Surveying support device and program of the same

Abstract

To provide a device capable of appropriately detecting a surveying target even when a foundation upper surface of a building has a complex shape.SOLUTION: A surveying support device 1 according to the present invention is a device that accurately identifies surveying positions 4, 5 on a foundation upper surface 3 from point cloud data 6 as a surveying target 2, measures a height of the surveying position from a reference point 25, and measures a height of a predetermined position on the foundation upper surface 3. The surveying support device 1 includes point cloud contour extraction means 13, parallel line estimation means 14, skeletal element extraction means 15, surveying position identification means 16, and height surveying means 17. The skeletal element extraction means 15 extracts a position of a skeletal element 24 from two parallel lines 22, 22 along a point cloud contour 21, extracts both end portions 24a of the skeletal element 24 from the point cloud contour 21, and the surveying position identification means 16 accurately identifies the surveying positions 4, 5.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a surveying support device and a program that are capable of measuring the height of a specific location of a feature on the ground, such as the foundation of a building. [Background technology]

[0002] When constructing a building such as a house, it is important to inspect whether the foundation of the completed building has been constructed according to the design drawings. In particular, since the height of a specific point on the top surface of the foundation of a building has a significant impact on the stability and durability of the entire building, it is essential to measure the height of a specific point on the top surface of the foundation during construction.

[0003] Patent Document 1 discloses technology related to a building foundation inspection system that analyzes the point cloud contained in three-dimensional point cloud data and measures the position of surveying targets such as anchor bolts using the position of a reference line estimated from the edge of the rising part of the building's foundation as a guide. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-161615 Summary of the Invention [Problem to be solved by the invention]

[0005] The technology described in Patent Document 1 analyzes three-dimensional point cloud data, estimates a reference line from the three-dimensional point cloud contour located around the edge of the rising part of the building foundation, and collates the design data using the reference line as a guide to identify the measurement positions of anchor bolts, etc. However, with the technology described in Patent Document 1, it was difficult to accurately identify the measurement positions of things other than the anchor bolt positions, such as the height of the foundation top surface.

[0006] Specifically, when measuring the height of a specific location on the top surface of a building's foundation, it is preferable to measure the height of a location that has a large impact on the stability and durability of the building, such as near the edge of the top surface of the foundation.However, with the technology described in Patent Document 1, if there is an object (obstacle) such as a stone or gravel on the top surface of the foundation, the obstacle may make it impossible to properly identify the position of the edge, and as a result, it may not be possible to extract an accurate measurement position.

[0007] The present invention has been made in consideration of the above problems, and aims to provide a surveying support device that can accurately identify a surveying position from three-dimensional point cloud data and perform height measurements, etc. [Means for solving the problem]

[0008] In order to achieve the above object, the surveying support device of the present invention is characterized by comprising: a point cloud contour extraction means for extracting the point cloud contour of a feature from point cloud data; a parallel line estimation means for performing estimation processing for estimating two parallel lines along the point cloud contour; a skeletal element extraction means for performing skeletal element position extraction processing for extracting the positions of skeletal elements of the feature from the two parallel lines; a skeletal element end extraction processing for extracting both end portions of the skeletal elements from the point cloud contour; a surveying position identification means for identifying a surveying position where height is measured using the skeletal elements; and a height surveying means for measuring the height of the surveying position from a reference point.

[0009] The surveying support device of the present invention extracts the point cloud contour of a feature from point cloud data, extracts skeletal elements from the point cloud contour and two parallel lines along the point cloud contour, and identifies the surveying position using the skeletal elements as a reference line.Therefore, the surveying position can be identified with greater accuracy than when the measurement position is identified from a reference line that is biased to one side of the base surface, as in Patent Document 1.

[0010] In the surveying support device of the present invention, the point cloud contour extraction means may extract closed point cloud contours as partial extracted bodies, and the skeletal element extraction means may extract the positions and both end portions of the skeletal elements for the partial extracted bodies. With this configuration, when multiple partial extracted bodies are extracted from the point cloud contour, efficient and highly accurate processing can be achieved by performing element position extraction processing and skeletal element end extraction processing on each partial extracted body.

[0011] In the surveying support device of the present invention, if there are other point cloud contours from which no skeletal elements have been extracted in addition to the point cloud contours present on the skeletal elements extracted by the skeletal element extraction means, the estimation process, the skeletal element position extraction process, and the skeletal element end extraction process may be repeated until the number of other point cloud contours from which no skeletal elements have been extracted becomes 0. With this configuration, skeletal elements can be extracted with high accuracy even if the point cloud contours have complex shapes.

