KR20160019613A - Apparatus for modeling 3d of underground structure and method thereof - Google Patents

Abstract

Disclosed are a three-dimensional modeling apparatus of an underground structure, and a method thereof. The three-dimensional modeling apparatus of the underground structure comprises: a laser sensor for measuring the distance from a structure; a plurality of red, green, blue-distance (RGB-D) cameras installed to obtain a three-dimensional image; a horizontal support stand for mounting and fixing the laser sensor, the RGB-D cameras, and a global positioning system (GPS) module onto a safety helmet; a storage unit for storing a design drawing and a three-dimensional model of an underground structure, and second-dimensional geographic information system (GIS) data; and a control unit for generating a depth map image through the distance and the three-dimensional image inputted by the laser sensor and the RGB-D cameras to be combined with the design drawing of the underground structure stored in the storage unit so as to generate the three-dimensional model of the underground structure, and storing two-dimensional GIS data extracted in a GIS shape in the storage unit by converting the three-dimensional model of the underground structure into a two-dimensional coordinate.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional modeling device for an underground structure,

The present invention relates to an apparatus and method for three-dimensional modeling of an underground structure, and more particularly, to an apparatus and method for modeling an underground structure by using an RGB-D camera which can be easily worn by an investigator, Dimensional modeling apparatus for a ground structure, and a method thereof, which enables a geometric relationship between underground structures to be grasped by storing them as two-dimensional GIS data.

In recent economic maturity, the interest and importance of maintenance of facilities such as bridges, tunnels, buildings, roads, etc. has been increased with explosive economic growth in the past. Also, maintenance of the facilities is becoming more important for the safety of the unspecified number of people using the above facilities.

Generally, the most basic thing in performing maintenance of a facility is to identify the damage to the state or facility of the facility through periodic / non-periodic inspection of the facility and systematically manage it so that the manager Judgments and actions.

In recent years, with the rapid progress of urbanization, the installation of water supply and drainage pipes, city gas supply pipes, oil transfer pipes, electricity and communication lines, etc. has been increasing rapidly in order to expand infrastructure such as electricity, communication and water supply and sewage. These facilities are mostly buried in the ground due to aesthetics and facility protection.

However, since the information about the location and depth of such underground facilities is not accumulated, it takes time and expense to visually ascertain its position and condition, and the existing underground materials are destroyed during the construction, do. In other words, if there is a lot of pipelines buried in a densely populated area, failure to understand the location and condition of pipelines can lead to accidents.

In order to prepare for this, a guide plate is displayed on the road where a communication cable line or a gas supply pipe passes. However, accurate information on the position and depth of the guide plate depends on existing design schemes.

Therefore, in order to measure the subsurface buried material on the ground, methods of measuring the wavelength change propagated through the medium and the buried material were used after propagating electromagnetic wave, ultrasonic wave or microwave to the ground. As another method, there is proposed a method of measuring the magnetic field of a current generated in a magnetic coil by installing a magnetic coil in an upper part of a subterranean buried object and inducing magnetism on a ground measuring instrument.

BACKGROUND ART [0002] The background art of the present invention is disclosed in Korean Patent Laid-Open Publication No. 2011-0072468 (published on June 29, 2011, entitled POWER PORT MONITORING SYSTEM).

In this way, when the measurement is made on the ground, there are areas that can not be explored by the surrounding ground structures, and in general, there is a problem that the exploration equipment is expensive and thus it is difficult to apply in actual work sites.

In addition, there are devices that can accurately acquire the two-dimensional coordinate data of the underground pipeline while directly driving the underground pipeline. However, these devices include a plurality of sensor devices such as a sensor for measuring the travel distance of the underground pipe, a tilt sensor, There is a problem in that it is difficult to use in a practical practical field because the volume and size of the load body are large and the maintenance cost is extremely high.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to provide an image processing apparatus and method, in which an information of an underground structure is extracted through an RGB- Dimensional modeling apparatus and method of the underground structure, which enables the geometrical relationship between the underground structures to be grasped by storing them as two-dimensional GIS data.

An apparatus for three-dimensional modeling of an underground structure according to an aspect of the present invention includes: a laser sensor for measuring a distance to a structure; A plurality of RGB-D cameras installed to acquire three-dimensional images; A horizontal support for attaching and fixing the laser sensor and RGB-D camera to the helmet; A storage unit for storing design drawings of an underground structure, a three-dimensional model of an underground structure, and two-dimensional GIS data; And 3-D models of underground structures are created by combining the depth map images from the distance input from the laser sensor and the RGB-D camera and the 3D map images and combining them with the design drawings of the underground structures stored in the storage unit. And a control unit for converting the 2D model into two-dimensional coordinates and storing the two-dimensional GIS data extracted in the GIS shape in the storage unit.

