Method for calculating the completed state of the slope frame

Abstract

To provide an accurate and efficient method for calculating a completed part of a slope frame.SOLUTION: A method for calculating a completed part of a slope frame is to convert three-dimensional point group data of a slope G on which a slope frame F is constructed, as original data 10, into triangle group data, and the method includes: performing generation of non-convex triangle group data L1 in which the inside of the slope frame is drawn and generation of convex triangle data L2 in which the inside of the slope frame is not drawn in the generation of the triangle group data; superimposing both the data L1 and the data L2 and converting a surface of the slope frame F into slope frame surface triangle group data according to the difference between them; deleting an overlapping line segment shared by triangles adjacent to each other; when an angle formed by line segments adjacent to each other is 90±25°, defining shared points as corner points 11; and calculating a completed part of the slope frame F by using the corner points 11.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for calculating the shape of a curb formwork.

Background Art

[0002] As a method for measuring the shape of a curb formwork constructed on a slope surface, for example, there is a method of obtaining three-dimensional point cloud data of the slope surface with a laser scanner, analyzing this three-dimensional point cloud data to estimate a surface parallel to the slope surface, and calculating the shape of the curb formwork based on this estimated surface (see Patent Document 1). According to this method, the safety and efficiency of the measurement work can be achieved.

[0003] However, the method of Patent Document 1 is not a method specialized for measuring the shape of a curb formwork, and there is a search for a method of processing three-dimensional point cloud data in a more accurate and efficient curb formwork work.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The problem to be solved by the present invention is to provide a method for calculating the shape of a curb formwork with high precision and efficiency.

Means for Solving the Problems

[0006] The present invention that solves the above problems is a method for calculating the shape of the curb formwork from the original data of the three-dimensional point cloud data of the slope surface on which the curb formwork is constructed, wherein the original data is converted into triangular mesh data, In creating this triangular group data, we create non-convex triangular group data in which the area within the slope frame is drawn relatively, and convex triangular group data in which the area within the slope frame is not drawn relatively. The non-convex triangular group data and the convex triangular group data are superimposed, and the surface of the slope frame is converted into slope frame surface triangular group data based on the differences between the two triangular group data. In this set of slope surface triangle data, duplicate line segments shared by mutually adjacent triangles are removed. In the set of line segments remaining after deletion, if the angle formed by mutually adjacent line segments is 90±25°, the intersection point of these mutually adjacent line segments is defined as the corner point. This corner point is used to calculate the completed shape of the aforementioned slope frame. This is a method for calculating the completed state of a slope frame, characterized by the following features. [Effects of the Invention]

[0007] According to the present invention, a highly accurate and efficient method for calculating the completed shape of a slope frame is provided. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic diagram of the legal framework to be processed. [Figure 2] This is a block diagram of the processing system in this configuration. [Figure 3] This is a diagram illustrating the processing of the editing means of this embodiment. [Figure 4] This is a diagram illustrating the processing of the editing means of this embodiment. [Figure 5] This is a diagram illustrating the processing of the editing means of this embodiment. [Figure 6] This is a diagram illustrating the processing of the editing means of this embodiment. [Figure 7] This is a diagram illustrating the processing of the editing means of this embodiment. [Figure 8] This is a diagram illustrating the processing of the editing means of this embodiment. [Figure 9] This is a schematic diagram of the intersection point of the slope frame. [Figure 10] This is a diagram illustrating the processing of the editing means of this embodiment. [Figure 11]This is a processing explanatory diagram of the editing means of this form.

Embodiment for Carrying Out the Invention

[0009] Next, an embodiment for carrying out the invention will be described. Note that this embodiment is an example of the present invention. The scope of the present invention is not limited to the scope of this embodiment.

[0010] The processing system of this form is, for example, a system that calculates the formed shape of the formwork F constructed on the slope surface G as shown in FIG. 1. In this example, the formwork F is constructed in a lattice shape by a plurality of vertical beams F1 and a plurality of horizontal beams F2.

[0011] In the processing system of this form, the three-dimensional point cloud data of the slope surface G on which the formwork F is constructed is used as the original data. This three-dimensional point cloud data can be obtained, for example, by performing terrestrial laser surveying. Also, for example, aerial photographic surveying can be performed, and the obtained image data can be prepared by converting it into three-dimensional point cloud data. When converting this three-dimensional point cloud data from image data, commercially available software such as Metashape and Pix4D can be used, for example.

