KR102614482B1 - Groundwater level measurement system using Distribution type Time Domain Reflectometry device - Google Patents

Abstract

The black ice detection system includes a plurality of distributed TDR (Time Domain Reflectometry) measuring devices that diagnose the presence of black ice in each assigned road area, and the areas covered by the multiple distributed TDR (Time Domain Reflectometry) measuring devices. In dimensional graphics, the presence or absence of black ice is calculated and managed based on measurement data transmitted from a plurality of distributed TDR (Time Domain Reflectometry) measuring devices and the location information of the plurality of distributed TDR (Time Domain Reflectometry) measuring devices. It includes a management server that receives black ice diagnosis information from the management server, maps it and displays it in a three-dimensional graphic form, and includes a user terminal.

Description

Black ice detection system using distribution type TDR measuring device {Groundwater level measurement system using Distribution type Time Domain Reflectometry device}

The present invention relates to a measuring device, and more specifically, to a black ice detection system using a distributed TDR measuring device.

Black ice refers to snow or rain that falls during the day seeping into the cracks of an asphalt road and then mixing with road oil and dust during the night and freezing thinly on the road. It is also called 'road freezing phenomenon'.

Accidents caused by black ice are increasing every year because it is not noticeable to drivers when driving on the road and it is easy to think that the road is simply a little wet. Although technology development is being promoted to prevent this, it takes too much time and cost due to the design. There is a problem.

As a related technology, Korea Patent Publication No. 10-1041022, 'Road ice forecast management system and method for drivers', is installed in a random section of the road when receiving an information lead signal and senses the weather environment on the road surface to provide weather environment information. At least one freezing data collection sensor module that wirelessly transmits, and a camera, transmitting the information lead signal to the freezing data collection sensor module when an information collection event occurs, and providing the weather environment information in response to the information lead signal. After receiving and comparing the icing prediction condition information stored in advance and satisfying the icing prediction condition, notifying the road icing prediction, the camera is driven to detect the road predicted to be likely to be iced by the icing data collection sensor module. It includes an ice prediction device that photographs a section, analyzes the captured video data, and determines whether or not the road is frozen based on light reflectivity and reports it.

The above-described prior art also has the problem of requiring a long design time and high cost as it requires the installation of multiple sensor modules to sense the weather environment of the road surface. Although freezing is determined based on the reflectivity of light, the reflectivity is determined by external conditions. There was a problem of false detection and the inability to determine freezing when a special environment occurred that did not satisfy the freezing prediction conditions.

KR 10-1041022 B

The present invention was proposed to solve the above technical problems, and is a black ice system that can provide black ice diagnosis information by graphically depicting the road area covered by a plurality of distributed TDR (Time Domain Reflectometry) measuring devices in three dimensions. A detection system is provided.

According to an embodiment of the present invention to solve the above problem, a plurality of distributed TDR (Time Domain Reflectometry) measuring devices for diagnosing the presence of black ice in each allocated road area, and a plurality of distributed TDR (Time Domain Reflectometry) measuring devices Reflectometry) The area covered by the measuring device is rendered in 3D graphics, based on the measurement data transmitted from multiple distributed TDR (Time Domain Reflectometry) measuring devices and the location information of the multiple distributed TDR (Time Domain Reflectometry) measuring devices. A black ice detection system is provided that includes a management server that calculates and manages whether black ice is generated, and a user terminal that receives black ice diagnosis information from the management server and maps it to display in a three-dimensional graphic form.

In addition, a plurality of distributed TDR (Time Domain Reflectometry) measurement devices included in the present invention each transmit a pulse signal to a TDR measurement line and receive a reflected pulse signal reflected through the TDR measurement line, using a reference clock. A reference clock signal generator that generates a signal, a clock signal distributor that generates the pulse signal for transmission to the TDR measurement line using the reference clock signal, and a sampling pulse signal that has a higher frequency than the reference clock signal. It is characterized by comprising a sampling pulse signal generation unit and a reflection signal sampling unit that samples a reflection pulse signal reflected through the TDR measurement line in response to the sampling pulse signal.

