JP2020076674A - Current situation survey drawing creation system, method, and program - Google Patents

Abstract

To provide a system and the like for easily creating a current situation survey drawing by utilizing a drone.SOLUTION: An image photographed by air by a drone flying at a prescribed height with an object to be measured captured right below is acquired (step S10). Then, an image suited for a reference point is selected from acquired images (step S12). "The image suited for the reference point" is, for instance, an image where the reference point is positioned on a center line of a linear area of a prescribed width (for example, 10 m). Image selection is performed with each of a plurality of reference points. Reduction factor correction processing of the selected image is performed (step S14). In reduction factor correction, the selected image is divided into a plurality of areas, correction factor is calculated according to altitude of the measured reference point for every divided area is calculated, and an image is expanded or contracted. Finally, the image in each area where reduction factor is performed is replaced by an image before reduction factor correction, arranged two-dimensionally, and a current situation survey drawing is created (step S16).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a current survey map creation system, method and program, and more specifically to a current survey map creator system, method and program that utilizes a drone.

  Conventionally, it is known that an existing survey map is created by measuring heights of a plurality of reference points. In this case, when the survey target includes roads and rivers, it was necessary to survey many locations for each curved shape or location having a height difference. However, for example, when conducting a survey at a location where there was a disaster, there were many places where the survey could not be performed, and the existing survey map could not be created appropriately.

  Therefore, it is currently known to make a map of the ground surface by utilizing a drone, measuring the altitude with a laser, and converting the data into three-dimensional data. For example, Patent Document 1 below discloses a technique relating to error correction in laser surveying using a moving body.

JP, 2018-77051, A

  However, in surveying using such a moving body and a laser, the software for analysis is expensive and the mechanism is complicated. Therefore, it is desired to create an existing survey map by a simple method that makes use of drones.

  The present invention has been made in view of the above problems, and an object thereof is to provide a system, method, and program for creating a current survey map that can easily create a current survey map using a drone.

  The present invention is a current-state survey map creation system that creates a current-state survey map based on images taken by a drone, and captures an aerial image of a measurement target directly below by a drone flying at a certain height. Image acquisition means for acquiring and dividing the image into a plurality of regions, and for each of the divided regions, a correction factor is calculated from the elevation of the surveyed reference point, and reduction ratio correction for enlarging or reducing the image is performed. An existing survey map creation system comprising reduction ratio correction means and creating means for creating a current situation survey map by arranging the images of the respective regions that have been subjected to the reduction ratio replacement in two-dimensional order by replacing the images before the reduction ratio correction. I will provide a.

  Further, the present invention is a method for creating an existing survey map based on an image taken by a drone, wherein the drone flying at a certain height captures an object under measurement and is aerial photographed. Obtaining an image, dividing the image into a plurality of regions, and for each of the divided regions, calculating a correction factor from the altitude of a surveyed reference point, and performing a reduction factor correction for enlarging or reducing the image. The present invention provides a method for creating a current survey map, comprising the steps of: replacing the image of each region that has been subjected to the reduction ratio with the image before the reduction correction and arranging the images in a two-dimensional manner to create an existing survey map.

  Furthermore, the present invention is a program for causing a computer to execute a current-state survey map creation process for creating a current-state survey map based on an image taken by a drone, and a measurement target by a drone flying at a certain height. A step of capturing an aerial image by capturing the image directly below, dividing the image into a plurality of regions, calculating a correction factor from the elevation of the surveyed reference point for each divided region, and The step of performing reduction ratio correction for enlarging or reducing and the step of creating an existing survey map by replacing the image of each region subjected to the reduction ratio correction with the image before reduction ratio correction and arranging in two dimensions Providing a program for

  According to the present invention, the image of the measurement target taken by the drone is subjected to reduction ratio correction for enlarging or reducing based on the elevation of the surveyed reference point, and is arranged two-dimensionally in place of the image before correction. Since it was decided to create an existing survey map, it is possible to create an appropriate existing survey map with a simple method.

