JP2020190502A - Landform measuring method and marker for measuring landform - Google Patents

Abstract

To easily combine a plurality of pieces of three-dimensional landform data.SOLUTION: In a landform measuring method in which three-dimensional landform data D1-D4 acquired by a three-dimensional scanner are combined, for acquiring three-dimensional landform data in almost whole area in a measuring object region, the three-dimensional landform data D1 is acquired through: a marker installation step for installing a marker on at least three points P1.1, P1.2 and P1.3 on a section α1 corresponding to the three-dimensional landform data D1; a marker coordinate acquiring step for acquiring coordinates of points P1.1, P1.2 and P1.3 on one coordinate system; and a scan step for scanning the surrounding by installing the three-dimensional scanner at a point in which all markers installed in the points P1.1, P1.2 and P1.3 are in a visual field. The subsequent three-dimensional landform data D2-D4 are also acquired in a similar way, and by arranging on the one coordinate system, the three-dimensional landform data D1-D4 with a coordinate of the marker as a reference, the three-dimensional landform data D1-D4 are combined.SELECTED DRAWING: Figure 11

Description

The present invention relates to a terrain measurement method for measuring terrain and a terrain measurement marker used when measuring terrain.

In the investigation of tumuli, it is important to measure their three-dimensional shape. The measurement of the three-dimensional shape of an ancient burial mound has long been performed by flat plate surveying. However, flat plate surveying has a drawback that the measurement accuracy is low in addition to the enormous amount of human labor. For this reason, in recent years, it has become possible to measure the three-dimensional shape of an ancient burial mound by irradiating a laser from above the ancient burial mound (see, for example, paragraph 0036 of Patent Document 1). However, this method has a drawback that it is not possible to capture the undulations of the ground surface in the part covered with a canopy or the like and hidden from the sky. Therefore, the measurement from the sky using a laser is only used as an aid to the field survey until it gets tired, and the field survey is still required to accurately measure the three-dimensional shape of the tumulus.

In view of such circumstances, the applicant has proposed a method of installing a three-dimensional scanner on the ground to measure the three-dimensional shape of the topography of the tumulus (see, for example, Patent Document 2). However, in addition to the undulating surface of the tumulus, there are many obstacles such as trees and weeds on the surface of the tumulus. Therefore, it is not possible to measure the three-dimensional shape of the entire tumulus with one measurement. In this regard, in the topographical measurement method of Patent Document 2, measurement by a three-dimensional scanner is performed at a plurality of points, and by synthesizing the three-dimensional topographical data obtained by each measurement, the entire area to be measured such as an ancient burial mound is substantially covered. I am trying to get a three-dimensional shape.

In addition, as described above, when synthesizing three-dimensional terrain data measured at multiple points, it is necessary to specify the three-dimensional direction in each three-dimensional terrain data, and for that purpose, each tertiary It is necessary to know the coordinates of at least three points in the original terrain data. In this regard, in the terrain measurement method of Patent Document 2 described above, the GPS coordinates of the point where the three-dimensional scanner is installed are used for the coordinates of one point, and the points where the markers are installed for the coordinates of the remaining two points. By using the GPS coordinates of, the three-dimensional direction in each three-dimensional topographical data is specified.

Japanese Unexamined Patent Publication No. 2009-014643 Japanese Patent No. 6479718

However, in the topographical measurement method of Patent Document 2, it is not always possible to easily synthesize a plurality of three-dimensional topographical data in which three-dimensional directions are specified.

This is because, in the terrain measurement method of Patent Document 2, each three-dimensional terrain data is measured by a three-dimensional scanner so that a plurality of three-dimensional terrain data after the three-dimensional direction is specified can be connected well. When doing so, a sphere called a "sphere" is placed at a location that overlaps with the adjacent measurement range in each measurement range, and when synthesizing the obtained 3D terrain data, the sphere in each 3D terrain data is used. Numbering is performed on the reflection points of, and adjacent 3D topographical data are connected so that the same spheres overlap.

However, on the three-dimensional terrain data, round fruits hanging on trees, round signboards standing on the ground, balls rolling on the ground, etc. may be mistakenly recognized as spheres. When such a misrecognition occurs, the three-dimensional topographical data will not be connected well. In this case, even if it is known that "the connection is not good", it is not possible to identify which sphere the misrecognition occurred in by a machine such as a computer, and a human being can image the three-dimensional terrain data. This is because it is necessary to actually see the above, which requires a great deal of labor.

Further, in the terrain measurement method of Patent Document 2, it was later found that the three-dimensional terrain data of the area where it was necessary to acquire the three-dimensional terrain data could not be acquired, and the tertiary of the area was found. There is also a drawback that a great deal of labor is required when trying to remeasure the original topographical data with a three-dimensional scanner.

This is because, after finishing the topographical measurement method of Patent Document 2, all the markers and spheres are usually in a state of being removed. For this reason, when re-measuring the 3D terrain data in an area where the 3D terrain data could not be acquired, it is not enough to install a marker or a 3D scanner in that area and measure it, and the above sphere is next to it. This is because it is necessary to make measurements while considering the cooperation with the surrounding 3D topographical data, such as the need to arrange them so that they match the positions of the spheres in the 3D topography data.

Further, in the topographical measurement method of Patent Document 2, it is necessary to acquire the GPS coordinates of the point where the marker is installed and the GPS coordinates of the point where the three-dimensional scanner is installed. For this reason, the marker and the three-dimensional scanner must be installed in a place where the upper part is not covered with a canopy or the like, and the measurement work cannot be efficiently performed in a place where trees are overgrown. In addition, it was not easy to accurately acquire the GPS coordinates of the center of the marker and the center of the three-dimensional scanner.

The present invention has been made to solve the above problems, and provides a terrain measurement method capable of easily synthesizing a plurality of three-dimensional terrain data. In addition, even if it is later found that the 3D terrain data of the area where it was necessary to acquire the 3D terrain data could not be acquired, the 3D terrain data of the area can be obtained by the 3D scanner. It is also an object of the present invention to provide a topographical measurement method that can be easily remeasured. Furthermore, it is also an object of the present invention to provide a terrain measurement method that does not require acquisition of GPS coordinates at a point where a three-dimensional scanner or marker is installed. Furthermore, it is also an object of the present invention to provide a terrain measurement marker that can be suitably used when carrying out such a terrain measurement method.

The above issues are
It is a terrain measurement method that obtains 3D terrain data of almost the entire area in the measurement target area by synthesizing a plurality of 3D terrain data D _{1 to DN} (N is an integer with 2 or more) obtained by a 3D scanner. hand,
Three-dimensional terrain data D ₁
A marker installation process for installing markers at at least three points P _1.1 , P _1.2 , and P _1.3 in the area corresponding to the three-dimensional terrain data D ₁ in the measurement target area.
A marker coordinate acquisition process for acquiring the coordinates of points P _1.1 , P _1.2 , and P _1.3 in one coordinate system, and
Obtained through a scanning process in which a 3D scanner is installed at a point where all the markers installed at points P _1.1 , P _1.2 , and P _1.3 can be seen, and the surroundings of the 3D scanner are scanned.
Subsequent three-dimensional terrain data D _{2 to DN} are also acquired through the same process as the three-dimensional terrain data D ₁ .
Based on the coordinates of the acquired marker each marker coordinate obtaining step in acquiring three-dimensional topography data D ₁ to D _N, continue to place a three-dimensional topography data D ₁ to D _N to the one coordinate system This is solved by providing a terrain measurement method characterized in that the three-dimensional terrain data D _{1 to DN} are combined.

