Facility structure estimation device and facility structure estimation program

Abstract

To reduce the amount of work required for creating a three dimensional model of a steel tower.SOLUTION: The central processing unit of the computer creates a three dimensional model in which the pylon is framed based on the three dimensional coordinates of each point in the three dimensional point group representing the pylon. The central processing unit sequentially executes an extraction process, a division process, a tower body frame creation process, a cross arm frame creation process, a top portion frame creation process, and a model creation process as processes for creating the three dimensional model. The three dimensional model thus created is a framed model having a tower body frame corresponding to the tower body of the steel tower, a cross arm frame corresponding to the cross arm of the steel tower, and a top frame corresponding to the top of the tower body. Even if the amount of data of the three dimensional point group representing the pylon is enormous, the creation of the three dimensional model can be performed while reducing the amount of work through the above-described processes based on the data.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to an equipment structure estimation device and an equipment structure estimation program. [Background technology]

[0002] A steel tower for power transmission, etc., has a tower body extending upward and cross arms protruding widthwise from the tower. The tower body is a rectangular prism. A tower mast is located at each of the four corners of the tower body. The tower body of a steel tower has legs located below the lowest cross arm and a top located above the highest cross arm. The cross arms are used to support electric wires via insulators.

[0003] Inspections of the steel towers may be carried out using an aircraft such as a drone as follows: The aircraft is moved along a predetermined flight path around the steel tower, and the steel tower is photographed with a camera mounted on the aircraft. The images of the steel tower captured by the camera are then inspected for any abnormalities. Furthermore, inspections of the steel towers may also include checking whether an appropriate distance is maintained between the tower and surrounding trees and other objects.

[0004] When determining the flight path of the aircraft or checking the distance between the aircraft and surrounding objects, it is possible to use a three-dimensional model of the tower. To create such a three-dimensional model, data representing the tower as a three-dimensional point cloud is used. Patent Document 1 describes the acquisition of a three-dimensional point cloud representing a tower. If a three-dimensional model of the tower is created based on the acquired three-dimensional point cloud data, it becomes possible to use the three-dimensional model to determine the flight path of the aircraft or check the distance between the aircraft and surrounding objects. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2023-4929 Summary of the Invention [Problem to be solved by the invention]

[0006] However, because the three-dimensional point cloud data representing the above-mentioned steel tower is enormous, if one were to create a three-dimensional model based on that data while checking each piece of data, the amount of work required to create the three-dimensional model would be large. [Means for solving the problem]

[0007] Next, various aspects of an equipment structure estimation device and an equipment structure estimation program that solve the above problems will be described. (Aspect 1) The present invention is directed to a steel tower having cross arms protruding in the width direction from a tower body extending upward, and includes a control unit that creates a three-dimensional model of the steel tower by framing the steel tower based on the three-dimensional coordinates of each point in a three-dimensional point cloud representing the steel tower, and the control unit sequentially executes an extraction process, a division process, a tower body frame creation process, a cross arm frame creation process, a top frame creation process, and a model creation process, and the extraction process extracts each point representing the tower body and each point representing the cross arms from the three-dimensional point cloud representing the steel tower and its surroundings, and the division .... The points are divided into points within an arm region, which is a region on the steel tower where the arm exists, points within a leg region, which is a region located below the lowest arm on the steel tower, and points within a top region, which is a region located above the highest arm on the steel tower, and the tower body frame creation process uses the points representing the tower body to create a tower body frame that frames tower columns extending up and down at the four corners of the tower body, and the arm frame creation process removes the points representing the tower body from the points within the arm region, and selects points corresponding to the bases of the arm from the remaining points to create arm base characteristics. The top frame creation process extracts the remaining points as feature points, determines the outline of the arm connected to the arm base feature point, and further determines a point corresponding to the tip of the arm as an arm tip feature point using the outline of the arm. The top frame creation process creates an arm frame by framing the arm using the arm base feature point, the outline of the arm, and the arm tip feature point. The top frame creation process finds points within the top region that correspond to the lower ends of the four corners at the top of the tower body, and uses the points within the top region to find points corresponding to the lower ends of the four corners at the top of the tower body. an outer outline of the top connected to points corresponding to the top corners of the tower body, and a point corresponding to the tip of the top as a top tip characteristic point using the outer outline; a top frame that frames the top is created using points corresponding to the lower ends of the four corners of the top of the tower body, the outer outline of the top, and the top tip characteristic point; and the model creation process combines the tower body frame, the cross arm frame, and the top frame to create a three-dimensional model having the tower body frame, the cross arm frame, and the top frame as a three-dimensional model of the steel tower.

[0008] According to the above configuration, even if the amount of data in the three-dimensional point cloud representing the steel tower is enormous, a three-dimensional model of the steel tower can be created based on such data while minimizing the amount of work. That is, the created three-dimensional model is a framed model having a tower body frame, an arm frame, and a top frame, created through extraction processing, classification processing, tower body frame creation processing, arm frame creation processing, top frame creation processing, and model creation processing. The creation of the framed three-dimensional model of the steel tower can be performed based on the data through the above processes while minimizing the amount of work, even if the amount of data in the three-dimensional point cloud representing the steel tower is enormous. Therefore, when creating the three-dimensional model of the steel tower, the amount of work required for its creation can be minimized.

[0009] (Aspect 2) The tower body frame creation process is a process of sequentially executing a first framing process, a second framing process, and a third framing process, and the first framing process converts each point representing the tower body into a point in a first two-dimensional coordinate system excluding the width of the tower body by setting the coordinate of the tower body in the width direction at each point representing the tower body to 0, obtains an outline of the tower body in the first two-dimensional coordinate system represented by each point using the points in the first two-dimensional coordinate system, restores the coordinate of the tower body in the width direction before the transformation for each point on the outline, and creates a tower pillar frame in which tower pillars located at the corners of the tower body are framed from the restored outline, and the second framing process converts the coordinate of the tower body in the width direction at each point representing the tower body into a point in a first two-dimensional coordinate system excluding the width of the tower body by setting the coordinate of the tower body in the width direction at each point representing the tower body to 0, and then uses the coordinate of the tower body in the first two-dimensional coordinate system to obtain an outline of the tower body represented by each point in the first two-dimensional coordinate system, restores the coordinate of the tower body in the width direction before the transformation for each point on the outline, and creates a tower pillar frame in which tower pillars located at the corners of the tower body are framed from the restored outline, and The equipment structure estimation device according to aspect 1 converts each of the points into each point of a second two-dimensional coordinate system excluding the depth of the tower body by setting the coordinate of the depth direction of the tower body to 0, obtains the outline of the tower body in the second two-dimensional coordinate system represented by each of the points using each of the points in the second two-dimensional coordinate system, restores the coordinate of the depth direction of the tower body before the conversion for each point on the outline, and creates a tower pillar frame by framing the tower pillars located at the corners of the tower body from the restored outline, and the third framing process creates a tower body frame by framing the tower pillars located at the four corners of the tower body based on the tower pillar frames created by the first framing process and the second framing process.

[0010] According to the above configuration, the first frame process and the second frame process of the tower body frame creation process create tower column frames located at the corners of the quadrangular prism-shaped tower body. Furthermore, the third frame process of the tower body frame creation process creates a tower body frame based on the tower column frames. The tower body frame created in this way is a framed version of the quadrangular prism-shaped tower body of a steel tower. Therefore, a quadrangular prism-shaped tower body having four tower columns of a steel tower can be framed as a tower body frame.

[0011] (Aspect 3) The arm frame creation process is a process of sequentially executing a removal process, an outline estimation process, and a frame determination process. The removal process is a process of determining a center line of the tower frame within the arm region, and excluding each point inside a circle having the center line as its center and passing through the tower frame from each point within the arm region. The outline estimation process is a process of extracting each point on the tower frame on the bottom surface and top surface of the arm region from each point remaining after the removal process at each point within the arm region as the arm base characteristic points, and then classifying each remaining point into four arm base characteristic points. and dividing the points in the first group into a first group located closer to one of the arm base characteristic points on the underside of the arm region and a second group located closer to the other of the arm base characteristic points, determining a first outer line of the arm connected to one of the arm base characteristic points using each point in the first group, and determining a second outer line of the arm connected to the other of the arm base characteristic points using each point in the second group, and when the first outer line and the second outer line intersect, determining the intersection as the arm tip characteristic point, and calculating a distance from the arm tip characteristic point by a third outline extending to one of the arm base characteristic points on the upper surface of the arm region is determined, and a fourth outline extending from the arm tip characteristic point to the other of the arm base characteristic points on the upper surface of the arm region is determined; the arm frame is created based on the four arm base characteristic points, the first outline, the second outline, the third outline, the fourth outline, and the arm tip characteristic point; when the first outline and the second outline do not intersect, a point on the first outline that is farthest from one of the arm base characteristic points is determined as the arm tip characteristic point; The facility structure estimation device according to (Aspect 1) or (Aspect 2) generates the arm frame by determining a third outline extending from an arm tip characteristic point to one of the arm base characteristic points on the upper surface of the arm region, and further determining a point on the second outline that is farthest from the other arm base characteristic point as the arm tip characteristic point, and determining a fourth outline extending from the arm tip characteristic point to the other arm base characteristic point on the upper surface of the arm region.

