KR102242366B1 - RTK drone based GRP auto-arrangement apparatus for digital map creation of earthwork site - Google Patents

Abstract

A drone-based ground reference point arrangement automation device for creating a digital map of earthworks is provided. A drone-based ground reference point arrangement automation device comprises: a ground reference point extractor that analyzes images acquired from a camera provided in a real-time kinematic (RTK) drone and extracts ground control points (GCP); and a long-distance surveying unit that calculates absolute coordinates of each of the ground reference points using the distance between each extracted ground reference point and a laser distance measurer, RTK-GPS information of the RTK drone, and a 3-axis inclination of the RTK drone.

Description

Drone based GRP auto-arrangement apparatus for digital map creation of earthwork site {RTK drone based GRP auto-arrangement apparatus for digital map creation of earthwork site}

The present invention relates to a drone-based ground reference point arrangement automation device for generating a digital map of an earthwork site, and more particularly, for the generation of a digital map of an earthwork site that can determine a ground reference point using an image captured by an RTK drone. It relates to a drone-based ground control point arrangement automation device.

The process of creating a digital map of an earthmoving site using existing drones is 1) ground control point (GCP) and detection point setting, 2) drone image acquisition plan establishment, 3) drone image acquisition, 4) image-based point cloud data ( PCD: Point Cloud Data) generation, 5) orthogonal image generation, 6) DSM (Digital Surface Model) or DEM (Digital Elevation Model) generation sequence.

Among these processes, the processes of 3)~6) can be automated to some extent by using the currently established system, but the processes of 1)~2) are difficult to automate until now and require the input of manpower.

In particular, the process of setting a ground control point (GCP) and a detection point is labor-intensive because a person must visit the actual location corresponding to the ground control point and measure and collect the coordinate values of the point to be set as the ground control point. Very long.

For this reason, the process of setting the ground control point and the detection point is regarded as a representative factor of lowering productivity and economic efficiency in the creation of a digital map of an earthwork site using a drone. need.

In addition,'How to set a ground reference point using a drone' described in Registration No. 10-1853348 causes trouble in measuring because it is necessary to directly measure the ground reference point using a height adjustment leg stored in the drone, and use it as a ground reference point. There is a limit in that it cannot be used as a ground reference point if the location of the is not flat.

Korean Patent Publication No. 10-2018-0021604 (published on March 05, 2018)

In order to solve the above-described problems, the technical problem to be achieved by the present invention is a digital map of an earthwork site that solves the trouble of a person directly visiting the actual location corresponding to the ground reference point, and quickly extracts the ground reference point without inputting manpower. It is to present a drone-based ground control point arrangement automation device for creation.

The problem of the present invention is not limited to those mentioned above, and other problems that are not mentioned will be clearly understood by those skilled in the art from the following description.

As a means for solving the above-described technical problem, according to an embodiment of the present invention, a drone-based ground reference point arrangement automation device for generating a digital map of an earthwork site is acquired from a camera provided in a Real-Time Kinematic (RTK) drone. A ground control point extraction unit that analyzes the generated images and extracts ground control points (GCP); And calculating the absolute coordinates of each of the extracted ground reference points using the distance between the extracted ground reference points and the laser distance meter, the RTK-GPS information of the RTK drone, and the 3-axis tilt of the RTK drone. It includes; remote surveying unit.

The ground reference point extracting unit may include an orthogonal image generation unit generating an orthogonal image for the entire earthwork site from a plurality of images captured by the camera; A candidate extraction unit that extracts objects or points that can be visually identifiable among the orthogonal images as candidate objects; A target extraction unit that extracts candidate objects capable of extracting feature points from among the extracted candidate objects as target objects; And a feature point extracting unit that extracts feature points for each of the extracted target objects and determines them as ground reference points.

When the feature point extractor calculates feature points for each of the target objects, divides the orthogonal image into a predetermined size to generate a plurality of areas, and a plurality of feature points exist in an area to be processed currently among the plurality of areas. , After calculating the priority of the plurality of feature points in consideration of at least one of the contrast ratio between each of the plurality of feature points and the background, the positions of the plurality of feature points, and the image overlap degree of the point to which the plurality of feature points belong A feature point having a high priority is extracted as a ground reference point of the area to be processed.

And a control unit for controlling the autonomous driving of the RTK drone so that the RTK drone is close to each of the extracted ground reference points by a preset distance so that the camera takes a close-up picture in real time.

