Lightning protection range generating device, lightning protection range generating method, and program

Abstract

To generate an overall shape of a lightning protection range.SOLUTION: A lightning protection range generation device is provided with: a first generation unit that generates a first equidistant surface equidistant from the first target part; a second generation unit that generates a second equidistant surface equidistant from the second target part; a derivation unit that derives an intersection where the first equidistant surface generated by the first generation unit and the second equidistant surface generated by the second generation unit intersect; a protection surface generation unit that generates a protection surface equidistant from the intersection derived by the derivation unit; a curve generation unit that generates a curve connecting a point at which the protection surface generated by the protection surface generation unit and the first target part are in contact with each other and a point at which the protection surface generated by the protection surface generation unit and the second target part are in contact with each other in the shortest distance on the protection surface; and a lightning protection range shape generation unit that generates a shape of a lightning protection range using the curve generated by the curve generation unit.SELECTED DRAWING: Figure 16

Description

[Technical field]

[0001] The present invention relates to a lightning protection area generating device, a lightning protection area generating method, and a program. [Background technology]

[0002] Methods used to protect structures and the like from lightning strikes include the rolling sphere method (JIS A 4201:2003), the protective angle method, and the mesh method. Of these, the rolling sphere method is a method in which the protected object side is the envelope of the sphere surface when a sphere is rotated so that it is in contact with two or more lightning receiving parts at the same time, or in contact with one or more lightning receiving parts and the ground at the same time. Technology related to this rolling sphere method is disclosed in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2005-99942 A Summary of the Invention [Problem to be solved by the invention]

[0004] As mentioned above, in the rotating sphere method, when a sphere is rotated, the protection area is the area from the envelope of the sphere surface to the protected object, so the shape of the lightning protection area often becomes complex depending on the shape of the building and the position of the lightning rod.

[0005] For example, the shape of the lightning protection area may be checked by looking at the cross-section of a portion of a building, but it is difficult to check the overall shape of the lightning protection area by looking at only that portion, which results in difficulty in verifying the lightning protection area.

[0006] The present invention has been made to solve the above problems, and has an object to provide a lightning protection area generating device, a lightning protection area generating method, and a program capable of generating the overall shape of a lightning protection area. [Means for solving the problem]

[0007] In order to solve the above problems, one aspect of the present invention is a lightning protection area generating device comprising: a first generation unit that generates a first equidistant surface that is equidistant from a first target portion; a second generation unit that generates a second equidistant surface that is equidistant from a second target portion; a derivation unit that derives an intersection point where the first equidistant surface generated by the first generation unit and the second equidistant surface generated by the second generation unit intersect; a protection surface generation unit that generates a protection surface that is equidistant from the intersection point derived by the derivation unit; a curve generation unit that generates a curve that connects on the protection surface in the shortest distance between a point where the protection surface generated by the protection surface generation unit and the first target portion contacts a point where the protection surface generated by the protection surface generation unit and the second target portion contacts; and a lightning protection area shape generation unit that generates the shape of a lightning protection area using the curve generated by the curve generation unit.

[0008] Moreover, one aspect of the present invention is that, in the above-mentioned lightning protection range generating device, when the first target part is a lightning receiving part represented by a single point, the first equidistant surface is a spherical surface centered on the first target part, and when the second target part is a lightning receiving part represented by a single point, the second equidistant surface is a spherical surface centered on the second target part.

[0009] Moreover, one aspect of the present invention is that, in the above-mentioned lightning protection range generating device, when the first target portion is a lightning receiving portion represented by a line segment, the first equidistant surface is a cylindrical surface with the first target portion as its axis, and when the second target portion is a lightning receiving portion represented by a line segment, the second equidistant surface is a cylindrical surface with the second target portion as its axis.

[0010] Moreover, one aspect of the present invention is that, in the above-mentioned lightning protection range generating device, when the first target portion is a plane representing the earth, the first isodistant plane is a plane parallel to the first target portion, and when the second target portion is a plane representing the earth, the second isodistant plane is a plane parallel to the second target portion.

[0011] In addition, one embodiment of the present invention, in the above-mentioned lightning protection range generating device, includes a third generation unit that generates a third isodistant surface that is equidistant from a third target portion, and the derivation unit derives an intersection portion where a composite isodistant surface that is a combination of the first isodistant surface generated by the first generation unit and the second isodistant surface generated by the second generation unit intersects with the second isodistant surface generated by the second generation unit.