[0012] In the surveying support device of the present invention, the skeleton element extraction means may perform the skeleton element position extraction process to extract the center line between the two parallel lines as the position of the skeleton element, and the surveying position specifying means may specify the intersection of the center lines as the center of the skeleton element intersection. With this configuration, the center line of the top surface of the foundation of the building is extracted as the skeleton element, and by setting the surveying position on the skeleton element, it is possible to accurately measure the height of a predetermined position on the top surface of the foundation of the building.

[0013] In the surveying support device of the present invention, the skeleton element extraction means may perform the skeleton element position extraction process to extract the center line between the two parallel lines as the position of the skeleton element, and the surveying position specifying means may specify any position between the center line and the two parallel lines as the surveying position. With this configuration, even if the distance between the two parallel lines is wide and it is necessary to measure the position between the center line and the two parallel lines, the required position can be specified as the surveying position.

[0014] In order to achieve the above object, the survey support program of the present invention is a program for causing a computer to operate as the survey support device having the above configuration. [Effects of the Invention]

[0015] According to the present invention, a surveying support device can be provided that can accurately identify surveying positions from three-dimensional point cloud data and perform height measurements, etc., even if the top surface of a foundation has a complex shape. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is an explanatory diagram showing the functional configuration of a survey support device according to an embodiment of the present invention. [Figure 2] FIG. 2 is an explanatory diagram showing a base and a laser scanner for surveying using the survey support device of the present embodiment. [Figure 3] An image captured by a laser scanner converted into point cloud data. [Figure 4] FIG. 10 is an explanatory diagram showing the position of a point cloud occupying the upper end portion of a survey object. [Figure 5] FIG. 4 is an explanatory diagram showing a point cloud contour extracted from point cloud data. [Figure 6] FIG. 10 is an explanatory diagram of a repetitive process for a partial extracted object extracted from a point cloud contour. [Figure 7] FIG. 10 is an explanatory diagram showing the measurement positions of skeletal elements. [Figure 8] FIG. 10 is an explanatory diagram showing another example of the measurement positions of the skeleton elements. DETAILED DESCRIPTION OF THE INVENTION

[0017] Next, a survey support device 1 as an example of an embodiment of the present invention will be described with reference to Figures 1 to 7. In this embodiment, a device and a program will be described that use point cloud data 6 to measure the height of a specific location on the foundation top surface 3 of a building (land feature) that is a survey target 2.

[0018] In this embodiment, the surveying support device 1 is configured by a surveying support program 1a installed in a user terminal 7, which is a computer used by a user. As shown in Fig. 1, the surveying support device 1 has, as its functional configuration, a point cloud data acquisition means 11, a foundation top surface position determination means 12, a point cloud contour extraction means 13, a parallel line estimation means 14, a skeletal element extraction means 15, a surveying position identification means 16, and a height surveying means 17.

[0019] The point cloud data acquisition means 11 is a functional unit that imports three-dimensional point cloud data 6 (see FIG. 3) obtained by a laser scanner 18 (see FIG. 2) or the like into the surveying support device 1. The point cloud data 6 may be stored in a user terminal 7 and imported by the point cloud data acquisition means 11, or may be uploaded to the point cloud data acquisition means 11 via a network such as the Internet.

[0020] The foundation top surface position determining means 12 is a functional unit that determines the position of a point cloud 61 (see FIG. 4) that occupies the upper end portion of the survey object 2. In this embodiment, the angle of the normal vector of the point cloud data 6 that represents the survey object 2 is analyzed to estimate the height position y of the foundation top surface 3, and the surrounding point cloud 61 is determined as the processing target of the point cloud contour extraction means 13, which will be described later. Note that for the analysis method, please refer to the method described in Patent Publication No. 6730502 of the applicant of this application.

[0021] In addition, the foundation top surface position determination means 12 may allow the user to observe the point cloud data displayed on the display of the surveying support device 1 and manually determine the height position y of the foundation top surface 3 using a mouse, touch panel, etc.

[0022] The point cloud contour extraction means 13 is a functional unit that extracts a point cloud contour 21 (see FIG. 5) that indicates the contour of the foundation upper surface 3 from the point cloud 61 that occupies the upper end portion of the survey object 2. In this embodiment, an orthoimage of the foundation upper surface 3 is generated from the point cloud 61, and the point cloud contour 21 is extracted based on the orthoimage.

[0023] An orthoimage is an image obtained by converting (orthotransforming) an image obtained by taking a photograph at an angle into an image with correct dimensions without tilt, as if viewed from directly above. In this embodiment, by extracting the point cloud contour 21 based on the orthoimage, it is possible to extract the point cloud contour 21 showing the contour of the foundation top surface 3 with high accuracy.