The far-field survey unit, when an image obtained by real-time close-up of the ground reference point to be processed among the ground reference points to be processed is input from the camera, the ground reference point recognition unit to recognize the actual position of the ground reference point by analyzing the real-time close-up image ; A distance calculation unit for calculating a distance between the ground reference point and the laser distance finder by irradiating a laser to the ground reference point when the laser distance finder directs the ground reference point corresponding to the recognized real position vertically for a predetermined time; And a ground reference point coordinate extracting unit for extracting the coordinates of the ground reference point by correcting Z among the (X, Y, Z) coordinates of the RTK-GPS information of the RTK drone by the distance calculated by the distance calculating unit.

The control unit, while the camera takes a real-time close-up picture of the ground reference point, the laser range finder irradiates a laser, and the distance surveying unit extracts the coordinates of the ground reference point, the roll and pitch values of the inclination of the RTK drone are It controls the autonomous driving of the RTK drone to keep it at zero.

On the other hand, according to another embodiment of the present invention, a drone-based ground reference point placement automation method for generating a digital map of an earthmoving site includes (A) an electronic device acquired from a camera provided in a Real-Time Kinematic (RTK) drone. Analyzing images to extract ground control points (GCP); And (B) the electronic device, the extracted ground reference points using the distance between the extracted ground reference points and the laser distance meter, the RTK-GPS information of the RTK drone, and the 3-axis tilt of the RTK drone. It includes; calculating the absolute coordinates of each of the.

The step (A) includes the steps of: (A1) generating an orthogonal image of the entire earthwork site from a plurality of images captured by the camera; (A2) extracting objects or points that can be visually identifiable among the orthogonal images as candidate objects; (A3) extracting candidate objects capable of extracting feature points from among the extracted candidate objects as target objects; And (A4) extracting feature points for each of the extracted target objects and determining them as ground reference points.

In the step (A4), after calculating feature points for each of the target objects, a plurality of areas are generated by dividing the orthogonal image into a predetermined size, and a plurality of feature points exist in an area to be processed currently among the plurality of areas. In this case, the priority of the plurality of feature points is calculated in consideration of at least one of a contrast ratio between each of the plurality of feature points and a background, the positions of the plurality of feature points, and an image overlap degree of a point to which the plurality of feature points belong. After that, the feature point having the highest priority is extracted as the ground reference point of the area to be processed.

(C) the electronic device, after the step (A), controlling the autonomous driving of the RTK drone so that the RTK drone is close to each of the extracted ground reference points by a preset distance so that the camera takes close-up pictures in real time. It further includes;

In the step (B), (B1), when a real-time close-up image of the ground reference point to be processed is input from the camera, the real-time position of the ground reference point is recognized by analyzing the real-time close-up image. The step of doing; (B2) when the laser distance finder directs the ground reference point corresponding to the recognized real position vertically for a predetermined time, calculating a distance between the ground reference point and the laser distance finder by irradiating a laser to the ground reference point ; And (B3) correcting Z among the (X, Y, Z) coordinates of the RTK-GPS information of the RTK drone by the distance calculated in step (B2) to extract the coordinates of the ground reference point.

In the step (C), while the camera takes a close-up picture of the ground reference point in real time, the laser range finder irradiates the laser, and extracts the coordinates of the ground reference point, the roll and pitch values of the inclination of the RTK drone are 0. It controls the autonomous driving of the RTK drone to maintain it.

According to the present invention, by automatically extracting the ground reference point using the orthogonal image of the earthwork site, human error that may occur in the process of generating the digital map of the earthwork site can be minimized, and the measurement of the position coordinates of the detection point is also the same. As the method is automatically performed, consistent error rate measurement results can be provided to system users.

In addition, according to the present invention, it is possible to automatically measure the position of the ground reference point by using a long-distance surveying unit. Accordingly, if the location to be used as the ground reference point among earthworks sites is not flat, the existing point cannot be used as a ground reference point. You can solve the problem of technology.

The effects of the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the following description.