Additionally, 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 a first output signal. and a sampler circuit that samples the reflected pulse signal in response to the second output signal.

The black ice detection system according to an embodiment of the present invention provides convenience of inspection and management by providing black ice diagnosis information by graphicalizing the road area covered by a plurality of distributed TDR (Time Domain Reflectometry) measuring devices in 3D. You can.

1 is a conceptual diagram of the black ice detection system 10.
2 is a block diagram of the black ice detection system 10.
3 is another block diagram of the black ice detection system 10.
Figure 4 is a first example of a monitoring screen provided by the black ice detection system 10.
Figure 4a is a second example of a monitoring screen provided by the black ice detection system 10.
Figure 4b is a third example of a monitoring screen provided by the black ice detection system 10.
Figure 4c is a fourth example of a monitoring screen provided by the black ice detection system 10.
Figure 5 is a conceptual diagram of a distributed TDR (Time Domain Reflectometry) sensor.
Figure 6 is a diagram showing the principle of a distributed TDR (Time Domain Reflectometry) sensor.
Figure 7 is a block diagram of a distributed TDR (Time Domain Reflectometry) measurement device 1 according to an embodiment of the present invention.
Figure 8 is a circuit diagram according to the first embodiment of the TDR (Time Domain Reflectometry) measuring device 1.
Figure 8a is a circuit diagram according to the second embodiment of the TDR (Time Domain Reflectometry) measuring device 1.
Figure 9 is a block diagram of a distributed TDR (Time Domain Reflectometry) measurement device 2 according to another embodiment of the present invention.
Figure 10 is an exemplary operation diagram of the sampling pulse signal generator 300A of Figure 9.
Figure 11 is a diagram showing pulse signals and reflected pulse signals output from the TDR measuring devices 1 and 2.

Hereinafter, in order to explain the present invention in detail so that a person skilled in the art can easily implement the technical idea of the present invention, embodiments of the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a conceptual diagram of the black ice detection system 10, FIG. 2 is a block diagram of the black ice detection system 10, FIG. 3 is another block diagram of the black ice detection system 10, and FIG. 4 is a black ice detection system 10. FIG. 4A is a first example of a monitoring screen provided by the detection system 10, FIG. 4A is a second example of a monitoring screen provided by the black ice detection system 10, and FIG. 4B is a diagram of the monitoring screen provided by the black ice detection system 10. This is a third example of a monitoring screen provided, and FIG. 4C is a fourth example of a monitoring screen provided by the black ice detection system 10.

Referring to FIGS. 1 to 4, the black ice detection system 10 includes a plurality of distributed time domain reflectometry (TDR) measuring devices (1-1, 1-2, 1-3, 1-4) and a management server. (2) and a user terminal (3).

The proposed black ice measurement system is defined as a system that remotely controls black ice measurement devices installed in various areas, including highways, and measures and collects temperature, humidity, wind volume, and rainfall from environmental sensors attached to the black ice measurement devices. .

This system is equipped with login and membership registration functions to allow access only to authorized users, and allows registration through authentication through the mobile phone number of the member wishing to join. (Identity verification function)

A plurality of distributed TDR (Time Domain Reflectometry) measuring devices (1-1, 1-2, 1-3, 1-4) installed on the road diagnose black ice distribution in the allocated road area, and each TDR ( It is assumed that the Time Domain Reflectometry (TDR) measuring device is comprised of the Time Domain Reflectometry (TDR) measuring device shown in FIGS. 5 to 11, which will be described later.

The management server (2) creates three-dimensional graphics on the road area covered by a plurality of distributed TDR (Time Domain Reflectometry) measuring devices (1-1, 1-2, 1-3, 1-4). Measurement data transmitted from a type TDR (Time Domain Reflectometry) measurement device (1-1, 1-2, 1-3, 1-4) and a plurality of distributed TDR (Time Domain Reflectometry) measurement devices (1-1, 1) Based on each satellite location information (-2, 1-3, 1-4), the location requiring inspection is calculated.