[0012] According to the above configuration, points representing the tower body within the arm region are removed through the removal process of the arm frame creation process, so that points representing the arm remain within the arm region. Then, through the outline estimation process of the arm frame creation process, points on the tower body frame on the bottom and top surfaces of the arm region among the points representing the arm within the arm region are extracted as arm base characteristic points, which are points corresponding to the arm bases. Furthermore, the points representing the arm within the arm region are divided into a first group located closer to one of the four arm base characteristic points on the bottom surface of the arm region, and a second group located closer to the other arm base characteristic point. After that, a first outline connecting each point in the first group to one of the arm base characteristic points is determined, and a second outline connecting each point in the second group to the other arm base characteristic point is determined. The first and second outlines represent the outline of the lower end of the arm from its tip to its base. Then, a frame determination process of the arm frame creation process creates an arm frame that frames the arm. More specifically, when the first outline and the second outline intersect, their intersection is determined as the arm tip characteristic point. Furthermore, a third outline extending from the arm tip characteristic point to one arm base characteristic point on the top surface of the arm region is determined, and a fourth outline extending from the arm tip characteristic point to the other arm base characteristic point on the top surface of the arm region is determined. Then, the arm frame is created based on the four arm base characteristic points, the first outline, the second outline, the third outline, the fourth outline, and the arm tip characteristic point. Furthermore, when the first outline and the second outline do not intersect, a point on the first outline that is farthest from one of the arm base characteristic points is determined as an arm tip characteristic point, and a third outline extending from the arm tip characteristic point to one of the arm base characteristic points on the upper surface of the arm region is determined. Furthermore, a point on the second outline that is farthest from the other of the arm base characteristic points is also determined as an arm tip characteristic point, and a fourth outline extending from the arm tip characteristic point to the other of the arm base characteristic points on the upper surface of the arm region is determined. Then, an arm frame is created based on the four arm base characteristic points, the first outline, the second outline, the third outline, the fourth outline, and the two arm tip characteristic points.Therefore, whether the cross arm on the steel tower protrudes in a triangular shape or in a rectangular shape, the cross arm can be framed as a cross arm frame.

[0013] (Aspect 4) The top frame creation process determines four points on the tower frame on the underside of the top region as points within the top region that correspond to the four corners of the bottom end of the top of the tower body, and when the four outlines of the top that connect to these points intersect, determines the intersections of the outlines as the top tip characteristic points, creates the top frame based on the top tip characteristic points and the outlines, and when the outlines of the top do not intersect, determines the intersections of the horizontal planes in the case where multiple horizontal planes are set in the top region. The equipment structure estimation device according to aspect 3 determines the outline line L1 and the outline line L2 of the horizontally extending portion of the top, as well as the top tip feature point, which is a point corresponding to the tip of the portion, in the same manner as the method for determining the first outline line, the second outline line, and the arm tip feature point in the arm frame creation process, based on each point on the horizontal plane that is furthest out on the horizontal plane, and creates the top frame based on the four outline lines, the outline line L1, the outline line L2, and the top tip feature point.

[0014] According to the above configuration, the top frame creation process determines four points on the tower frame on the underside of the top region as points within the top region that correspond to the lower ends of the four corners of the top of the tower body. When the four outlines of the top that connect to the points corresponding to the lower ends of the four corners of the top intersect, the intersection of the outlines is determined as the top tip characteristic point. Furthermore, the top frame is created based on the above top tip characteristic point and the outlines. On the other hand, when the outlines of the top that connect to the points corresponding to the lower ends of the four corners of the top do not intersect, the outlines L1 and L2 of the horizontally extending portions of the top, as well as the top tip characteristic point, which is the point corresponding to the tip of the above portion, are determined in the same manner as the first outline, the second outline, and the arm tip characteristic point are determined by the arm frame creation process, based on the points of the horizontal plane that has the most points spread out on the horizontal plane when multiple horizontal planes are set in the top region. Then, a top frame is created based on the four outlines, the outline L1, the outline L2, and the top tip characteristic points. Therefore, whether the top of the tower is a quadrangular pyramid that protrudes upward or a shape that protrudes in the width direction of the tower body like an arm, the top can be framed as a top frame.

[0015] (Aspect 5) In the top frame creation process, when the four outlines of the top do not intersect, four vertices located on the outlines of the points on the horizontal plane that are the widest on the horizontal plane are found, and the center points of the four vertices are found. Points located inside a circle that passes through the four vertices and has the center point as its center are excluded, and the remaining points are divided into a group G1 located closer to the first vertex of the two vertices that correspond to the base of the horizontally extending portion of the top, and a group G2 located closer to the second vertex. The outline L1 of the horizontally extending portion of the top connected to the first vertex is found using the points in group G1, and the outline L2 of the horizontally extending portion of the top connected to the second vertex is found using the points in group G2. and when the outline line L1 and the outline line L2 intersect, the intersection point of the outline line L1 and the outline line L2 is determined as the top tip characteristic point. The top frame is created based on the four outline lines of the top, the outline line L1, the outline line L2, and the top tip characteristic point. When the outline line L1 and the outline line L2 do not intersect, the point on the outline line L1 that is farthest from the first vertex is determined as the top tip characteristic point, and the point on the outline line L2 that is farthest from the second vertex is also determined as the top tip characteristic point. The equipment structure estimation device described in Aspect 4.

[0016] According to the above configuration, in the top frame creation process, when the four outlines of the top do not intersect, the four vertices located on the outlines of the horizontal plane that are the most widely distributed are determined. The center point of these four vertices is then determined, and points located within a circle centered on the center point and passing through the four vertices are removed from the top region. The remaining points in the top region are then divided into two groups: group G1, which is closer to the first vertex of the two vertices that correspond to the base of the horizontally distributed portion of the top, and group G2, which is closer to the second vertex. The outline L1 connected to the first vertex is then determined using the points in group G1, and the outline L2 connected to the second vertex is then determined using the points in group G2. The outline L1 and the outline L2 represent the outline of the horizontally distributed portion of the top. When the outline line L1 and the outline line L2 intersect, the intersection point between the outline line L1 and the outline line L2 is determined as the top tip characteristic point. A top frame is created based on the four outline lines, the outline line L1, the outline line L2, and the top tip characteristic point. When the outline line L1 and the outline line L2 do not intersect, the point on the outline line L1 that is farthest from the first vertex is determined as the top tip characteristic point, and the point on the outline line L2 that is farthest from the second vertex is also determined as the top tip characteristic point. A top frame is created based on the four outline lines, the outline line L1, the outline line L2, and the two top tip characteristic points. Therefore, when the top of a steel tower has a shape that protrudes in the width direction of the tower body like an arm, the top can be framed as a top frame regardless of whether the protruding portion is triangular or rectangular.

[0017] (Aspect 6) The target is a steel tower having cross arms protruding in the width direction from a tower body extending upward, and a process for creating a three-dimensional model of the steel tower by framing the steel tower based on the three-dimensional coordinates of each point in a three-dimensional point cloud representing the steel tower is to have a computer sequentially execute an extraction process, a division process, a tower body frame creation process, a cross arm frame creation process, a top frame creation process, and a model creation process, and the extraction process extracts each point representing the tower body and each point representing the cross arm from the three-dimensional point cloud representing the steel tower and its surroundings, and The processing divides the points representing the tower body and the points representing the cross arms into points in a cross arm region, which is a region where the cross arms are present on the steel tower, points in a leg region, which is a region located below the lowest cross arm on the steel tower, and points in a top region, which is a region located above the highest cross arm on the steel tower, and the tower body frame creation processing uses the points representing the tower body to create a tower body frame in which tower columns extending up and down at the four corners of the tower body are framed, and the cross arm frame creation processing , excluding the points representing the tower body from the points within the arm region, extracting a point corresponding to the base of the arm from the remaining points as an arm base characteristic point, determining an outline of the arm connected to the arm base characteristic point using the remaining points, and further determining a point corresponding to the tip of the arm as an arm tip characteristic point using the outline of the arm, and creating an arm frame by framing the arm using the arm base characteristic point, the outline of the arm, and the arm tip characteristic point. the top frame creation process determines points within the top region that correspond to the lower ends of the four corners of the top of the tower body, and determines an outline of the top that connects to the points that correspond to the lower ends of the four corners of the top of the tower body using the points within the top region, and determines points that correspond to the tip of the top as top tip characteristic points using the outline, and creates a top frame that frames the top using the points that correspond to the lower ends of the four corners of the top of the tower body, the outline of the top, and the top tip characteristic points; The model creation process is an equipment structure estimation program that creates a three-dimensional model having the tower body frame, the cross arm frame, and the top frame as a three-dimensional model of the steel tower by combining the tower body frame, the cross arm frame, and the top frame.