1 is a perspective view of a Real-Time Kinematic (RTK) drone 100 to which a drone-based ground reference point arrangement automation device for digital map generation of an earthwork site according to an embodiment of the present invention is applied,
2 is a block diagram of an RTK drone 100 according to an embodiment of the present invention,
3 is a block diagram showing in detail the ground reference point extraction unit 174;
Figure 4 is a block diagram showing in detail the distance surveying unit 176,
5 is a flowchart schematically showing a drone-based ground control point arrangement automation method for generating a digital map of an earthwork site according to an embodiment of the present invention; and
6 is a flowchart illustrating in detail a drone-based ground control point arrangement automation method for generating a digital map of an earthwork site according to an embodiment of the present invention.

The above objects, other objects, features, and advantages of the present invention will be easily understood through the following preferred embodiments related to the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided so that the disclosed contents may be thorough and complete, and the spirit of the present invention may be sufficiently conveyed to those skilled in the art.

In some cases, it is mentioned in advance that parts that are commonly known in describing the invention and are not largely related to the invention are not described in order to avoid confusion in the description of the invention for no apparent reason.

Where an element, component, device, or system is stated to contain a program or a component made of software, the element, component, device, or system is the execution or operation of the program or software, even if not explicitly stated. It should be understood to include hardware (for example, memory, CPU, etc.) or other programs or software (for example, a driver required to run an operating system or hardware).

In addition, it should be understood that the element (or component) may be implemented in software, hardware, or any form of software and hardware, unless otherwise specified in the implementation of a certain element (or component).

Hereinafter, with reference to the accompanying drawings, specific technical content to be implemented in the present invention will be described in detail.

Each configuration of the drone-based ground control point arrangement automation device for digital map generation of the earthwork site of the present invention may be functionally and/or logically separated, and each configuration must be classified as a separate physical device or a separate code. It may be easily inferred by an average expert in the art that it does not mean that it is written.

The drone-based ground control point arrangement automation device for generating a digital map of the earthwork site may be installed in a predetermined data processing device to implement the technical idea of the present invention.

1 is a perspective view of a real-time kinematic (RTK) drone 100 to which a drone-based ground reference point arrangement automation device for digital map generation of an earthwork site according to an embodiment of the present invention is applied. According to a block diagram of the RTK drone 100, FIG. 3 is a block diagram showing the ground reference point extraction unit 174 in detail, and FIG. 4 is a block diagram showing the far-field survey unit 176 in detail.

The RTK drone 100 shown in FIG. 1 or the drone-based ground reference point placement automation device for digital map generation of an earthwork site directly visits the actual location corresponding to the ground reference point and measures the coordinate value of the point to be set as the ground reference point. And it is possible to automate the existing process of collecting.

The digital map generation server 200 generates a digital map of the earthwork site using the image of the earthwork site received from the RTK drone 100 and the position coordinates of the measured and collected ground reference points.

1 and 2, the RTK drone 100 according to an embodiment of the present invention includes a body 110, a communication interface unit 120, a camera 130, a laser distance meter 140, an autonomous driving unit ( 150), a memory 160, and a processor 170 may be included.

The communication interface unit 120 provides a communication path between the RTK drone 100 and the RTK-GPS base 10 provided on the ground or in the field, and the base 10 can provide the coordinates of the drone 100 in real time. have.

In addition, the communication interface unit 120 is a digital map of the earthmoving site image, orthogonal image, the extracted feature points, the position coordinates of the feature points captured by the camera 130 in real time, periodically, or according to a user's request. It may be transmitted to a database (not shown) of the generation server 200.

The body 110 serves as a case for the RTK drone 100.

The camera 130 may be provided under the body 110 to photograph the ground. The camera 130 may adjust the photographing angle while adjusting the direction of the lens (not shown).

The laser range finder 140 is a laser scanner that is provided to form perpendicular to the bottom surface of the body 110, and the laser irradiated by the laser range finder 140 and the bottom of the body 110 may form vertical.

The autonomous driving driving unit 150 drives the RTK drone 100 to automatically arrange ground control points (GCP) while the RTK drone 100 flies over the earthwork site under the control of the control unit 172 to be described later. can do.

The memory 160 may include volatile memory and/or nonvolatile memory. In the memory 160, for example, in order to implement and/or provide operations, functions, etc. provided by the RTK drone 100, commands or data related to the components 110 to 170, one or more programs, and/or Software, operating system, etc. may be stored.

The program stored in the memory 160 may include an automatic ground reference point arrangement program for automatically arranging ground reference points by analyzing an aerial image captured by the RTK drone 100 flying over an earthmoving site.

The processor 170 controls the overall operation of the RTK drone 100 by executing one or more programs stored in the memory 160.