The user terminal 3 receives black ice information of the road area from the management server 2, maps it and displays it in a three-dimensional graphic form. In this embodiment, the user terminal is a general term for devices that the user can carry and use, such as a mobile phone, smartphone, smart pad, etc., and a business computer. In this embodiment, it is assumed that the user terminal is composed of a smartphone.

In other words, the user terminal 3, which is pre-registered in the management server 2, maps and displays the black ice diagnostic information of the road area provided by the management server 2 in a three-dimensional graphic form, so the on-site inspector can view the black ice information, etc. You can carry out inspection more conveniently.

In addition, if a wireless communication device is linked to the TDR measuring device, information can be obtained from the communication base station and the location is displayed, and the distance of the abnormal part can be accurately determined using a sensor line connected from the TDR measuring device, allowing the manager to know the actual location of the problem. I can tell you. In other words, the location information of the TDR measurement device is generated by the server knowing the satellite location information of the TDR measurement device in advance, the method of transmitting the satellite location information from the TDR measurement device, and the signal transmitted from the communication device of the TDR measurement device to multiple base stations. Methods such as checking and understanding may be applied.

Additionally, as shown in FIG. 3, the measuring device can use only USB communication, only wireless communication, or both depending on the user's intention. Additionally, by configuring a measuring device and a wireless communication device as one set, multiple devices can be managed from a remote management server.

In addition, the measuring device has an ID selection function, so multiple devices can be connected in parallel through RS485 communication and managed by communicating with the management server through a single wireless communication device.

Referring to FIGS. 4 to 4C, the black ice detection system 10 manages the address and location of the measuring device, shows the installed location and determines the current status, and allows you to easily specify the installation location when registering the device. You can.

In addition, the operation history and error occurrence status of the installed measuring device can be logged to check whether it is operating or whether an error has occurred.

In addition, it provides the ability to check the latest sensor information of the installed measuring device and control it on the web screen, and as a responsive website, it provides an optimized screen suitable for PC environments and mobile environments such as mobile phones.

Figure 5 is a conceptual diagram of a distributed time domain reflectometry (TDR) sensor, and Figure 6 is a diagram showing the principle of a distributed time domain reflectometry (TDR) sensor.

Referring to Figures 5 and 6, TDR (Time Domain Reflectometry) is a radar principle that radiates electromagnetic waves or electrical signals and uses the waveform reflected by an object to measure the location and type of the cause of the reflection. It's technology.

This is a method of analyzing the time domain response of a system. It applies a pulse or step signal to the measurement target system (TDR measurement line) and measures the reflected signal to determine the state of the system (black ice on the road surface). It can be analyzed.

TDR (Time Domain Reflectometry) and TDT (Time Domain Transmission) are time domain analyzers that analyze the response of how pulse signals propagate through an interconnect. In other words, Time Domain Reflectometry is a measurement principle used to evaluate the frequency-dependent electrical and dielectric properties of various materials and substances.

We will describe a portable and miniaturized distributed TDR (Time Domain Reflectometry) measuring device that can sample repetitive square waves used as output pulse signals and an underground facility diagnostic visualization system using the same.

Figure 7 is a block diagram of a distributed time domain reflectometry (TDR) measurement device 1 according to an embodiment of the present invention.

The TDR (Time Domain Reflectometry) measuring device 1 according to this embodiment includes only a brief configuration to clearly explain the technical idea to be proposed.

Referring to FIG. 7, the TDR (Time Domain Reflectometry) measuring device 1 includes a reference clock signal generator 100, a clock signal distribution unit 200, a sampling pulse signal generator 300, and a reflection signal sampling unit 400. ), a logic control unit 500, a line driver 600, an amplifier 700, and an analog-to-digital converter 800.