[0018] According to the above configuration, even if the amount of data in the three-dimensional point cloud representing the steel tower is enormous, a three-dimensional model of the steel tower can be created based on such data while minimizing the amount of work. That is, the created three-dimensional model is a framed model having a tower body frame, an arm frame, and a top frame, created through extraction processing, classification processing, tower body frame creation processing, arm frame creation processing, top frame creation processing, and model creation processing. The creation of the framed three-dimensional model of the steel tower can be performed based on the data through the above processes while minimizing the amount of work, even if the amount of data in the three-dimensional point cloud representing the steel tower is enormous. Therefore, when creating the three-dimensional model of the steel tower, the amount of work required for its creation can be minimized.

[0019] (Aspect 7) The tower body frame creation process is a process of sequentially executing a first framing process, a second framing process, and a third framing process, in which the first framing process converts each point representing the tower body into a point in a first two-dimensional coordinate system excluding the width of the tower body by setting the coordinate of the tower body in the width direction at each point representing the tower body to 0, obtains an outline of the tower body in the first two-dimensional coordinate system represented by each point using the points in the first two-dimensional coordinate system, restores the coordinate of the tower body in the width direction before the conversion for each point on the outline, and creates a tower pillar frame by framing tower pillars located at the corners of the tower body from the restored outline, and the second framing process converts the coordinate of the tower body at each point representing the tower body into a point in a first two-dimensional coordinate system excluding the width of the tower body by setting the coordinate of the tower body in the width direction at each point representing the tower body to 0, and then creates a tower pillar frame by using the restored outline of the tower body. a tower column frame in which the tower columns located at the four corners of the tower body are framed based on the tower column frames created by the first framing process and the second framing process.

[0020] According to the above configuration, the first frame process and the second frame process of the tower body frame creation process create tower column frames located at the corners of the quadrangular prism-shaped tower body. Furthermore, the third frame process of the tower body frame creation process creates a tower body frame based on the tower column frames. The tower body frame created in this way is a framed version of the quadrangular prism-shaped tower body of a steel tower. Therefore, a quadrangular prism-shaped tower body having four tower columns of a steel tower can be framed as a tower body frame.

[0021] (Aspect 8) The arm frame creation process is a process of sequentially executing a removal process, an outline estimation process, and a frame determination process. The removal process is a process of determining a center line of the tower frame within the arm region, and excluding each point inside a circle having the center line as its center and passing through the tower frame from each point within the arm region. The outline estimation process is a process of extracting each point on the tower frame on the lower surface and upper surface of the arm region as the arm base characteristic point from each point remaining after the removal process at each point within the arm region, and classifying each remaining point into four of the arm base characteristic points. The frame determination process divides the arm regions into a first group located closer to one of the arm base characteristic points on the underside of the arm region and a second group located closer to the other of the arm base characteristic points, and determines a first outer line of the arm connected to one of the arm base characteristic points using each point in the first group, and determines a second outer line of the arm connected to the other of the arm base characteristic points using each point in the second group. When the first outer line and the second outer line intersect, the frame determination process determines the intersection point as the arm tip characteristic point, and calculates a distance from the arm tip characteristic point to the arm. a third outline extending to one of the arm base characteristic points on the upper surface of the arm region, and a fourth outline extending from the arm tip characteristic point to the other of the arm base characteristic points on the upper surface of the arm region, and the arm frame is created based on the four arm base characteristic points, the first outline, the second outline, the third outline, the fourth outline, and the arm tip characteristic point; when the first outline and the second outline do not intersect, a point on the first outline that is farthest from one of the arm base characteristic points is determined as the arm tip characteristic point; a third outline extending from the first outline feature point to one of the arm base feature points on the top surface of the arm region, a point on the second outline farthest from the other arm base feature point on the second outline feature point is also determined as the arm tip feature point, a fourth outline extending from the arm tip feature point to the other arm base feature point on the top surface of the arm region is determined, and the arm frame is created based on the four arm base feature points, the first outline, the second outline, the third outline, the fourth outline, and the two arm tip feature points.

[0022] According to the above configuration, points representing the tower body within the arm region are removed through the removal process of the arm frame creation process, so that points representing the arm remain within the arm region. Then, through the outline estimation process of the arm frame creation process, points on the tower body frame on the bottom and top surfaces of the arm region among the points representing the arm within the arm region are extracted as arm base characteristic points, which are points corresponding to the arm bases. Furthermore, the points representing the arm within the arm region are divided into a first group located closer to one of the four arm base characteristic points on the bottom surface of the arm region, and a second group located closer to the other arm base characteristic point. After that, a first outline connecting each point in the first group to one of the arm base characteristic points is determined, and a second outline connecting each point in the second group to the other arm base characteristic point is determined. The first and second outlines represent the outline of the lower end of the arm from its tip to its base. Then, a frame determination process of the arm frame creation process creates an arm frame that frames the arm. More specifically, when the first outline and the second outline intersect, their intersection is determined as the arm tip characteristic point. Furthermore, a third outline extending from the arm tip characteristic point to one arm base characteristic point on the top surface of the arm region is determined, and a fourth outline extending from the arm tip characteristic point to the other arm base characteristic point on the top surface of the arm region is determined. Then, the arm frame is created based on the four arm base characteristic points, the first outline, the second outline, the third outline, the fourth outline, and the arm tip characteristic point. Furthermore, when the first outline and the second outline do not intersect, a point on the first outline that is farthest from one of the arm base characteristic points is determined as an arm tip characteristic point, and a third outline extending from the arm tip characteristic point to one of the arm base characteristic points on the upper surface of the arm region is determined. Furthermore, a point on the second outline that is farthest from the other of the arm base characteristic points is also determined as an arm tip characteristic point, and a fourth outline extending from the arm tip characteristic point to the other of the arm base characteristic points on the upper surface of the arm region is determined. Then, an arm frame is created based on the four arm base characteristic points, the first outline, the second outline, the third outline, the fourth outline, and the two arm tip characteristic points.Therefore, whether the cross arm on the steel tower protrudes in a triangular shape or in a rectangular shape, the cross arm can be framed as a cross arm frame.

[0023] (Aspect 9) The top frame creation process determines four points on the tower frame on the underside of the top region as points within the top region that correspond to the four corners of the bottom end of the top of the tower body, and when the four outlines of the top that connect to these points intersect, determines the intersections of the outlines as the top tip characteristic points, creates the top frame based on the top tip characteristic points and the outlines, and when the outlines of the top do not intersect, determines the intersections of the horizontal planes when multiple horizontal planes are set in the top region. Based on the points on the horizontal plane that are furthest apart on the horizontal plane, the outline line L1 and the outline line L2 of the horizontally extending part at the top, as well as the top tip feature point, which is the point corresponding to the tip of the part, are determined in the same manner as the first outline line, the second outline line, and the arm tip feature point are determined by the arm frame creation process, and the top frame is created based on the four outline lines, the outline line L1, the outline line L2, and the top tip feature point (described in embodiment 8).

[0024] According to the above configuration, the top frame creation process determines four points on the tower frame on the underside of the top region as points within the top region that correspond to the lower ends of the four corners of the top of the tower body. When the four outlines of the top that connect to the points corresponding to the lower ends of the four corners of the top intersect, the intersection of the outlines is determined as the top tip characteristic point. The top frame is created based on the top tip characteristic point and the outlines. On the other hand, when the outlines of the top that connect to the points corresponding to the lower ends of the four corners of the top do not intersect, the outlines L1 and L2 of the horizontally extending portions of the top, as well as the top tip characteristic point, which is the point corresponding to the tip of the portion, are determined in the same manner as the first outline, the second outline, and the arm tip characteristic point determined by the arm frame creation process, based on the points of the horizontal plane that has the most points spread out on the horizontal plane when multiple horizontal planes are set in the top region. Then, a top frame is created based on the four outlines, the outline L1, the outline L2, and the top tip characteristic points. Therefore, whether the top of the tower is a quadrangular pyramid that protrudes upward or a shape that protrudes in the width direction of the tower body like an arm, the top can be framed as a top frame.