For example, the processor 170 executes a ground reference point automatic arrangement program stored in the memory 160 to extract a feature point usable as a ground reference point based on the image acquired from the RTK drone 100, and determine the location of the corresponding feature point. The coordinates indicated may be precisely measured, and the processor 170 may operate as a drone-based ground reference point arrangement automation device for generating a digital map of an earthwork site according to an embodiment of the present invention.

To this end, when the ground reference point automatic placement program is executed, the processor 170 applied as the ground reference point placement automation device according to an embodiment of the present invention includes a control unit 172, a ground reference point extracting unit 174, and a distance surveying unit 176. It may include.

The controller 172 may control the RTK drone 100 to operate in a feature point extraction mode in which feature points are extracted from an orthogonal image of an earthwork site and a survey mode in which coordinates of the extracted feature points are measured.

When operating in the feature point extraction mode, the controller 172 may control the driving of the autonomous driving driver 150 to fly over the earthwork site of the RTK drone 100. The control unit 172 allows the RTK drone 100 to fly vertically or transversely over the earthwork site, and allows it to fly at various angles.

In addition, the control unit 172 controls the camera 130 to photograph the earthwork site while the RTK drone 100 is flying, and the camera 130 is, for example, in the longitudinal direction for each frame while photographing the earthwork site. 80%, 80% or more in the horizontal direction, and photographing so that consecutive frames are overlapped, and the controller 172 may control the flight speed to maintain the degree of frame overlap in consideration of the shutter period of the camera 130. The frame overlapping degree of 80% can be changed according to flight altitude, flight speed, shutter period of the camera 130, weather, etc., as an example.

The controller 172 controls the ground reference point extraction unit 174 to analyze the captured image and extract ground reference points applicable to the earthwork site.

When all of the ground reference points are extracted by the ground reference point extraction unit 174, the control unit 172 switches to the survey mode, and the RTK drone 100 moves to the ground reference points extracted by the ground reference point extraction unit 174 by a preset distance. In proximity, the camera 130 may control the autonomous driving of the RTK drone 100 and the camera 130 to take a real-time close-up picture of an area including the ground reference points. In this case, the control unit 172 may check the positions of the ground reference points stored in the memory 160 so that the RTK drone 100 is positioned above the ground reference points.

Then, the control unit 172 moves the RTK drone 100 above the ideal ground reference point arranged to generate a digital map of the earthwork site within the orthogonal image of the earthwork site, and then the remote survey unit 176 The coordinates are measured, and when the coordinates are measured, the autonomous driving driving unit 150 and the long-distance surveying unit 176 may be controlled so that the RTK drone 100 returns to its initial position.

In addition, the controller 172 measures the distance to the ground reference point by the camera 130 taking a real-time close-up picture of the ground reference point, the laser distance measurer 140 irradiates the laser to the ground reference point, and the distance measurement unit 176 While extracting the coordinates of the ground reference point, the autonomous driving of the RTK drone 100 can be controlled so that the values of the roll, pitch, yaw roll and pitch sensed by the 3-axis tilt sensor of the RTK drone 100 remain 0. have. This is to maintain the horizontal level of the RTK drone 100, and it is possible to minimize an error when correcting coordinates for extracting a ground reference point.

Hereinafter, the ground reference point extraction unit 174 mainly operating in the feature point extraction mode and the long-distance survey unit 176 operating mainly in the survey mode will be described.

When the RTK drone 100 operates in the feature point extraction mode, the ground reference point extraction unit 174 may extract ground reference points by analyzing images acquired from the camera 130 provided in the RTK drone 100.

To this end, the ground reference point extracting unit 174 may include an orthogonal image generating unit 174a, a candidate extracting unit 174b, a target extracting unit 174c, and a feature point extracting unit 174d as shown in FIG. 3.

The orthogonal image generation unit 174a generates an orthogonal image of the entire earthwork site from a plurality of images taken by the camera 130 of the earthwork site to generate a digital map of the earthwork site.

The candidate extracting unit 174b may extract objects or points that can be visually identifiable among the orthogonal images as candidate objects. The candidate extraction unit 174b analyzes the orthogonal image and selects an object or point having a plane size of at least 30cm by 30cm within 3cm of the Ground Sample Distance (GSD) as a candidate object when considering the photographing altitude and the size of the object. Can be extracted. Examples of objects or points that can be visually identifiable include fixed objects such as manholes or road markings.