Here, the "measurement target area" is a concept that includes a peripheral area of the measurement target. Therefore, for example, when measuring the overall shape of a tumulus, not only when a marker is placed on the tumulus to be measured, but also when a marker is placed in the area around the tumulus, or both (inside the tumulus and the tumulus). The placement of a marker in the surrounding area) is also included in the technical scope of the present invention.

Further, "the subsequent three-dimensional terrain data D _{2 to DN} are also acquired through the same process as the three-dimensional terrain data D ₁ " specifically means that n is an integer of 2 or more and N or less. To,
Three-dimensional terrain data D _n ,
Of the measurement target area, at least three points in the area corresponding to the three-dimensional topography data D _n P _{n. 1} , P _{n. 2} , P _n. Marker installation process to install the marker in ₃ and
Point P _{n. In} one coordinate system _{. 1} , P _{n. 2} , P _n. Marker coordinate acquisition process to acquire the coordinates of ₃ and
Point P _{n. 1} , P _{n. 2} , P _n. All markers placed ₃ is installed a three-dimensional scanner point entering the field of view, which means that to get through the scanning process of scanning the surrounding three-dimensional scanners.

In the terrain measurement method of the present invention, the directions and positions of a plurality of (N) three-dimensional terrain data D _{1 to DN} are set to the coordinates of at least three points included in the respective three-dimensional terrain data D _{1 to DN} ( It can be specified by the coordinates of the point where the markers are installed), and based on the coordinates of those markers, the three-dimensional topographical data D _{1 to DN} are arranged in a common coordinate system (the one coordinate system). As a result, the three-dimensional topographical data D _{1 to DN} are combined. Therefore, the three-dimensional terrain data D _{1 to DN} can be naturally synthesized only by giving the coordinates to the reflection points of the markers in the three-dimensional terrain data D _{1 to DN} obtained by the measurement by the three-dimensional scanner. It is possible to synthesize three-dimensional terrain data D _{1 to DN} without using a sphere. Therefore, it is possible to easily synthesize the three-dimensional topographical data D _{1 to DN} . In addition, when measuring with a three-dimensional scanner, it is not necessary to install a sphere at the site, and it is possible to efficiently perform the measurement work with the three-dimensional scanner.

Further, in the terrain measurement method of the present invention, as described above, it is not necessary to install a sphere at the site when measuring with a three-dimensional scanner. Therefore, even if it is later found that the 3D terrain data of the area where it was necessary to acquire the 3D terrain data could not be acquired, it is possible to link with the surrounding 3D terrain data. Without consideration, if a marker or a three-dimensional scanner is appropriately installed in an area where the three-dimensional topography data could not be acquired, the three-dimensional topography data in that area can be remeasured. Therefore, it is possible to easily remeasure the 3D terrain data of the area where it was necessary to acquire the 3D terrain data.

In the terrain measurement method of the present invention, the method of acquiring the coordinates of the marker is not particularly limited. The coordinates of the marker can be acquired by GPS, but in this case, as described above, it is difficult to install the marker in a place where it is difficult to acquire GPS coordinates because the upper part is covered with a tree canopy. However, at least three markers installed in the same area must be installed in a place where all the markers are in the field of view of the 3D scanner, and the marker installation location is to some extent even in relation to the 3D scanner. Be restricted. For this reason, it is possible that the efficiency of the marker installation work is significantly reduced if the marker is installed while being aware of the presence or absence of an obstacle (such as a canopy) above. Therefore, it is preferable to acquire the coordinates of the marker by measurement by transit as follows, instead of GPS.

That is,
The marker coordinate acquisition process when acquiring the three-dimensional terrain data D ₁
The transit installation process for installing the transit in or near the area corresponding to the three-dimensional terrain data D ₁ and
The transit coordinate acquisition process for acquiring the coordinates of the point where the transit is installed in the one coordinate system, and
It is performed by going through the marker coordinate measurement step of acquiring the coordinates of the points P _1.1 , P _1.2 , and P _{1.3 in} the one coordinate system by the measurement by the transit.
It is preferable that the subsequent marker coordinate acquisition step when acquiring the three-dimensional terrain data D _{2 to DN} is also performed through the same step as the marker coordinate acquisition step when acquiring the three-dimensional terrain data D ₁ .

Here, "The subsequent marker coordinate acquisition process for acquiring the three-dimensional terrain data D _{2 to DN} is also performed through the same process as the marker coordinate acquisition process for acquiring the three-dimensional terrain data D _1. " Specifically, when n is an integer of 2 or more and N or less,
The marker coordinate acquisition process when acquiring the three-dimensional terrain data D _n ,
A transit installing step of installing a transit in the area or near corresponding to the three-dimensional topography data D _n,
The transit coordinate acquisition process for acquiring the coordinates of the point where the transit is installed in the one coordinate system, and
By the measurement by the transit, the point _{Pn. In the} one coordinate system _{. 1} , P _{n. 2} , P _n. It means that it is performed by going through the marker coordinate measurement step of acquiring the coordinates of ₃ .

As a result, the marker can be installed even in a place where an obstacle such as a canopy exists above, and the marker installation work can be performed efficiently.

However, as described above, when the coordinates of the marker are acquired by transit, the coordinates of the marker will not be determined unless the coordinates of the point where the transit is installed are determined, so it is necessary to acquire the coordinates of the transit. is there. The method of acquiring the coordinates of the transit is also not particularly limited. However, as in the case of acquiring the coordinates of the marker described above, if the coordinates are acquired by GPS, it becomes difficult to install the transit in a place where it is difficult to acquire the GPS coordinates because the upper part is covered with a tree canopy. Therefore, it is preferable that the coordinates of the transit are also acquired by the measurement by the transit as shown below, instead of GPS.

That is,
Prior to scanning with a 3D scanner
A reference point setting process for setting a reference point in or near the measurement target area,
The reference point coordinate acquisition step of acquiring the coordinates of the reference point in the one coordinate system is performed in advance.
In the transit coordinate acquisition step when acquiring the three-dimensional terrain data D ₁ , by measuring the reference point in transit, the coordinates of the point where the transit is installed in the one coordinate system are acquired, and the coordinates are acquired.
In the subsequent transit coordinate acquisition step when acquiring the three-dimensional terrain data D _{2 to DN} , the transit coordinates are acquired by the same procedure as the transit coordinate acquisition step when acquiring the three-dimensional terrain data D _1. Is preferable.

Here, "In the subsequent transit coordinate acquisition step when acquiring the three-dimensional terrain data D _{2 to DN} , the transit coordinates are obtained in the same procedure as the transit coordinate acquisition step when acquiring the three-dimensional terrain data D _1. Specifically, when n is 2 or more and an integer of N or less, the plurality of reference points are measured in transit in the transit coordinate acquisition step when acquiring the three-dimensional terrain data D _n. By doing so, it means that the coordinates of the point where the transit is set in the one coordinate system are acquired.

As a result, the transit can be installed even in a place where an obstacle such as a canopy exists above, and the installation work of the transit can be performed efficiently.

In the terrain measurement method of the present invention, the marker installed in the marker installation process is not particularly limited as long as it can be identified from the surrounding landscape.
Supports for standing on the ground and
It is preferable to use a marker display unit that is arranged on the upper part of the column and is provided with coordinate acquisition points for which coordinates are acquired in the marker coordinate acquisition step.