The present invention further includes a horizontal sensing unit for measuring the horizontal state of the horizontal support and providing it to the control unit, wherein the control unit corrects the horizontal error of the image input from the plurality of RGB-D cameras.

The present invention further includes a GPS module for measuring the position, wherein the control unit registers the viewpoint position of the underground structure which starts the survey based on the position input from the GPS module.

According to another aspect of the present invention, a three-dimensional modeling method of an underground structure includes: registering a design drawing of a selected underground structure by a control unit; Receiving a distance between the control unit and the ground structure measured from the laser sensor and a three-dimensional image of the ground structure from the RGB-D camera; Creating a cluster for the underground structure by generating and image-processing a distance to the underground structure and a depth map for the underground structure from the three-dimensional image; And generating a three-dimensional model of the underground structure by creating a surface on the geometric boundary of the design drawing based on the cluster for the underground structure and mapping the three-dimensional image to the surface by the control unit. do.

The present invention is characterized by further comprising the step of registering a viewpoint position of an underground structure from which the control unit starts surveying.

The step of registering the viewpoint position in the present invention is characterized in that the viewpoint position is registered with the position input from the GPS module.

In the present invention, the control unit calculates the boundary of the cross section with respect to the three-dimensional model of the underground structure, converts the underground structure into the two-dimensional coordinate based on the reference line line generated by connecting the center line of the boundary, The method of claim 1, further comprising:

An apparatus and method for three-dimensional modeling of an underground structure according to the present invention extracts position information of an underground structure through an RGB-D camera mounted on a helmet, which can be easily worn by an investigator, It is possible to measure the geometry of the underground structures while walking on foot because it is possible to grasp the geometrical relationship between the underground structures by storing them as the dimension GIS data.

In addition, according to the present invention, by precisely measuring the position and size of an underground structure and storing data in real time, it is possible to prevent breakage of the underground pipe during maintenance of the underground structure or repair the damaged part quickly, The three-dimensional model of the structure can provide a basis for managing the information recorded in a repetitive maintenance process based on BIM (Building Information Modeling).

1 is a block diagram illustrating an apparatus for modeling a three-dimensional structure of an underground structure according to an embodiment of the present invention.
FIG. 2 is an exemplary view illustrating an apparatus for three-dimensional modeling of an underground structure according to an embodiment of the present invention.
3 is a flowchart illustrating a three-dimensional modeling method of an underground structure according to an embodiment of the present invention.
FIGS. 4 to 19 are views for explaining respective steps of a three-dimensional modeling method of an underground structure according to an embodiment of the present invention.

Hereinafter, an apparatus and method for three-dimensional modeling of an underground structure according to an embodiment of the present invention will be described with reference to the accompanying drawings. In this process, the thicknesses of the lines and the sizes of the components shown in the drawings may be exaggerated for clarity and convenience of explanation.

In addition, the terms described below are defined in consideration of the functions of the present invention, which may vary depending on the intention or custom of the user, the operator. Therefore, definitions of these terms should be made based on the contents throughout this specification.

FIG. 1 is a block diagram illustrating a three-dimensional modeling apparatus for an underground structure according to an embodiment of the present invention, and FIG. 2 is an exemplary view illustrating an apparatus for modeling a three-dimensional structure according to an exemplary embodiment of the present invention.

1 and 2, an apparatus for three-dimensional modeling of an underground structure according to an embodiment of the present invention includes a laser sensor 10, an RGB-D camera 20, a GPS module 30, 70, a storage unit 50, and a control unit 40, as well as a horizontal sensing unit 60.

The laser sensor 10 measures and provides a distance to an underground structure.

The RGB-D camera 20 is installed in a plurality to acquire a three-dimensional image of an underground structure to provide a stereo image.

The GPS module 30 receives the navigation message from a plurality of GPS satellites (not shown) located above the earth, and provides the navigation message to calculate the position.

The calculated location is used to register the viewpoint location at the entrance of the underground structure to begin the survey.

The horizontal support 70 mounts and fixes the laser sensor 10, the RGB-D camera 20, and the GPS module 30 to the safety helmet 80. When the user wears and irradiates the safety helmet 80, So that the horizontal position of the RGB-D camera 20 can be matched.

The storage unit 50 stores the design drawings of the underground structure, the three-dimensional model of the underground structure, and the two-dimensional GIS data.

The design drawing of the underground structure stored in the storage unit 50 can be utilized in correcting an area not acquired by the surrounding environment.