[0012] Moreover, one aspect of the present invention is a lightning protection area generation method comprising: a first generation step of generating a first equidistant surface that is equidistant from a first target portion; a second generation step of generating a second equidistant surface that is equidistant from a second target portion; a derivation step of deriving an intersection point where the first equidistant surface generated by the first generation step and the second equidistant surface generated by the second generation step intersect; a third generation step of generating a protection surface that is equidistant from the intersection point derived by the derivation step; a curve generation step of generating a curve that connects, in the shortest distance, on the protection surface between a point where the protection surface generated by the third generation step and the first target portion contacts and a point where the protection surface generated by the third generation step and the second target portion contacts; and a range generation step of generating the shape of the lightning protection area using the curve generated by the curve generation step.

[0013] Moreover, one aspect of the present invention is a program for causing a computer to execute the following steps: a first generation step of generating a first isodistant surface that is equidistant from a first target portion; a second generation step of generating a second isodistant surface that is equidistant from a second target portion; a derivation step of deriving an intersection point where the first isodistant surface generated by the first generation step and the second isodistant surface generated by the second generation step intersect; a third generation step of generating a protection surface that is equidistant from the intersection point derived by the derivation step; a curve generation step of generating a curve that connects, in the shortest distance, on the protection surface between a point where the protection surface generated by the third generation step and the first target portion contacts a point where the protection surface generated by the third generation step and the second target portion contacts; and a range generation step of generating the shape of a lightning protection range using the curve generated by the curve generation step. Effect of the Invention

[0014] According to the invention it is possible to generate the overall shape of the lightning protection area. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a schematic block diagram illustrating an example of a lightning protection range generating device. [Diagram 2] FIG. 1 shows an iso-distance surface. [Diagram 3] FIG. 1 shows an iso-distance surface. [Figure 4] FIG. [Diagram 5] FIG. 2 is a diagram showing the shape of a protection surface and a lightning protection range. [Figure 6] FIG. [Figure 7] FIG. 13 is a diagram showing the shape generation process of the protection range A. [Figure 8] 13 is a diagram showing the shape generation process of the protection range B. FIG. [Figure 9] FIG. 13 is a diagram showing the shape generation process of a protection range C. [Figure 10] 13 is a diagram showing the shape generation process of a protection range D. FIG. [Figure 11] 13 is a diagram showing the shape generation process of the protection range E. FIG. [Figure 12] 13 is a diagram showing the shape generation process of the protection range F. FIG. [Figure 13] FIG. 13 is a diagram showing the process of generating a shape of a lightning protection area. [Figure 14] FIG. [Figure 15] FIG. 2 is a diagram showing the positions of lightning rods and lightning conductors. [Figure 16] FIG. 2 is a diagram showing the shape of a lightning protection range. [Figure 17] This is a two-dimensional diagram showing the shape of the lightning protection area. [Figure 18] FIG. [Figure 19] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A lightning protection range generating device according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic block diagram showing an example of a lightning protection range generating device 100 according to the present embodiment. The lightning protection range generating device 100 is composed of an input unit 110, a first target acquisition unit 121, a second target acquisition unit 122, a third target acquisition unit 123, a first generation unit 131, a second generation unit 132, a third generation unit 133, an intersection portion derivation unit 140, a protection surface generation unit 150, a curve generation unit 160, and a lightning protection range shape generation unit 170.

[0017] The input unit 110 receives input of CAD data of a building, the radius r of the lightning range (sphere) used in the rolling sphere method, the height of the ground surface of the earth, etc. The input CAD data includes information indicating the position of the lightning receiving part (lightning rod, lightning conductor).

[0018] The first target acquisition unit 121, the second target acquisition unit 122, and the third target acquisition unit 123 acquire information indicating the lightning receiving unit or the ground (the ground surface in this embodiment) that is the target in the rotating sphere method. The first target acquisition unit 121, the second target acquisition unit 122, and the third target acquisition unit 123 all acquire the power receiving unit as the target, or at least one acquires the ground surface as the target, and the others acquire the power receiving unit as the target. The target acquired by the first target acquisition unit 121 may be expressed as the first target unit, the target acquired by the second target acquisition unit 122 may be expressed as the second target unit, and the target acquired by the third target acquisition unit 123 may be expressed as the third target unit. In addition, when the first target unit, the second target unit, and the third target unit are not particularly distinguished, they are simply expressed as target units. Note that when there are two targets in the rotating sphere method, the third target acquisition unit 123 and the third generation unit 133 do not operate.