In this way, by arranging the marker display unit (the portion recognized by the three-dimensional scanner) in the marker on the upper part of the support column, the marker display unit can be arranged at a place higher than the ground. Therefore, even if there are undulations or obstacles in the measurement target area, the marker display unit can be visually recognized even from a distance. Therefore, it becomes possible to measure a wide range of areas with a three-dimensional scanner installed at a certain location, and it is possible to reduce the number of areas to be measured by the three-dimensional scanner. Therefore, it is possible to perform topographical measurement more efficiently.

At this time, the marker (the marker for terrain measurement installed on the ground when measuring the terrain by scanning with a three-dimensional scanner) makes the direction of the marker display unit horizontal without moving the position of the coordinate acquisition point on the marker display unit. It is preferable that it can be adjusted in the direction and the vertical direction. More specifically
Marker,
Supports for standing on the ground and
A marker display unit located at the top of the column and provided with coordinate acquisition points for which coordinates are acquired in the marker coordinate acquisition process.
A horizontal angle adjustment mechanism for adjusting the orientation of the marker display in the horizontal direction,
It shall be equipped with a vertical angle adjustment mechanism for adjusting the orientation of the marker display in the vertical direction.
It is assumed that the coordinate acquisition points are arranged at the intersections of the rotation center line of the marker display unit by the horizontal angle adjustment mechanism and the rotation center line of the marker display unit by the vertical angle adjustment mechanism in the marker display unit. Is preferable.

This is because it is preferable that the marker display unit faces the three-dimensional scanner or the transit, but at the measurement site, the orientation of the marker display unit may be adjusted. Also, if the coordinate acquisition point on the marker display moves when the orientation of the marker display is adjusted, an error will occur in the coordinates of the marker acquired by transit, etc., so even if the orientation of the marker display is changed By preventing the position of the coordinate acquisition point from moving, it is possible to prevent such an error from occurring.

As described above, the present invention makes it possible to provide a terrain measurement method capable of easily synthesizing a plurality of three-dimensional terrain data. In addition, even if it is later found that the 3D terrain data of the area where it was necessary to acquire the 3D terrain data could not be acquired, the 3D terrain data of the area can be obtained by the 3D scanner. It also becomes possible to provide a terrain measurement method that can be easily remeasured. Further, it becomes possible to provide a terrain measurement method that does not require acquisition of GPS coordinates at a point where a three-dimensional scanner or a marker is installed. Furthermore, it is also possible to provide a terrain measurement marker that can be suitably used when carrying out such a terrain measurement method.

It is a figure which showed an example of the 3D topographical data obtained by the topographical measurement method of this invention. It is a flowchart which showed an example of the basic flow of the terrain measurement method of this invention. It is a figure which showed an example of the acquisition order of 3D terrain data in the terrain measurement method of this invention. Is a flowchart illustrating an example of a flow for acquiring the three-dimensional topography data D ₁ in topography measuring method of the present invention. It is a perspective view which showed an example of the marker used in the terrain measurement method of this invention. It is a perspective view which showed the other example of the marker used in the terrain measurement method of this invention. It is a perspective view which showed the state which the marker display part in the marker of FIG. 6 was rotated 180 ° around the horizontal axis L ₁ . It is a flowchart which showed an example of the flow of the marker coordinate acquisition process in the terrain measurement method of this invention. It is a flowchart which showed an example of the flow of the transit coordinate acquisition process in the terrain measurement method of this invention. It is a figure which showed the state that the scanning process is performed in the terrain measuring method of this invention. It is a figure which showed the state that the 3D terrain data synthesis process is performed in the terrain measurement method of this invention.

A preferred embodiment of the terrain measurement method of the present invention will be described more specifically with reference to the drawings. The technical scope of the terrain measurement method of the present invention is not limited to the embodiments described below, and can be appropriately modified as long as the gist of the present invention is not impaired.

1. 1. Basic Flow of Topographical Measurement Method of the Present Invention FIG. 1 is a diagram showing an example of three-dimensional topographical data D obtained by the topographical measurement method of the present embodiment. FIG. 1 shows a measurement of the three-dimensional shape of the tumulus as the three-dimensional topographical data D. In the following, for convenience of explanation, the topographical measurement method of the present invention will be described by taking as an example the case of measuring the three-dimensional shape of the tumulus shown in FIG. However, the application of the topographical measurement method of the present invention is not limited to the investigation of ancient burial mounds, and can be suitably adopted in various applications.

FIG. 2 is a flowchart showing an example of the basic flow of the topographical measurement method of the present invention. In the terrain measurement method of the present embodiment, first, three-dimensional terrain data D _{1 to DN} (N is an integer having 2 or more) are sequentially sequentially as shown in steps S100, S200, S300, S400, and S500 in FIG. I will get it. That is, the work of acquiring the three-dimensional terrain data D ₁ and then the three-dimensional terrain data D ₂ and then acquiring the three-dimensional terrain data D ₂ and then acquiring the three-dimensional terrain data D ₃ ... This is repeated until the three-dimensional topographical data _DN (Nth three-dimensional topographical data _DN ) is acquired.

The work of acquiring the three-dimensional topographical data D _{1 to DN} is performed by bringing a predetermined instrument (three-dimensional scanner or the like) to the site (measurement target area) and performing the measurement, as will be described later. Therefore, when the measurement work can be divided into a plurality of groups and performed in parallel, it is not necessary to acquire the three-dimensional terrain data D _{1 to DN} one by one, and a plurality of three-dimensional terrain data D _{1 to DN} need to be acquired in parallel. You can also get it. When the last 3D terrain data _DN (Nth 3D terrain data _DN ) is acquired, as shown in step 600 in FIG. 2, the acquired N 3D terrain data D _{1 to} D _N is synthesized and synthetic data D is generated. This composite data D corresponds to the three-dimensional topography data D shown in FIG.

Hereinafter, the three-dimensional terrain data acquisition step S300 and the three-dimensional terrain data synthesis step S600 in FIG. 2 will be described in detail.

2. 2. Three-dimensional terrain data acquisition process FIG. 3 is a diagram showing an example of the acquisition order of three-dimensional terrain data in the terrain measurement method of the present invention. In the three-dimensional terrain data acquisition process, N three-dimensional terrain data D corresponding to each of _N areas α _{1 to} α _N (4 areas α _{1 to} α _{4 in} the example of FIG. 3) in the measurement target area. _The process is to acquire _{1 to DN} (4 three-dimensional topographical data D _{1 to} D _{4 in} the example of FIG. 3). Therefore, the three-dimensional topography data acquisition step, from which to obtain the three-dimensional topography data D ₁ of the area alpha _1, zone alpha three-dimensional topography data D _{N (third} zone alpha ₄ in the example of FIG. 3-dimensional _N in the example of N steps (Figure 3 until configured to acquire topographical data D ₄₎ there are four steps).

That is, dividing the measurement target area into N areas alpha ₁ to? _N, first, obtains the three-dimensional topography data D ₁ by performing measurements in the area alpha _1, followed by zone by performing measurements in the area alpha ₂ Gets the three-dimensional topography data _{D 2} of the alpha _2, then the three-dimensional topography data _D 3 _{~D N-1} of the area α ₃ ~α _N-1 by performing a sequential measurement in the area α ₃ ~α _N-1 We get, finally, so as to obtain a three-dimensional topography data D _N for zone alpha _N performed measuring in the area alpha _N.