The control unit 40 generates a depth map image through the distance inputted from the laser sensor 10 and the RGB-D camera 20 and the three-dimensional image, Combine with the design drawings to create a three-dimensional model of the underground structure. In addition, the control unit 40 stores the two-dimensional GIS data obtained by extracting a GIS (Geographic Information System) shape by converting the three-dimensional model of the underground structure into two-dimensional coordinates in the storage unit 50.

The horizontal sensing unit 60 measures the horizontal state of the horizontal support 70 and provides the measured horizontal state to the control unit 40 so that the control unit 40 calculates the horizontal error of the image input from the plurality of RGB- So that it can be corrected.

In addition, when the control unit 40 can analyze the positional relationship with a plurality of underground structures, the control unit 40 registers the viewpoint position of the underground structure to start the survey based on the position input from the GPS module 30.

On the other hand, by using the tablet PC as the control unit 40, it is possible for the investigator to easily carry the portable robot while walking on the ground while the robot is moving.

As described above, according to the three-dimensional modeling apparatus for an underground structure according to an embodiment of the present invention, the information of an underground structure is extracted through an RGB-D camera mounted on a helmet which can be easily worn by an investigator, Modeling is performed and it is stored as 2-dimensional GIS data, so that the geometric relationship between the underground structures can be grasped, so that the shape of the underground structure can be measured while moving on foot.

FIG. 3 is a flow chart for explaining a three-dimensional modeling method of an underground structure according to an embodiment of the present invention, and FIGS. 4 to 19 are diagrams for explaining respective processes of a three-dimensional modeling method of an underground structure according to an embodiment of the present invention Fig.

As shown in FIG. 3, in the 3D modeling method of an underground structure according to an embodiment of the present invention, the control unit 40 registers a design drawing of a selected underground structure (S10).

When a design drawing for a plurality of underground structures is stored in the storage unit 50, a design drawing of the selected underground structure is registered as shown in FIG. 4, so that it can be utilized in correcting an area not acquired by the surrounding environment.

Then, the control unit 40 registers the viewpoint position as the input position from the GPS module 30 at the entrance of the underground structure to start the survey (S20) as shown in FIG.

In this way, the point of view and the direction of travel are initialized at the entrance of the structure that starts the survey. However, registration of such a viewpoint position is necessary when analyzing the position relation with a plurality of underground structures. It is possible to observe the shape of an independent underground structure and to omit the registration of the viewpoint position when not related to the GIS.

After registering the viewpoint position at the entrance of the underground structure for survey in step S20, the control unit 40 calculates the distance from the ground structure measured from the laser sensor 10 and the distance from the RGB-D camera 20 to the three- An image is input (S30).

The distance to the underground structure and the three-dimensional image are continuously measured and photographed while the investigator moves inside the underground structure.

The control unit 40 generates a depth map for the underground structure from the input image of the underground structure and a depth map for the underground structure from the three-dimensional image, and implements the depth map to generate a cluster for the observed underground structure (S40).

More specifically, as shown in FIG. 6, the control unit 40 generates a depth map and extracts a depth image using a distance from the structure and a three-dimensional image. Then, as shown in FIG. 7, the control unit 40 converts the first-corrected two-dimensional depth image into three-dimensional data in the form of point cloud data to extract points and perform subsampling.

At this time, it is possible to reduce the total data capacity by disposing a three-dimensional point in a predefined cell and merging points in each cell to generate new one points.

Then, as shown in FIG. 8, the control unit 40 extracts a normal vector of each of the pointers through association analysis with neighboring points, and performs layering.

At this time, a shadow correction filter for the object object is applied using the calculated normal vector and coordinate information of the points to remove the filtered portion on the depth image.

Then, as shown in FIG. 9, the control unit 40 smoothing the normal vector value of each point to reduce the variation of the value, and calculates the intensity information of the generated three-dimensional point cloud data and the normal vector The layered image is segmented using information to create clusters that are distinguished from the surrounding environment.

Then, as shown in Fig. 10, the control unit 40 first removes the shields other than the tunnels to which the shape matching algorithm is applied for the generated clusters. Then, this process is repeated to create clusters of a number of block-shaped underground structures. The control unit 40 then extracts keypoints for the clusters for the entire section of the underground structure. These keypoints are objects that exist stably among the entire point cloud data and are moved to a reference node when merging a plurality of image images observed while moving. That is, the point cloud data of the next frame is coordinate-converted into the x, y, z and normal vector values of the key-point in the current frame.

After creating the clusters for the underground structure, the control unit 40 creates a surface on the geometric boundaries of the design drawing based on the clusters for the underground structure, and maps the three-dimensional image to the surface by texture mapping, (S50).

