KR20140126600A - Method for calculating communication coverage using 3D Object Intersection and Storage medium thereof - Google Patents

Abstract

The present invention relates to communications relay technology and, more particularly, to a method for calculating a communications coverage, capable of calculating the communications relay coverage by using a 3D object intersection in an ad-hoc network for an unmanned vehicle on the ground. According to the present invention, a stable communications environment is constructed by setting a region to overlap the communications coverage between nodes as a relay location when a relay function is performed for expanding a mission performance region, a link failure is generated due to movement, or a node is damaged in the moving ad-hoc network by calculating the communications coverage by improving a shortage to analyze a communications visible line at a specific position by applying a general Fresnel zone algorithm and a 3D object intersection algorithm.

Description

Field of the Invention [0001] The present invention relates to a method for computing a communicable area using an intersection of three-dimensional objects,

Field of the Invention [0002] The present invention relates to a communication relay technique, and more particularly, to a communication area calculation method for obtaining a communication relay area using an intersection of three-dimensional objects in an ad hoc network for an unmanned vehicle on the ground.

The present invention also relates to a storage medium storing program command codes for executing a communication area calculation method for obtaining a communication relay area using an intersection of three-dimensional objects in an ad hoc network for an unmanned vehicle on the ground.

Ad hoc networks can experience diverse environments such as node movements, obstacles, or bad weather, resulting in frequent link failures.

That is, the mobility of the node and irregularity of the wireless channel are the main factors determining the performance of the network. And a communication relay function is required in order to expand the communication distances limited by necessity.

For this reason, in order to establish a stable communication environment, a relay function is essential for the communication apparatus constituting the ad-hoc network. Especially, in the terrestrial environment where terrain or obstacles are dominant, the location of the repeater determines the actual performance of the whole network.

The location of the repeater becomes even more important if the nodes move to perform various tasks.

1. Korean Patent Publication No. 10-2012-0059203 2. Korean Patent No. 10-1031300 3. Korean Patent Publication No. 10-2008-0051494

The present invention has been proposed in order to solve the problems raised in the above background art, and it is an object of the present invention to improve the disadvantage that the intersectional algorithm of a three-dimensional object and a conventional Fresnel area algorithm are applied to perform a communication line- And to provide a communication area calculation method capable of a secure communication environment.

It is another object of the present invention to provide a storage medium storing a program command code for executing a communication area calculation method capable of a secure communication environment.

In order to achieve the above-mentioned object, the present invention has been made to solve the above-mentioned disadvantages of applying a conventional Fresnel domain algorithm and an intersection algorithm of a three-dimensional object to perform a communication line-of-sight analysis for a specific point, A possible area calculation method is provided.

The communication area calculation method includes:

A virtual three-dimensional ellipse calculating step of calculating a virtual three-dimensional ellipse using a Fresnel domain algorithm;

A three-dimensional elliptic full 3D object generating step of rotating the calculated virtual three-dimensional ellipses to generate a three-dimensional elliptic whole 3D object;

A 3D terrain object generation step of generating a 3D terrain object of the image information by stereoscopicizing and rendering the image information using image information and digital altitude information;

A crossing part calculating step of obtaining the intersection part by an aggregate calculation by showing the 3D object and the 3D terrain object in the same coordinate system; And

A final 3D object creation step of removing the intersection part from the stereoscopic elliptic rotation 3D object and calculating a final 3D object; And

Displaying the final 3D object on a three-dimensional map to calculate a communicable area; And a control unit.

In this case, the stereoscopic ellipsoidal revolver 3D object is generated by rotating the virtual stereoscopic ellipse based on a transmitter.

The angle of rotation may be 360 degrees.

In addition, the set operation may be calculated using a CSG (Constructive Solid Geometry) technique and a Ray Casting technique.

Further, the set operation may be characterized by using at least one of a union, an intersection, and a difference set.

In addition, the communicable area may be a communicable area of an ad hoc (AD-HOC) network.

In addition, the coordinate system may be a virtual 3D rectangular coordinate system.

On the other hand, another embodiment of the present invention provides a storage medium for storing program command code for executing a communication area calculation method using the intersection of three-dimensional objects described above.

According to the present invention, by applying a conventional Fresnel domain algorithm and an intersection algorithm of a three-dimensional object, it is possible to perform communication line-of-sight analysis for a specific point, Or when a relay failure occurs due to movement of the mobile terminal or when a relay function is to be performed in order to enlarge a task execution region, a safe communication environment can be established by selecting an area capable of overlapping a communicatable region between nodes as a relay position.