The TDR (Time Domain Reflectometry) measurement device (1) is an inspection device that can detect abnormalities in the road by transmitting a pulse signal to the TDR measurement line and receiving the reflected pulse signal reflected through the TDR measurement line. TDR measuring lines can be installed directly on the road surface and median strip to detect black ice, and can also be placed along pipes under the road or underground facilities.

The TDR (Time Domain Reflectometry) measuring device 1 may be composed of 4 channels. The number of channels can be configured to expand from at least 1 to more.

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

To summarize the functions and configuration of the proposed TDR (Time Domain Reflectometry) measuring device (1), the TDR (Time Domain Reflectometry) measuring device (1) is defined as a sensing system for detecting changes in temperature and water leakage (water content ratio), It is configured to measure at least one channel, preferably 4 channels of sensing lines (TDR measurement lines).

In other words, since the size of the reflected pulse signal changes due to changes in dielectric constant around the TDR measurement line placed along the road, the waveform change and time of the reflected pulse signal are analyzed to determine at which point in the pipeline an abnormality occurred. can do.

The TDR (Time Domain Reflectometry) measuring device (1) can measure water content (%) within 200 m (maximum 1 km) with a distance resolution of 6.7 cm, and can measure temperature (°C) using an additional temperature sensing line. It can be measured.

In addition, the TDR (Time Domain Reflectometry) measuring device (1) has a 485 communication port for communication with the management server, supports RS232 to USB communication, and displays measured results through a PC (or smartphone) viewer program (serial plotter). It is configured to be displayed as .

In addition, the TDR (Time Domain Reflectometry) measuring device (1) can use an SD card (memory card) so that the manager 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 25KHz rectangular pulse (2ns rise time) with a duty ratio of 50%, and the signal is converted into signal through repeated measurement using an A/D converter. By capturing the waveform, defects within 200 m (up to 1 km) can be measured with a resolution of 10 cm. (Detection distance and resolution change depending on the wavelength and frequency of the pulse used)

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 maximum k = 6, so the effective sampling frequency is 1.5 GHz, At this time, the time resolution is 4ns/6=0.67ns, and the distance resolution is 6.7cm. Amplitude resolution is maintained at 10 bits, while the system maintains 0.67ns time resolution to track rising edges with a rise time of approximately 2ns.

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 approximately 6.7 cm. In particular, when measuring a coaxial cable at 67% of the speed of light, 1 ns time is needed to measure the location of the defect with a resolution of 10 cm. If we estimate a typical round-trip radio wave travel time of 1 ns per 10 cm, the equivalent distance resolution of 10 cm is The time resolution is 1ns. Additionally, in the case of a 200m transmission line, the travel time (T_travel) in one direction is approximately 1,000ns. 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 travel time in one direction (line) of the signal. . In this embodiment, it is 8 times the signal travel time in one direction.

Additionally, 25 KHz is selected as the basic repetition frequency of the TDR signal (pulse signal) as a compromise between 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 25KHz, it can be designed with a time resolution of 0.67ns and a distance resolution of 6.7cm as a compromise between amplitude resolution and required acquisition time. The sampling period of the analog-to-digital converter (A/D) is 4,000ns, which matches the period of the output (step wave pulse signal). For reference, the Hz of the basic frequency and the form and duty ratio of the output waveform of the pulse signal may be set in various ways depending on the embodiment.

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

In other words, 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 section, and then sequentially outputs the internal signal. While delaying, the reflected pulse signal received next is sampled again during one pulsing section and output.

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

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

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

The clock signal distribution unit 200 distributes the 250 MHz reference clock signal at a predetermined ratio and generates a 25 KHz pulse signal 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 generator 300 divides a 250 MHz reference clock signal into a plurality of phases and generates a sampling pulse signal (SYNC) with a higher frequency than the reference clock signal.

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

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

The signal sampled and output from the reflected signal sampling unit 400 is transmitted to the logic control unit 500 through the amplifying unit 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 user terminal, and, if equipped with a liquid crystal display device, controls it to display the measured results.

FIG. 8 is a circuit diagram of a Time Domain Reflectometry (TDR) measurement device 1 according to a first embodiment, and FIG. 8A is a circuit diagram of a Time Domain Reflectometry (TDR) measurement device 1 according to a second embodiment.