[0019] The first generating unit 131 generates a first isodistant surface that is equidistant from the first target portion. The second generating unit 132 generates a second isodistant surface that is equidistant from the second target portion. The third generating unit 133 generates a third isodistant surface that is equidistant from the third target portion. When there is no particular distinction between the first generating unit 131, the second generating unit 132, and the third generating unit 133, they may be expressed as an isodistant surface generating unit 130. The intersection portion derivation unit 140 derives an intersection portion where the first isodistant surface generated by the first generating unit 131 and the second isodistant surface generated by the second generating unit 132 intersect.

[0020] The protection surface generation unit 150 generates a protection surface that is equidistant from the intersection portion derived by the intersection portion derivation unit 140. The curve generation unit 160 generates a curve that connects, in the shortest distance on the protection surface, a point where the protection surface and a target portion contact each other and a point where the protection surface and another target portion contact each other. The curve that connects in the shortest distance on the protection surface is a circular arc. The range generation unit 170 uses the curve generated by the curve generation unit 160 to generate the shape of the lightning protection range.

[0021] Next, generation of an equidistance surface by the above-mentioned equidistance surface generating unit 130 will be described. Fig. 2 is a diagram showing an equidistance surface. In Fig. 2, r is the radius r of the lightning strike range. As described above, the target parts are the lightning receiving part (lightning rod, lightning conductor) and the ground surface.

[0022] In the case of a lightning rod, the tip of the rod is the target. In this way, when the target is a lightning-receiving part represented by a single point, the equidistant surface is a sphere with the target at its center, as shown in Figure 2(A).

[0023] In the case where the target part is a lightning receiving part represented by a line segment, such as a lightning conductor, the equidistant surface in Figure 2(B) is a cylindrical surface with the target part as its axis. Also, since the two ends of the line segment are lightning receiving parts whose target part is represented by a single point, the equidistant surface is a hemisphere with the target part as its center. Therefore, in the case where the target part is a lightning receiving part represented by a line segment, the equidistant surface has a shape like a capsule that envelops the line segment. Note that a lightning conductor may also be a curved line, and in this case too, the equidistant surface is a set of points where the length of the perpendicular line dropped onto the curve is r. In the following explanation, an equidistant surface when the target part is represented by a line segment may be referred to as a capsule.

[0024] When the target portion is a plane representing the earth, such as the ground surface, the equidistant surface is a plane parallel to the target portion, as shown in FIG. 2(C).

[0025] The equidistant surface explained in Figure 2 is a surface on which the center of a sphere of radius r exists without exception when the sphere is rotated around the target part in the rotating sphere method. In other words, the center of the sphere always exists on the equidistant surface.

[0026] Next, the process of generating the shape of the lightning protection area will be described using a concrete example. Figure 3 is a diagram showing an equidistance surface specifically showing a lightning rod and a lightning conductor as an example. Both Figure 3(A) and Figure 3(B) show a building with two lightning rods installed on the roof. In the building, the roof frame shown by a dashed line indicates the lightning conductor.

[0027] In Fig. 3(A), since there are two lightning rods, two spheres are generated with their respective tips as their centers. In Fig. 3(B), since the roof frame is composed of six sides, a capsule is generated for each side.

[0028] 3, when there are multiple target parts, multiple equidistant surfaces may overlap when viewed from the building. In this case, only the equidistant surface that is on the outside when viewed from the building is set as the isodistant surface to be processed by the intersection derivation unit 140 (hereinafter, referred to as the "synthetic isodistant surface").

[0029] Fig. 4 is a diagram showing an intersection where equidistant surfaces intersect. In the explanation of Fig. 4, the composite equidistant surface generated for two lightning rods is expressed as a lightning rod equidistant surface, and the equidistant surface generated for a lightning conductor (rooftop frame) is expressed as a lightning conductor equidistant surface. Fig. 4(A) is a diagram in which the lightning rod equidistant surface and the lightning conductor equidistant surface are superimposed. In this case, the dashed line shown in Fig. 4(B) is the intersection.

[0030] FIG. 5(A) is a diagram showing a protection surface that is equidistant from the intersection. The protection surface is a surface obtained by moving a sphere of radius r so that its center is the intersection. FIG. 5(B) is a diagram showing the shape of the lightning protection range. The shape of the lightning protection range is a curve that connects the point where the protection surface and the first target part contact each other and the point where the protection surface and the second target part contact each other on the protection surface in the shortest distance. For example, as shown in FIG. 5(B), a curve C1 is shown that connects the points where the protection surface contacts two lightning rods in the shortest distance on the protection surface. Also, a curve C2 is shown that connects the points where the protection surface contacts one lightning rod and one lightning conductor in the shortest distance on the protection surface. The shape formed by these curves (arcs) is the shape of the lightning protection range.