3cm and 30cm are examples, which can be changed according to the photographing height. In particular, the orthogonal image photographed by the drone 100 has a degree of overlap and stores a plurality of frames. In this case, it is determined as an example that it must have a size of at least 30cm by 30cm in order to be able to recognize at the same time in a plurality of frames.

The target extraction unit 174c may extract candidate objects capable of extracting feature points from among the extracted candidate objects, as target objects. The target extraction unit 174c inputs the extracted candidate object into a pre-learned target object extraction AI (artificial intelligence) algorithm, and determines that a feature point exists in the orthogonal image because the contrast ratio with the background exceeds a preset criterion. Candidate objects can be extracted as target objects. As a result, the ground reference point can be extracted irrespective of the leveling of the ground as long as the contrast with the background is clear and conditions applicable as feature points are present.

The preset criterion is a condition for extracting target objects, for example, the contrast between the background in the orthogonal image and the candidate object, which is a criterion that can be identified with the naked eye and at the same time extracting the center point or edge is possible. Means the minimum percentage of.

Therefore, the target extraction unit 174c enlarges and analyzes the orthogonal image, and if the contrast ratio between the candidate object (extracted object or point) and the background is greater than or equal to a preset first criterion and the sharpness of the outline is greater than or equal to a preset second criterion, (Or, if the contour line is crushed less than the second criterion), the corresponding candidate object may be extracted as a target object determined to have a feature point.

When the first mode is set in the device 170, the feature point extracting unit 174d automatically determines the feature point as a ground reference point by extracting the feature point for each extracted target object, and location information and feature point (or candidate objects) of the feature point in the orthogonal image. When taking a picture, the coordinates (X, Y, Z) of the RTK drone 100 can be checked and mapped and stored in the memory 160.

In addition, when a point corresponding to a feature point in an orthogonal image is checked, there are cases in which several to dozens of confirmed points are overlapped with images taken at different angles or different positions. In this case, the feature point extracting unit 174d can extract and match feature points of target objects that are overlapped from the plurality of overlapping images, which extracts common points of images captured from multiple angles, and automatically combines the extracted common points. It can also be set as the ground reference point by matching with the points of.

In addition, when the second mode is set in the device 170, the feature point extracting unit 174d generates a plurality of areas by dividing the orthogonal image into a predetermined size after calculating the feature points for each of the extracted target objects. If there are multiple feature points, only one feature point may be selected for each area.

In detail, the feature point extracting unit 174d has a plurality of feature points (hereinafter referred to as'target feature points') in an area to be processed currently (hereinafter, referred to as a'target area') among a plurality of generated areas. In this case, a plurality of target feature points is considered in consideration of at least one of a contrast ratio between each of the plurality of target feature points and the background, a location where it is easy to extract each of the plurality of target feature points, and an image overlap degree of a point to which the plurality of target feature points belong Calculate their priorities.

The feature point extracting unit 174d extracts the target feature points more as the number of nearby candidate objects existing within an n-meter radius based on each of the target feature points in the target area decreases, or the distance from the neighboring candidate objects increases. It can be determined that this is an easy location.

In addition, the feature point extracting unit 174d may calculate the priority of the target feature points by assigning the highest weight to the contrast ratio with the background, the lowest weight to the image overlap degree, or vice versa. Alternatively, the feature point extracting unit 174d may calculate the priority of the target feature points by assigning the same weight to the contrast ratio with the background, the position of the feature point, and the image overlap degree.

Explaining the degree of image overlap, when checking the point corresponding to the feature point in the orthogonal image, the identified points are overlapped with images taken from several to dozens of different angles or different positions, and the number of overlaps is proportional to the image overlap degree. do. This is because the accuracy as a feature point increases when an object or point that can be recognized simultaneously from a plurality of images is extracted.

In addition, the feature point extracting unit 174d extracts the target feature point having the highest priority as the ground reference point of the target area to be processed currently, checks the location of the extracted ground reference point in the orthogonal image, and stores it in the memory 160. have.

On the other hand, when the feature point extraction is completed for all target objects extracted from the orthogonal image, or feature point extraction for each area is completed, that is, when all ground reference points usable in the orthogonal image are extracted, the operation mode of the RTK drone 100 is It is switched to the surveying mode, and the distance surveying unit 176 operates.