The number of areas to be divided into the measurement target area (the value of N above. In the following, it may be referred to as “the number of divisions of the measurement target area N”) is not particularly limited as long as it is 2 or more. .. The number of divisions N of the measurement target area usually increases as the measurement target area becomes wider, the degree of undulations becomes more severe, or the number of obstacles increases. In the terrain measurement method of the present embodiment, the number of divisions N of the measurement target area is set to 4 for convenience of explanation, but the number of divisions N of the measurement target area is as many as 5 or more, 10 or more, 15 or more, or 20 or more. Even if it is possible.

On the other hand, there is no particular upper limit to the number of divisions N of the measurement target area, but it is usually 1000 or less. In the terrain measurement method of the present embodiment, the number of divisions N per unit area (1 are) of the measurement target area is set to 1 or less, 0.5 or less, or 0.3 or less. , 0.1 or less, or 0.05 or less. Depending on the terrain and the performance of the three-dimensional scanner described later, it is possible to set the number of divisions N per are of the measurement target area to 0.01 or less (one area is 100 ares or more).

In the terrain measurement method of the present embodiment, each of the three-dimensional terrain data D _{1 to} D ₄ is acquired as follows. First, a method for acquiring three-dimensional topographical data D ₁ will be described. Figure 4 is a flowchart illustrating an example of a flow for acquiring the three-dimensional topography data D ₁ in topography measuring method of the present invention. As shown in FIG. 4, the three-dimensional terrain data D ₁ is acquired through the marker setting step S320, the marker coordinate acquisition step S330, and the scanning step S340.

2.1 Marker installation step As shown in FIG. 3, the marker installation step S320 is performed at at least three points P _1.1 , P _1.2 , P _1.3 in the area α ₁ in the measurement target area, and FIG. It is a process of installing the marker 10 shown in. FIG. 5 is a perspective view showing an example of the marker 10 used in the terrain measurement method of the present invention. In the terrain measurement method of the present embodiment, the points P _1.1 , P _1.2 , and P _1.3 on which the marker 10 is provided are all the burial mounds to be measured (areas shown by shaded hatching in FIG. 3). Although it is arranged above, it is not limited to this, and it can be provided in the surrounding area of the measurement target.

As will be described later, the marker 10 measures the coordinates of the point where it is installed (the coordinates of points P _1.1 , P _1.2 , and P _1.3 ). The marker 10 is also on the three-dimensional topography data D ₁ is identified as a feature point, measured coordinates are given. That is, the marker 10 has a important for providing coordinates to three different points in the three-dimensional topography data D _1. Thus, by determining the coordinates of three different points in the three-dimensional topography data D _1, it is possible to uniquely determine the position and orientation of the three-dimensional topography data D ₁ in the coordinate system.

For the three points P _1.1 , P _1.2 , and P _1.3 on which the marker 10 is placed, discrete points that are not on the same straight line are selected. As will be described later, all of the markers 10 installed in the area α ₁ are required to be arranged in the field of view of the three-dimensional scanner installed at the point S ₁ (FIG. 3). In addition, in the terrain measurement method of the present embodiment, it is required that all of the markers 10 installed in the area α ₁ are arranged at the points where the markers can be measured by the transit installed at the point Q ₁ (FIG. 3). To.

In this respect, in the terrain measurement method of the present embodiment, as the marker 10, as shown in FIG. 5, a support column 11 for standing on the ground and a marker display unit 12 supported on the upper part of the support column are configured. I am using something. As shown in FIG. 10 described later, the marker display unit 12 is a portion recognized by the three-dimensional scanner 20, and the marker display unit 12 is supported by the support column 11 at a position higher than the ground. Even if there are obstacles such as trees and weeds or undulations between the marker display unit 12 and the three-dimensional scanner 20, the three-dimensional scanner 20 can read the marker display unit 12. ..

The height H (FIG. 5) from the lower end of the support column 11 of the marker 10 to the center C of the marker display unit 12 is not particularly limited. However, if the height H is made too low, the marker display unit 12 cannot be supported at a high position. Therefore, the height H is usually set to 30 cm or more. The height H is preferably 50 cm or more, more preferably 70 cm or more, and further preferably 90 cm or more. On the other hand, if the height H is made too high, the marker 10 may become large and difficult to carry or install. Therefore, the height H is usually set to 300 cm or less. The height H is preferably 250 cm or less, and more preferably 200 cm or less. In the terrain measurement method of this embodiment, the height H is set to 100 cm.

The marker display unit 12 of the marker 10 is provided with a display that can be identified by the three-dimensional scanner 20 (FIG. 10). The display applied to the marker display unit 12 is usually given a pattern or color that stands out from the surrounding landscape. In the terrain measurement method of the present embodiment, the marker display unit 12 having a rectangular shape is divided into two rows and two columns of rectangular sections, and a pattern in which white and black are alternately arranged in each section is used as the above display. Giving. Even when this pattern is located in front of the ground, trees, weeds, rocks, or the sky, the three-dimensional scanner 20 can easily identify only the pattern.

By the way, in the conventional terrain measurement method, it is necessary to carefully examine and determine the location where the marker 10 is to be installed at the time of preliminary reconnaissance or the like so that the marker 10 can be installed efficiently. However, if the points P _1.1 , P _1.2 , and P _{1.3 on} which the marker 10 is installed are far apart from each other, there is a risk that any one of them will not be in the field of view of the three-dimensional scanner installed at the point S _1. , there may not be measured in transit that either is placed at the point Q _1. Therefore, in practice, for safety reasons, the distance between points P _1.1 , P _1.2 , and P _1.3 has been shortened.

However, if the distance between the points P _1.1 , P _1.2 , and P _1.3 is shortened, the markers 10 will be unevenly distributed only in a narrow area in the area α ₁ , and the markers 10 will be ubiquitously installed. The accuracy of determining the position and orientation of the original topographical data D ₁ may decrease. In addition, it becomes impossible to secure a wide area α _1, and in order to acquire the three-dimensional shape of the entire measurement target area, it is necessary to perform measurement in a large number of areas (three-dimensional topographical data necessary for obtaining composite data D). (The number of) may increase.

On the other hand, in the terrain measurement method of the present embodiment, as described above, as the marker 10, the marker display unit 12 is supported on the upper part of the support column 11, and the marker display unit 12 is recognized from a wide range. (Visual) is possible. Therefore, in the terrain measurement method of the present embodiment, not only the installation location of the marker 10 can be easily determined, but also the number of areas to be measured in order to acquire the three-dimensional shape of the entire measurement target area can be suppressed to a small number. It has become.

The marker 10 may be installed so that the support column 11 is inclined with respect to the vertical direction (gravity direction), but usually, the support column 11 is installed so as to be parallel to the vertical direction. In the terrain measurement method of the present embodiment, a spirit level (not shown) for confirming the direction of the support column 11 is attached to the marker 10. The column 11 of the marker 10 can be maintained in the vertical direction by a marker supporting means 40 (see FIG. 6) such as a tripod.

Further, as the marker 10, in addition to the marker 10 shown in FIG. 5, it is also preferable to use the marker 10 shown in FIG. FIG. 6 is a perspective view showing another example of the marker 10. The marker 10 in FIG. 6 includes a horizontal angle adjusting mechanism 14 and a vertical angle adjusting mechanism 13.

