KR20180074960A - Gps signal receiver and reflectometry method for detecting road surface freezing - Google Patents

Abstract

Disclosed is an apparatus for measuring a global positioning system (GPS) reflection signal to detect an icy road, capable of preventing loss of life and property caused by a traffic accident. An apparatus for receiving a GPS signal to detect an icy road includes: a data logger for storing icy road detection information including phase information of the GPS signal, GPS satellite positioning information, and road position information; a reception module for receiving satellite observation information including the GPS signal and a phase and a unique number of the GPS signal, and a GPS reflection signal including right hand circular polarization (RHCP) and left hand circular polarization (LHCP), which are reflection signals of the GPS signal observed on a road which is a target observation point; and a determination module for determining a freezing state of the road based on a signal intensity of the GPS reflection signal collected by the reception module, the phase information of the GPS signal, and the satellite positioning information.

Description

Technical Field [0001] The present invention relates to a GPS signal measurement device and method for detecting road surface freezing,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a GPS reflection signal measuring apparatus, and more particularly, to a GPS reflection signal measuring apparatus and method for detecting a freezing state of a road surface by receiving GPS reflected waves.

Unless otherwise indicated herein, the contents set forth in this section are not prior art to the claims of this application and are not to be construed as prior art to be included in this section.

If the temperature drops sharply in winter, the road surface of the main road will freeze, raising the risk of accidents. In particular, the 'black ice' phenomenon that occurs every winter during the road surface freezing phenomenon creates an invisible ice road on the road, causing a very dangerous traffic accident. Black ice is a phenomenon in which transparent ice covers over asphalt as if it were coated, and the driver's eyes appear dry without ice on the road. The rain falls from the image temperature, but when the surface temperature falls below zero and the surface temperature of the road falls below zero, it freezes on the floor as it rains. Black ice occurs frequently on shady roads at dawn or in the morning with low temperatures in the winter, and is often seen in a way similar to or slightly wetted by road colors, causing many drivers to make mistakes. Recently, the National Police Agency has investigated 706 traffic accidents in the past five years, out of 7,236 deaths. Among the 892 deaths, 706 people died from black ice (NewSis, Dec. 11, 2014).

 The conventional road surface temperature analysis technique for detecting the road surface freezing state is an indirect prediction method based on the road surface state prediction model, in which the approach to the freezing point and the temperature change are detected and predicted It is not accurate. In particular, the conventional infrared / laser scattering reflection analysis technology detects frost on the road through analysis of scattering and reflection characteristics of infrared rays / laser. It is a comparatively high priced import product of about tens of thousands of won for one ordinary product, It is a disadvantage that it can be applied to a limited range. In addition, the image analysis technique is vulnerable to the detection of road surface condition because it is difficult to secure visibility in the cloudy, cloudy day or dark night.

1. Korean Patent Publication No. 10-2014-0169747 (December 1, 2014) 2. Korean Patent Publication No. 10-2014-0009744 (Apr. 21, 2014)

GPS signal intensity and phase are measured and analyzed and the road surface condition is classified into dry, wet, iced, snow, etc., Apparatus and method.

The apparatus for measuring a GPS signal for road surface freezing according to an embodiment includes a data logger (not shown) for storing road surface freezing detection information including phase information of GPS (Global Positioning System) signals, GPS satellite positioning information, ); GPS signal, topological information of GPS signal and unique number, right hand circular polarization (RHCP) and left hand circular polarization (LHCP), which are reflection signals of GPS signals observed on road surface, A reception module for receiving a GPS reflection signal; And a determination module for determining a freezing state of the road surface based on the signal intensity of the GPS reflection signal collected by the reception module, the phase information of the GPS signal, and the satellite positioning information. .