Referring to FIGS. 7, 8, and 8A at the same time, the clock signal distribution unit 200 distributes the 250 MHz reference clock signal at a predetermined ratio to generate a 25 KHz pulse signal (T_PULSE) for transmission to the TDR measurement line. , The line driver 600 is composed of a circuit that drives a 25KHz pulse signal (T_PULSE) to the TDR measurement line.

The reflected signal sampling unit 400 samples the reflected pulse signal (R_PULSE) in response to the differential signals (R_DIFF, 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 is 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 matcher 410 and a sampler circuit (sampler, 420).

The sampling signal coupled matcher 410 receives the sampling pulse signal (SYNC) and outputs a first output signal (first differential signal (R_DIFF)) and a second output signal ( Outputs the second differential signal (F_DIFF). Since the sampling signal coupled matcher 410 of FIG. 8 and the sampling signal coupled matcher 410A of FIG. 8A perform the same function, the following description will focus on the circuit diagram according to the first embodiment of FIG. 8.

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

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

In this embodiment, the sampler circuit 420 includes a first resistor (R57) connected between the first differential signal (R_DIFF) input node and the ground voltage terminal (VSS), the second differential signal (F_DIFF) input node and the ground voltage terminal. A second resistor (R72) connected between (VSS), a first diode whose anode is connected to the first differential signal (R_DIFF) input node and whose cathode is connected to the sampling output signal (R_SYNC) output node (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) is connected to the output node of the output signal (R_SYNC) and its cathode is connected to the input node of the second differential signal (F_DIFF), and its anode is connected to the input node of the reflected pulse signal (R_PULSE). The cathode is composed of a fourth diode (D4) 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 from the reflected signal sampling unit 400 is transmitted to the logic control unit 500 through the amplifying unit 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 period of the TDR signal (pulse signal (T_PULSE)) and then outputs an output signal.

In other words, the analog-to-digital converter (A/D) samples and outputs the sequentially received sampling output signal (R_SYNC) once in response to an internal signal equal to the period of the TDR signal (pulse signal (T_PULSE)) during one pulsing section. Then, while sequentially delaying the internal signals, 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 received sequentially, the analog-to-digital converter 800 samples and outputs the signal once during the pulsing period of the first sampling output signal (R_SYNC). Afterwards, it is sampled and output again during the pulsing section of the second sampling output signal (R_SYNC). At this time, the sampling timing of the second sampling output signal (R_SYNC) is delayed by a certain time compared to the first sampling output signal (R_SYNC). In this embodiment, the analog-to-digital converter 800 samples and outputs 1000 sequentially received sampling output signals (R_SYNC), and the logic control unit 500 analyzes the waveform based on this to determine the leak (abnormality) and the location of the leak. Determine.

FIG. 9 is a block diagram of a distributed time domain reflectometry (TDR) measurement device 2 according to another embodiment of the present invention, and FIG. 10 is a diagram illustrating an operation of the sampling pulse signal generator 300A of FIG. 9.

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 one embodiment, and includes the sampling pulse signal generator 300A. The detailed structure was constructed using analog circuits. Therefore, descriptions of overlapping functions are omitted.

Referring to FIGS. 9 and 10, the TDR (Time Domain Reflectometry) measuring device 2 includes a reference clock signal generator 100, a clock signal distributor 200, a sampling pulse signal generator 300A, and a reflected signal sampling unit. It is comprised of a unit 400, a logic control unit 500, a line driver 600, an amplifier 700, and an analog-to-digital converter 800.

The TDR (Time Domain Reflectometry) measurement device (2) is an inspection device that can detect abnormalities in roads and pipelines by transmitting pulse signals to the TDR measurement line and receiving reflected pulse signals reflected through the TDR measurement line. TDR measuring lines can be installed directly on the road surface or median strip to detect changes in the road (moisture content), and can also be placed along pipelines or underground facilities under the road.