The horizontal angle adjusting mechanism 14 rotates the marker display unit 12 in the left-right direction (direction of arrow A ₃ or arrow A ₄ in FIG. 6) around the vertical axis L ₂ to rotate the marker display unit 12 in the vertical axis L. The angle (horizontal angle) of _two turns can be adjusted. That is, when the laser beam emitted from the three-dimensional scanner 20 is incident on the front surface of the marker display unit 12 substantially vertically, it is easily recognized by the three-dimensional scanner 20, but in the marker 10 of FIG. By rotating the marker display unit 12 in the left-right direction, the front surface of the marker display unit 12 can be adjusted to be perpendicular or nearly vertical to the laser beam emitted from the three-dimensional scanner 20. It has become like.

The specific configuration of the horizontal angle adjusting mechanism 14 is not particularly limited as long as it can exhibit the above functions. In the marker 10 of FIG. 6, the horizontal angle adjusting mechanism 14 is configured by the clamp 14a that is fitted onto the upper end of the support column 11 to grip the upper end portion of the support column 11 and the clamp operating means 14b that operates the clamp 14a. There is.

In this horizontal angle adjusting mechanism 14, when the clamp operating means 14b is operated to loosen the clamp 14a, the portion of the marker 10 above the clamp 14a (marker display portion 12) is rotated in the left-right direction with respect to the support column 11. While the horizontal angle of the marker display unit 12 can be adjusted, when the clamp operating means 14b is operated to tighten the clamp 14a, the portion of the marker 10 above the clamp 14a (marker display unit 12) is moved with respect to the support column 11. The horizontal angle of the marker display unit 12 can be fixed by preventing the marker from rotating in the left-right direction.

On the other hand, the vertical angle adjusting mechanism 13 rotates the marker display unit 12 in the vertical direction (direction of arrow A ₁ or arrow A ₂ in FIG. 6) around the horizontal axis L ₁ to make the marker display unit 12 horizontal. It has become what can modulate axis L ₁ about the angle (vertical angle). That is, as already described, the front surface of the marker display unit 12 is easily recognized by the three-dimensional scanner 20 when the laser beam emitted from the three-dimensional scanner 20 is incident substantially vertically. In the marker 10 of FIG. 6, by rotating the marker display unit 12 in the vertical direction, the front surface of the marker display unit 12 is in a state of being perpendicular to or nearly vertical to the laser beam emitted from the three-dimensional scanner 20. It can be adjusted to.

The specific configuration of the vertical angle adjusting mechanism 13 is not particularly limited as long as it can exhibit the above functions. In the marker 10 of FIG. 6, a front view “U” -shaped support frame 13a fixed to the upper end portion (upper portion of the clamp 14a) of the support column 11 and a pair of left and right sides arranged on both side surfaces of the marker display portion 12. The side plate portion 13b, the connecting shaft portion 13c which connects the side plate portions 13b to each other and is fixed to the back side of the marker display portion 12, and the left and right arm portions of the support frame 13a with respect to the left and right side plate portions 13b, respectively. The vertical angle adjusting mechanism 13 is composed of a support shaft portion 13d that is connected in a movable state and a tightening means 13e that tightens the support section portion 13d.

In the vertical angle adjusting mechanism 13, when the tightening means 13e is loosened, the side plate portion 13b can rotate with respect to the support frame 13a, whereby the marker display portion 12 is rotated in the vertical direction, and the marker display portion 12 is rotated. While the vertical angle can be adjusted, when the tightening means 13e is tightened, the vertical angle of the marker display portion 12 can be fixed by preventing the side plate portion 13b from rotating with respect to the support frame 13a. There is.

However, in the marker 10 of FIG. 6, if the coordinate of the center C on the front surface of the marker display unit 12 changes when adjusting the horizontal angle or the vertical angle of the marker display unit 12, the marker display unit 20 will be described later. When scanning 12, an error may occur in the position of the center C of the marker display unit 12, and when measuring the coordinates of the marker display unit 12 in a transit, an error occurs in the coordinates of the center C of the marker display unit 12. There is a risk that it may not be possible to acquire accurate three-dimensional topographical data D in the measurement target area.

In this regard, in the marker 10 shown in FIG. 6, the vertical axis L ₂ and the horizontal axis L ₁ intersect, and the center C of the marker display unit 12 is located at the intersection of the vertical axis L ₂ and the horizontal axis L _1. I try to be located. Therefore, the marker display unit 12 is rotated around the vertical axis L ₂ to adjust the horizontal angle of the marker display unit 12, or the marker display unit 12 is rotated around the horizontal axis L ₁ to adjust the horizontal angle of the marker display unit 12. The position of the center C of the marker display unit 12 does not change when the marker display unit 12 is adjusted.

Further, in the marker 10 shown in FIG. 6, as shown in FIG. 7, a light reflecting portion 12a is provided at the center of the back surface of the marker display portion 12. Figure 7 is a perspective view showing a state of being rotated 180 ° the marker display section 12 in the marker 10 to the horizontal axis L ₁ about 6.

This is because the marker 10 is the target of the transit measurement in the marker coordinate acquisition step S330 (FIG. 4), which will be described later. By providing the light reflecting portion 12a on the back surface of the marker display unit 12, the marker 10 can be moved in transit. This is because it can be easily measured. The light reflecting unit 12a is not particularly limited as long as it can reflect the light emitted from the transit (usually, laser light). The light reflection unit 12a can be provided by attaching a reflection sticker (not shown) to the back surface of the marker display unit 12.

In the region alpha ₁ finishes the marker setting step S320 (FIG. 4) and (zone alpha ₁ point _{P 1.1,} P _1.2, finishes installing the marker 10 to _{P 1.3),} followed by zone alpha ₁ In the marker coordinate acquisition step S330 (FIG. 4).

2.2 Marker coordinate acquisition step The marker coordinate acquisition step S330 is a step of acquiring the coordinates of the points P _1.1 , P _1.2 , and P _1.3 in which the marker 10 is installed in the area α ₁ . The coordinates of the points P _1.1 , P _1.2 , and P _{1.3 where} the marker 10 is installed can also be obtained by GPS, but in this case, the GPS coordinates are such that the upper part is covered with a tree canopy. It becomes difficult to install the marker 10 in a place where it is difficult to obtain.

Therefore, in the terrain measurement method of the present embodiment, the coordinates of the points P _1.1 , P _1.2 , and P _1.3 in which the marker 10 of the area α ₁ is installed are acquired by the transit measurement. .. Specifically, as shown in FIG. 8, the marker coordinate acquisition step S330 is performed by going through the transit installation step S332, the transit coordinate acquisition step S333, and the marker coordinate measurement step S334. FIG. 8 is a flowchart showing an example of the flow of the marker coordinate acquisition process.

2.2.1 transit placing step transit setting step S332 is a step of installing a transit in the area alpha ₁ or near. The topography measuring method of the present embodiment, the transit installed in the point _{Q 1} in FIG. 3, a point _P 1.1 area alpha ₁ in this _transit, P _1.2, so as to obtain the coordinates of _{P 1.3} ing. Point _{Q 1} is, in transit was placed therein, the point _{P 1.1,} P _1.2, must be arranged at a position capable of measuring the marker display section 12 of all markers 10 installed in _{P 1.3.}

By the way, the transit is one of the surveying instruments for measuring the angle, and is sometimes called "theodolite" or "history". Some transits are equipped with a laser rangefinder (so-called total station) that measures the distance to the target. If a total station is used as the transit, the distance and angle to the target can be measured at the same time, so that the position of the marker 10 with respect to the transit can be measured easily and accurately. Also in the terrain measurement method of this embodiment, a total station is used as a transit.