[0025] (Aspect 10) In the top frame creation process, when the four outlines of the top do not intersect, four vertices located on the outlines of the points on the horizontal plane that are the widest on the horizontal plane are found, and the center points of the four vertices are found. Points located inside a circle that passes through the four vertices and has the center point as its center are excluded, and the remaining points are divided into a group G1 located closer to the first vertex of the two vertices that correspond to the bases of the horizontally extending portions of the top, and a group G2 located closer to the second vertex. The outline L1 of the horizontally extending portion of the top that is connected to the first vertex is found using the points in group G1, and the outline L2 of the horizontally extending portion of the top that is connected to the second vertex is found using the points in group G2. and when the outline line L1 and the outline line L2 intersect, the intersection of the outline line L1 and the outline line L2 is determined as the apex tip characteristic point. The apex frame is created based on the four outline lines of the apex, the outline line L1, the outline line L2, and the apex tip characteristic point. When the outline line L1 and the outline line L2 do not intersect, the point on the outline line L1 that is farthest from the first vertex is determined as the apex tip characteristic point, and the point on the outline line L2 that is farthest from the second vertex is also determined as the apex tip characteristic point. The equipment structure estimation program described in Aspect 9.

[0026] According to the above configuration, in the top frame creation process, when the four outlines of the top do not intersect, the four vertices located on the outlines of the horizontal plane that are the most widely distributed are determined. The center point of these four vertices is then determined, and points located within a circle centered on the center point and passing through the four vertices are removed from the top region. The remaining points in the top region are then divided into two groups: group G1, which is closer to the first vertex of the two vertices that correspond to the base of the horizontally distributed portion of the top, and group G2, which is closer to the second vertex. The outline L1 connected to the first vertex is then determined using the points in group G1, and the outline L2 connected to the second vertex is then determined using the points in group G2. The outline L1 and the outline L2 represent the outline of the horizontally distributed portion of the top. When the outline line L1 and the outline line L2 intersect, the intersection point between the outline line L1 and the outline line L2 is determined as the top tip characteristic point. A top frame is created based on the four outline lines, the outline line L1, the outline line L2, and the top tip characteristic point. When the outline line L1 and the outline line L2 do not intersect, the point on the outline line L1 that is farthest from the first vertex is determined as the top tip characteristic point, and the point on the outline line L2 that is farthest from the second vertex is also determined as the top tip characteristic point. A top frame is created based on the four outline lines, the outline line L1, the outline line L2, and the two top tip characteristic points. Therefore, when the top of a steel tower has a shape that protrudes in the width direction of the tower body like an arm, the top can be framed as a top frame regardless of whether the protruding portion is triangular or rectangular. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a schematic diagram showing the configuration of a computer. [Figure 2] FIG. 1 is a perspective view showing a three-dimensional model of a steel tower. [Figure 3]2 is a flowchart showing the execution procedure of an equipment structure estimation program executed by the computer of FIG. 1. [Figure 4] FIG. 1 is a perspective view showing a three-dimensional point cloud representing a steel tower and its surroundings. [Figure 5] FIG. 5 is a perspective view showing points representing the tower body and cross arms of a steel tower extracted from the three-dimensional point cloud of FIG. 4. [Figure 6] FIG. 6 is a side view showing a top region, an arm region, and a leg region that divide the three-dimensional point cloud of FIG. 5. [Figure 7] 6 is a perspective view showing each point when the three-dimensional point cloud of FIG. 5 is transformed into points on a first two-dimensional coordinate system. FIG. [Figure 8] 6 is a side view showing each point when the three-dimensional point cloud of FIG. 5 is transformed into points on a second two-dimensional coordinate system. [Figure 9] FIG. 7 is a plan view showing each point within the arm region of FIG. 6. [Figure 10] FIG. 10 is a plan view showing a point cloud representing one of the brackets in FIG. 9. [Figure 11] FIG. 10 is a plan view showing a point cloud representing one of the brackets in FIG. 9. [Figure 12] FIG. 12 is a perspective view showing an arm frame created based on a point cloud representing one arm in FIG. [Figure 13] FIG. 10 is a plan view showing a point cloud representing another example of an arm; [Figure 14] FIG. 14 is a perspective view showing an arm frame created based on the point cloud representing the arm of FIG. 13. [Figure 15] 7 is a perspective view showing a point cloud representing a vertex in the vertex region of FIG. 6 and the outline of the vertex. FIG. [Figure 16] FIG. 10 is a perspective view showing a point cloud representing the top of another example. [Figure 17] FIG. 17 is a plan view showing the cloud of points representing the apex of FIG. 16. [Figure 18] FIG. 18 is a plan view showing a point cloud representing one side of the top of FIG. 17. [Figure 19] FIG. 18 is a plan view showing a point cloud representing one side of the top of FIG. 17. [Figure 20]FIG. 10 is a plan view showing a point cloud representing the top of another example. [Figure 21] FIG. 3 is a perspective view showing a three-dimensional model of the steel tower in FIG. 2 and each of its characteristic points. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, an embodiment of an equipment structure estimation device and an equipment structure estimation program will be described with reference to FIGS. The computer 11 shown in Figure 1 functions as an equipment structure estimation device that creates a three-dimensional model of a power transmission tower. The tower has a tower body extending upward and cross arms protruding widthwise from the tower. The tower body is shaped like a rectangular pillar. Tower columns are located at each of the four corners of the tower body. The tower body has legs located below the lowest cross arm and a top located above the highest cross arm. The cross arms support electric wires via insulators.

[0029] The computer 11 comprises a central processing unit 12, a storage unit 13, and a communication unit 14. The central processing unit 12 controls various devices in the computer 11, such as the storage unit 13 and the communication unit 14, and performs arithmetic processing based on various data. The storage unit 13 stores various data. The communication unit 14 exchanges data with the outside of the computer 11.

[0030] The central processing unit 12 serves as a control unit that creates a three-dimensional model of the steel tower as a frame based on the three-dimensional coordinates of each point in the three-dimensional point cloud representing the steel tower. The three-dimensional model of the steel tower created in this way is shown in Figure 2. This three-dimensional model has a tower body frame 15, an arm frame 16, and a top frame 17. The tower body frame 15 is a frame of the tower column of the steel tower body. The arm frame 16 is a frame of the arm of the steel tower. The top frame 17 is a frame of the top of the steel tower body.

[0031] The central processing unit 12 of the computer 11 shown in Fig. 1 executes an equipment structure estimation program for creating the above-mentioned three-dimensional model of the steel tower. This equipment structure estimation program causes the computer 11 to sequentially execute an extraction process, a division process, a tower body frame creation process, an arm frame creation process, a top frame creation process, and a model creation process in order to create the above-mentioned three-dimensional model. In detail, the computer 11 creates the above-mentioned frames 15 to 17 based on the three-dimensional coordinates of each point in the three-dimensional point cloud representing the above-mentioned steel tower through the execution of each of the above-mentioned processes, and then creates the above-mentioned three-dimensional model by combining the above-mentioned frames 15 to 17.

[0032] The flowchart in FIG. 3 shows the procedure for executing the facility structure estimation program. In step 101 (S101) of the flowchart, the central processing unit 12 acquires three-dimensional point cloud data representing the pylon, more specifically, the three-dimensional coordinates of each point in the three-dimensional point cloud. The three-dimensional point cloud data can be acquired by laser surveying the pylon using an aircraft such as a drone. However, the three-dimensional point cloud data may also be acquired by other methods.

[0033] Such three-dimensional point cloud data may be stored in advance in the memory unit 13 of the computer 11. In this case, the central processing unit 12 retrieves the three-dimensional point cloud data from the memory unit 13. The central processing unit 12 may also retrieve the three-dimensional point cloud data directly from the aircraft via the communication unit 14. The three-dimensional point cloud data may also be stored in a server or the like. In this case, the central processing unit 12 may retrieve the three-dimensional point cloud data stored in the server via a network connection via the communication unit 14.

[0034] The processes in S102 to S107 in the above flowchart correspond to the extraction process, division process, tower body frame creation process, cross arm frame creation process, top frame creation process, and model creation process, respectively. These processes will be individually described in detail below.