Specifically, as shown in FIG. 11, a user manually removes the entrance portion of a cluster model for an underground structure using geometric coordinates.

12, the control unit 40 arranges the surface on the basis of the geometric information of the design drawing of the registered underground structure, calculates the boundary and the center point for the result, Extract the line.

13, the control unit 40 arranges a cross section of the underground structure, aligns the cross section with the point cloud as shown in FIG. 14, and convex hulls for mesh generation using points as shown in FIG. 15 hull. This creates a merged surface model.

Next, as shown in FIG. 16, the control unit 40 performs interpolation on a surface model that has no shape of a completely closed underground structure due to an unobserved region such as a region removed in the filtering process of the shielding data or raw data Thereby creating a completely closed surface model as shown in Fig.

Then, the control unit 40 performs texture mapping on the RGB information observed from the raw data to the surface model thus generated to generate a three-dimensional model of the underground structure as shown in FIG.

Thereafter, the control unit 40 extracts the three-dimensional model of the underground structure in a two-dimensional GIS shape (S60).

Generally, since the tunnel type underground structure is linearly displayed on the GIS, the boundary of the section of the underground structure of the generated three-dimensional model is calculated, and then the center line of the boundary is continuously connected to the reference line of the three- Create a line. Then, it transforms the underground structures into 2D coordinates through matrix operation and extracts them into GIS shape.

At this time, when the underground structure is displayed on the GIS, the control unit 40 reflects the movement and rotation of the model with reference to the viewpoint position and direction of the underground structure, and changes the model position to real coordinates to assign the coordinates. If the viewpoint position is not registered, the absolute coordinates of the model may be directly input.

As described above, according to the three-dimensional modeling method of the underground structure according to the embodiment of the present invention, the location information of the underground structure is extracted through the RGB-D camera mounted on the helmet which can be easily worn by the surveyor, Modeling is performed and it is stored as 2-dimensional GIS data, so that the geometric relationship between the underground structures can be grasped, so that the shape of the underground structure can be measured while moving on foot.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill 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. I will understand.

Accordingly, the technical scope of the present invention should be defined by the following claims.

10: Laser sensor 20: RGB-D camera
30: GPS module 40: control unit
50: storage unit 60: horizontal sensing unit
70: Horizontal support 80:

Claims (7)

A laser sensor for measuring the distance to an underground structure;
A plurality of RGB-D cameras installed to acquire three-dimensional images;
A horizontal support for mounting and fixing the laser sensor and the RGB-D camera on the safety helmet;
A storage unit for storing a design drawing of the underground structure, a three-dimensional model of the underground structure, and two-dimensional GIS data;
A depth map image is generated through the distance input from the laser sensor and the RGB-D camera and the three-dimensional image, and is combined with a design drawing of the underground structure stored in the storage unit to generate a three-dimensional model of the underground structure And a control unit for converting the three-dimensional model of the underground structure into two-dimensional coordinates and storing the two-dimensional GIS data extracted in the GIS shape into the storage unit.
The image processing apparatus according to claim 1, further comprising: a horizontal sensing unit for measuring a horizontal state of the horizontal support and providing the measured horizontal state to the control unit, wherein the control unit corrects a horizontal error of an image input from the plurality of RGB- A three - dimensional modeling device for an underground structure.
The GPS module according to claim 1, further comprising a GPS module for measuring a position, wherein the control unit registers a viewpoint position of the underground structure to start an investigation based on a position input from the GPS module 3D modeling device of structure.
Registering a design drawing of a selected underground structure by the control unit;
Receiving the three-dimensional image of the underground structure from the RGB-D camera and the distance from the underground structure measured from the laser sensor to the control unit;
The control unit generating and image-processing a depth map for the underground structure from the distance and the three-dimensional image with the underground structure to create a cluster for the underground structure; And
Generating a three-dimensional model of the underground structure by creating a surface on a geometric boundary of the design drawing based on the clusters for the underground structure, and mapping the three-dimensional image to the surface by the control unit; Dimensional modeling of the underground structure.
5. The method of claim 4, further comprising: registering a viewpoint position of the underground structure in which the control unit starts the survey.
6. The method according to claim 5, wherein the step of registering the viewpoint position registers the viewpoint position as a position input from the GPS module.
The method according to claim 4, wherein the control unit calculates the boundary of the cross section with respect to the three-dimensional model of the underground structure, and connects the underground structure to the two-dimensional coordinates based on the reference line line generated by connecting the center line of the boundary Dimensional GIS shape, and then extracting the two-dimensional GIS shape.

Images