It is a flow chart which shows an example of the processing procedure by the present situation survey map creation system of one embodiment of the present invention. It is a block diagram which shows the hardware constitutions of the present condition survey map creation system of the said embodiment. It is a block diagram which shows the function structure of the present condition survey map creation system of the said embodiment. It is an example of a traversing network diagram which is the basis of the aerial photography survey of the said embodiment. It is the figure which showed the line which shows the flight position of a drone in the said traverse network diagram. FIG. 3 is a tentative present condition photograph diagram which serves as confirmation data of a flight route of the drone. It is a schematic diagram which shows an example of the preparation procedure of the whole photograph block diagram by the said embodiment. FIG. 7 is a diagram in which the traversal network diagram is provided with squares as a unit for pasting a reduction-corrected image. It is an example of a completed-type existing survey map in which reduction ratio-corrected images are pasted on all squares. It is a schematic diagram which shows the concept of the reduction rate correction process by the altitude difference in the said embodiment. It is a schematic diagram which shows the concept of the reduction rate correction process by the altitude difference in the said embodiment.

  The present invention performs reduction ratio correction for enlarging or reducing an image of a measurement target captured by a drone based on the elevation of a surveyed reference point, and arranging it in two dimensions by replacing the image before correction. Then, the existing survey map is created. Hereinafter, the best mode for carrying out the present invention will be described in detail based on examples.

  <Outline of Embodiment> ... First, with reference to FIG. 1, an outline of the current survey map creation system of the present embodiment will be described. FIG. 1 is a flowchart showing an example of a processing procedure by the present-state survey map creation system of the present embodiment. First, a drone flying at a certain height captures the measurement target directly below and acquires an aerial image (step S10). It is assumed that the measurement target includes a plurality of surveyed reference points. The image to be acquired may be a moving image or a large number of still images continuously shot.

  Next, an image suitable for the reference point is selected and extracted from the acquired images (step S12). The “image suitable for the reference point” in the present embodiment is an image that can use the reference point as a reference for image processing. For example, it means that the reference point is located on the center line of a linear region having a predetermined width (for example, 10 m). Such image selection is performed for each of the plurality of reference points.

  Then, reduction ratio correction processing of the extracted image is performed (step S14). In the reduction ratio correction, the image selected in step S12 is divided into a plurality of regions, a correction factor is calculated from the elevation of the surveyed reference point for each divided region, and the image is enlarged or reduced. The rate is corrected. If no correction is necessary, the correction rate is set to 1: 1 and the image as it is is used in the next step S14.

  Finally, the images of the respective regions that have been subjected to the reduction ratio correction are replaced with the images before the reduction ratio correction, and are arranged two-dimensionally to create a current state survey map (current state survey photo map) (step S16). At this time, for locations where the difference in elevation is large, the reference points are provided in high locations and low locations, respectively, and by arranging the images after the reduction ratio correction around each reference point, the enlargement / reduction rate is increased. The existing survey map with small error is completed.

  <Hardware Configuration of System> ... Next, the hardware configuration of the existing survey map creation system will be described with reference to FIG. An existing survey map creation system (hereinafter simply referred to as “this system”) 10 includes a processor 12, a memory 14, a storage 16, and a communication unit 18, which are connected by a bus (not shown). The processor 12 includes, for example, a CPU (Central Processing Unit), and performs various processes by reading and executing various programs stored in the memory 14. The memory 14 stores a program executed by the CPU 12, and is configured by, for example, a ROM (Read Only Memory) or a RAM (Random Access Memory). For example, various means shown in FIG. 3 are stored.

  The storage 16 stores the reference point data 16A, the captured image 16B, a control program (not shown), and the like. The reference point data 16A stores X coordinates, Y coordinates, and Z coordinates for a plurality of reference points for each reference point. In addition to the reference point data, survey data for a “single point” described later is also stored in the storage 16. The captured image 16B is an image captured by the camera 82 (see FIGS. 10 and 11) mounted on the drone 80, and may be a moving image or a still image. The communication unit 18 acquires an image taken by the drone 80 through the network.

  <Functional Configuration of System> ... Next, the functional configuration of the present system will be described with reference to FIG. The system 100 includes an image acquisition unit 20, an image selection unit 2, a reduction ratio correction unit 24, and an existing survey map creation unit 26.