[0031] In actual processing, it is not possible to generate spheres centered on all points on the intersection, so the protection surface is generated by combining spheres centered on points spaced equally apart on the intersection. Accordingly, in actual processing, arcs are also generated for each protection surface. In this way, the shape of the lightning protection area is generated by the group of arcs. The shape of the lightning protection area is generated as a surface by using a CAD function that interpolates adjacent arcs on a plane for this group of arcs.

[0032] As mentioned above, the target part may be represented by a single point such as the tip of a lightning rod, a line segment such as a lightning conductor, or a plane such as the ground. The protection range is generated based on a combination of these targets.

[0033] 6 is a diagram showing combinations. Each combination corresponds to a protection range A to F. These protection ranges A to F are generated and output to the lightning protection range shape generation unit 170. The lightning protection range shape generation unit 170 synthesizes them to generate the overall shape of the lightning protection range.

[0034] The protection ranges A to F are generated according to the number of lightning rods that the building has. When the number of lightning rods is zero, the protection ranges A and B are generated, and the lightning protection range shape generating unit 170 combines them to generate the overall shape of the lightning protection range. When the number of lightning rods is one, the protection ranges A, B, C, and F are generated, and the lightning protection range shape generating unit 170 combines them to generate the overall shape of the lightning protection range. When the number of lightning rods is two, the protection ranges A, B, C, D, and F are generated, and the lightning protection range shape generating unit 170 combines them to generate the overall shape of the lightning protection range. When the number of lightning rods is three or more, the protection ranges A, B, C, D, E, and F are generated, and the lightning protection range shape generating unit 170 combines them to generate the overall shape of the lightning protection range.

[0035] When the number of lightning rods is N (N is 3 or more), protection range D is generated by all combinations of selecting two lightning rods from the N number of lightning rods. Protection range E is generated by all combinations of selecting three lightning rods from the N number of lightning rods.

[0036] As shown in FIG. 6, protection range A is a protection range generated from a lightning conductor and the ground surface. Protection range B is a protection range generated from lightning conductors. Protection range C is a protection range generated from a lightning rod and a lightning conductor. Protection range D is a protection range generated from two lightning rods and a lightning conductor. Protection range E is a protection range generated from three lightning rods. Protection range F is a protection range generated from a lightning rod and the ground surface. The lightning protection range generating device 100 generates the shape of the lightning protection range by performing shape generation processing on all target parts without omission.

[0037] The shape generation process for generating the shapes of protection areas A to F will be described below in order. Note that in the shape generation process, it is assumed that CAD data has been input in advance to the lightning protection area generation device 100. In addition, for IS(α, β) used in the shape generation process described below, α and β are equidistant surfaces, and IS(α, β) indicates the intersection of α and β. For ARC(M, N), M and N are target parts, and ARC(M, N) indicates the curve that connects the junction of the protection surface with M and the junction of the protection surface with N in the shortest distance on the protection surface.

[0038] 7 is a diagram showing the process of generating the shape of the protected area A. The input unit 110 inputs the lightning strike area radius r. The input unit 110 also inputs the height of the ground surface.

[0039] The first object acquisition unit 121 acquires a line segment P of the lightning conductor from the CAD data as a first object. The first generation unit 131 generates a capsule X as an equidistant surface of the line segment P. The second object acquisition unit 122 acquires a ground surface Q as a second object from the input height of the ground surface. The second generation unit 132 generates a plane Y as an equidistant surface of the ground surface Q.

[0040] The intersection portion derivation unit 140 derives an intersection portion IS (capsule X, plane Y) where the capsule X generated by the first generation unit 131 intersects with the plane Y generated by the second generation unit 132. The protection surface generation unit 150 generates a protection surface that is equidistant from the intersection portion IS (capsule X, plane Y) derived by the intersection portion derivation unit 140.

[0041] The curve generating unit 160 generates a curve ARC (line segment P, ground surface Q) that connects, on the protection surface, the point where the protection surface generated by the protection surface generating unit 150 contacts the line segment P and the point where the protection surface generated by the protection surface generating unit 150 contacts the ground surface Q in the shortest distance, and outputs a protection area A obtained by interpolating adjacent curves to the lightning protection area shape generating unit 170. An example of the interpolation method is a method of generating a surface with straight lines.

