KR101396887B1 - Method for displaying communication line of sight on 3d map - Google Patents

Abstract

The present specification relates to a method capable of effectively displaying a communications sight line, and the communications sight line display method involves reflecting a predetermined weighted value in the calculation of a Fresnel zone for analyzing a communications sight line, adopting Hata model to estimate a distance range by RF output reflecting a path loss, and restricting a Fresnel zone calculation range to effectively display a communications sight line.

Description

METHOD FOR DISPLAYING COMMUNICATION LINE OF SIGHT ON 3D MAP [0002]

TECHNICAL FIELD [0001] The present invention relates to a method of displaying a communication line in a three-dimensional map.

In general, in order to carry out the stable operation mission of the ground unmanned combat system in the network-based future battlefield, large-capacity image information and status information acquired by a plurality of ground unmanned vehicles are reliably transmitted to a command- And should be controlled in real time through autonomous wireless network construction in which command control vehicles' remote control commands and information between ground unmanned vehicles are shared smoothly.

Unmanned vehicles are arranged by analyzing the area where communication between the command control vehicle corresponding to the base station and the ground unmanned vehicle is possible before the operation through the ground unmanned vehicle, and when the communication in the shaded area is disconnected, the communication repeater So that reliability can be secured. In other words, before performing the mission, after analyzing the communication line of sight using the spatial information based on the 3D map, setting the position of the command control vehicle and the location of the unmanned vehicle is set up so that the wireless channel environment can be stably operated in the ground operating environment, So that the operator can remotely control unmanned vehicles.

Visible distance area The area for analyzing the influence of an obstacle in the transmission line is the Fresnel zone. In other words, the propagation at the receiving point of the radio wave is affected not only by the direct wave (direct wave) but also by the diffraction wave or reflected wave, so that there is no obstacle which influences the reflection or the diffraction wave in a certain region of the ellipse to be. Although it is possible to roughly observe that communication performance degrades due to the obstacles located between the transceivers when the communication line line analysis method using the Fresnel zone is performed, when the RF output of the transmitter is limited, accurate communication line performance is confirmed In addition, there are limitations such as the result of Fresnel analysis and different communication performance depending on the antenna height when operating a communication device in actual outdoor operating environment.

The present invention aims at providing a method of efficiently displaying a communication line.

A method of displaying a line of sight communication according to an embodiment disclosed herein is a method of displaying a communication line for communication between a base station and a terminal mounted on the ground unmanned vehicle so as to remotely control the ground unmanned vehicle, Analyzing a communication line for communication between the base station and the terminal by using a first analysis; Calculating a path loss between the base station and the terminal using a Hata model; Estimating a maximum communication distance between the base station and the terminal; A second analysis of a Fresnel area operation in which a predetermined weight is reflected and a communication line of sight reflecting the result of predicting the maximum operation distance, and a step of overlaying the secondarily analyzed communication line of sight on the three- have.

The second step of analyzing the line of sight of the communication line may include analyzing the communication distance by the RF output between the base station and the terminal by considering the calculated path loss, Limiting the operation range.

As an example related to the present specification, the step of calculating the path loss may include calculating the path loss through an equation of path loss (Lo) = Lu-4.78 * log (f) ² +18.33 * log (f) where, Lu is an urban model (urban model) of the Hata model (Hata model), Lu is f, h _B, h _M, and hamsuyi of d, wherein f is the frequency, h _B is the height of the antenna at the base station, h _M is the antenna height of the terminal, and d is the distance between the base station and the terminal.

As an example related to the present specification, the step of predicting the maximum communication distance d is d = maximum communication distance if the output (receiver power) at the receiver = the reception sensitivity (RS) . The output of the receiver is the sum of the transmission output and the antenna gain minus the connection loss and the path loss (Lo).

A method of displaying a line of communication according to an embodiment of the present invention is a method for calculating a radius of a Fresnel zone in order to analyze a line of sight of a communication line by considering a predetermined weight and applying a Hata model, It is possible to efficiently display the communication visual line by limiting the calculation range of the Fresnel Zone.