[0035] <Extraction process (S102)> FIG. 4 shows a three-dimensional point cloud representing the pylon and its surroundings. In the process of S102, the central processing unit 12 extracts points representing the pylon body and points representing cross arms from the three-dimensional point cloud. Specifically, the central processing unit 12 classifies the three-dimensional point cloud into points representing the pylon body, points representing cross arms, points representing insulators, points representing electric wires, and points representing forests around the pylon using semantic segmentation or the like. The central processing unit 12 then extracts points representing the pylon body and points representing cross arms from the classified points. Furthermore, the central processing unit 12 removes points that are a predetermined distance away from a group of points representing the extracted pylon body, thereby removing noise from each of the extracted points representing the pylon body. Furthermore, the central processing unit 12 also removes points that are a predetermined distance away from a group of points representing the extracted cross arms. In this way, noise is removed from each of the extracted points representing the cross arms. FIG. 5 shows the points representing the tower body after noise removal, and the points representing the cross arm after noise removal.

[0036] <Sorting process (S103)> In the processing of S103, the central processing unit 12 divides each point representing the tower body and each point representing the cross arm into each point within the cross arm region 18, each point within the base region 19, and each point within the top region 20, as shown in Fig. 6. The cross arm region 18 is the region where the cross arms of the steel tower exist, and is defined for each of the multiple levels of cross arms of the steel tower. The base region 19 is the region located below the lowest cross arm of the steel tower. The top region 20 is the region located above the highest cross arm of the steel tower.

[0037] <Tower frame creation process (S104)> In the process of S104, the central processing unit 12 creates the tower frame 15 shown in Fig. 2 using the points representing the tower body extracted in S102. This tower frame 15 is formed by framing the tower columns extending up and down at the four corners of the tower body of the steel tower. To create the tower frame 15 in the process of S104, the central processing unit 12 sequentially executes the first framing process, second framing process, and third framing process described below.

[0038] In the first framing process, the coordinate in the width direction of the tower body at each point representing the tower body, i.e., the coordinate on the Y axis in Figure 2, is set to 0, and each of the above points is converted to each point in a first two-dimensional coordinate system that excludes the width direction of the tower body. This first two-dimensional coordinate system is shown in Figure 7. Then, using each point in the first two-dimensional coordinate system, the outline lines 21, 22 of the tower body represented by each of these points are obtained in the first two-dimensional coordinate system. Furthermore, by restoring the coordinate in the width direction of the tower body for each point on the outline lines 21, 22 before the above conversion, a tower pillar frame is created that frames the tower pillars located at the corners of the tower body from the restored outline lines.

[0039] In the second framing process, the depth coordinate of each point representing the tower body, i.e., the coordinate on the X-axis in Figure 2, is set to 0, and each of the above points is converted into a point in a second two-dimensional coordinate system that excludes the depth of the tower body. This second two-dimensional coordinate form is shown in Figure 8. Then, using each point in the second two-dimensional coordinate system, the outline lines 23, 24 of the tower body represented by each of these points in the second two-dimensional coordinate system are obtained, and the depth coordinate of the tower body before the above conversion is restored for each point on these outline lines 23, 24, and a tower pillar frame is created that frames the tower pillars located at the corners of the tower body from the restored outline lines.

[0040] The third framing process creates a tower frame 15 shown in Figure 2, in which the tower pillars located at the four corners of the tower are framed based on the tower pillar frames created by the first framing process and the second framing process.

[0041] <Arm frame creation process (S105)> In the process of S105, the central processing unit 12 creates a multi-stage cross arm frame 16 by framing the multi-stage cross arms of the tower using each point in each cross arm region 18 divided in S103. To create the cross arm frame 16 in the process of S105, the central processing unit 12 sequentially executes the following removal process, outline estimation process, and frame determination process.

[0042] The elimination process is for removing each point representing the tower body from each point within the cross arm region 18. Figure 9 shows each point within the cross arm region 18 viewed from above. In the elimination process, after determining the center line Lc of the tower body frame 15 within the cross arm region 18, each point inside a circle C1 that has the center line Lc and passes through the tower body frame 15 is removed from each point within the cross arm region 18.

[0043] In the outline estimation process, of the points remaining after the removal process at each point in the arm region 18, points corresponding to the base of the arm are extracted as arm base feature points 25, 26. More specifically, of the remaining points, the points on the tower frame 15 on the bottom and top surfaces of the arm region 18 are set as arm base feature points 25, 26. Note that Fig. 9 only shows the arm base feature points 25, 26 located on the bottom surface of the arm region 18.

[0044] Figures 10 and 11 show point clouds representing one arm in Figure 9. Note that Figures 10 and 11 also show only arm base feature points 25, 26 located on the underside of the arm region 18. After the arm base feature points 25, 26 are extracted as described above, the remaining points are used to determine the outline of the arm connected to the arm base feature points 25, 26, i.e., the outlines 27, 28 shown in Figure 11.

[0045] More specifically, the remaining points are divided into a first group GA and a second group GB shown in Fig. 10. The points in the first group GA are a point group located closer to one of the two arm base feature points 25, 26, the arm base feature point 25. The points in the second group GB are a point group located closer to the other of the two arm base feature points 25, 26, the arm base feature point 26. Then, using the points in the first group GA, a first outer contour 27 of the arm connected to one of the arm base feature points 25 is obtained as shown in Fig. 11. Furthermore, using the points in the second group GB, a second outer contour 28 of the arm connected to the other arm base feature point 26 is obtained as shown in Fig. 11. The first outer contour 27 and second outer contour 27 may be obtained by RANSAC (Random Sample Consensus) or the like.

[0046] The frame determination process is for creating an arm frame 16 in which the arm is framed using the first external line 27, the second external line 28, etc. The arm of a steel tower may protrude in a triangular shape from the tower body or in a rectangular shape from the tower body. In the frame determination process, the arm frame 16 is created in accordance with the protruding shape of the arm.

[0047] More specifically, in the frame determination process, when the first outline 27 and the second outline 28 intersect, the intersection point between the first outline 27 and the second outline 28 is determined as an arm tip characteristic point 29. The arm tip characteristic point 29 is a point corresponding to the tip of the arm in the direction in which it projects from the tower body. Thereafter, as shown in Fig. 12, a third outline 27a is determined, extending from the arm tip characteristic point 29 to one of the arm base characteristic points 25, 26 located on the upper surface of the arm region 18. Furthermore, a fourth outline 28a is also determined, extending from the arm tip characteristic point 29 to the other of the arm base characteristic points 25, 26 located on the upper surface of the arm region 18. Then, the arm frame 16 is created based on the four arm base characteristic points 25 and 26, the first outer shape line 27, the second outer shape line 28, the third outer shape line 27a, the fourth outer shape line 28a, and the arm tip characteristic point 29.

[0048] 13, when the first outline 27 and the second outline 28 do not intersect, the arm frame 16 is created as follows. That is, the point on the first outline 27 that is farthest from one arm base feature point 25 is determined as the arm tip feature point 30, and the point on the second outline 28 that is farthest from the other arm base feature point 25 is determined as the arm tip feature point 31. Furthermore, as shown in Fig. 14, a third outline 27a is determined that extends from the arm tip feature point 30 to one of the arm base feature points 25, 26 on the upper surface of the arm region 18. Also, a fourth outline 28a is determined that extends from the arm tip feature point 31 to the other of the arm base feature points 25, 26 on the upper surface of the arm region 18. Then, the arm frame 16 is created based on the four arm base characteristic points 25, 26, the first outer shape line 27, the second outer shape line 28, the third outer shape line 27a, the fourth outer shape line 28a, and the two arm tip characteristic points 30, 31.

[0049] The above-described removal process, outline estimation process, and frame determination process are performed for each cross arm region 18. As a result, in the cross arm frame creation process, a cross arm frame 16 is created for each of multiple stages of cross arms on the tower.

[0050] <Top frame creation process (S106)> In the process of S106, the central processing unit 12 uses each point in the top region 20 divided in S103 to create a top frame 17 that frames the top of the tower body of the steel tower. FIG. 15 is a perspective view showing each point in the top region 20. The central processing unit 12 determines four points 32 on the tower body frame 15 on the underside of the top region 20 as points within the top region 20 that correspond to the four corners of the lower end of the top of the tower body. Then, using each point within the top region 20, the central processing unit 12 determines four outlines 33 of the top that connect to the points 32 that correspond to the lower ends of the four corners of the top of the tower body. Then, the determined outlines 33 are used to create the top frame 17 that frames the top.

[0051] When the top of the pylon protrudes upward in a quadrangular pyramid shape, the top frame 17 is created as follows. That is, when the top is quadrangular pyramid-shaped, the outlines 33 of the top that connect to the above-mentioned points 32 intersect. When the outlines 33 that connect to four points 32 intersect in this way, the intersection of the outlines 33 is determined as the top tip characteristic point 34. Then, the top frame 17 is created based on the top tip characteristic point 34 and the outlines 33.