[0024] 5, the point cloud contour extraction means 13 is equipped with a functional unit that extracts and divides closed parts of the point cloud contour 21 into partial extraction bodies 21a to 21s. By dividing the point cloud contour 21 into a plurality of partial extraction bodies 21a to 21s and individually performing the estimation process, skeletal element position extraction process, and skeletal element end extraction process described below, it is possible to perform efficient and highly accurate processing.

[0025] The parallel line estimation means 14 is a functional unit that estimates two parallel lines 22, 22 that run along the contour of the long side 211 of the point cloud contour 21 (partial extraction body 21 a). As shown in FIG. 6, the two parallel lines 22, 22 are reference lines for extracting a skeleton element 24 that serves as a reference for the measurement positions 4, 5. In this embodiment, the two parallel lines 22, 22 are estimated so as to include the short side 212 of the point cloud contour 21 (partial extraction body 21 a).

[0026] The skeletal element extraction means 15 is a functional part that extracts a skeletal element 24 based on two parallel lines 22, 22, and is composed of a skeletal element position extraction means 151 that extracts the position of the skeletal element 24, and a skeletal element end extraction means 152 that extracts both ends of the skeletal element 24.

[0027] The skeleton element position extraction means 151 is a functional unit that extracts the inclination and linear position of the skeleton element 24 on the foundation upper surface 3 based on the two parallel lines 22, 22. In this embodiment, the center line 23 passing through the center position of the two parallel lines 22, 22 is extracted as the position of the skeleton element 24.

[0028] The skeleton element end extraction means 152 is a functional unit that extracts both end portions 24a of the skeleton element 24 based on the point cloud contour 21 (partial extraction body 21a). In this embodiment, the intersection point where the center line 23 of the two parallel lines 22, 22 intersects with the short side 212 of the point cloud contour 21 (partial extraction body 21a) is extracted as the end portion 24a of the skeleton element 24.

[0029] The measurement position specifying means 16 is a functional unit that specifies measurement positions 4 and 5 for measuring the height of the foundation upper surface 3. In this embodiment, a point that is a predetermined distance away from both end portions 24a of the skeletal element 24 toward the center is specified as the measurement position 4. In addition, a skeletal element intersection where multiple skeletal elements 24 intersect is specified as the measurement position 5.

[0030] The height measurement means 17 is a functional unit that measures the height of the measurement positions 4 and 5 on the foundation upper surface 3. In this embodiment, the height from an arbitrary reference point 25 on the survey object 2 to the measurement positions 4 and 5 is detected. The reference point 25 can be provided, for example, on the installation surface on which the laser scanner 18 is installed. The height of the survey object 2 can be detected, for example, from the coordinates of the reference point 25 and the coordinates of the center of gravity of the survey object 2 in a planar view in the point cloud data 6. As a result, for example, if the change in height between the measurement positions 4 and 5 is not within a predetermined range, it can be determined that the construction is poor.

[0031] Here, the user terminal 7 is primarily composed of a computer, which includes a processor such as a CPU (Central Processing Unit) and a GPU (Graphics Processing Unit), a hard disk, a storage means such as memory, a means for connecting to various networks, a keyboard, a mouse, a display, etc. (not shown).

[0032] In this embodiment, the survey support program 1a is installed in the user terminal 7, but it may also be installed in a server (not shown) and used on a client terminal. It may also be stored on a CD-ROM, DVD-ROM, or the like, or may be uploaded to a server and made downloadable via a network.

[0033] Next, we will explain the operation of the surveying support device 1 of this embodiment. In this embodiment, the survey object 2 is formed in a lattice pattern as shown in Figure 2, and the heights of a surveying position 4 representing the vicinity of the end of the foundation upper surface 3 of the survey object 2 and a surveying position 5 (see Figure 7) representing a skeleton element intersection where multiple skeleton elements 24 intersect are measured.

[0034] In this embodiment, data on the survey object 2 is acquired by a laser scanner 18 installed on the installation surface, and this data is used as point cloud data 6. In this embodiment, a reference point 25 is provided on the installation surface of the laser scanner 18, and the heights of the survey positions 4 and 5 (near the end of the foundation upper surface 3 and the intersection of the skeletal elements) are detected using the coordinates of this reference point 25 as a reference.

[0035] Figure 3 shows an image of the survey object 2 captured by a laser scanner 18, expressed as point cloud data 6. This point cloud data 6 is used to detect the heights of the survey positions 4 and 5 (near the edge of the foundation top surface 3 and at the intersection of the skeletal elements). Note that in Figure 3, the data for the inside of the survey object 2 has been smoothed.