1 is a flowchart illustrating a method of analyzing a visual line according to an exemplary embodiment of the present invention.
FIG. 2 is a conceptual diagram illustrating a Fresnel zone used in a communication line visualization method according to an exemplary embodiment of the present invention. Referring to FIG.
3 is an exemplary diagram illustrating a process of analyzing a communication line of sight by applying the Fresnel area algorithm.
4 is a diagram illustrating an example of a link budget for predicting maximum drill distance.
5 is an exemplary diagram illustrating a screen menu for communication line graph analysis using a Fresnel area algorithm and a hatamodel.
FIG. 6 is an exemplary diagram showing a result screen in which a result of analyzing the line-of-sight line analyzed through the FOVEL algorithm and a line-of-sight line analysis algorithm using a hat model is superimposed on a three-dimensional map.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals are used to designate identical or similar elements, and redundant description thereof will be omitted. The suffix "module" and " part "for the components used in the following description are given or mixed in consideration of ease of specification, and do not have their own meaning or role. In the following description of the embodiments of the present invention, a detailed description of related arts will be omitted when it is determined that the gist of the embodiments disclosed herein may be blurred. In addition, it should be noted that the attached drawings are only for easy understanding of the embodiments disclosed in the present specification, and should not be construed as limiting the technical idea disclosed in the present specification by the attached drawings.

Hereinafter, a method of predicting the distances in a three-dimensional map and setting a communication line-of-sight region through application of predetermined experimental weights will be described with reference to FIGS. 1 to 6, .

1 is a flowchart illustrating a method of analyzing a visual line according to an exemplary embodiment of the present invention.

First, the controller analyzes the communication line (communication range) for communication between the command control vehicle (base station) and the ground unmanned vehicle (terminal) using the Fresnel area algorithm.

FIG. 2 is a conceptual diagram illustrating a Fresnel zone used in a communication line visualization method according to an exemplary embodiment of the present invention. Referring to FIG. The Fresnel Zone algorithm is typically used for line of sight communications analysis. For example, in the ground unmanned combat system, an operational plan should be established by disposing ground unattended vehicles in the communicable area (position) between the command control vehicle and the ground unmanned vehicle to remotely control the ground unmanned vehicle (terminal). To do this, we analyze the line of sight of the communication using the spatial information of the map obtained before the operation. When the line of sight communication network needs to be configured, the most basic factor for determining the height of the antenna or calculating the diffraction loss or the like for suppressing the influence of reflected waves such as surface reflection or sea surface reflection is Fresnel area Zone. That is, when there is an obstacle in the visible range transmission path, it is an area for analyzing the influence of the obstacle. When communicating at the transmitter side and the receiver side, if there is no obstacle in the inner space of the zone (stereoscopic ellipse) You do not need to consider it. The radius equation (r) of the Fresnel zone is expressed by the following equation (1).

[Equation 1]

Where D represents the distance between a transmitter (e.g., a transmitter applied to a command control vehicle or a base station) and a receiver (e.g., a receiver applied to a terminal mounted on a ground unmanned vehicle) Is the radius of the first Fresnel Zone (n = 1), and P is a distance d1 away from the transmitter and a distance d2 away from the receiver. For example, r = 17.31 * sqrt (1 * (1000 * 1000) / (2437 * 2000)) = 7.84 meters when D: 2km, d1, d2: 1km, f: 2.437Ghz in equation (1) , And the height of the P position is H _p = Hr and the height of the P position (H _p ) is higher than the altitude of the digital terrain elevation data (DTED), the communication line of sight is secured.

3 is an exemplary diagram illustrating a process of analyzing a communication line of sight by applying the Fresnel area algorithm.

3, and calculates the distance r of the Fresnel area by a specific distance sampling unit and compares it with the spatial information of the map, that is, the DTED altitude. For example, when analyzing the communication line by applying the Fresnel area algorithm as shown in FIG. 3, two objects are first selected to obtain a virtual extension line of the two objects, and then the Fresnel area is calculated. Then, the altitude information of the object is added to the three-dimensional coordinates of the two objects using the spatial information of the map. That is, the height of the command control vehicle (base station) is the height of the DTED plus the height of the antenna. Then, the imaginary extension line is repeatedly computed for the radius r of the Fresnel area at a specific distance sampling unit. When compared to the height of the height (H _P) and DTED of sampling (Sampling) the position (P) in units of a DTED height greater than the height H of the _P position P is not visible is obtained.