  The image acquisition unit 20 acquires an aerial image of a measurement target captured right below by a drone 80 flying at a fixed height (for example, 100 m from a reference altitude). The acquired image is stored in the storage 16 as a captured image 16B.

  The image selection means 22 selects an image suitable for the reference point from the images acquired by the image acquisition means 20. The “image suitable for the reference point” is an image in which the reference point is present on the center line of a linear measurement target region having a width of 10 m, for example. The selected image may be a series of still images converted from a moving image, or may be one extracted from a large number of still images captured continuously.

  The reduction ratio correction unit 24 divides the image selected by the image selection unit 22 into a plurality of regions, and refers to the correction ratio from the elevation of the surveyed reference point for each divided region to enlarge the image. Alternatively, a reduction ratio correction process for reducing the size is performed. For example, when the measurement target is a portion having a difference in elevation, the image taken from the drone 80 flying at a constant height has an enlarged image at a point where the ground surface is higher than the basic altitude, and the ground surface is enlarged. The image at the point where is lower than the basic altitude is taken in a reduced size. The reduction ratio correction unit 24 performs reduction ratio correction processing of the captured image in consideration of such a correction ratio.

  The present-state survey map creating means 26 replaces the image of each region that has been subjected to the reduction ratio correction with the image of the region before the reduction ratio correction, and arranges it in a two-dimensional manner to create a current-state survey photograph 60 (see FIG. 9). . When there are multiple reference points, multiple images with each reference point as a reference for reduction ratio correction are acquired and selected, and for each of these multiple images, the image is divided into a plurality of regions, and each divided region is divided. The current state survey map is created by arranging the image after the reduction ratio correction described above.

  <Aerial photography by drone> ... Next, aerial photography of the measurement target by the camera 82 of the drone 80 will be described. It should be noted that the imaging of the measurement target by the drone is performed as a preliminary preparation in this embodiment. FIG. 4 is a traverse network diagram 30, which is the basis of the aerial image survey by the drone. The traversal network diagram 30 includes a plurality of reference points 32A, 32B, .... It is necessary to determine the flight position of the drone 80 in order to create a current survey map based on the traverse network diagram 30. In FIG. 5, a vertical line 40 having a width of 10 m is drawn in the X-axis direction on the traversing network diagram 30 of FIG. 4, and the vertical line 40 is at a position where the drone 80 flies on site. In the illustrated example, the drone 80 will fly 12 times.

  In the case of actually performing aerial shooting and moving image shooting, a temporary current state picture diagram 60 as shown in FIG. 6 is created in advance. The provisional present-state photograph 60 shown in FIG. 6 is a photograph obtained by copying the vertical line 40 of FIG. In the case of aerial photography by the drone 80 at the site, this provisional current-state photograph 60 is used as a material for confirming the flight route.

  In addition, in order to confirm the flight route and flight direction, it is advisable to put a target object that can be seen on the local monitor. As the target object, for example, about 2 to 3 color cones or the like are arranged for one row (the route along which the drone 80 flies in one flight). As targets other than the color cone, a mat-shaped anti-aircraft sign, an anti-aircraft sign having a parasol type light source, a reflection-compatible anti-aircraft sign, an anti-aircraft sign suitable for high places, etc. may be used in combination.

  <Procedure of Present Survey Map by this System> ... First, with reference to FIG. 7, an example of a procedure for creating an overall photograph block diagram in the system 100 of the present embodiment will be shown. FIG. 7A shows a plurality of linear regions L1 to L3 in the measurement target. There is a reference point 32C on the center line 40 of the area L1 and another reference point 32D on the center line 40 of the area L3. Regarding the region L2, it is assumed that the reference point exists in a portion outside the illustrated range.