[0036] When measuring the height of the foundation top surface 3 using this point cloud data 6, the user starts the surveying support program 1a on the user terminal 7, and after performing user authentication, etc., the point cloud data 6 is acquired by the point cloud data acquisition means 11. In this embodiment, the point cloud data 6 is acquired by specifying data stored in the storage means of the user terminal 7.

[0037] When the point cloud data 6 is acquired, the foundation top surface position determining means 12 detects the point cloud 61 occupying the upper end portion of the survey object 2, as shown in Fig. 4. If the point cloud 61 occupying the upper end portion of the survey object 2 is not properly detected, the user may observe the point cloud data 6 displayed on the display of the survey support device 1 and adjust the height position y using a mouse or the like.

[0038] Next, the point cloud contour extraction means 13 extracts a point cloud contour 21 representing the edge portion of the foundation upper surface 3 from the point cloud 61 occupying the upper end portion of the survey object 2. Furthermore, the point cloud contour extraction means 13 divides the point cloud contour 21 into a plurality of partial extraction bodies 21a to 21s, as shown in Fig. 5. These partial extraction bodies 21a to 21s are processed in a later step to extract skeletal elements 24 individually from each of them.

[0039] FIG. 6 illustrates a process for repeatedly extracting a skeleton element 24 from one partial extracted body 21a extracted from the point cloud contour 21 in this embodiment.

[0040] FIG. 6(A) shows the results of first performing estimation processing on the partial extraction body 21a to obtain two parallel lines 22, 22, and then performing skeleton element position extraction processing and skeleton element end extraction processing.

[0041] In this embodiment, first, the parallel line estimation means 14 determines two parallel lines 22, 22 that serve as reference lines for extracting the skeleton elements 24. At this time, the two parallel lines 22, 22 are straight lines calculated by analyzing the contour of the partial extraction body 21a. By using the straight lines as the reference lines in this way, the position of the skeleton elements 24 can be identified with higher accuracy than when the contour of the partial extraction body 21a is used directly as the reference line.

[0042] A known method can be used to find the two parallel lines 22 from the partial extract 21a. In this embodiment, the two parallel lines 22 are calculated using RANSAC (Random Sample Consensus), which is a type of robust method.

[0043] Specifically, two points are randomly selected from the contour of the partial extracted body 21a, and a line segment model is generated by connecting these two points. At this time, two line segment models are generated simultaneously. Next, it is evaluated whether these two line segment models are parallel or not.

[0044] If the two line segment models are parallel, the two line segment models are adopted as two parallel lines 22, 22. If the two line segment models are not parallel, new two line segment models are generated, and the estimation process is repeated until two line segment models that are parallel are found.

[0045] After the two parallel lines 22, 22 are obtained, a skeleton element 24 is extracted by the skeleton element extraction means 15. Specifically, a center line 23 passing through the center position of the two parallel lines 22, 22 is extracted as the position of the skeleton element 24 by a skeleton element position extraction process, and an intersection of the center line 23 and the short side 212 of the partial extraction body 21a is extracted as the end 24a of the skeleton element 24 by a skeleton element end extraction process.

[0046] Next, as shown in Fig. 6(A), if there are other point cloud contours from which no skeletal elements have been extracted for the partial extraction body 21a in addition to the point cloud contours used to extract the skeletal elements 24, the estimation process, skeletal element position extraction process, and skeletal element end extraction process are repeated as shown in Fig. 6(B) to (D). When the number of other point cloud contours from which no skeletal elements 24 have been extracted becomes zero as shown in Fig. 6(D), the process of extracting the skeletal elements 24 is terminated.

[0047] In this way, by repeating the estimation process, skeleton element position extraction process, and skeleton element end extraction process, the skeleton elements 24 can be extracted with high accuracy even if the partial extraction body 21a has a complex shape.

[0048] Next, the survey position specifying means 16 specifies survey positions 4 and 5 on the survey object 2. In this embodiment, as shown in FIG. 7, a point that is a predetermined distance (for example, 50 to 60 mm) away from both ends 24a of the skeletal element 24 toward the center is specified as survey position 4, and a skeletal element intersection where multiple skeletal elements 24 intersect is specified as survey position 5.

[0049] Since the surveying positions 4 and 5 of the skeletal element 24 are important elements that have the function of transferring the load of the building to the ground, by using these elements as the surveying positions 4 and 5 for measuring the height of the survey object 2, the construction status of the building can be evaluated with high accuracy. The surveying positions may be defined at any position on the skeletal element 24. For example, if the distance between these surveying positions 4 and 5 is greater than a certain amount, the surveying position 4' (see Figures 2 and 7), which is the midpoint between these surveying positions, may be used as the surveying position.