[0052] In addition, the top of the steel tower may protrude in the width direction of the tower body. In this case, the four outlines 33 connecting the four points 32 do not intersect, as shown in Figure 16. When the outlines 33 do not intersect, the top frame 17 is created as follows.

[0053] That is, first, each outline and arm tip characteristic point of the horizontally extending portion at the top are obtained based on each point of horizontal plane F, which is the most horizontally extending of the horizontal planes when multiple horizontal planes are set in the top region 20. The outline and arm tip characteristic points are obtained in the same way as the first outline 27, second outline 28, and arm tip characteristic points 29, 30, 31 are obtained in the arm frame creation process.

[0054] Specifically, when the outlines 33 do not intersect, four vertices 35, 36 located on the outlines 33 of the points on the horizontal plane F are found, and the center point Pc of these vertices 35, 36 is found. Figure 17 shows the points on the horizontal plane F in the apex region 20 as viewed from above. Then, points located inside a circle C2 that is centered at the center point Pc and passes through the four vertices 35, 36 are excluded from the points on the horizontal plane F. Furthermore, the remaining points are divided into group G1 and group G2 as shown in Figure 16.

[0055] 18 and 19 show point clouds representing one side of the portion of the apex of FIG. 17 that protrudes in the width direction of the pylon. The above-mentioned vertices 35 and 36 are located at the base of the one side of the apex, in other words, at the base of the portion that extends horizontally at the apex. As shown in FIG. 18, the points of group G1 are a point cloud representing one side of the portion, located closer to the first vertex 35 of the vertices 35 and 36. The points of group G2 are a point cloud representing one side of the portion, located closer to the second vertex 36 of the vertices 35 and 36. Then, using the points in group G1, an outline L1 of the portion that extends horizontally at the apex connected to the first vertex 35 is determined as shown in FIG. 19. Furthermore, using the points in group G2, an outline L2 of the portion that extends horizontally at the apex connected to the second vertex 36 is determined as shown in FIG. 19.

[0056] The horizontally extending portion of the top may protrude from the tower body in a triangular shape or in a rectangular shape. When the portion protrudes in a triangular shape, the outline L1 and the outline L2 intersect as shown in FIG. 19. In this case, the intersection of the outline L1 and the outline L2 is determined as the top tip characteristic point 37. Then, the top frame 17 is created based on the four vertices 35 and 36 of the top, the outline L1, the outline L2, and the top tip characteristic point 37.

[0057] On the other hand, if the portion protrudes in a quadrangular shape, the outline L1 and the outline L2 do not intersect, as shown in Figure 20. In this case, the top frame 17 is created as follows: The point on the outline L1 that is farthest from the first vertex 35 is determined as the top tip characteristic point 38, and the point on the outline L2 that is farthest from the second vertex 36 is also determined as the top tip characteristic point 39. Then, the top frame 17 is created based on the four outlines 33 of the top, the outline L1, the outline L2, and the two top tip characteristic points 38, 39.

[0058] <Model Creation Process (S107)> In the process of S107, the central processing unit 12 creates a three-dimensional model of the steel tower by combining the tower body frame 15, the cross arm frames 16, and the top frame 17. Fig. 21 shows the three-dimensional model created in this way. This three-dimensional model has the tower body frame 15, the multiple stages of cross arm frames 16, and the top frame 17, as well as cross arm base feature points 25 and 26, a cross arm tip feature point 29, and a top tip feature point 34. The cross arm base feature points 25 and 26, the cross arm tip feature point 29, and the top tip feature point 34 in the three-dimensional model are used as three-dimensional coordinate points that are important when inspecting steel towers using an aircraft such as a drone.

[0059] According to the present embodiment described above in detail, the following advantageous effects can be obtained. (1) Even if the amount of data in the three-dimensional point cloud representing the steel tower is enormous, a three-dimensional model of the steel tower can be created based on such data while minimizing the amount of work. That is, the three-dimensional model created is a framed model having a tower body frame 15, an arm frame 16, and a top frame 17, which is created through extraction processing, classification processing, tower body frame creation processing, cross arm frame creation processing, top frame creation processing, and model creation processing. The creation of the framed three-dimensional model of the steel tower can be performed based on the data through the above processes while minimizing the amount of work, even if the amount of data in the three-dimensional point cloud representing the steel tower is enormous. Therefore, when creating the three-dimensional model of the steel tower, the amount of work required for its creation can be minimized.

[0060] (2) The first and second frame processes of the tower body frame creation process create tower pillar frames located at the corners of the quadrangular pillar-shaped tower body. Furthermore, the third frame process of the tower body frame creation process creates a tower body frame 15 based on the tower pillar frames. The tower body frame 15 created in this way is a framed version of the quadrangular pillar-shaped tower body of a steel tower. Therefore, a quadrangular pillar-shaped tower body having four tower pillars of a steel tower can be framed as the tower body frame 15.

[0061] (3) By removing each point representing the tower body within the arm region 18 through the removal process of the arm frame creation process, each point representing the arm remains within the arm region 18. Then, by the outline estimation process of the arm frame creation process, among each point representing an arm within the arm region 18, each point on the tower body frame 15 on the bottom surface and top surface of the arm region 18 is extracted as arm base feature points 25, 26, which are points corresponding to the base of the arm. Furthermore, each point representing an arm within the arm region 18 is divided into a first group GA located closer to one arm base feature point 25 on the bottom surface of the arm region 18 among the four arm base feature points 25, 26, and a second group GB located closer to the other arm base feature point 26. Thereafter, a first outer line 27 connecting each point in the first group GA to one arm base feature point 25 is obtained, and a second outer line 28 connecting each point in the second group GB to the other arm base feature point 26 is obtained.

[0062] The first outer line 27 and the second outer line 28 represent the outer line of the lower end of the arm from the tip to the base. Then, by the frame determination process of the arm frame creation process, an arm frame 16 is created by framing the arm. More specifically, when the first outer line 27 and the second outer line 28 intersect, the intersection point of the first outer line 27 and the second outer line 28 is determined as an arm tip characteristic point 29. Furthermore, a third outer line 27a extending from the arm tip characteristic point 29 to one arm base characteristic point 25 on the upper surface of the arm region 18 is determined, and a fourth outer line 28a extending from the arm tip characteristic point 29 to the other arm base characteristic point 26 on the upper surface of the arm region 18 is determined. Then, the arm frame 16 is created based on the four arm base characteristic points 25 and 26, the first outer shape line 27, the second outer shape line 28, the third outer shape line 27a, the fourth outer shape line 28a, and the arm tip characteristic point 29.

[0063] Furthermore, when the first outline 27 and the second outline 28 do not intersect, the point on the first outline 27 that is farthest from one of the arm base characteristic points 25 is determined as the arm tip characteristic point 30, and a third outline 27a is determined extending from the arm tip characteristic point 30 to one of the arm base characteristic points 25 on the upper surface of the arm region 18. Furthermore, the point on the second outline 28 that is farthest from the other arm base characteristic point 26 is also determined as the arm tip characteristic point 31, and a fourth outline 28a is determined extending from the arm tip characteristic point 31 to the other arm base characteristic point 26 on the upper surface of the arm region 18. Then, the arm frame 16 is created based on the four arm base feature points 25, 26, the first outer shape line 27, the second outer shape line 28, the third outer shape line 27a, the fourth outer shape line 28a, and the two arm tip feature points 30, 31.

[0064] Therefore, whether the cross arm of the steel tower protrudes in a triangular shape or in a rectangular shape, the cross arm can be framed as the cross arm frame 16. (4) By the top frame creation process, four points on the tower frame 15 on the underside of the top region 20 are determined as points 32 corresponding to the lower ends of the four corners at the top of the tower body among the points in the top region 20. Then, when the four outlines 33 of the top that connect to the points 32 corresponding to the lower ends of the four corners at the top intersect, the intersection of the outlines 33 is determined as a top tip characteristic point 34. Then, the top frame 17 is created based on the top tip characteristic point 34 and the outlines 33.

[0065] On the other hand, when the apex outlines 33 connecting to points 32 corresponding to the lower ends of the four corners do not intersect, the outline L1 and outline L2 of the horizontally extending portions of the apex, as well as apex tip feature points 37, 38, and 39 corresponding to the tips of the above-mentioned portions, are determined in the same manner as the first outline 27, second outline 28, and arm tip feature points 29, 30, and 31 are determined in the arm frame creation process, based on the points of horizontal plane F that has the widest horizontal extent among the horizontal planes when multiple horizontal planes are set in the apex region 20. Then, the apex frame 17 is created based on the four outlines 33, outline L1, outline L2, and apex tip feature points 37, 38, and 39.