According to another embodiment of the present invention, there is provided a road surface freezing detection method comprising the steps of: (A) selecting a freezing area of a road surface; (B) monitoring the temperature and humidity change of the freezing danger zone after installation of the GPS reflection receiver in the selected freezing hazard area; (C) logging a satellite signal through a right hand circular polarization (LHCP), a left hand circular polarization (LHCP), and a downward RHCP antenna, which receive GPS reflected waves from the receiving module; (D) visualizing a surface area range where each signal is reflected in each GPS satellite signal in the receiving module; (E) collecting GPS signal strength, GPS reflection signal strength, GPS signal phase, and satellite positioning information according to time lapse of each GPS satellite signal in the receiving module; (F) determining a change in signal intensity according to the surface medium recorded in the uplink antenna and the downlink antenna in the reception module; And (G) determining a road surface freezing state on the basis of the GPS signal intensity change in the receiving module and the temperature and humidity change information of the freezing dangerous area; .

Through this disclosure, it is possible to prevent loss of lives and property loss caused by traffic accidents by predicting and predicting black ice, which is the main cause of traffic accidents in winter,

It is possible to more precisely grasp various indicator medium information due to various physical characteristics of the ground surface by measuring and analyzing the signal intensity and phase by the GPS reflection wave and detecting the road surface state even at night or in the cloudy or foggy weather can do.

In addition, the method of grasping the freezing condition of the road surface by the GPS reflection measurement is a passive method and it is possible to measure the freezing of the road in a relatively wide range and distance with a low maintenance cost.

It should be understood that the effects of the present invention are not limited to the above effects and include all effects that can be deduced from the detailed description of the present invention or the configuration of the invention described in the claims.

1 is a diagram showing a configuration of a road surface freezing detection system according to an embodiment
2A is a block diagram showing a detailed configuration of a GPS signal receiving apparatus according to an embodiment
FIG. 2B is a block diagram of a position adjusting device of a GPS signal receiving apparatus according to an embodiment.
FIG. 3A is a flowchart showing a road surface detection method using GPS reflected waves according to an embodiment
FIG. 3B is a view showing an embodiment of visualizing the first index reflection surface position tracking information of a signal for each GPS satellite according to time
Figs. 4A and 4B are diagrams showing an experiment example of reception of GPS reflected waves for proving that the intensity of the GPS reflected signal is different according to the road surface state
4C is a diagram showing an example of measurement data recorded in the GPS reflected wave receiving module

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention, and the manner of achieving them, will be apparent from and elucidated with reference to the embodiments described hereinafter in conjunction with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like numbers refer to like elements throughout.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The following terms are defined in consideration of the functions in the embodiments of the present invention, which may vary depending on the intention of the user, the intention or the custom of the operator. Therefore, the definition should be based on the contents throughout this specification.

1 is a diagram showing a configuration of a road surface freezing detection system according to an embodiment.

1, the road surface freezing detection system may include a GPS signal receiving apparatus 100 and an analysis server 200. The GPS signal receiving apparatus 100 may include a receiving module 110 and a determination module 130). The GPS signal receiving apparatus 100 is installed in a dangerous area on road surface freezing to collect GPS signals, GPS reflected signal intensity, phase information of GPS signals, and location information of freezing dangerous areas. In an embodiment, the GPS reflected wave includes Right Hand Circular Polarization (RHCP) and Left Hand Circular Polarization (LHCP) microwaves, which are GPS reflected signals at the object observation point. In an embodiment, the GPS receiver may collect GPS signals with an upward RHCP antenna and an upward and downward RHCP / LHCP dual antenna. An upward RHCP antenna may collect GPS direct signals, a downward RHCP and LHCP dual antenna GPS signals can be collected. The RHCP and LHCP collected by the downward RHCP and LCHP dual antennas are reflected signals of the GPS signals and are polarized signals that periodically rotate within a cross section orthogonal to the traveling direction of the electromagnetic waves radiated from the antenna. If we combine horizontal and vertical polarizations with the same size and phase difference of 90 degrees, the resultant circular vector will form a circle, so that when it rotates clockwise, it will be Right Hand Circular Polarization, Left Hand Circular Polarization. In the embodiment, RHCP and LHCP can be various polarized signals including the right and left handed circularly polarized waves that are transmitted while the polarization plane changes horizontally, vertically, and horizontally in a spiral shape like time and distance. Specifically, the RHCP and the LHCP are designed so that the oscillation direction of the electric displacement vector (or the magnetic field displacement vector) of the light wave is circularly polarized in the cross section perpendicular to the traveling direction of the electromagnetic wave radiated from the antenna, A rotating circular polarized signal, and a circular polarized signal in which the deflecting surface of the linear polarized light rotates at a constant angular velocity about the traveling direction of the light.