[0042] 8 is a diagram showing the shape generation process of the protection range B. The input unit 110 inputs the lightning strike range radius r. The first target acquisition unit 121 acquires a line segment P of the lightning conductor from the CAD data as a first target part. The first generation unit 131 generates a capsule X as an equidistant surface of the line segment P. The second target acquisition unit 122 acquires a line segment Q of the lightning conductor from the CAD data as a second target part. The second generation unit 132 generates a capsule Y as an equidistant surface of the line segment Q.

[0043] The intersection portion derivation unit 140 derives an intersection portion IS (capsule X, capsule Y) where the capsule X generated by the first generation unit 131 and the capsule Y generated by the second generation unit 132 intersect. The protection surface generation unit 150 generates a protection surface that is equidistant from the intersection portion IS (capsule X, capsule Y) derived by the intersection portion derivation unit 140.

[0044] The curve generating unit 160 generates a curve ARC (line segment P, line segment Q) that connects, on the protection surface, the point where the protection surface generated by the protection surface generating unit 150 contacts the line segment P and the point where the protection surface generated by the protection surface generating unit 150 contacts the line segment Q in the shortest distance, and outputs a protection range B obtained by interpolating adjacent curves to the lightning protection range shape generating unit 170. An example of the interpolation method is a method of generating a surface using straight lines.

[0045] 9 is a diagram showing the shape generation process of the protection area C. The input unit 110 inputs the lightning stroke area radius r. The first target acquisition unit 121 acquires the lightning receiving point P at the tip of the lightning rod from the CAD data as the first target part. The first generation unit 131 generates a spherical surface X as an equidistant surface of the lightning receiving point P. The second target acquisition unit 122 acquires the line segment Q of the lightning conductor closest to the lightning rod of the first target part from the CAD data as the second target part. The second generation unit 132 generates a capsule Y as an equidistant surface of the line segment Q.

[0046] The intersection portion derivation unit 140 derives an intersection portion IS (sphere X, capsule Y) where the sphere X generated by the first generation unit 131 and the capsule Y generated by the second generation unit 132 intersect. The protection surface generation unit 150 generates a protection surface that is equidistant from the intersection portion IS (sphere X, capsule Y) derived by the intersection portion derivation unit 140.

[0047] The curve generating unit 160 generates a curve ARC (lightning receiving point P, line segment Q) that connects, on the protection surface, the point where the protection surface generated by the protection surface generating unit 150 contacts the lightning receiving point P and the point where the protection surface generated by the protection surface generating unit 150 contacts the line segment Q in the shortest distance, and outputs a protection range C obtained by interpolating adjacent curves to the lightning protection range shape generating unit 170. An example of the interpolation method is a method of generating a surface using straight lines.

[0048] FIG. 10 is a diagram showing the shape generation process of the protection range D. The input unit 110 inputs the lightning stroke range radius r. The first target acquisition unit 121 acquires the lightning receiving point P at the tip of the lightning rod from the CAD data as the first target part. The first generation unit 131 generates a sphere X as an equidistant surface of the lightning receiving point P. The second target acquisition unit 122 acquires the lightning receiving point Q at the tip of the lightning rod from the CAD data as the second target part. The second generation unit 132 generates a sphere Y as an equidistant surface of the lightning receiving point Q. The third target acquisition unit 123 acquires the line segment R of the lightning conductor closest to the lightning rod of the first target part and the lightning rod of the second target part from the CAD data as the third target part. The third generation unit 133 generates a capsule Z as an equidistant surface of the line segment R.

[0049] The intersection portion derivation unit 140 derives an intersection portion IS (a composite isodistant surface of the sphere X and the sphere Y, capsule Z) where the composite isodistant surface of the sphere X generated by the first generation unit 131 and the sphere Y generated by the second generation unit 132 intersects with the capsule Z generated by the third generation unit 133. The protection surface generation unit 150 generates a protection surface that is equidistant from the intersection portion IS derived by the intersection portion derivation unit 140 (a composite isodistant surface of the sphere X and the sphere Y, capsule Z).

[0050] The curve generating unit 160 generates a curve ARC (lightning receiving point P, lightning receiving point Q) that connects, on the protection surface, the point where the protection surface generated by the protection surface generating unit 150 contacts the lightning receiving point P and the point where the protection surface generated by the protection surface generating unit 150 contacts the lightning receiving point Q in the shortest distance, and outputs a protection range A obtained by interpolating adjacent curves to the lightning protection range shape generating unit 170. An example of the interpolation method is a method of generating a surface using straight lines.