  The system 100 acquires the image 70 captured by the camera 82 of the drone 80, which captures the center lines of the regions L1 to L3 directly below and flies at a constant height in the X-axis direction, by the image acquisition unit 20. Then, as shown in FIG. 7B, the image of the portion corresponding to the region L1 is selected from the image 70A captured by the drone flying along the center line of the region L1. Similarly, from the image 70B captured from the drone flying along the center line of the area L2, the image of the portion corresponding to the area L2 is selected. Similarly, from the image 70C captured from the drone flying along the center line of the area L3, the image of the portion corresponding to the area L3 is selected. Such image selection is performed by the image selection means 22.

  In this way, an image of the area under the measurement is captured directly from the drone 80 flying along the center line of each of the areas L1 to L3, and the acquired images are arranged as shown in FIG. 7C. As a result, the entire photograph block diagram is created. In this embodiment, twelve moving images are actually taken, and twelve still images are obtained from each moving image and arranged.

  FIG. 8 shows a diagram in which the traverse network diagram 30 is provided with squares for arranging reduction-corrected images. The square M is, for example, a square surrounded by the vertical line 42 and the horizontal line 50, and has a side of 10 m. For each of the squares M, the reduction ratio correction unit 24 performs reduction ratio correction processing of enlargement or reduction in consideration of the height of the elevation with respect to the surveyed reference point. Then, the present-state survey map creating unit 62 creates the present-state survey map by replacing the image that has been subjected to the reduction ratio correction with the image before the reduction ratio correction and pasting it on all the squares M.

  Here, with reference to FIG. 10 and FIG. 11, an example of the image reduction ratio correction processing with the altitude of the reference point as a reference will be described. A camera 82 of the drone 80 flying at a certain height captures an image of each square directly under the ground surface shown by the uneven surface in FIGS. 10 and 11 as a measurement target. The flying height of the drone 80 is, for example, 100 m above the basic altitude. The basic altitude is set based on the Z coordinate of the surveyed reference point.

In the case of the above settings, the original image 90 before correction at the position P1 on the ground surface in FIGS. 10 and 11 is an enlarged image because it is captured at a position higher than the basic altitude. For example, when the altitude at the position P1 is 18 m higher than the basic altitude, the photo correction ratio is 0.82 (1: 0.82), which is obtained by dividing “100-18.00 = 82.00” by 100. . On the other hand, with respect to the photograph figure correction ratio, if one side of the square centered at the position P1 is 8.2 m, the area of the original image 90 is 8.20 × 8.20 = 67.24 m ² , and The area of one square M formed on the surface 100 is 0.67 times the area of 100 m ² . Here, the reduction ratio correction unit 24 performs a process of enlarging the original image 90 so that it fits the area of the square M (1 / 0.82≈1.22 times per side). The area is 1.22 × 1.22 = 1.49 times (100 ÷ 0.67 = 149). The elevation point at the position P1 is calculated by a plotting type ground survey as in the known traverse survey. The required points (single points) are similarly measured including the following positions P2 and P3 to obtain elevation points necessary for the calculation.

On the contrary, the uncorrected original image 94 at the position P3 on the ground surface in FIGS. 10 and 11 is a reduced image because it is captured at a position lower than the basic altitude. For example, when the altitude at the position P3 is 15 m lower than the basic altitude, the photo correction ratio is 1.15 (1: 1.15) obtained by dividing “100 + 15.00 = 115.00” by 100. On the other hand, with respect to the photograph figure correction ratio, if one side of the square centered at the position P3 is 11.5 m, the area of the original image 94 is 11.50 × 11.50 = 132.25 m ² , The area of one square M formed on the surface 100 is 1.32 times the area of 100 m ² . Here, the reduction ratio correction unit 24 performs a reduction process (1 / 1.15≈0.87 times per side) so that the original image 94 fits the area of the square M. The area is 0.87 × 0.87 = 0.76 (100 ÷ 132.25 = 0.76).

  On the other hand, the original image 92 before correction at the position P2 on the ground surface in FIGS. 10 and 11 is taken at the same height as the basic altitude, and thus is an image that is not enlarged or reduced. In this case, the photo correction ratio is 1: 1. In addition, the ratio of correction of photographic drawing is 1.0. Therefore, the reduction ratio correction unit 24 does not perform reduction ratio correction on the original image 92.