Although an embodiment is described centering on GPS signals, the analytical signals for road icing detection are not limited to GPS signals and GPS reflected signals. The signal that can be analyzed for road surface freezing may include various satellite signals such as GPS, GLONASS, Galileo, Beidou and GNSS Reflectometry among GNSS (Global Positioning System) signals.

The analysis server 200 detects the road surface state of the road surface freezing danger zone based on the GPS reflection signal and the satellite phase information collected by the reception apparatus 100. The road surface freezing detection system includes an analysis server 200 for analyzing a GPS reflection signal. When the analysis server 200 determines the road surface state or does not include the analysis server 200, The road surface freezing danger area may be determined by comparing the GPS signal intensity data stored in the judgment module 130 with the collected reflected signal intensity data.

2A is a block diagram showing a detailed configuration of a GPS reflected wave receiving apparatus according to an embodiment.

2A, the GPS reflected wave receiving apparatus may include a receiving module 110 and a determining module 130. The receiving module 110 of the GPS signal receiving apparatus may include an uplink RHCP antenna 110, a downlink LHCP And may include an antenna 120, a downstream RHCP antenna, a measurement unit 130, a control unit 140, a preprocessing unit 150, and a data logger 170. The term " module ", as used herein, should be interpreted to include software, hardware, or a combination thereof, depending on the context in which the term is used. For example, the software may be machine language, firmware, embedded code, and application software. As another example, the hardware may be a circuit, a processor, a computer, an integrated circuit, an integrated circuit core, a sensor, a micro-electro-mechanical system (MEMS), a passive device, or a combination thereof.

The data logger 116 stores road surface freeze detection information. The road surface freeze detection information stores a series of data required for road surface detection such as the phase information of the GPS signal, the GPS satellite positioning information, and the road surface position information. The data logger 170 may collect experimental data including the GPS signal reflection intensity of the road surface state, which is compared with collected GPS reflected wave data, from another server when the GPS receiver apparatus judges the road surface state.

In the embodiment, the upward RHCP antenna 111 collects GPS signals, the downward right hand circular polarization (RHCP) antenna collects the right polarized signals of the GPS reflected signals, and the downward LHCP (Left Hand Circular Polarization) Collects the left polarized signal of the GPS reflected signal.

The measuring unit 113 measures the intensity of the reflected signal collected through the RHCP / LHCP antennas 110 and 120 according to the road position of the freezing danger area and the phase of the GPS signal.

The preprocessor 114 visualizes the measured signal intensity according to the road surface position and visualizes the satellite altitude and the first Fresnel Zone (FFZ) location tracking information. In an embodiment, the preprocessing unit 150 may include a satellite signal (C / No), which includes a carrier signal to noise ratio (C / No) for each antenna according to satellite altitude and surface reflection plane location tracking information The receiving strength can be visualized.

The control unit 115 controls the connection between the reception module 110 and the determination module 130 and the inclination and direction of the upward RHCP antenna 111 and the downward RHCP LHCP antenna 112. [

The determination module 130 compares the GPS reflection intensity data of each road surface state previously stored in the data logger 116 with the data collected by the reception module 110 to determine the road surface state of each road as dry, Wet, icing, snow, and so on. In the embodiment, the GPS receiving apparatus 100 may further include a position adjusting device, a temperature sensor, a humidity sensor, and a thermal imager.

2B is a diagram showing a design example of a position adjusting device for adjusting the position of the GPS receiving device 100. As shown in FIG.