이며, 여기서

값은 실제 야외 실험 결과와 프레넬 영역 연산 결과를 참조하여 결정한다. 본 특허에서는 프레넬 영역 반경 r이 아닌, 실제 통신 운용 환경을 고려하여

값이 적용된 변형 프레넬 영역 반경 r'을 통신 가시선 분석에 활용한다. 상기 TBD는 To Be Determined의 약자로서 상황에 따라 해당 수치가 다르게 적용될 수 있음을 의미한다.When the communication line is analyzed by the Fresnel area algorithm, when the antenna height is less than a certain level, actual communication is performed, but there is a problem that the communication line result is determined to be impossible (output). For example, if the distance between a command control vehicle (for example, a base station) and a ground unmanned vehicle (for example, a terminal) is 1 km (d1: 0.5 km, d2: 0.5 km, D = 1 km) m, it is determined that communication is impossible if the height of the command control vehicle (base station) and ground unmanned vehicle (terminal) antenna is 7.07 m or less. However, in actual situations, it is a sufficient condition for communication. This is because the Fresnel domain operation does not consider that the magnitude of the electric field due to diffraction is reduced but not completely eliminated. Therefore, in order to solve the situation that does not match with the result of the experiment in the actual environment, in the present invention, when calculating the Fresnel area radius, a predetermined weighting factor reflecting the experimental result is applied so that the communication line is secured even if the distance is short.

, Where

The value is determined by referring to the actual field test result and the Fresnel area operation result. In this patent, considering the actual communication operating environment rather than the Fresnel area radius r

The modified Fresnel area radius r 'applied with the value is used for line of sight analysis. The TBD is an abbreviation of To Be Determined, which means that the corresponding value can be applied differently depending on the situation.

In addition, if the communication line is analyzed by the Fresnel area algorithm, there arises a problem that the communication line area is set to be the same regardless of the RF output. If the antenna height is above a certain level, the distance to the antenna is infinite. This is because the Fresnel domain operation does not take into account the RF output. In the present invention, the Fourier domain operation range is limited by previously estimating the distance traveled by the RF output of the antenna. For this, the link budget can be used to estimate the distance traveled by the RF output. The link budget uses RF output, antenna gain (A _g ), reception sensitivity (RS), path loss (Lo), etc. as shown in FIG.

4 is a diagram illustrating an example of a link budget for predicting maximum drill distance.

First, the controller calculates a path loss model using a Hata model (S10). Hata model is divided into urban, suburban, and open environment models. Ground unmanned vehicles operated in ground unmanned combat systems are close to open environment, so open area model can be applied . As shown in Equation (2), an open area model (Hata model) is applied to estimate the distances by considering the path loss. In the open area model, Lu is defined as in Equation 2 It is a result obtained by applying the urban model (Urban model), and is a value obtained by taking as input the frequency, the height of the base station antenna, the height of the terminal antenna, and the distance between the base station and the terminal.

&Quot; (2) "

(Lo) = Lu-4.78 * log (f) ² +18.33 * log (f) -40.94,

Here, Lu is an urban model (Urban model) of the Hata model (Hata model), Lu is a function of _{f, h B, h M,} d. At this time, f: frequency, h _B : Base station antenna height, h _M ,: terminal antenna height, and d: communication distance between the base station and the terminal. Numerical values such as 4.78, 18.33, and 40.94 are the results of existing research that measured the path loss between the base station and the terminal in a real urban environment and modeled the curve fitting by the two-dimensional equation based on the measurement of the path loss according to the operating frequency .

The controller predicts a maximum communication distance between the base station and the terminal (S20). The controller can estimate the maximum distance d between the base station and the terminal through Equation (3). The output of the receiver is the sum of the transmission output and the antenna gain minus the value of Lo corresponding to the connection loss and the path loss. The controller determines that when the output (receiver power) at the receiver is equal to the reception sensitivity (RS), then the maximum is the maximum distance d.

&Quot; (3) "

P _r = P _t + A _g - G _I - Lo

If P _{r =} RS, d = maximum communication distance (Max.

Where P _r is the receiver power [dBm], P _t is the transmission power [dBm], A _g is the total antenna gain [dB], G _I is the total power Total Connection Loss [dB], and RS represents Receiver Sensitivity. Among these, the RF output, the antenna gain, and the reception sensitivity value excluding the path loss (Lo) are predetermined values and input to the controller.

The controller analyzes the position of the ground unmanned vehicles (terminals), the position of the command control vehicle (base station) and the moving direction of the unmanned vehicles by using the spatial information on the three-dimensional map, The communication line line analysis is performed by inputting necessary information through the setting menu of the communication line line analysis simulator of FIG. That is, the controller analyzes the communication line of sight by reflecting the results of the Fresnel area calculation and the distraction distance considering the predetermined weighting factor reflecting the results of the outdoor experiment (S30).