[0051] FIG. 11 is a diagram showing the shape generation process of the protection range E. The input unit 110 inputs the lightning stroke range radius r. The first target acquisition unit 121 acquires the lightning receiving point P at the tip of the lightning rod from the CAD data as the first target part. The first generation unit 131 generates a sphere X as an equidistant surface of the lightning receiving point P. The second target acquisition unit 122 acquires the lightning receiving point Q at the tip of the lightning rod from the CAD data as the second target part. The second generation unit 132 generates a sphere Y as an equidistant surface of the lightning receiving point Q. The third target acquisition unit 123 acquires the lightning receiving point R at the tip of the lightning rod from the CAD data as the third target part. The third generation unit 133 generates a sphere Z as an equidistant surface of the lightning receiving point R.

[0052] The intersection portion derivation unit 140 derives an intersection portion IS (IS(sphere X, sphere Y), sphere Z) where the sphere X generated by the first generation unit 131, the sphere Y generated by the second generation unit 132, and the sphere Z generated by the third generation unit 133 intersect. The protection surface generation unit 150 generates a protection surface that is equidistant from the intersection portion IS (IS(sphere X, sphere Y), sphere Z) derived by the intersection portion derivation unit 140.

[0053] The curve generating unit 160 generates a curve ARC (lightning receiving point P, lightning receiving point Q) that connects, in the shortest distance, on the protection surface between the point where the protection surface generated by the protection surface generating unit 150 and the lightning receiving point P contact and the point where the protection surface generated by the protection surface generating unit 150 and the lightning receiving point Q contact. The curve generating unit 160 generates a curve ARC (lightning receiving point P, lightning receiving point R) that connects, in the shortest distance, on the protection surface between the point where the protection surface generated by the protection surface generating unit 150 and the lightning receiving point P contact and the point where the protection surface generated by the protection surface generating unit 150 and the lightning receiving point R contact. The curve generating unit 160 generates a curve ARC (lightning receiving point Q, lightning receiving point R) that connects, in the shortest distance, on the protection surface between the point where the protection surface generated by the protection surface generating unit 150 and the lightning receiving point Q contact and the point where the protection surface generated by the protection surface generating unit 150 and the lightning receiving point R contact.

[0054] The adjacent curves of ARC (lightning receiving point P, lightning receiving point Q) are interpolated, the adjacent curves of ARC (lightning receiving point P, lightning receiving point R) are interpolated, and the adjacent curves of ARC (lightning receiving point Q, lightning receiving point R) are interpolated to obtain a protection range E, which is output to the lightning protection range shape generation unit 170. Note that if lightning receiving points P, Q, and R exist on the same sphere, the protection range becomes a sphere, and if lightning receiving points P, Q, and R do not exist on the same sphere (if the lightning rods are too far apart), no protection range is generated.

[0055] 12 is a diagram showing the shape generation process for protected area F. The input unit 110 inputs the lightning strike area radius r. The input unit 110 also inputs the height of the ground surface. In the shape generation process for protected area E, an equidistant surface is generated for all lightning rods. Here, it is assumed that there are k lightning rods, and the first target acquisition unit 121 loops k times to generate a spherical surface.

[0056] The first object acquisition unit 121 acquires the lightning receiving points P(1) to P(k) at the tips of all lightning rods as object parts from the CAD data. The first generation unit 131 generates spherical surfaces X(1) to X(k) as equidistant surfaces of the lightning receiving points P(1) to P(k). The second object acquisition unit 122 acquires ground surface Q as a second object part from the input height of the ground surface. The second generation unit 132 generates plane Y as an equidistant surface of ground surface Q.

[0057] The intersection portion derivation unit 140 derives an intersection portion IS (a composite isodistant surface of the spherical surfaces X(1) to X(k), plane Y) where the composite isodistant surface of the spherical surfaces X(1) to X(k) generated by the first generation unit 131 intersects with the plane Y generated by the second generation unit 132. The protection surface generation unit 150 generates a protection surface that is equidistant from the intersection portion IS derived by the intersection portion derivation unit 140 (a composite isodistant surface of the spherical surfaces X(1) to X(k), plane Y).

[0058] The curve generating unit 160 generates a curve ARC(lightning receiving point P(1), ground surface Q), ..., ARC(lightning receiving point P(k), ground surface Q) that connects, in the shortest distance on the protection surface, the points where the protection surface generated by the protection surface generating unit 150 and the lightning receiving points P(1) to P(k) meet and the points where the protection surface generated by the protection surface generating unit 150 and the ground surface Q meet.

[0059] For each of ARC (lightning receiving point P(1), ground surface Q), ..., ARC (lightning receiving point P(k), ground surface Q), a protection area F obtained by interpolating adjacent curves is output to the lightning protection area shape generating unit 170. An example of the interpolation method is a method of generating a surface using straight lines.