FIG. 2B is a plan view of the position adjusting device, and FIGS. 2B and 2C are enlarged views of a portion of the position adjusting device to which the antenna of the GPS receiving device is connected. 2B, the position adjustment device includes a fixed bar 1, a cradle 4 for connecting the fixed bar 1 and the antenna, a fixed cable 3, an upward RHCP antenna 7 and a downward LHCP antenna And an antenna tilt adjusting device (6) for adjusting the angle and tilt of the antenna (5).

The sensor (not shown) monitors the temperature and humidity in the vicinity of the freezing danger area, and the thermal imager captures the area around the road surface to determine the temperature of the freezing area, To be used as additional data.

Hereinafter, the road surface freezing detection method will be described in order of the present invention. Since the function (function) of the road surface freezing detection method according to the present invention is essentially the same as that of the GPS receiver for a road surface freeze detection and the system, a description overlapping with those of FIGS. 1 to 2B will be omitted.

     3A is a flowchart illustrating a road surface detection method using GPS reflected waves according to an embodiment.

In step S310, a road surface hazardous area, which is likely to freeze on the road surface, is selected. In step S320, a GPS reflective wave receiving module is installed in the selected road surface dangerous area.

In step S330, the video camera or the thermal camera monitors the temperature and the humidity change of the road around the GPS reflection wave measurement time zone.

In step S340, the satellite signal is logged through the upward RHCP and the downward LHCP / RHCP antennas of the GPS reception module.

In step S350, the range of the surface on which each signal is reflected is visualized for each GPS satellite signal. As shown in FIG. 3B in which the first index reflection surface position tracking information of the GPS satellite signal according to the time flow is visualized, the point and the intensity of the reflection signal are intuitively recognized according to the satellite number and the position, It is possible to visualize it with graphic such as color.

In step S360, GPS signal intensity, phase, GPS satellite positioning information, and the like are collected / stored for each GPS satellite signal over time.

In step S370, the change in signal intensity of the surface medium recorded on the upper and lower antennas in the receiving module is determined.

In step S380, the road surface freezing state is determined based on dryness, wetness, ice, snow, and the like based on the signal strength change and other information of the sensor.

In the present disclosure, it is possible to measure and analyze the signal intensity and phase by GPS (microwave) reflected waves, thereby making it possible to more accurately grasp various indicator medium information caused by various physical characteristics of the ground surface, It is also possible to detect the road surface condition in the weather. In addition, the method of grasping the freezing condition of the road surface by the GPS reflection measurement is a passive method, and the maintenance cost is low and it is possible to measure in a relatively wide range and distance.

FIGS. 4A and 4B are graphs showing examples of reception of GPS reflected waves for proving different GPS signal strengths according to road surface conditions.

FIG. 4A is a view for measuring GPS reflected waves from ice, FIG. 4B is a view for measuring GPS reflected waves from asphalt, FIG. 4B is a view for measuring the GPS reflected waves from asphalt, Fig.

4B, when the road surface is frozen, it can be seen that the reflection ratio in the LHCP antenna and the RHCP antenna are different from the reflection ratio in the asphalt state. In the embodiment, the reflection ratio and the reflection signal intensity data according to the road surface state (for example, dry, wet, ice, snow, etc.) ) And the GPS signal strength of the reflected signal is measured in accordance with the comparison result, it is possible to determine the freezing state of the road surface.

      4C is a diagram illustrating an example of measurement data recorded in the GPS reflected wave receiving module. As shown in FIG. 4C, in the GPS receiving module, the measured time elapsed, the carrier signal-to-noise ratio (C / No) of upward RHCP, the carrier signal-to-noise ratio at downlink LHCP and RHCP, (Lon) and satellite arrangement information (El, AZ) can be measured and converted into a database.

In this disclosure, the intensity and phase of the GPS signal reflected by the road surface are measured through upward RHCP (Right Hand Circular Polarization), downward LHCP (Left Hand Circular Polarization) and downward RHCP antenna, It is recommended that road users freeze on the road surface, which is divided into wet, wet, snow, and snow conditions to prevent loss of life and loss of property due to winter traffic accidents.