[0066] Therefore, whether the top of the steel tower is a pyramidal shape that protrudes upward or a shape that protrudes in the width direction of the tower body like an arm, the top can be framed as a top frame 17.

[0067] (5) In the top frame creation process, when the four outlines 33 of the top do not intersect, four vertices 35, 36 located on the outlines 33 are found from among the points on the horizontal plane F where the points are most spread out horizontally. Then, the center point Pc of the four vertices 35, 36 is found, and the points located inside a circle C2 that passes through the four vertices 35, 36 and has the center point Pc as its center are removed from the top region 20. Furthermore, the remaining points in the top region 20 are divided into a group G1 located closer to the first vertex 35 of the two vertices 35, 36 that correspond to the base of the horizontally spreading portion of the top, and a group G2 located closer to the second vertex 36. Then, the outline L1 connected to the first vertex 35 is found using the points in group G1, and the outline L2 connected to the second vertex 36 is found using the points in group G2. The outline L1 and the outline L2 represent the outline of the horizontally extending portion of the top.

[0068] When the outline L1 and the outline L2 intersect, the intersection point between the outline L1 and the outline L2 is determined as the apex tip characteristic point 37. The apex frame 17 is created based on these four outline lines 33, the outline L1, the outline L2, and the apex tip characteristic point 37. When the outline lines L1 and L2 do not intersect, the point on the outline L1 that is farthest from the first vertex 35 is determined as the apex tip characteristic point 38, and the point on the outline L2 that is farthest from the second vertex 36 is also determined as the apex tip characteristic point 39. The apex frame 17 is created based on the four outline lines 33, the outline L1, the outline L2, and the two apex tip characteristic points 38 and 39.

[0069] Therefore, when the top of the steel tower has a shape that protrudes in the width direction of the tower body like an arm, the top can be framed as a top frame 17 regardless of whether the protruding part is triangular or rectangular.

[0070] The above embodiment can be modified as follows, for example: The above embodiment and the following modifications can be combined and implemented within the scope of technical compatibility. The number of cross arms in a steel tower does not necessarily have to be three; it can be one, two, or four or more.

[0071] The shape of the cross arm on the tower may be changed as appropriate. The shape of the top of the tower body may be changed as appropriate. Although a power transmission tower has been given as an example of a steel tower for which a three-dimensional model can be created, other steel towers, such as a radio tower, a communication tower, a ropeway tower, or a ski lift tower, may also be used as the target for creating a three-dimensional model. [Explanation of symbols]

[0072] 11...Computer 12...Central processing unit 13...Storage section 14…Communications Department 15...Tower frame 16...Brace frame 17...Top frame 18...Arm area 19...Leg area 20…Top area 21~24...Outline 25,26...Bracelet base characteristic points 27,28...Outline 29... Bracket tip characteristic point 30, 31... Bracket tip characteristic points 32 points 33...Outline 34...Apex tip feature point 35,36...Vertex 37, 38, 39...Apical tip feature points

Claims

1. The system is configured to target a steel tower having cross arms protruding in a width direction from a tower body extending upward, and includes a control unit that creates a three-dimensional framed model of the steel tower based on the three-dimensional coordinates of each point in a three-dimensional point cloud representing the steel tower, the control unit sequentially executes an extraction process, a division process, a tower body frame creation process, an arm frame creation process, a top frame creation process, and a model creation process, the extraction process extracts points representing the tower body and points representing the cross arm from a three-dimensional point cloud representing the steel tower and its surroundings; The division process divides the points representing the tower body and the points representing the cross arms into points within a cross arm region, which is a region in which the cross arms exist on the steel tower, points within a leg region, which is a region located below the lowest cross arm on the steel tower, and points within a top region, which is a region located above the highest cross arm on the steel tower, The tower body frame creation process uses each point representing the tower body to create a tower body frame in which tower columns extending up and down at the four corners of the tower body are framed, the arm frame creation process excludes points representing the tower body from the points within the arm region, extracts points corresponding to the base of the arm from the remaining points as arm base characteristic points, obtains an outline of the arm connected to the arm base characteristic points using the remaining points, further obtains points corresponding to the tip of the arm as arm tip characteristic points using the outline of the arm, and creates an arm frame by framing the arm using the arm base characteristic points, the outline of the arm, and the arm tip characteristic points; the top frame creation process determines points within the top region that correspond to the lower ends of the four corners of the top of the tower body, and determines an outline of the top that connects to the points that correspond to the lower ends of the four corners of the top of the tower body using the points within the top region, and determines a point that corresponds to the tip of the top as a top tip characteristic point using the outline, and creates a top frame that frames the top using the points that correspond to the lower ends of the four corners of the top of the tower body, the outline of the top, and the top tip characteristic point; The model creation process is an equipment structure estimation device that creates a three-dimensional model having the tower body frame, the cross arm frame, and the top frame as a three-dimensional model of the steel tower by combining the tower body frame, the cross arm frame, and the top frame.

2. The tower body frame creation process sequentially executes a first framing process, a second framing process, and a third framing process, The first framing process converts each point representing the tower body into a point in a first two-dimensional coordinate system excluding the width of the tower body by setting the coordinate of the point in the width direction of the tower body to 0, obtains an outline of the tower body in the first two-dimensional coordinate system represented by each point using the points in the first two-dimensional coordinate system, restores the coordinate of the width direction of the tower body before the conversion for each point on the outline, and creates a tower pillar frame by framing tower pillars located at the corners of the tower body from the restored outline, The second framing process converts each point representing the tower body into a point in a second two-dimensional coordinate system excluding the depth of the tower body by setting the coordinate of the depth of the tower body at each point representing the tower body to 0, obtains an outline of the tower body in the second two-dimensional coordinate system represented by each point using the points in the second two-dimensional coordinate system, restores the coordinate of the depth of the tower body before the conversion for each point on the outline, and creates a tower pillar frame by framing tower pillars located at the corners of the tower body from the restored outline, The facility structure estimation device according to claim 1, wherein the third framing process creates a tower body frame in which tower pillars located at the four corners of the tower body are framed based on the tower pillar frames created by the first framing process and the second framing process.

3. the arm frame creation process is a process of sequentially executing a removal process, a contour line estimation process, and a frame determination process; the removal process is to determine a center line of the tower body frame within the cross arm region, and remove each point inside a circle having the center line as its center and passing through the tower body frame from each point within the cross arm region; the outline estimation process extracts, from among the points remaining after the removal process at each point in the arm region, each point on the tower body frame on the bottom surface and the top surface of the arm region as the arm root characteristic point, divides the remaining points into a first group located closer to one of the arm root characteristic points on the bottom surface of the arm region and a second group located closer to the other of the arm root characteristic points, and obtains a first outline of the arm connected to one of the arm root characteristic points using each point in the first group, and obtains a second outline of the arm connected to the other of the arm root characteristic points using each point in the second group, The frame determination process includes: when the first outline and the second outline intersect, the intersection point is determined as the arm tip characteristic point, a third outline extending from the arm tip characteristic point to one of the arm base characteristic points on the upper surface of the arm region is determined, and a fourth outline extending from the arm tip characteristic point to the other of the arm base characteristic points on the upper surface of the arm region is determined, and the arm frame is created based on the four arm base characteristic points, the first outline, the second outline, the third outline, the fourth outline, and the arm tip characteristic points; 2. The equipment structure estimating device according to claim 1, wherein, when the first outline and the second outline do not intersect, a point on the first outline that is farthest from one of the arm base feature points is determined as the arm tip feature point, a third outline extending from the arm tip feature point to one of the arm base feature points on the upper surface of the arm region is determined, a point on the second outline that is farthest from the other of the arm base feature points is also determined as the arm tip feature point, a fourth outline extending from the arm tip feature point to the other of the arm base feature points on the upper surface of the arm region is determined, and the arm frame is created based on the four arm base feature points, the first outline, the second outline, the third outline, the fourth outline, and the two arm tip feature points.

4. The top frame creation process includes: Four points on the tower frame on the underside of the top region are determined as points within the top region that correspond to the four corners of the lower end of the top of the tower body; When the four outlines of the apex connected to these points intersect, the intersection of the outlines is determined as the apex tip characteristic point, and the apex frame is created based on the apex tip characteristic point and the outlines; 4. The equipment structure estimation device according to claim 3, wherein, when the outline lines of the top do not intersect, the outline line L1 and the outline line L2 of the horizontally extending portion of the top, as well as the top tip feature point, which is a point corresponding to the tip of the portion, are determined in the same manner as the first outline line, the second outline line, and the arm tip feature point are determined by the arm frame creation process, based on the points of the horizontal plane that has the most points spread out on the horizontal plane when multiple horizontal planes are set in the top region, and the top frame is created based on the four outline lines, the outline line L1, the outline line L2, and the top tip feature point.