[0060] 13 is a diagram showing the process of generating the shape of the lightning protection area. The generated shapes of the protection areas A to F are input to the lightning protection area shape generating unit 170. The lightning protection area shape generating unit 170 generates the overall shape of the lightning protection area by combining the protection areas A to F. Depending on the relationship between the objects, multiple protection areas may overlap when viewed from the building. In this case, only the lightning protection area that is outermost when viewed from the building is used.

[0061] An example of applying the above-mentioned shape generation process to actual CAD data will be described. Fig. 14 is a perspective view of a building. Fig. 15 is a diagram showing the positions of lightning rods and lightning conductors in a building. The dashed lines indicate the lightning conductors. The target parts of the building shown in Fig. 15 are one lightning rod and the lightning conductor indicated by the dashed lines. The lightning protection area generation device 100 generates the shapes of the above-mentioned protection areas A to F, and generates the overall shape of the lightning protection area by combining the protection areas A to F.

[0062] Fig. 16 is a diagram showing the shape of the lightning protection area obtained by the shape generation process. As shown in Fig. 16, the lightning protection area generation device 100 generates a shape of the lightning protection area that allows the overall shape of the lightning protection area to be seen at a glance. Since the shape of this lightning protection area is output as CAD data, it is possible to rotate and enlarge / reduce the protection area shown in Fig. 16. In addition, for example, as shown in Fig. 17, the shape of the lightning protection area can be displayed in a two-dimensional diagram.

[0063] Furthermore, the shape of the lightning protection range in any cross-sectional direction can also be displayed. FIG. 18 is a plan view of a building. FIG. 19(A) shows a cross-section when the plan view shown in FIG. 18 is cut vertically in the A-A' direction. FIG. 19(B) shows a cross-section when the plan view shown in FIG. 18 is cut vertically in the B-B' direction. The arcs shown in FIG. 19(A) and FIG. 19(B) are the protection shapes in the cross-section. For example, the shape of the lightning protection range connecting the lightning rod and the lightning conductor shown in FIG. 15 is different even if the cross-sectional direction is changed slightly. Therefore, by displaying the shape of the lightning protection range in any cross-sectional direction as in this embodiment, verification can be easily performed.

[0064] In this way, the protection shape in a cross section in any direction can be displayed using CAD data that shows the shape of the lightning protection range, making it easy to verify the lightning protection range.Compared to the conventional method of verification, which required preparing a cross section and applying the rolling sphere method to the cross section, this makes it very efficient and easy to verify the lightning protection range.

[0065] As described above, the lightning protection range generating device 100 according to this embodiment first generates a first equidistant surface that is equidistant from the first target portion. This generates a surface on which the center of a sphere of radius r tangent to the first target portion exists. Similarly, the lightning protection range generating device 100 generates a second equidistant surface that is equidistant from the second target portion. This generates a surface on which the center of a sphere of radius r tangent to the second target portion exists.

[0066] Next, the lightning protection range generating device 100 derives an intersection where the first equidistant surface and the second equidistant surface intersect. This derives the position of the center of a sphere that touches both the first target portion and the second target portion. Then, the lightning protection range generating device 100 generates a protection surface that is equidistant from the intersection. This results in a sphere that touches both the first target portion and the second target portion.

[0067] The lightning protection range generating device 100 generates a curve that connects, in the shortest distance, the point where the protection surface and the first target portion meet and the point where the protection surface generated by the third generating unit and the second target portion meet on the protection surface, thereby generating the shape of the lightning protection range.

[0068] In this way, the lightning protection range generating device 100 performs the above-mentioned shape generation process for all target parts, two target parts at a time, thereby generating the shape of the lightning protection range without any omissions, and can generate the shape of the lightning protection range with extremely high accuracy.

[0069] Each of the components of the lightning protection range generating device 100 described above has an internal computer system. A program for realizing the functions of each of the components of the lightning protection range generating device 100 described above may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read into a computer system and executed to perform processing in each of the components of the lightning protection range generating device 100 described above. Here, "reading a program recorded on a recording medium into a computer system and executing it" includes installing the program into a computer system. The "computer system" referred to here includes hardware such as an OS and peripheral devices.

[0070] Furthermore, a "computer system" may include multiple computer devices connected via a network including the Internet, WAN, LAN, dedicated lines, and other communication lines. Furthermore, a "computer-readable recording medium" refers to portable media such as flexible disks, optical magnetic disks, ROMs, and CD-ROMs, and storage devices such as hard disks built into a computer system. In this way, the recording medium storing the program may be a non-transitory recording medium such as a CD-ROM.