As a result, the RTK drone 100 checks the location of each ground reference point stored in the memory 160 and moves to be close by a preset distance from each ground reference point, and the camera 130 is an area (or target object) including the ground reference point. A close-up picture is taken in real time, and the laser distance finder 140 irradiates the laser to an actual position of the extracted feature point based on the image being taken in real-time close-up so that the distance between the laser distance finder 140 and the ground reference point is calculated.

The distance survey unit 176 is the extracted distance between each of the ground reference points and the laser distance meter 140, the RTK-GPS information of the RTK drone 100, and the ground extracted using the 3-axis tilt of the RTK drone 100. The absolute coordinates of each of the reference points can be calculated.

To this end, the distance measuring unit 176 may include a ground reference point recognition unit 176a, a distance calculation unit 176b, and a ground reference point coordinate extraction unit 176c as shown in FIG. 4.

The ground reference point recognition unit 176a receives a real-time close-up image of the currently processed ground reference point (hereinafter referred to as a'target ground reference point') among the extracted ground reference points, and the real-time close-up image It is possible to recognize the target ground reference point by analyzing.

If the distance calculating unit 176b determines that the laser distance meter 140 is vertically pointing the target ground reference point corresponding to the actual position recognized by the ground reference point recognition unit 176a for a predetermined time, the target ground reference point The distance between the target ground reference point and the laser distance meter 140 is calculated using the time at which the irradiated laser is reflected and reached and the laser irradiation speed.

The control unit 172 compares the time when the roll value and the pitch value acquired from the 3-axis inclination sensor (not shown) are maintained at 0, and the real-time close-up image frame input from the camera 130 compared with the previous frame. If it is less than a certain ratio, it is determined that the ground reference point is oriented vertically, and the distance calculating unit 176b may be controlled to calculate the distance.

The ground reference point coordinate extraction unit 176c corrects Z among the (X, Y, Z) coordinates of the RTK-GPS information of the RTK drone 100 by the distance calculated by the distance calculation unit 176b to correct the coordinates of the target ground reference point. It can be finally extracted.

Accordingly, the processor 170 applied as a drone-based ground reference point placement automation device for generating a digital map of an earthwork site extracts all the location coordinates of the ground reference points located on the target objects, and extracts the location coordinates of each of the extracted ground reference points. The orthogonal image generated by the orthogonal image generator 174a or images (or moving pictures) photographed of the earthwork site used for generating the orthogonal image are processed to be transmitted to the digital map generation server 200.

That is, the processor 170 transmits the image used for the ground reference point extraction to the digital map generation server 200 without performing an operation of re-photographing the earthwork site after the location coordinates of the ground reference points are extracted. Resources and procedures used for map creation can be minimized.

The digital map generation server 200 stores the earthmoving site photographed images used to generate the orthogonal image or orthogonal image received from the RTK drone 100 and the location coordinates of the ground reference points in a database (not shown), and uses this It generates point cloud data (PCD), and generates digital maps of earthworks sites such as DSM or DEM using PCD.

According to the above-described embodiment of the present invention, instead of the existing technology in which the setter directly moves to a position corresponding to the ground reference point and measures and collects the coordinate value of the ground reference point, the ground reference point is automatically collected by a drone. Of course, the collected ground control points can be automatically recorded in the database. In particular, in the past, a method of installing a mark such as a chess board at the position of the ground reference point prior to shooting a drone image has been used, but when the embodiment of the present invention is applied, a ground reference point based on a feature point of a fixed terrain feature is used. Regardless of whether or not signs such as chess boards are installed, digital maps of the earthwork site can be generated. In other words, it is possible to more flexibly plan the digital map creation process of the earthwork site, adaptively responding to rapidly changing site conditions, and improve work productivity and efficiency.

In addition, the input of the ground reference point and the measurement of the location coordinates of the detection point currently being performed are performed in a way that the system user directly checks, inputs and measures the ground reference point and the detection point in the digital map of the final earthwork site. Therefore, it has a limitation that input and measurement values are different depending on the user.

In an embodiment of the present invention, a human error that may occur in the process of generating a digital map of an earthmoving site is applied by applying an algorithm that automatically matches the position of the ground reference point in the entire earthwork site photographed image based on the image used to extract the ground reference point. Can be minimized, and a consistent error rate measurement result can be provided to the system user as the location coordinate measurement of the detection point is also automatically performed in the same manner as the GCP measurement described above.