In the present disclosure, the road surface freezing determination example using the GPS reflection signal measurement has been described in detail, but the use of the present disclosure is not limited to the embodiments mentioned. In particular, the present disclosure relates to a method and apparatus for measuring altitude, snow depth, snow / soil moisture, altimetry of the ocean, or sea).

It is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. It is not limited to the embodiment.

110: receiving module
111: RHCP antenna
112: LHCP antenna
113:
114:
115:
116: Data logger
130: Judgment module

Claims (8)

A GPS reflection signal measuring apparatus for road surface freeze detection,
A data logger for storing road surface freeze detection information including phase information of a Global Positioning System (GPS) signal, GPS satellite positioning information, and road surface position information;
(Right hand circular polarization) and left hand circular polarization (LHCP), which are reflection signals of GPS signals observed on a road surface, which is a target observation point, and satellite observation information including a GPS signal, A receiving module for receiving a GPS reflection signal; And
A determination module for determining a freezing state of a road surface based on the signal intensity of the GPS reflection signal collected by the reception module, the phase information of the GPS signal, and the satellite positioning information; And a GPS signal reflection signal measuring device for detecting road surface freezing.
2. The method of claim 1, wherein the receiving module
A measuring unit for measuring a GPS reflected signal strength including RHCP and LHCP polarized signals through an upward RHCP single antenna and a downward RHCP LHCP dual antenna;
A pre-processing unit for visualizing the measured signal intensity according to the road surface position and visualizing the first elevation reflection surface position tracking information of the satellite altitude and the GPS signal; And
A controller for controlling the connection between the receiving module and the determining module and controlling the inclination and direction of the upward RHCP single antenna and the downward RHCP LHCP dual antenna for measuring the GPS reflected signal strength; And a GPS receiver for measuring GPS signals.
3. The apparatus of claim 2, wherein the pre-
(C / No, Carrier to Noise Power Density), which is a carrier signal-to-noise ratio for each antenna according to satellite altitude and surface reflectance position tracking information, is visualized as a graphical image including a graph. Signal measuring device.
The GPS receiver according to claim 1, wherein the GPS signal receiving device
A position adjustment device for adjusting a GPS reflection wave measurement position of the reception module and fixing a reception device installed on the road surface; Further comprising a GPS receiver for receiving GPS signals from the GPS receiver.
The GPS receiver according to claim 1, wherein the GPS receiver for road surface freeze detection comprises:
A sensor for measuring temperature and humidity of the road surface; And
An infrared camera for photographing the road surface around the road; Further comprising a GPS receiver for receiving the GPS signal.
A road surface freezing detection method,
(A) selecting a freezing area of a road surface;
(B) monitoring the temperature and humidity change of the freezing danger zone after installing the GPS reflection receiver in the selected freezing danger zone;
(C) logging a satellite signal through an uplink Right Hand Circular Polarization (RHCP) and a downlink LHCP (Left Hand Circular Polarization) / RHCP antenna receiving a GPS reflected wave from the receiving module;
(D) visualizing a surface area range where each signal is reflected in each GPS satellite signal in the receiving module;
(E) collecting GPS signal strength, GPS reflection signal strength, GPS signal phase, and satellite positioning information according to time lapse of each GPS satellite signal in the receiving module;
(F) determining a change in signal intensity according to the surface medium recorded in the uplink antenna and the downlink antenna in the reception module; And
(G) determining a road surface freezing state on the basis of GPS signal intensity change and temperature and humidity change information of a freezing hazard area in a receiving module; And a road surface freezing detection method.
7. The method of claim 6, wherein the GPS reflected wave
Wherein the GPS signal includes a polarized signal reflected at an observation point, a Right Hand Circular Polarization (RHCP), and a Left Hand Circular Polarization (LHCP).
The method of claim 6, further comprising: (G) determining a road surface freezing state based on GPS signal intensity change and temperature and humidity change information in a freezing hazard area in the receiving module; The
We compared the intensity of the GPS signal reflected by the stored road surface condition with the intensity of the GPS signal reflected by the receiving module, and compared the results of the comparison with those of the dry, wet, wet, snow, State of the road surface freezing.

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