2.2.2 transit coordinate obtaining step transit coordinate obtaining step S333 has a step of acquiring the coordinates of the points were established transit _{Q 1} (Figure 3). This transit coordinate acquisition step S333 is necessary for the following reasons. That is, the location where the transit is installed usually changes every area α _{1 to} α ₄ (every three-dimensional terrain data D _{1 to} D ₄ ). For this reason, unless the coordinates of the location where the transit is installed are acquired each time the location where the transit is installed is moved, the relative positional relationship of the acquired three-dimensional terrain data D _{1 to} D ₄ cannot be grasped. ..

Transit coordinates (coordinate point Q ₁ in FIG. 3) can also be obtained by GPS, in this case, and the point where the GPS coordinates are not easily obtained by such above is covered by the canopy, the transit It becomes difficult to install. Therefore, it is preferable that the coordinates of the transit are acquired by the measurement by the transit as follows, instead of GPS.

That is, as shown in FIG. 9, the transit coordinate acquisition step S333 can be performed by going through the reference point setting step S333.2, the reference point coordinate acquisition step S333.3, and the transit coordinate measurement step S333.4. preferable. FIG. 9 is a flowchart showing an example of the flow of the transit coordinate acquisition process.

2.2.2.1 Reference point installation process Reference point installation process S333.2 (FIG. 9) is a process of installing a reference point in or near the measurement target area. Reference points are usually set at multiple locations. The topography measuring method of the present embodiment, so as to surround the tumulus a measurement object, so as to set up a reference point to the point _{R 1, R 2, R 3} , R 4, R 5, R 6 in FIG. 3 There is. As the reference point, a mirror pole, a prism pole, or the like used in conventional surveying can be used. These reference points are made to those used as a reference in obtaining the coordinates of the points were established transit _{Q 1, Q 2, Q 3} , Q 4. It is preferable that the reference point setting step S333.2 (FIG. 9) is performed in advance prior to the marker setting step S320 (FIG. 4) described above.

Installation number of reference points (total number of points _{R 1, R 2, R 3} , R 4, R 5, R 6) is also different depending on the size of the measurement target region is not particularly limited. However, the transit needs to be installed at a place where any reference point can be measured, but if the number of reference points installed is too small, the degree of freedom in arranging the transit may be reduced. Therefore, the number of reference points (N ₂ ) for the total number of markers 10 (N ₁ ) installed in the areas α _{1 to} α _N (areas α _{1 to} α _{4 in} the example of FIG. 3) The ratio N ₂ / N ₁ is preferably 0.1 or more. The ratio N ₂ / N ₁ is more preferably 0.2 or more, and further preferably 0.3 or more. However, if the number of reference points installed is too large, the labor required for the reference point coordinate acquisition step S333.3 (FIG. 9), which will be described later, increases. Therefore, the ratio N ₂ / N ₁ is usually set to 1 or less.

2.2.2.2 Reference point coordinate acquisition process In the reference point coordinate acquisition process S333.3 (Fig. 9), the points R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , and R ₆ (where the reference points are set) are set. This is a process of acquiring the coordinates of FIG. 3). The coordinates of the reference point can be obtained by using GPS when the measurement target area is outdoors. Also in the topographical measurement method of this embodiment, the coordinates of the reference point are acquired by GPS. However, if there is an obstacle above the measurement target area, or if the measurement target area is indoors in a large facility such as a factory, the coordinates of the reference point cannot be obtained using GPS. In some cases.

The coordinate system representing the coordinates of this point and the reference point is the coordinates of the marker 10 (coordinates of points P _1.1 , P _1.2 , P _1.3, etc.) and the coordinates of transit (coordinates of point Q _1, etc.). And, the coordinate system may be the same, and the coordinate system does not have to be an absolute coordinate system such as a GPS coordinate system (a coordinate system consisting of latitude and longitude on the earth). Therefore, when the reference point coordinate acquisition step S333.3 is carried out in an environment where GPS is difficult to use, such as indoors, the points R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ where the reference point is set are installed. the relative position of, was measured using a surveying instrument, such as transit or major, these reference points (points _{R 1, R 2, R 3} , R 4, R 5, R 6) coordinate system defined by It is preferable to acquire the coordinates of the marker 10 and the coordinates of the transit by using.

2.2.2.3 Transit coordinate measurement process The transit coordinate measurement process S333.4 (Fig. 9) was installed at points R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ (Fig. 3). This is a step of measuring the coordinates of the transit at that time by measuring one of the reference points in the transit. The topography measuring method of the present embodiment, in transit installed in the point Q ₁ in FIG. 3, by measuring the reference point was set at the point R _1, R _2, position of the point Q ₁ with respect to the point R _1, R ₂ That is, the coordinates of the transit are measured. The coordinates of the transit can be obtained by the backward association method or the like.

When the transit coordinate measurement step S333.4 (FIG. 9) is completed, the transit coordinate acquisition step S333 (FIG. 8) is completed, followed by the marker coordinate measurement step S334 (FIG. 8).

2.2.3 marker coordinate measuring step marker coordinate measuring step S334 (FIG. 8) is obtained by measurement by transit installed in the point _{Q 1,} the point _{P 1.1,} P _1.2, the coordinates of _{P 1.3} It is a process to do. As already mentioned, the coordinates _{Q 1} that was installed transit point _R 1, because it is determined from the relationship between the reference point provided in such _{R 2,} point _P 1.1 in this _{transit, P 1.2} if collimate the marker 10 installed in _{P 1.3,} the point _{P 1.1,} P _1.2, it is possible to determine the coordinates of _{P 1.3.} When the marker coordinate measurement step S334 is completed, the marker coordinate acquisition step S330 (FIG. 4) is completed, followed by the scanning step S340.

2.3 Scanning process In the scanning process S340 (Fig. 4), a 3D scanner is installed at a point where all the markers installed at points P _1.1 , P _1.2 , and P _1.3 (Fig. 3) can be seen. Then, as shown in FIG. 10, it is a step of scanning (spatial measurement) around the three-dimensional scanner 20. FIG. 10 is a diagram showing a state in which the scanning process is performed. In FIG. 10, for convenience of illustration, of the three markers 10 placed at points P _1.1 , P _1.2 , and P _1.3 in the area α ₁ , the marker 10 placed at point P _1.3 The illustration is omitted.

Of the measurement target area, the case of performing the scanning step S340 in the area alpha ₁ (FIG. 3), the scanner 20 is normally or near the center of the area alpha _1, point to place the marker 10 in the area alpha _{1 P 1.1,} It is installed inside the triangle formed by P _1.2 and P _1.3 . In terrain measuring method of the present embodiment, when performing a scan process in the area alpha ₁ is designed so as to install the scanner 20 to a point S ₁ in FIG. Further, when performing the scanning process in the area α ₂ , the scanner 20 is installed at the point S ₂ , and when performing the scanning process S340 in the area α ₃ , the scanner 20 is installed at the point S ₃ and the area α ₄ when performing a scan process in is designed so as to install the scanner 20 to the point S _4.

The type of the three-dimensional scanner 20 is not particularly limited as long as it can measure the three-dimensional shape of the surrounding terrain, but it is usually obtained by irradiating a light wave such as a laser beam. A scanning laser rangefinder (so-called laser scanner) that measures the three-dimensional shape of the surrounding terrain is used.