5 is a flowchart schematically showing a drone-based ground control point arrangement automation method for generating a digital map of an earthwork site according to an embodiment of the present invention, and FIG. 6 is a digital map generation of an earthwork site according to an embodiment of the present invention. This is a flow chart showing in detail how to automate the deployment of drone-based ground control points for the purpose.

The electronic device that performs the method for automating ground reference point placement illustrated in FIGS. 5 and 6 may be the RTK drone 100 described with reference to FIGS. 1 to 4 or an apparatus for automating ground reference point placement.

Referring to FIG. 5, in the feature point extraction mode, the electronic device extracts ground reference points (GCPs) by analyzing images acquired by photographing an earthmoving site from a camera 130 provided in the RTK drone 100 (S510).

The electronic device switches to the survey mode so that the RTK drone 100 approaches each ground reference point and takes a real-time close-up picture of an area including the ground reference point (S520).

The electronic device is the ground reference point extracted in step S510 using the distance between the respective ground reference points and the laser distance meter 140, RTK-GPS information of the RTK drone 100, and the 3-axis tilt of the RTK drone 100. The absolute coordinates of each of them are calculated (S530).

When the coordinates of all the ground reference points are extracted in step S530, the electronic device transmits the coordinates of all the ground reference points and the photographed image (or orthogonal image) of the earthwork site photographed by the camera 130 to the digital map generation server 100 Do (S540).

The digital map generation server 200 stores the coordinates of all the received ground reference points and the photographed image (or orthogonal image) of the earthmoving site photographed by the camera 130 in a DB, and uses this to store the image-based point cloud data (PCD). ), it is possible to generate a digital map of DSM or DEM (S550, S560). In step S550, the digital map generation server 200 may generate a digital map after regenerating an orthogonal image of an earthmoving site or correcting the received orthogonal image by using the coordinates and point group data of the ground reference points.

As a result, in the past, human resources directly visit the actual location corresponding to the ground reference point, install a mark such as a chess board, set the ground reference point and the detection point to acquire coordinates, and then use a drone to acquire an image of the earthmoving site. While each of the above processes is performed, in the present invention, the coordinates of the ground reference point can be acquired from the earthwork site image while acquiring the photographed image of the earthwork site using the drone 100. And, without performing the process of photographing the earthwork site again after acquiring the coordinates of the ground reference point, the already captured image and the coordinates of the ground reference point are transmitted to the digital map generation server 200, thereby simplifying the existing classification process. Digital maps such as DSM or DEM can be created accurately and quickly.

Referring to FIG. 6, steps S510 and S530 will be described in detail. In the feature point extraction mode, the electronic device is a plurality of images captured by the camera 130 so that each frame overlaps while the RTK drone 100 moves through the earthwork site. Generates an orthogonal image of the entire earthwork site from the field (S511).

The electronic device determines objects or points that can be visually identifiable among the generated orthogonal images and extracts them as candidate objects (S513). In this case, the electronic device may map and store location information of the drone 100 at a point where candidate objects are extracted, identification information of candidate objects, and location information of candidate objects in an orthogonal image.

The electronic device determines candidate objects capable of extracting feature points among the extracted candidate objects and extracts them as target objects (S515).

The electronic device extracts feature points for each extracted target object and extracts a plurality of ground reference points (S517).

When all the ground reference points are extracted from the orthogonal image of the earthwork site, the electronic device switches to the surveying mode, and the RTK drone 100 is close to each of the extracted ground reference points by a preset distance, so that the camera 130 takes a real-time close-up shot. Let it be (S520). In step S520, the electronic device may take a photograph close to the ground reference point by using the location information of the drone 100 that is mapped and stored in step S513.

In addition, when an image obtained by real-time close-up of the ground reference point to be processed among the ground reference points is input from the camera 130, the electronic device analyzes the real-time close-up image to recognize the actual position of the ground reference point (S531).

The electronic device calculates the distance between the ground reference point and the laser distance finder 140 by irradiating the laser to the ground reference point when the laser distance finder 140 directs the ground reference point corresponding to the recognized real position vertically for a predetermined time. Do (S533).

The electronic device extracts the coordinates of the ground reference point to be processed by subtracting Z from the coordinates of (X, Y, Z), which is the RTK-GPS information of the RTK drone 100, by the distance calculated in step S533 (S535).