[0050] Furthermore, the surveying position may be defined at any position as long as it is specified based on the skeletal element 24. For example, as shown in Figure 8, if the width of the foundation upper surface 3 is equal to or greater than a certain length, a reference line 26 perpendicular to the skeletal element 24 may be generated at the midpoint between surveying positions 4 and 5, and points at a predetermined distance from the center of this reference line 26 to both ends may be set as surveying positions 5'.

[0051] Next, the height from an arbitrary reference point 25 to the measurement positions 4 and 5 is detected by the height measurement means 17. If there is an intermediate position 4', the height of this intermediate position 4' is also detected. In this way, by detecting the heights of the multiple measurement positions 4 and 4' and the measurement position 5, it is possible to check whether the foundation upper surface 3 has been constructed as designed.

[0052] According to the surveying support device 1 of this embodiment, by performing a skeleton element position extraction process and a skeleton element end extraction process, the heights of the surveying positions 4 and 5 on the foundation top surface 3 can be accurately detected even when the foundation top surface 3 has a complex shape as shown in Figure 6.

[0053] In the above embodiment, the reference point 25 is provided on the installation surface on which the laser scanner 18 is installed, but the reference point 25 can be provided at any location. For example, the reference point 25 may be provided on the top surface 3 of the foundation that is ensured to be flat. Furthermore, the point cloud data 6 may be image data captured by a drone or the like, in addition to the image data captured by the laser scanner 18.

[0054] In the above embodiment, the point cloud contour extraction means 13 may generate a color-coded image for the point cloud data 6, in which colors are coded based on the vector angle, and extract the point cloud contour 21 based on this color-coded image. Alternatively, the point cloud contour extraction means 13 may extract the point cloud contour 21 using vector angles within a predetermined range, for example, ±10 degrees with respect to the horizontal.

[0055] Furthermore, in the above embodiment, the skeletal element end extraction process extracts the intersection of the center line 23 and the short side 212 of the partial extraction body 21a as the end 24a of the skeletal element 24, but this is not limited to this. Two parallel lines corresponding to the short side 212 may be estimated by the parallel line estimation means 14, and the intersection of these parallel lines and the center line 23 may be taken as the end 24a of the skeletal element 24. [Explanation of symbols]

[0056] 1…Survey support equipment 1a…Survey support program 2...Survey target 6...Point cloud data 13...Point cloud contour extraction means 14...Parallel line estimation means 15...Skeletal element extraction means 151...skeletal element position extraction means 152...skeletal element end extraction means 16…Survey position identification means 17...Means of height measurement 21...Point cloud contour 21a~21s…partial extract 22...Two parallel lines 24...Skeletal elements

Claims

1. a point cloud contour extraction means for extracting a point cloud contour of a feature from the point cloud data; a parallel line estimation means for performing an estimation process to estimate two parallel lines along the point cloud contour; a skeleton element extraction means for performing a skeleton element position extraction process for extracting the positions of the skeleton elements of the feature from the two parallel lines, and a skeleton element end extraction process for extracting both ends of the skeleton elements from the point cloud contour; a measurement position specifying means for specifying a measurement position for measuring height using the skeleton elements; A surveying support device comprising height measuring means for measuring the height of the surveying position from a reference point.

2. the point cloud contour extraction means extracts a point cloud contour that is closed as a partial extraction body; 2. A surveying support device according to claim 1, wherein said skeleton element extracting means extracts the position and both end portions of said skeleton elements with respect to said partial extractor.

3. The surveying support device according to claim 1, characterized in that, in addition to the point cloud contours present on the skeletal elements extracted by the skeletal element extraction means, if there are other point cloud contours from which the skeletal elements have not been extracted, the estimation process, the skeletal element position extraction process, and the skeletal element end extraction process are repeated until the number of other point cloud contours from which the skeletal elements have not been extracted becomes 0.

4. the skeleton element extraction means performs the skeleton element position extraction process to extract the center line between the two parallel lines as the position of the skeleton element; 2. A surveying support device according to claim 1, wherein said surveying position specifying means specifies an intersection point where said center lines intersect as the center of a skeleton element intersection portion.

5. the skeleton element extraction means performs the skeleton element position extraction process to extract the center line between the two parallel lines as the position of the skeleton element; 2. A surveying support device according to claim 1, wherein said surveying position specifying means specifies an arbitrary position between said center line and said two parallel lines as said surveying position.

6. A survey support program that causes a computer to operate as the survey support device according to any one of claims 1 to 5.

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