Further, the maximum measurement distance of the three-dimensional scanner 20 varies depending on the size of the measurement target area α and the like, and is not particularly limited. However, if the maximum measurement distance of the three-dimensional scanner 20 is too short, it becomes necessary to divide the measurement target area into more areas in order to measure the three-dimensional shape of substantially the entire measurement target area, and the scanning process is performed. The number of areas that must be done increases. Therefore, the maximum measurement distance of the three-dimensional scanner 20 is usually 10 m or more. The maximum measurement distance of the three-dimensional scanner 20 is preferably 30 m or more, more preferably 50 m or more, and further preferably 100 m or more. The upper limit of the maximum measurement distance of the three-dimensional scanner 20 is not particularly limited, but is usually about 500 to 1000 m.

In the terrain measurement method of the present embodiment, "FARO Laser Scanner Focus ^3D " (model: Focus ^3D X330), which is a laser scanner manufactured by FARO, is used as the three-dimensional scanner 20. The three-dimensional scanner 20 has a maximum measurement distance of 330 m, a maximum measurement speed of 976000 points / second, and a maximum range error of ± 2 mm. The laser beam emitting unit 21 in the three-dimensional scanner 20 (FIG. 10) is adapted to rotate (scan) in the direction of arrow A ₅ around the vertical axis L ₂ passing through the point S _1, around The range of 360 ° falls within the measurement range.

2.4 In the region alpha ₁ after finishing the areas alpha ₁ scan step completes the scanning process S340 (FIG. 4), the three-dimensional scanner 20, a state in which three-dimensional topography data _{D 1} of the areas alpha ₁ is acquired It has become. When the three-dimensional terrain data D ₁ is acquired, the other three-dimensional terrain data D ₂ , D ₃ , and D ₄ are also acquired (see steps S300, S400, and S500 in FIG. 2). The three-dimensional terrain data D ₂ , D ₃ , and D ₄ of the other areas α ₂ , α ₃ , and α ₄ are acquired in the same procedure as the three-dimensional terrain data D ₁ of the area α ₁ .

However, in the terrain measurement method of the present embodiment, when the three-dimensional terrain data D ₂ of the area α ₂ is acquired, the markers installed at the points P _2.1 , P _2.2 , and P _2.3 in FIG. the am trying to scan a three-dimensional scanner installed at a point S ₂ in the drawing, when acquiring a three-dimensional topography data D ₃ zones alpha ₃ is the point P _3.1 in FIG. _{3, P 3. 2,} the installation markers to P _3.3 is to be scanned in three dimensions scanner installed in the point S ₃ in the drawing, when acquiring a three-dimensional topography data D ₄ zones alpha ₄ is 3 The markers installed at points P _4.1 , P _4.2 , and P _4.3 in the figure are scanned by the three-dimensional scanner installed at point S ₄ in the figure. Of the areas α ₁ , α ₂ , α ₃ , and α ₄ , in the areas adjacent to each other, some markers are shared (for example, in the area where the area α ₁ and the area α ₂ in FIG. 3 overlap). (Point P _1.2 and point P _2.1 may be placed at the same point, etc.).

Further, in the terrain measurement method of the present embodiment, the coordinates of the points P _2.1 , P _2.2 , and P _2.3 where the markers are installed in the area α ₂ are the transits installed at the point Q ₂ in FIG. in the acquired area alpha ₃ within a point were placed markers _{P 3.1,} P _3.2, the coordinates of _{P 3.3,} obtained in transit installed in the point _{Q 3} in FIG. 3, the area alpha ₄ The coordinates of the points P _4.1 , P _4.2 , and P _4.3 where the markers are set in are obtained by the transit set at the point Q ₄ in FIG. From transit installed in one of the points _{Q 1, Q 2, Q 3} , Q 4, when all of the markers belonging to two or more sections enters the field of view, in those areas, to move the transit It is also possible to obtain the coordinates of the markers in those areas by measuring from the same point.

Further, in the terrain measuring method of the present embodiment, the transit of coordinates placed at the point Q _2, acquired by collimating the reference point established from the transit point R _3, R _4, to the point Q ₃ coordinates of the installed transit obtains by collimating the reference point established from the transit point R _4, R _5, transit coordinates installed in the point Q ₄ are, the point R ₁ from the _transit, R ₆ It is acquired by collimating the reference point set in, but it is not limited to this. The coordinates of the transit can be obtained using any reference point that can be collimated by the transit installed at that point.

Finished scanning process S340 (FIG. 4) in all areas alpha ₁ to? _4, when all the three-dimensional topography data _D 1 to D ₄ zones alpha ₁ to? ₄ can be obtained (at step S400 in FIG. 2, "YES ], Then, the three-dimensional terrain data synthesis step S600 is performed.

3. 3. Three-dimensional terrain data synthesis step The terrain data synthesis step synthesizes the three-dimensional terrain data D _{1 to} D ₄ acquired in the above-mentioned three-dimensional terrain data acquisition step S300 (FIG. 2), and synthesizes substantially the entire area in the measurement target area. This is a step of obtaining three-dimensional terrain data D (see FIG. 1). FIG. 11 is a diagram showing a state in which the three-dimensional terrain data synthesis process is performed. In the terrain measurement method of the present embodiment, not only the three-dimensional terrain data D _{1 to} D ₄ shown in FIG. 11 can be acquired but also the three-dimensional terrain at the stage when all the above-mentioned three-dimensional terrain data acquisition steps S300 are completed. In each of the data D _{1 to} D ₄ , the coordinates of the points where the markers are placed can be acquired at least three points each.

Therefore, as shown in FIG. 11, points P _1.1 , P _1.2 , and P in which markers are placed in the area α ₁ in one common coordinate system (xyz coordinate system in the example of the same figure). Coordinates of _1.3 , points where markers are placed in area α ₂ , coordinates of P _2.1 , P _2.2 , P _2.3 , points where markers are placed in area α ₃ , points P _3.1 , P _{3 .2} , P _3.3 coordinates and the coordinates of the points P _4.1 , P _4.2 , P _4.3 where the marker was placed in the area α ₄ are plotted, and the three-dimensional topographical data of the area α ₁ The three points at which the markers are identified in D ₁ overlap the points P _1.1 , P _1.2 , and P _1.3 in the one coordinate system, respectively, and the markers are displayed in the three-dimensional topographical data D ₂ of the area α _2. The three identified points overlap the points P _2.1 , P _2.2 , and P _2.3 in the one coordinate system, respectively, and the three markers are identified in the three-dimensional topographical data D ₃ of the area α ₃ . point _P 3.1 points are in the one coordinate _system, P _3.2, overlap each _{P 3.3,} 3 a point where the marker is identified in the three-dimensional topography data _{D 4} zones alpha ₄ is the one The composite data shown in FIG. 1 is obtained by simply superimposing the three-dimensional topographical data D _{1 to} D ₄ on the one coordinate system so as to overlap the points P _4.1 , P _4.2 , and P _4.3 in the coordinate system, respectively. D is generated.

This three-dimensional terrain data synthesis process is usually performed by processing on a computer. Even manpower interposed its synthesis work, and a particular working point marker has been identified in the three-dimensional topography data D ₁ to D _4, which is an input work of about coordinates of the point. Therefore, human error is unlikely to intervene in the synthesis work. Further, even if a human error occurs, it is possible to easily grasp which part the error occurred in by looking at the composite data D and promptly correct it.

