the on-site inspector selects a pipeline in the form of a three-dimensional graphic displayed on the user terminal 3 on the screen, the virtual reality content is displayed in the form of a pop-up window, and information such as specifications, management subject, and design drawings of the pipeline are additionally provided. can be

In addition, in the drawing in which the underground piping drawing is synthesized from the satellite map, the measuring device has a GPS function, so it is possible to accurately measure the abnormal underground piping from the location at 10cm intervals and display it on the screen of the administrator PC or user terminal.

In addition, if a wireless communication device is linked to the TDR measuring device, information from the communication base station is obtained and the location is displayed, and the distance of the abnormal part can be accurately determined with the sensor line connected from the TDR measuring device, so that the manager is informed of the location of the actual problem. can tell you That is, the location information of the TDR measurement device is a method in which the server knows the satellite location information of the TDR measurement device in advance, a method for transmitting the satellite location information from the TDR measurement device, and a signal transmitted from the communication device of the TDR measurement device to a plurality of base stations The method of checking and understanding in , etc. may be applied.

In addition, as shown in FIG. 9A , the measurement device may use only USB communication, may use only the wireless communication device, or both may be used according to the user's intention. In addition, by configuring a measuring device and a wireless communication device as a set, a plurality of devices can be managed by a remote management server.

In addition, since the measuring device has an ID selection function, it is possible to connect multiple units in parallel through RS485 communication and communicate with the management server through one wireless communication device for management.

The distributed time domain reflectometry (TDR) measuring apparatus according to an embodiment of the present invention may secure operational reliability by sampling the reflected pulse signal in response to a differential signal corresponding to the sampling pulse signal.

In addition, the underground facility diagnosis visualization system according to another embodiment of the present invention converts all underground facilities covered by a plurality of distributed time domain reflectometry (TDR) measurement devices into three-dimensional graphics and transmits them to the user terminal along with the diagnostic information. It can provide convenience in management.

As such, those skilled in the art to which the present invention pertains will understand that the present invention may be embodied in other specific forms without changing the technical spirit or essential characteristics thereof. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the following claims rather than the above detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts should be interpreted as being included in the scope of the present invention. do.

100: reference clock signal generator
200: clock signal distribution unit
300, 300A: Sampling pulse signal generator
400: reflected signal sampling unit
500: logic control unit
600: line driver
700: amplification unit
800: analog-to-digital converter

Claims (6)

In the TDR measurement device for transmitting a pulse signal to a TDR measurement line and receiving a reflected pulse signal reflected through the TDR measurement line,
a reference clock signal generator generating a reference clock signal;
a clock signal distribution unit generating the pulse signal for transmission to the TDR measurement line by using the reference clock signal;
a sampling pulse signal generator generating a sampling pulse signal having a higher frequency than the reference clock signal; and
a reflected signal sampling unit for sampling the reflected pulse signal reflected through the TDR measurement line in response to the sampling pulse signal;
Distributed Time Domain Reflectometry (TDR) instrumentation with
According to claim 1,
The reflected signal sampling unit,
A distributed time domain reflectometry (TDR) measuring apparatus, characterized in that the sampled pulse signal is sampled in response to a differential signal corresponding to the sampling pulse signal.
According to claim 1,
The reflected signal sampling unit,
a sampling signal coupled matcher receiving the sampling pulse signal and outputting a differential first output signal and a second output signal corresponding to the sampling pulse signal; and
and a sampler circuit for sampling the reflected pulse signal in response to the first output signal and the second output signal.
a plurality of distributed Time Domain Reflectometry (TDR) measuring devices for diagnosing each allocated underground facility;
All the underground facilities covered by the plurality of distributed time domain reflectometry (TDR) measurement devices are 3D graphic, but the measurement data transmitted from the plurality of distributed time domain reflectometry (TDR) measurement devices and the plurality of distributed type a management server that calculates a location requiring inspection based on location information of a time domain reflectometry (TDR) measurement device; and
a user terminal receiving diagnostic information of an underground facility from the management server and displaying the map in a three-dimensional graphic form;
An underground facility diagnosis visualization system comprising a.
5. The method of claim 4,
Each of the plurality of distributed time domain reflectometry (TDR) measurement devices,
In transmitting a pulse signal to the TDR measurement line and receiving the reflected pulse signal reflected through the TDR measurement line,
a reference clock signal generator generating a reference clock signal;
a clock signal distribution unit generating the pulse signal for transmission to the TDR measurement line by using the reference clock signal;
a sampling pulse signal generator generating a sampling pulse signal having a higher frequency than the reference clock signal; and
a reflected signal sampling unit for sampling the reflected pulse signal reflected through the TDR measurement line in response to the sampling pulse signal;
An underground facility diagnosis visualization system comprising a.
6. The method of claim 5,
The reflected signal sampling unit,
a sampling signal coupled matcher receiving the sampling pulse signal and outputting a differential first output signal and a second output signal corresponding to the sampling pulse signal; and
and a sampler circuit for sampling the reflected pulse signal in response to the first output signal and the second output signal.

Images