As shown in FIG. 10, the sampling pulse signal generator 300A includes a programmable delay generator, and when the input signal changes from a low level (LOW) to a high level (HIGH), the output voltage U _C becomes the supply voltage. is approximated exponentially. 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 can generate a sampling pulse signal (SYNC) having a higher frequency than the reference clock signal by delaying the reference clock signal of 250 MHz.

Figure 11 is a diagram showing the pulse signal and reflected pulse signal output from the TDR measuring device 1.

Referring to FIG. 11, when a fluid leak, etc. occurs, the size of the reflected pulse signal (R_PULSE) changes due to a change in dielectric constant around the TDR measurement line arranged along the road or pipe. By analyzing waveform changes and time, it is possible to determine at which point in the road or pipeline an abnormality presumed to be a water leak has occurred.

The black ice detection system according to an embodiment of the present invention provides convenience of inspection and management by providing black ice diagnosis information by graphicalizing the road area covered by a plurality of distributed TDR (Time Domain Reflectometry) measuring devices in 3D. You can.

In other words, using a distributed TDR measuring line for measuring water content and temperature and a TDR sensing system, changes in TDR data according to changes in temperature and moisture saturation can be analyzed, and abnormal signs such as black ice on the road can be discovered using this function. .

Advanced sensing technology scans electric pulses (step pulses) on distributed sensors (measuring lines) and wires installed in the median of the road, and then measures the reflected value to measure water content and temperature on the measuring lines, thereby reducing the black color on the road. It consists of a TDR measuring device using Time Domain Reflectometry to find the possibility of ice.

When wireless sensor network technology is applied to the system, the network devices (nodes, repeaters, bases) that make up the IoT sensing network and the network topology technology that makes up the IoT sensing network that spatially arranges the network devices are used to Data on road surface conditions is transmitted to the vehicle integrated control system.

By using distributed (line type) sensors for integrated safety management such as extensive highways and automobile roads, black ice on the road can be detected and accidents can be prevented with a 10cm interval detection sensor.

As such, a person skilled in the art to which the present invention pertains will understand that the present invention can be implemented in other specific forms without changing its technical idea or essential features. Therefore, the embodiments described above should be understood in all respects as illustrative and not restrictive. The scope of the present invention is indicated by the claims described below rather than the detailed description above, and all changes or modified forms 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 digital converter

Claims (4)

A plurality of distributed TDR (Time Domain Reflectometry) measuring devices that diagnose whether black ice is formed in each allocated road area;
The area covered by the plurality of distributed TDR (Time Domain Reflectometry) measuring devices is rendered in three-dimensional graphics, and the measurement data transmitted from the plurality of distributed TDR (Time Domain Reflectometry) measuring devices and the plurality of distributed TDR ( Time Domain Reflectometry) A management server that calculates and manages whether or not black ice is created based on the location information of the measuring device; and
It includes a user terminal that receives black ice diagnosis information from the management server, maps it and displays it in a three-dimensional graphic form,
The plurality of distributed TDR (Time Domain Reflectometry) measuring devices each include:
A reference clock signal generator that generates a reference clock signal when transmitting a pulse signal to a TDR measurement line and receiving a reflected pulse signal reflected through the TDR measurement line; a clock signal distribution unit that generates the pulse signal for transmission to the TDR measurement line using the reference clock signal; A sampling pulse signal generator that receives the reference clock signal based on phases of 0 degrees, 60 degrees, 120 degrees, 180 degrees, 240 degrees, and 300 degrees, respectively, and generates a sampling pulse signal with a higher frequency than the reference clock signal. ; And a reflected signal sampling unit that samples a reflected pulse signal reflected through the TDR measurement line in response to the sampling pulse signal,
The reflected signal sampling unit receives the sampling pulse signal and outputs a differential signal in which the rising section of the first output signal and the falling section of the second output signal match the sampling pulse signal. energy; and a sampler circuit that samples the reflected pulse signal in response to the first output signal and the second output signal. delete delete delete