5. The top frame creation process includes: When the four outlines of the apex do not intersect, find the four vertices located on the outlines of the horizontal plane among the points that are spread most widely on the horizontal plane, find the center point of these four vertices, and exclude the points located inside a circle that is centered at the center point and passes through the four vertices, The remaining points are divided into a group G1 located closer to the first vertex of the two vertices corresponding to the bases of the horizontally extending portions of the vertices, and a group G2 located closer to the second vertex, The outline L1 of the horizontally extending portion of the apex connected to the first vertex is determined using each point in the group G1, and the outline L2 of the horizontally extending portion of the apex connected to the second vertex is determined using each point in the group G2. When the outline L1 and the outline L2 intersect, the intersection of the outline L1 and the outline L2 is determined as the apex tip characteristic point, and the apex frame is created based on the four outlines of the apex, the outline L1, the outline L2, and the apex tip characteristic point; 5. The equipment structure estimation device according to claim 4, wherein when the outline line L1 and the outline line L2 do not intersect, a point on the outline line L1 that is farthest from the first vertex is determined as the apex tip characteristic point, and a point on the outline line L2 that is farthest from the second vertex is also determined as the apex tip characteristic point, and the apex frame is created based on the four outline lines of the apex, the outline line L1, the outline line L2, and the two apex tip characteristic points.

6. A steel tower having cross arms protruding in the width direction from a tower body extending upward is targeted, and a three-dimensional model of the steel tower is created by framing the steel tower based on the three-dimensional coordinates of each point in a three-dimensional point cloud representing the steel tower. The process involves having a computer sequentially execute an extraction process, a division process, a tower body frame creation process, a cross arm frame creation process, a top frame creation process, and a model creation process; the extraction process extracts points representing the tower body and points representing the cross arm from a three-dimensional point cloud representing the steel tower and its surroundings; The division process divides the points representing the tower body and the points representing the cross arms into points within a cross arm region, which is a region in which the cross arms exist on the steel tower, points within a leg region, which is a region located below the lowest cross arm on the steel tower, and points within a top region, which is a region located above the highest cross arm on the steel tower, The tower body frame creation process uses each point representing the tower body to create a tower body frame in which tower columns extending up and down at the four corners of the tower body are framed, the arm frame creation process excludes points representing the tower body from the points within the arm region, extracts points corresponding to the base of the arm from the remaining points as arm base characteristic points, obtains an outline of the arm connected to the arm base characteristic points using the remaining points, further obtains points corresponding to the tip of the arm as arm tip characteristic points using the outline of the arm, and creates an arm frame by framing the arm using the arm base characteristic points, the outline of the arm, and the arm tip characteristic points; the top frame creation process determines points within the top region that correspond to the lower ends of the four corners of the top of the tower body, and determines an outline of the top that connects to the points that correspond to the lower ends of the four corners of the top of the tower body using the points within the top region, and determines a point that corresponds to the tip of the top as a top tip characteristic point using the outline, and creates a top frame that frames the top using the points that correspond to the lower ends of the four corners of the top of the tower body, the outline of the top, and the top tip characteristic point; The model creation process is an equipment structure estimation program that creates a three-dimensional model having the tower body frame, the cross arm frame, and the top frame as a three-dimensional model of the steel tower by combining the tower body frame, the cross arm frame, and the top frame.

7. The tower body frame creation process sequentially executes a first framing process, a second framing process, and a third framing process, The first framing process converts each point representing the tower body into a point in a first two-dimensional coordinate system excluding the width of the tower body by setting the coordinate of the point in the width direction of the tower body to 0, obtains an outline of the tower body in the first two-dimensional coordinate system represented by each point using the points in the first two-dimensional coordinate system, restores the coordinate of the width direction of the tower body before the conversion for each point on the outline, and creates a tower pillar frame by framing tower pillars located at the corners of the tower body from the restored outline, The second framing process converts each point representing the tower body into a point in a second two-dimensional coordinate system excluding the depth of the tower body by setting the coordinate of the depth of the tower body at each point representing the tower body to 0, obtains an outline of the tower body in the second two-dimensional coordinate system represented by each point using the points in the second two-dimensional coordinate system, restores the coordinate of the depth of the tower body before the conversion for each point on the outline, and creates a tower pillar frame by framing tower pillars located at the corners of the tower body from the restored outline, The facility structure estimation program according to claim 6, wherein the third framing process creates a tower body frame in which tower columns located at the four corners of the tower body are framed based on each tower column frame created by the first framing process and the second framing process.

8. the arm frame creation process is a process of sequentially executing a removal process, a contour line estimation process, and a frame determination process; the removal process is to determine a center line of the tower body frame within the cross arm region, and remove each point inside a circle having the center line as its center and passing through the tower body frame from each point within the cross arm region; the outline estimation process extracts, from among the points remaining after the removal process at each point in the arm region, each point on the tower body frame on the bottom surface and the top surface of the arm region as the arm root characteristic point, divides the remaining points into a first group located closer to one of the arm root characteristic points on the bottom surface of the arm region and a second group located closer to the other of the arm root characteristic points, and obtains a first outline of the arm connected to one of the arm root characteristic points using each point in the first group, and obtains a second outline of the arm connected to the other of the arm root characteristic points using each point in the second group, The frame determination process includes: when the first outline and the second outline intersect, the intersection point is determined as the arm tip characteristic point, a third outline extending from the arm tip characteristic point to one of the arm base characteristic points on the upper surface of the arm region is determined, and a fourth outline extending from the arm tip characteristic point to the other of the arm base characteristic points on the upper surface of the arm region is determined, and the arm frame is created based on the four arm base characteristic points, the first outline, the second outline, the third outline, the fourth outline, and the arm tip characteristic points; 7. The equipment structure estimating program according to claim 6, wherein when the first outline and the second outline do not intersect, a point on the first outline that is farthest from one of the arm base characteristic points is determined as the arm tip characteristic point, a third outline extending from the arm tip characteristic point to one of the arm base characteristic points on the upper surface of the arm region is determined, a point on the second outline that is farthest from the other of the arm base characteristic points is also determined as the arm tip characteristic point, a fourth outline extending from the arm tip characteristic point to the other of the arm base characteristic points on the upper surface of the arm region is determined, and the arm frame is created based on the four arm base characteristic points, the first outline, the second outline, the third outline, the fourth outline, and the two arm tip characteristic points.

9. The top frame creation process includes: Four points on the tower frame on the underside of the top region are determined as points within the top region that correspond to the four corners of the lower end of the top of the tower body; When the four outlines of the apex connected to these points intersect, the intersection of the outlines is determined as the apex tip characteristic point, and the apex frame is created based on the apex tip characteristic point and the outlines; 9. The equipment structure estimating program according to claim 8, wherein, when the outline lines of the top do not intersect, the outline line L1 and the outline line L2 of the horizontally extending portion of the top, as well as the top tip feature point, which is a point corresponding to the tip of the portion, are determined in the same manner as the first outline line, the second outline line, and the arm tip feature point are determined by the arm frame creation process, based on the points of the horizontal plane that has the most points spread out on the horizontal plane when multiple horizontal planes are set in the top region, and the top frame is created based on the four outline lines, the outline line L1, the outline line L2, and the top tip feature point.

10. The top frame creation process includes: When the four outlines of the apex do not intersect, find the four vertices located on the outlines of the horizontal plane among the points that are spread most widely on the horizontal plane, find the center point of these four vertices, and exclude the points located inside a circle that is centered at the center point and passes through the four vertices, The remaining points are divided into a group G1 located closer to the first vertex of the two vertices corresponding to the bases of the horizontally extending portions of the vertices, and a group G2 located closer to the second vertex, The outline L1 of the horizontally extending portion of the apex connected to the first vertex is determined using each point in the group G1, and the outline L2 of the horizontally extending portion of the apex connected to the second vertex is determined using each point in the group G2. When the outline L1 and the outline L2 intersect, the intersection of the outline L1 and the outline L2 is determined as the apex tip characteristic point, and the apex frame is created based on the four outlines of the apex, the outline L1, the outline L2, and the apex tip characteristic point; 10. The equipment structure estimating program according to claim 9, wherein when the outline line L1 and the outline line L2 do not intersect, a point on the outline line L1 that is farthest from the first vertex is determined as the apex tip characteristic point, and a point on the outline line L2 that is farthest from the second vertex is also determined as the apex tip characteristic point, and the apex frame is created based on the four outline lines of the apex, the outline line L1, the outline line L2, and the two apex tip characteristic points.

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