  By arranging the corrected images 90A, 94A and the original image 92, which have been subjected to the reduction ratio correction in the above procedure, in each of the squares of the basic surface 100, the current state survey map (current state survey photo map) 60 shown in FIG. It In this embodiment, in a portion where the difference in height is extremely large (for example, a stone wall), reference points are set in the high portion and the low portion so that an error does not easily occur in the ratio of enlargement / reduction, and the vicinity thereof is provided. By cutting out the image with and performing the correction process, it is possible to arrange images with small errors.

  <Effect> ... According to the embodiment described above, the reduction ratio correction is performed in which the image of the measurement target captured by the drone is enlarged or reduced based on the elevation of the surveyed reference point. Since it was decided to create an existing survey map by replacing it with an image and arranging it in two dimensions, an appropriate existing survey map can be created with a simple mechanism.

  It should be noted that the above-described embodiment is an example, and can be appropriately modified within a range in which the same effect can be obtained. Further, the present invention may be provided as a program executed by a server. This program may be provided in a state of being recorded in a computer-readable recording medium, or may be downloaded via a network. The present invention may also be provided as a method invention.

  According to the present invention, the image of the measurement target taken by the drone is subjected to reduction ratio correction for enlarging or reducing based on the elevation of the surveyed reference point, and is arranged two-dimensionally in place of the image before correction. Since it is decided to create an existing survey map, it is suitable as an existing survey map creation system.

10: Current state survey map creation system 12: Processor 14: Memory 16: Storage 16A: Reference point data 16B: Photographed image 18: Communication unit 20: Image acquisition means 22: Image selection means 24: Reduction ratio correction means 26: Current situation survey map Creating means 30: Traverse network diagram 32A to 32D: Reference points 40, 42: Vertical line 44: Temporary current state photograph diagram 50: Horizontal line 60: Current state survey map 70A to 70C: Image 80: Drone 82: Camera 90, 92, 94: Original images 90A, 94A: Post-correction image 100: Basic plane H: Basic elevation heights L1 to L3: Area M: Squares P1 to P3: Position

Claims (5)

A current survey map creation system that creates a current survey map based on images taken by a drone,
Image acquisition means to capture an aerial image by capturing the measurement target directly below by a drone flying at a certain height,
The image is divided into a plurality of regions, for each divided region, a correction factor is calculated from the elevation of the surveyed reference point, and a reduction ratio correction unit that performs reduction ratio correction to enlarge or reduce the image,
Creating means for creating an existing survey map by replacing the images of the respective regions with the reduction ratios corrected with the images before the reduction ratios and arranging them in two dimensions.
An existing survey map creation system equipped with. Image selecting means for selecting an image centered on the reference point from among the images acquired by the image acquiring means,
Equipped with
The present situation survey map creation system according to claim 1, wherein the reduction ratio correction unit corrects the reduction ratio of the selected image. A plurality of the reference points are included in the measurement target,
The present survey map creation system according to claim 2, wherein the image selection means selects an image having a plurality of reference points as a center. A method for creating an existing survey map based on images taken by a drone,
A step of capturing an aerial image by capturing the measurement object directly below by a drone flying at a certain height,
Dividing the image into a plurality of areas, calculating a correction rate from the altitude of the surveyed reference points for each of the divided areas, and performing a reduction rate correction for enlarging or reducing the image,
Replacing the images of the respective regions that have undergone the reduction ratio correction with the images before the reduction ratio correction and arranging them in a two-dimensional manner, and creating an existing survey map;
A method for creating an existing survey map. A program for causing a computer to execute a current-state survey map creation process for creating a current-state survey map based on an image taken by a drone,
A step of capturing an aerial image by capturing the measurement object directly below by a drone flying at a certain height,
Dividing the image into a plurality of areas, calculating a correction rate from the altitude of the surveyed reference points for each of the divided areas, and performing a reduction rate correction for enlarging or reducing the image,
Replacing the images of the respective regions that have been subjected to the reduction ratio correction with the images before the reduction ratio correction and arranging them in a two-dimensional manner, and creating an existing survey map;
A program to execute.

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