While steps S520 and S530 are performed, the electronic device may control the autonomous driving of the RTK drone 100 so that the roll and pitch values of the three-axis tilt of the RTK drone 100 remain 0.

In the above, even if all the components constituting the embodiments of the present invention are described as being combined into one or operating in combination, the present invention is not necessarily limited to these embodiments. That is, within the scope of the object of the present invention, all the constituent elements may be selectively combined and operated in one or more. In addition, although all of the components may be implemented as one independent hardware, a program module that performs some or all functions combined in one or more hardware by selectively combining some or all of the components. It may be implemented as a computer program having Codes and code segments constituting the computer program may be easily inferred by those skilled in the art. Such a computer program is stored in a computer-readable storage medium, and is read and executed by a computer, thereby implementing an embodiment of the present invention.

As described above and illustrated in connection with a preferred embodiment for illustrating the technical idea of the present invention, the present invention is not limited to the configuration and operation as shown and described as described above, and deviates from the scope of the technical idea. It will be well understood by those skilled in the art that many changes and modifications can be made to the present invention without. Accordingly, all such appropriate changes and modifications and equivalents should be regarded as belonging to the scope of the present invention. Therefore, the true technical protection scope of the present invention should be determined by the technical idea of the attached registration claims.

100: RTK drone 110: body
120: communication interface unit 130: camera
140: laser range finder 150: autonomous driving drive unit
160: memory
170: Drone-based ground control point placement automation device for processor or digital map generation

Claims (6)

A ground control point extraction unit for extracting ground control points (GCPs) by analyzing images acquired from a camera provided in a real-time kinematic (RTK) drone; And
Long distance for calculating the absolute coordinates of each of the extracted ground reference points by using the distance between each of the extracted ground reference points and the laser range finder, the RTK-GPS information of the RTK drone, and the 3-axis tilt of the RTK drone Including;
The ground reference point extraction unit,
An orthogonal image generator for generating an orthogonal image for the entire earthwork site from a plurality of images captured by the camera on the earthwork site;
A candidate extraction unit for extracting objects or points that can be visually identifiable among the orthogonal images as candidate objects;
A target extraction unit that extracts candidate objects capable of extracting feature points from among the extracted candidate objects as target objects; And
A drone-based ground reference point placement automation device for generating a digital map of an earthwork site comprising a; feature point extracting unit that extracts feature points for each of the extracted target objects and determines as a ground reference point. delete The method of claim 1,
The feature point extraction unit,
After calculating feature points for each of the target objects, a plurality of areas are generated by dividing the orthogonal image into a predetermined size, and when a plurality of feature points exist in an area to be processed currently among the plurality of areas, the plurality of feature points After calculating the priority of the plurality of feature points in consideration of at least one of the contrast ratio between each of the feature points and the background, the location of the plurality of feature points, and the image overlap degree of the point to which the plurality of feature points belong, A drone-based ground reference point arrangement automation device for generating a digital map of an earthwork site, characterized in that extracting a feature point as a ground reference point of the currently processed area. The method of claim 1,
The digital map generation of the earthwork site further comprises a control unit for controlling the autonomous driving of the RTK drone so that the RTK drone is close to each of the extracted ground reference points by a preset distance so that the camera takes a real-time close-up picture. A drone-based ground control point placement automation device for The method of claim 4,
The distance surveying unit,
A ground reference point recognition unit that analyzes the real-time close-up image of the ground reference point to be processed from the camera and recognizes the actual position of the ground reference point;
A distance calculator configured to calculate a distance between the ground reference point and the laser distance finder by irradiating a laser to the ground reference point when the laser distance finder directs the ground reference point corresponding to the recognized real position vertically for a predetermined time; And
And a ground reference point coordinate extraction unit for extracting the coordinates of the ground reference point by correcting Z among the (X, Y, Z) coordinates of the RTK-GPS information of the RTK drone by the distance calculated by the distance calculation unit. A drone-based ground control point placement automation device for digital map creation of earthwork sites. The method of claim 5,
The control unit,
While the camera takes a close-up picture of the ground reference point in real time, the laser range finder irradiates the laser, and the distance surveying unit extracts the coordinates of the ground reference point, the roll and pitch values of the inclination of the RTK drone are maintained to be zero. A drone-based ground control point arrangement automation device for digital map generation of an earthwork site, characterized in that it controls the autonomous driving of RTK drones.

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