1 is a conceptual diagram of a general Fresnel domain algorithm.
FIG. 2 is a diagram showing a perspective view of a communication using general Fresnel area calculation. FIG.
FIG. 3 is a graph in which two points on a three-dimensional map according to FIG. 2 are objects (points) and altitude information of an object in three-dimensional coordinates is added to the graph.
FIG. 4 is an example of a screen in which a visual line between two points is analyzed by applying a Fresnel area algorithm in general.
FIG. 5 is a diagram illustrating an example of an intersection part or a difference set in an aggregate operation for two three-dimensional objects according to an embodiment of the present invention.
6 is a flowchart illustrating a process of calculating a communicable area using a 3D object according to an exemplary embodiment of the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Like reference numerals are used for similar elements in describing each drawing.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. The term "and / or" includes any combination of a plurality of related listed items or any of a plurality of related listed items.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Should not.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a communication coverage area calculation method using an intersection of three-dimensional objects according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a conceptual diagram of a general Fresnel domain algorithm. The Fresnel domain algorithm is commonly used for line of sight communications analysis. The Fresnel area algorithm is used for analysis of telescopic sight line by transmitting / receiving antenna height / interval, operating frequency and 3D map information.

1, D is the distance between the transmitter 110 and the receiver 100, r is the radius of the first Fresnel region (n = 1) at a point P, P is the radius of the transmitter 110, Lt; RTI ID = 0.0 > d1 < / RTI >

The Fresnel area (n = 1) is an area for analyzing the influence of an obstacle in the visible range transmission path. When there is no obstacle in the interior space of the Fresnel area (stereo oval) , The radius of the first Fresnel region is given by the following equation.

The height of the P point should be higher than the numerical altitude data to ensure the line of sight.

FIG. 2 is a diagram showing a perspective view of a communication using general Fresnel area calculation. FIG. In addition, FIG. 2 shows two points (200 and 210) on a three-dimensional map as an object (point) for adding a line-of-sight using the Fresnel region and adding the altitude information of the object in three-dimensional coordinates.

FIG. 2 is shown in FIG. 3 as a graph for easy understanding. That is, FIG. 3 is a graph in which two points on a three-dimensional map according to FIG. 2 are objects (points) and altitude information of the object in three-dimensional coordinates is added to the graph.

For the line-of-sight analysis, virtual extension lines of two objects were acquired and the fresnel radius r was repeatedly calculated in units of 30m sampling lines.

4 is an example of a screen for analyzing the visual line between two points by applying the Fresnel area algorithm according to an embodiment of the present invention. Referring to FIG. 4, using the Fresnel domain algorithm, only the visible line between two specific points can be obtained. In order to obtain the communicable area, it is necessary to perform calculations on a large number of points on the three-dimensional coordinate, so that the calculation amount becomes excessive.

If the distance between the transmitter (110 in FIG. 1) and the receiver (100 in FIG. 1) is set to a minimum distance capable of achieving a satisfactory level of communication performance and the communication device is operated at a specific frequency, An ellipse can be obtained.

When the three-dimensional ellipse is rotated 360 degrees about the transmitter 110 in the plane, and the rotating body of the three-dimensional ellipse is obtained, the inside of the rotating body becomes the communicable area of the transmitter.

A 3D map is created by rendering 3D objects using aerial photographs and / or satellite photographs and / or numerical altitude data (400).

If the Fresnel domain algorithm is applied to the general line of sight line analysis, the Fresnel radius must be calculated with respect to the points on the three-dimensional coordinate, so that the calculation amount becomes excessive.

Accordingly, a method according to an embodiment of the present invention for solving this will be described with reference to FIGS. 5 and 6. FIG.

FIG. 5 is a diagram illustrating an example of an intersection part or a difference set in an aggregate operation for two three-dimensional objects according to an embodiment of the present invention.

This means that 3D terrain can be viewed as a 3D object. CSG (Constructive Solid Geometry), which uses set operations on 3D objects, can create new 3D objects by using union, intersection, and difference among two sets of 3D objects. In general, Ray casting do.

Ray casting is a simple technique that casts light from a viewer's point of view (actually the point of view of the camera) through a particular pixel and then follows it until it comes out of the visible or visible area of the object, This is a technique to determine the color of the image and generate a rendering image.