5 is an exemplary diagram illustrating a screen menu for communication line graph analysis using a Fresnel area algorithm and a hatamodel.

The controller overlayes the communication visual line analysis result on the three-dimensional map as shown in FIG. 6 and displays (sets) on the display unit (S40).

FIG. 6 is an exemplary diagram showing a result screen in which a result of analyzing the line-of-sight line analyzed through the FOVEL algorithm and a line-of-sight line analysis algorithm using a hat model is superimposed on a three-dimensional map. For example, the controller calculates a path loss model using a hata model to set a communicable area between the command control vehicle (base station) and the ground unmanned vehicle (terminal), and outputs the RF output, the antenna gain, The maximum communication distance is estimated using the sensitivity, the communication line line reflecting the result of the Fresnel area calculation and the communication distance estimation reflecting the predetermined weighted value reflecting the outdoor test result is analyzed, and the communication line line analysis result is overlaid on the three- On the display unit.

As described above, in order to solve the problem of the Fresnel area algorithm, the method of setting the line of sight of the communication in the three-dimensional map according to the embodiment of the present invention uses the test result and the Fresnel area operation result in the actual outdoor environment Weights are applied to the Fresnel area radius. Also, in order to solve the problem that the communication distance is infinite when the antenna height is higher than a certain level, the communication line setting (display) method in the three-dimensional map according to the embodiment of the present invention uses a route using the Hata model The loss model is calculated, and the maximum communication distance is estimated using RF output, antenna gain, and reception sensitivity. That is, a communication line setting (display) method in a three-dimensional map according to an embodiment of the present invention is a method of setting a communication line between a command control vehicle (base station) and a ground unmanned vehicle (terminal) And set the position of the repeater when necessary. Accordingly, it is possible to maximize the ability to perform a mission in remote control of a large number of ground unmanned vehicles by maintaining a stable network in a ground operating environment in which a wireless channel environment continuously changes, and minimizing a disconnection of a network connection.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas falling within the scope of the same shall be construed as falling within the scope of the present invention.

Claims (4)

A method for displaying a communication line for communication between a command control vehicle and a terminal mounted on the ground unmanned vehicle for remotely controlling the ground unmanned vehicle,
First analyzing a communication line of sight for communication between the command control vehicle and the terminal using a Fresnel zone algorithm;
Calculating a path loss between the command control vehicle and the terminal using a Hata model;
Estimating a maximum communication distance between the command control vehicle and the terminal;
Secondly analyzing a Fresnel area operation in which a predetermined weight is reflected and a communication visual line reflecting the result of predicting the maximum operation distance, and overlaying the second visualized communication visual line on a three-dimensional map to display on the display unit,
The predetermined weight may be a weight
Wherein the step of analyzing the line of sight communication using the Fresnel area algorithm is a predetermined weight for correcting a line of sight line error when the height of the command and control vehicle and the terrestrial unmanned vehicle are less than or equal to a predetermined height A method of displaying communication line of sight in a three dimensional map. The method as claimed in claim 1, wherein the step of secondarily analyzing the line-
And limiting the calculation range of the Fresnel Zone by estimating the distances by RF output between the command control vehicle and the terminal in consideration of the calculated path loss. Display line of the communication line. 2. The method of claim 1, wherein calculating the path loss comprises:
The path loss is calculated by the following equation: Lu = 4.78 * log (f) ² + 18.33 * log (f) -40.94 where Lu is the Urban model of the Hata model ) as, Lu is a function of f, h _B, h _M, d, wherein f is the frequency, h _B is the antenna height, h _M is the height of the antenna at the terminal of the command-and-control car, d is the command and control the vehicle and Wherein the distance between the terminals indicates the distance between the terminals. 4. The method according to claim 3, wherein the step of predicting the maximum distances (d)
A receiver power (Pr) P _r = P _t + A _g - G _I -Lo equation, the distance d is predicted as a maximum communication distance when P _r is equal to the reception sensitivity _R S,
Where P _r is the receiver power [dBm], P _t is the transmission power [dBm], A _g is the total antenna gain [dB], G _I is the total power Wherein the total connection loss (dB) is RS and the RS is a receiver sensitivity.

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