[0012] Here, the three-dimensional point cloud data is a collection of point data representing the spatial position information (position information expressed in a three-dimensional space) of each component included in the formwork F to be processed and the slope surface G on which this formwork F is constructed.

[0013] As shown in FIG. 2, the processing system X of this form includes an importing means 100 that imports the three-dimensional point cloud data prepared as described above as the original data, an editing means 200 that edits the original data imported by this importing means 100, a calculating means 300 that calculates the formed shape of the formwork F from the edited data edited by this editing means 200, and an outputting means 400 that outputs the data calculated by this calculating means 300.

[0014] The capturing means 100 of this embodiment is constituted by a data capturing (input) device such as a keyboard, a pointing device, etc.

[0015] The editing means 200 of this embodiment is means such as an arithmetic processing device that converts original data into triangle group data. For this conversion, for example, algorithms such as Alpha shapes, Poisson surface reconstruction, Delaunay Triangulation, etc. can be used. However, it is preferable to use the Ball Pivoting Algorithm.

[0016] In this regard, the Ball Pivoting Algorithm is an algorithm that obtains data of a set of three contact points (a three-contact point group) where a sphere and the original data are in contact by rolling a sphere on the original data, and converts this three-contact point group data into a set of triangles (triangle group (TIN: triangulated irregular network) data).

[0017] In this algorithm, for example, first, a sphere is dropped onto the original data. As a result, the sphere gets caught on the original data, and three points (vertices) that form the first triangle are determined. Next, the sphere is rolled (pivoted) so as to cross the edge of the first triangle. As a result, the sphere stabilizes at a new location, and three points (vertices) that form a new triangle are determined. By repeating the above pivoting, a set of triangles (mesh) that covers the original data to be edited is formed. By using this algorithm to convert the original data into a set of triangle groups (data), while retaining the necessary data, the data volume can be significantly reduced, and the formed shape of the legal frame F can be calculated with high precision and efficiently.

[0018] Regarding how to use the Ball Pivoting Algorithm, various considerations can be made, but the following usage forms are recommended. First, as a premise, as shown in Figures 3 and 4 (although shown two-dimensionally in this explanation, it is actually three-dimensional), the spheres in the ball pivoting algorithm are represented by the codes C1 and C2. Then, by rolling these spheres C1 and C2 on the original data 10, a set of three points of contact (a group of three points of contact) where spheres C1 and C2 touch the original data 10 is obtained. Triangle group data L1 and L2 are obtained by combining this group of three points of contact, etc.

[0019] On the other hand, in obtaining the triangle group data L1 and L2, a relatively small sphere C1 is used to create non-convex triangle group data L1 in which the area within the slope frame F is relatively depicted, and a relatively large sphere C2 is used to create convex triangle group data L2 in which the area within the slope frame F is relatively not depicted. This is because if the radius of the rolling sphere is small, the frequency of contact with the original data 10 increases, resulting in a set of short line segments and the creation of data (non-convex triangle group data L1) in which the shape within the slope frame is depicted in more detail. On the other hand, if the radius of the rolling sphere is large (usually a sphere larger than the spacing between the vertical beams F1 and horizontal beams F2), the sphere will touch the surface of adjacent vertical beams F1 and horizontal beams F2 before touching the bottom of the slope frame, so the frequency of contact with the original data 10 decreases, a set of long line segments is obtained, and the creation of data (convex triangle group data L2) in which the shape within the slope frame is relatively not depicted (the area within the slope frame is filled).

[0020] In the above, "relatively" means whether one is larger or smaller than the other, or more detailed or less detailed, when comparing two types of balls C1 and C2 or two types of data L1 and L2, and is not absolute. Furthermore, the above assumes that two types of balls are rolled and two types of data are created, but if necessary, more than two types of balls can be used to create multiple types of data.

[0021] The non-convex triangular group data L1 and convex triangular group data L2 created as described above are compared to obtain editable data. Specifically, as shown in Figure 5, the non-convex triangular group data L1 and convex triangular group data L2 are superimposed, and the surface of the slope frame F (longitudinal beams F1 and transverse beams F2) is calculated from the differences between the two triangular group data L1 and L2. In other words, there is no significant difference D between the two triangular group data L1 and L2 in the surface (slope frame itself) part of the slope frame F compared to the inner (inside the frame) part FG part of the slope frame F. Therefore, by knowing the distance (D) between the two triangular group data L1 and L2, the surface (position) of the slope frame F can be determined and calculated.