Of course, if the light does not touch anything, the pixel becomes black, and when the light reaches an object's surface, the program computes the object's color at the point where the light is hitting ), And determines the value as the color of the corresponding pixel. The above process is repeated sequentially for each pixel of the entire image to be generated.

Since the Ray Casing technique is widely known, a detailed description will be omitted for the sake of clear understanding of the present invention.

Therefore, by using CSG (Constructive Solid Geometry) and Ray Casting technique, it is possible to perform set operation on two three-dimensional objects.

Referring to FIG. 5, a new three-dimensional object can be generated by calculating the two cubes 510 composed of the first hexahedron A and the second hexahedron B as follows.

One). (520): The sum of the sum of the first hexahedron (A) and the second hexahedron (B)

2). Intersection (530): Intersection where all of the first hexahedron (A) and the second hexahedron (B)

3). A-B difference set 540: a set obtained by subtracting the second hexahedron (B) from the first hexahedron (A)

4). B-A difference set 550: a set obtained by subtracting the first hexahedron A from the second hexahedron B

6 is a flowchart illustrating a process of calculating a communicable area using a 3D object according to an exemplary embodiment of the present invention. Referring to FIG. 6, a rotator of a three-dimensional ellipse which can be made by a Fresnel domain algorithm is obtained (steps S600 and S610).

A three-dimensional map, which is created by rendering a satellite image or an aerial photograph using three-dimensional height information, is already a three-dimensional object. A three-dimensional object is obtained by intersecting the three-dimensional ellipse with the three-dimensional map object in the same coordinate system to obtain the intersection portion (Step S620).

Once the three-dimensional object is obtained, the three-dimensional object is displayed on the three-dimensional map to obtain the communicable area (step S630).

In particular, the method of computing a communicable area using an intersection of three-dimensional objects according to an embodiment of the present invention may be implemented in the form of a program command code that can be executed through various computer means and recorded in a computer-readable storage medium.

The computer-readable storage medium may include program instructions, data files, data structures, and the like, alone or in combination.

The program instructions recorded on the medium may be those specially designed and constructed for the present invention or may be available to those skilled in the art of computer software.

Examples of computer-readable storage media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magneto-optical media such as floppy disks; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like.

The medium may be a transmission medium such as an optical or metal line, a wave guide, or the like, including a carrier wave for transmitting a signal designating a program command, a data structure, or the like.

Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

In addition, one embodiment of the present invention may be implemented in hardware, software, or a combination thereof. (DSP), a programmable logic device (PLD), a field programmable gate array (FPGA), a processor, a controller, a microprocessor, and the like, which are designed to perform the above- , Other electronic units, or a combination thereof.

In a software implementation, it may be implemented as a module that performs the functions described above. The software may be stored in a memory unit and executed by a processor. The memory unit or processor may employ various means well known to those skilled in the art.

100: receiver
110: Transmitter
510: Cube
520: Union
530: Intersection
540: AB difference set
550: BA difference set

Claims (8)

A virtual three-dimensional ellipse calculating step of calculating a virtual three-dimensional ellipse using a Fresnel domain algorithm;
A three-dimensional elliptic full 3D object generating step of rotating the calculated virtual three-dimensional ellipses to generate a three-dimensional elliptic whole 3D object;
A 3D terrain object generation step of generating a 3D terrain object of the image information by stereoscopicizing and rendering the image information using image information and digital altitude information;
A crossing part calculating step of obtaining the intersection part by an aggregate calculation by showing the 3D object and the 3D terrain object in the same coordinate system; And
A final 3D object creation step of removing the intersection part from the stereoscopic elliptic rotation 3D object and calculating a final 3D object; And
Displaying the final 3D object on a three-dimensional map to calculate a communicable area;
Dimensional objects using the intersection of the three-dimensional objects.
The method according to claim 1,
Wherein the 3D oval 3D object is generated by rotating the 3D oval about the transmitter.
3. The method of claim 2,
Wherein the angle of rotation is 360 degrees.
The method according to claim 1,
Wherein the set operation is calculated using a CSG (Constructive Solid Geometry) technique and a Ray Casting technique.
5. The method of claim 4,
Wherein the set operation uses at least one of a union, an intersection, and a difference set.
The method according to claim 1,
Wherein the communicable area is a communicable area of an ad hoc (AD-HOC) network.
The method according to claim 1,
Wherein the coordinate system is a virtual 3D Cartesian coordinate system.
A storage medium storing program code for executing a method of computing a communicable area using an intersection of three-dimensional objects according to any one of claims 1 to 7.

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