By the way, the composite data D (FIG. 1) may have a defective region (even if there are gaps in the three-dimensional terrain data D _{1 to} D ₄ after synthesis), but there is as little missing region as possible. It is preferable that it is in a continuous state. The defective region is preferably 30% or less, more preferably 20% or less, and further preferably 10% or less of the total area of the measurement target area. In the terrain measurement method of the present embodiment, even if it is found that there is a defective region after the three-dimensional terrain data D is generated, the remeasurement of the defective region can be performed relatively easily.

4. Other synthetic data D (Fig. 1) is based on the three-dimensional topographical data D _{1 to} D ₄ acquired as digital data in the above scanning step S340 (Fig. 4), and obstacles such as trees, weeds, and rocks are softened. It can also be removed (by digital processing). As a result, the synthetic data D can be made to be free of obstacles (substantially only the surface of the earth is represented). This process (hereinafter, may be referred to as “obstacle removal process”) may be performed at any timing as long as it is in the scanning step S340 or later. However, if the obstacle removal process is performed before the three-dimensional terrain data synthesis step S600 is performed, the obstacle removal process of the overlapping portion in the three-dimensional terrain data D _{1 to} D ₄ will be performed in duplicate, which is not possible. It is efficient. Therefore, it is preferable that the obstacle removal process is performed after the completion of the three-dimensional terrain data synthesis step S600.

The specific method (software) of the obstacle removal process is not particularly limited, but usually, a three-dimensional point cloud that can process the point cloud data (three-dimensional point cloud data) acquired in three dimensions. Data processing software is used. In the terrain measurement method of the present embodiment, obstacle removal processing is performed on a personal computer using the noise removal function (ground extraction function) of the three-dimensional point cloud data processing software "InfiPoints" manufactured by Elysium.

5. Use
By using the terrain measurement method of the present embodiment, it is possible to suppress the error of the three-dimensional terrain data D (see FIG. 2) of the measurement target object (measurement target area) to about several mm, so that the obtained tertiary is obtained. The original topographical data D can be effectively used for various analyzes and various studies of the measurement target. For example, from the three-dimensional topographical data D of the tumulus, it is possible to identify not only basic information such as the dimensional shape and orientation of the tumulus, but also the traces of the ground being scraped and the place where the soil is piled up with high accuracy. Therefore, it is possible to obtain detailed information such as traces of grave robbery.

The topographical measurement method of the present invention can be effectively used not only in the investigation of old burial mounds but also in various fields such as the investigation of the planned construction site of a golf course and the investigation of the planned construction site of a dam. Further, the terrain measurement method of the present invention can be used not only for measuring the outdoor shape but also for measuring the three-dimensional shape of the indoor space. For example, it can be used for surveying the current state of buildings such as factories (surveying whether there are any problems such as cracks on walls and ceilings, surveying the position of piping, etc.).

10 Marker 11 Strut 12 Marker display 12a Light reflector 13 Vertical angle adjustment mechanism 13a Support frame 13b Side plate 13c Connecting shaft 13d Support shaft 13e Tightening means 14 Horizontal angle adjustment mechanism 14a Clamp 14b Clamp operating means 20 Three-dimensional scanner 21 Laser light emitting part 40 Marker support means D Three-dimensional topographical data (after synthesis)
D _{1 to} D ₄ 3D terrain data (before composition)
P _{1 to} P ₄ Marker installation point Q _{1 to} Q ₄ Transit installation point R _{1 to} R ₆ Reference point installation point S _{1 to} S ₄ 3D scanner installation point α _{1 to} α ₄ area ( Measurement target area)

Claims (6)

A terrain measurement method that obtains three-dimensional terrain data of substantially the entire area in the measurement target area by synthesizing a plurality of three-dimensional terrain data D _{1 to DN} (N is an integer having 2 or more) obtained by scanning with a three-dimensional scanner. And
Three-dimensional terrain data D ₁
A marker installation process for installing markers at at least three points P _1.1 , P _1.2 , and P _1.3 in the area corresponding to the three-dimensional terrain data D ₁ in the measurement target area.
A marker coordinate acquisition process for acquiring the coordinates of points P _1.1 , P _1.2 , and P _1.3 in one coordinate system, and
Obtained through a scanning process in which a 3D scanner is installed at a point where all the markers installed at points P _1.1 , P _1.2 , and P _1.3 can be seen, and the surroundings of the 3D scanner are scanned.
Subsequent three-dimensional terrain data D _{2 to DN} are also acquired through the same process as the three-dimensional terrain data D ₁ .
Based on the coordinates of the acquired marker each marker coordinate obtaining step in acquiring three-dimensional topography data D ₁ to D _N, continue to place a three-dimensional topography data D ₁ to D _N to the one coordinate system As a result, the terrain measurement method is characterized in that the three-dimensional terrain data D _{1 to DN} are combined.
The marker coordinate acquisition process when acquiring the three-dimensional terrain data D ₁
The transit installation process for installing the transit in or near the area corresponding to the three-dimensional terrain data D ₁ and
The transit coordinate acquisition process for acquiring the coordinates of the point where the transit is installed in the one coordinate system, and
It is performed by going through the marker coordinate measurement step of acquiring the coordinates of the points P _1.1 , P _1.2 , and P _{1.3 in} the one coordinate system by the measurement by the transit.
The terrain according to claim 1, wherein the subsequent marker coordinate acquisition step when acquiring the three-dimensional terrain data D _{2 to DN} is also performed through the same process as the marker coordinate acquisition step when acquiring the three-dimensional terrain data D _1. Measurement method.
Prior to scanning with a 3D scanner
A reference point setting process for setting a reference point in or near the measurement target area,
A reference point coordinate acquisition step of acquiring the coordinates of the reference point in the one coordinate system is performed in advance.
In the transit coordinate acquisition process when acquiring the three-dimensional terrain data D ₁ , by measuring the reference point in transit, the coordinates of the point where the transit is installed in the one coordinate system are acquired, and the coordinates are acquired.
In the subsequent transit coordinate acquisition step when acquiring the three-dimensional terrain data D _{2 to DN} , the request for acquiring the transit coordinates in the same procedure as the transit coordinate acquisition step when acquiring the three-dimensional terrain data D _1. Item 2. The terrain measurement method according to item 2.
As a marker to be installed in the marker installation process
A support for standing on the ground and
The terrain measurement method according to any one of claims 1 to 3, wherein a marker display unit that is arranged on an upper part of a support column and is provided with a coordinate acquisition point for which coordinates are acquired in a marker coordinate acquisition step is used.
The terrain measurement method according to claim 4, wherein as the marker to be installed in the marker installation step, a marker capable of adjusting the orientation of the marker display unit in the horizontal direction and the vertical direction without moving the position of the coordinate acquisition point on the marker display unit is used.
A terrain measurement marker installed on the ground when measuring terrain by scanning with a three-dimensional scanner.
Supports for standing on the ground and
A marker display unit located at the top of the column and provided with coordinate acquisition points for which coordinates are acquired in the marker coordinate acquisition process.
A horizontal angle adjustment mechanism for adjusting the orientation of the marker display in the horizontal direction,
Equipped with a vertical angle adjustment mechanism for adjusting the orientation of the marker display in the vertical direction,
The feature is that the coordinate acquisition points are arranged at the intersections of the rotation center line of the marker display unit by the horizontal angle adjustment mechanism and the rotation center line of the marker display unit by the vertical angle adjustment mechanism in the marker display unit. Marker for terrain measurement.

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