[0022] From the edited data showing the surface of the slope frame F calculated as described above, preferably, at least one of the following is calculated: beam length (beam extension), frame center spacing, frame width, slope length, extension, and slope frame area, and these calculated values ​​are output as appropriate. The output destination is, for example, a display device such as a display, a printing device, a storage device such as a USB memory.

[0023] There are no particular limitations on the method for calculating the finished shape from the edited data showing the surface of the slope frame F, but for example, when calculating the beam length, it is recommended to use the following method (method for calculating the finished shape of the slope frame). In other words, the surface data of the slope frame calculated from the non-convex triangle group data L1 and the convex triangle group data L2 consists of multiple triangles (combinations of vertices). Among these, as shown in Figure 6, there are triangles that make analysis difficult, such as triangle Tx which includes a vertex located between beams (between the two crossbeams F2 in the illustrated example). Therefore, first, line segments shared (overlapping) by adjacent triangles are deleted from each side (line segment) of the triangles that constitute the surface of the slope frame F. Then, by joining the line segments that remain after this deletion, continuous lines representing the outer perimeter F3 of the slope frame and the inner shape F4 are created. Furthermore, if the angle formed by mutually adjacent line segments in this continuous line (set of line segments) is close to 90°, for example, 90±25°, the point of intersection of these mutually adjacent line segments is designated as the corner point 11 (see (1) in Figure 7), and constraint line segments are created by deleting all but the corner point 11 (unnecessary vertices 14; see (1) in Figure 7) from the continuous lines of the outer perimeter F3 of the slope frame and the inner shape F4.

[0024] Next, a set of triangles is created from the corner points 11 and constraint line segments, for example by using a constrained Delaunay partition. Then, based on the centroid of each triangle, the outer perimeter F3 of the slope frame, and the shape inside the frame F4, an inside / outside determination is made to identify triangles 15 that do not need to be analyzed (see (2) in Figure 7). Specifically, for example, as shown in Figure 8, triangle f2 is composed of vertices p2, p4, p5 and sides e3, e4, e5, and is adjacent to triangles f1, f3, and shares sides e3, e5. The spatial positional relationships of vertices, sides, and triangles are understood, and the number of adjacent triangles, etc., is determined for the triangles that make up the surface of the slope frame, excluding triangles 15 that do not need to be analyzed.

[0025] For example, for two triangles that are close to a square (tangent to three sides), a center line is drawn from the midpoint of the overlapping line segment to the midpoint of each of the four sides. For a triangle tangent to two sides, a center line is drawn from the midpoint of the shared side. For a triangle tangent to one side, the center line is drawn taking into account the connections of adjacent triangles. Note that "tangent" in the context of tangent to three sides, two sides, or one side means that the triangles are adjacent to each other by line segments that share the same vertex.

[0026] Then, the centerlines extracted under each condition are connected, taking into account the dominance of the vertical and horizontal axes (relationship with the axis) and the straightness of the connections, and converted into a continuous line. This continuous line is then processed by thinning out the vertices and smoothing the continuous line using algorithms such as the Douglas-Peucker algorithm as needed. Based on the line segments (frame centerlines) FL and frame intersections FC obtained in this way (see Figure 9), the completed quantities such as beam length are calculated.

[0027] However, the process after obtaining the corner point 11 can be improved, for example, as follows. Specifically, as shown in Figure 10, at corner points 11 and 12 (end corner points are indicated by reference numeral 12), the center points 11x and 12x are determined from the coordinate average of four points (two points in the case of end point 12) with short slant distances. Next, as shown in Figure 11, the line segment connecting these center points 11x and 12x does not intersect with the outer perimeter of the frame (continuous line) F3 or the shape inside the frame (continuous line) F4. By searching for conditions and distances such as these, unnecessary line segments 13 are identified, and the resulting shape such as beam length is calculated.

[0028] (others) As described above, when calculating the completed work, accuracy control and density control are usually performed, but this control can be performed separately from the calculation process before the calculation process is completed.

[0029] Furthermore, I would like to add the following regarding the calculation of the completed work. Beam length (beam extension) is measured for purposes such as determining quantity, measuring frequency of control items, calculating area within the frame, and determining water drainage volume. On slopes with uneven surfaces, it is necessary to measure each beam precisely by specifying measurement points including two points at the ends. In this case, the length of one side is made to be greater than or equal to the design length between the frame centers, and the cumulative measurement is taken as the length of one beam. Note that there is no rule to specify slope frame intersections when measuring continuously; for example, while checking the shape of the slope frame, bend points on the slope other than intersections are specified to follow the shape, and measurements are taken so that the interval is greater than or equal to the design value between the frame (for example, if the design length is 2.0m, the interval is 2.0m or greater). Furthermore, the measurement frequency is for all beams. Consequently, the workload is extremely large, and this form of processing system / method is extremely beneficial.

[0030] The frame center spacing is measured at a frequency of, for example, one point for every 100m of frame length, and two points per construction site for frame lengths of 100m or less. Therefore, for a total length of 980m, there will be 10 points. The measurement method is, for example, to measure two points that make up the end of the measurement site, and the distance between these points relative to the frame is defined as the frame center spacing.

[0031] Frame width and frame height are measured at one point for every 100m of frame length, and at two points per construction site for frame lengths of 100m or less. The measurement method involves, for example, calculating the vertical distance (height difference) between two points that constitute the ends of the height within a range of ±50mm from a survey line perpendicular to the frame at the measurement point, and calculating the horizontal distance between two points that constitute the width.

[0032] The slope length is measured at one point for every 40m of construction length, and at two points per construction site for lengths of 40m or less. The measurement method is the same as for beam length: the length of one side is made to be greater than or equal to the distance between the centers of the frame, and the cumulative diagonal distance connecting the three-dimensional coordinates is used as the slope length. For example, a cross-sectional drawing is made at the measurement point, and the measurement is taken on the cross-sectional drawing from the top to the bottom of the slope frame, following its shape.

[0033] The extension is measured at each construction site. Similar to beam length, the measurement method involves making the length of one side greater than or equal to the distance between the frame centers, and using the cumulative diagonal distance connecting the three-dimensional coordinates as the extension. This means measuring one crossbeam from end to end.

[0034] The area of ​​the slope frame is measured for purposes such as determining quantity and calculating the area within the frame. The measurement method involves, for example, measuring the shape of the surface of the slope frame. In conventional methods, for example, the measurer had to select all intersections and obtain their coordinates, making it the second most labor-intensive task after measuring the beam length. [Industrial applicability]

[0035] This invention can be used as a method for calculating the completed form of a slope frame. [Explanation of Symbols]

[0036] 10 Original Data 11,12 Corner points 11x, 12x corner center point 13 Unnecessary line segments 14 Unnecessary vertices 15 Unnecessary triangles 100 Intake means 200 editing methods 300 Calculation method 400 Output means C1, C2 Ball D Separation distance (difference) F Slope F1 vertical beam F2 crossbeam F3 Slope Retaining Frame Outer Perimeter F4 Frame Shape FC frame intersection FL frame center line FG (Field Gate) within frame G slope L1 Non-convex triangular group data L2 Convex Triangle Group Data Triangles that make Tx analysis difficult X Processing System

Claims

1. This method uses 3D point cloud data of the slope surface on which the slope frame has been constructed as the source data, and calculates the completed shape of the slope frame from this source data. The original data is converted into triangular group data. In creating this triangular group data, we create non-convex triangular group data in which the area within the slope frame is drawn relatively, and convex triangular group data in which the area within the slope frame is not drawn relatively. The non-convex triangular group data and the convex triangular group data are superimposed, and the surface of the slope frame is converted into slope frame surface triangular group data based on the differences between the two triangular group data. In this set of slope surface triangle data, duplicate line segments shared by mutually adjacent triangles are removed. In the set of line segments remaining after deletion, if the angle formed by mutually adjacent line segments is 90 ± 25°, the intersection point of these mutually adjacent line segments is defined as the corner point. This corner point is used to calculate the completed shape of the aforementioned slope frame. A method for calculating the completed state of a slope frame, characterized by the features described above.

2. In creating the aforementioned triangular group data, Using a ball pivoting algorithm, which obtains 3-point contact group data by rolling a ball on the aforementioned raw data and creates triangle group data from this 3-point contact group data, By making the aforementioned sphere relatively small, the non-convex triangular group data is created. The convex triangle group data is created by making the aforementioned sphere relatively large. A method for calculating the completed form of a slope frame according to claim 1.

3. A constraint line segment is created based on the aforementioned corner point, Based on this constraint line segment, create a group of triangle data. After removing unnecessary triangles from this triangular data set, the centerlines of the slope frames and the intersection points of the slope frames are calculated. Based on these calculated values, the completed form of the aforementioned slope frame is calculated. A method for calculating the completed form of a slope frame according to claim 1.

4. Based on the corner points, the intersection points of the slope frame are calculated, the center line of the slope frame is calculated based on these calculated values, and the completed shape of the slope frame is calculated based on the intersection points and the center line. A method for calculating the completed form of a slope frame according to claim 1.

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