[0071] The recording medium also includes a recording medium installed inside or outside and accessible from a distribution server to distribute the program. The program may be divided into a plurality of parts, downloaded at different times, and then combined by each component of the lightning protection range generating device 100, or each divided program may be distributed by a different distribution server. Furthermore, the "computer-readable recording medium" includes a recording medium that holds a program for a certain period of time, such as a volatile memory (RAM) in a computer system that becomes a server or a client when a program is transmitted via a network. The above program may be a recording medium for realizing part of the above-mentioned functions. Furthermore, the recording medium may be a so-called difference file (difference program) that can realize the above-mentioned functions in combination with a program already recorded in the computer system.

[0072] In addition, some or all of the above-mentioned functions may be realized as an integrated circuit such as LSI (Large Scale Integration). Each of the above-mentioned functions may be individually processed, or some or all of the functions may be integrated into a processor. The integrated circuit method is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. In addition, if an integrated circuit technology that can replace LSI appears due to advances in semiconductor technology, an integrated circuit based on that technology may be used. [Explanation of symbols]

[0073] 100 Lightning protection range generator 110 Input section 121 First Target Acquisition Department 122 Second Target Acquisition Department 130 Equidistant surface generator 131 1st generation part 132 Second generation part 133 Third generation part 140 Intersection Derivation 160 Curve generator 170 Lightning protection range shape generation unit

Claims

1. a first generator that generates a first isodistant surface that is equidistant from a first object portion; a second generator that generates a second equidistant surface that is equidistant from the second object portion; a derivation unit that derives an intersection portion where the first isodistant surface generated by the first generation unit and the second isodistant surface generated by the second generation unit intersect; a protection surface generating unit that generates a protection surface that is equidistant from the intersection portion derived by the derivation unit; a curve generating unit that generates a curve that connects, on the protection surface, a point where the protection surface generated by the protection surface generating unit contacts the first target portion and a point where the protection surface generated by the protection surface generating unit contacts the second target portion in the shortest distance; a lightning protection area shape generating unit that generates a shape of a lightning protection area based on the curve generated by the curve generating unit; A lightning protection range generator comprising:

2. The lightning protection range generating device of claim 1, wherein when the first target portion is a lightning receiving portion represented by a single point, the first equidistant surface is a spherical surface centered on the first target portion, and when the second target portion is a lightning receiving portion represented by a single point, the second equidistant surface is a spherical surface centered on the second target portion.

3. A lightning protection range generating device as described in claim 1 or claim 2, wherein when the first target portion is a lightning receiving portion represented by a line segment, the first equidistant surface is a cylindrical surface with the first target portion as its axis, and when the second target portion is a lightning receiving portion represented by a line segment, the second equidistant surface is a cylindrical surface with the second target portion as its axis.

4. A lightning protection range generating device as described in claim 1 or claim 2, wherein when the first target portion is a plane representing the earth, the first equidistant plane is a plane parallel to the first target portion, and when the second target portion is a plane representing the earth, the second equidistant plane is a plane parallel to the second target portion.

5. a third generation unit that generates a third isodistant surface that is equidistant from a third target portion; A lightning protection range generating device as described in any one of claims 1 to 4, wherein the derivation unit derives an intersection portion where a composite isodistant surface obtained by combining the first isodistant surface generated by the first generation unit and the second isodistant surface generated by the second generation unit intersects with the third isodistant surface generated by the third generation unit.

6. A first generation step in which a first generation unit generates a first isodistant surface that is equidistant from a first target portion; a second generation step in which a second generation unit generates a second isodistant surface that is equidistant from a second object portion; a derivation step in which the intersection portion derivation unit derives an intersection portion where the first isodistant surface generated by the first generation step and the second isodistant surface generated by the second generation step intersect; a third generation step in which a protection surface generation unit generates a protection surface that is equidistant from the intersection portion derived in the derivation step; a curve generating step in which a curve generating unit generates a curve that connects, on the protection surface, a point at which the protection surface generated in the third generating step and the first target portion contact with each other and a point at which the protection surface generated in the third generating step and the second target portion contact with each other in the shortest distance; a range generating step in which a lightning protection range shape generating unit generates a shape of a lightning protection range based on the curve generated by the curve generating step; A lightning protection range generating method comprising:

7. On the computer, a first generation step of generating a first isodistant surface that is equidistant from a first object portion; a second generation step of generating a second isodistant surface that is equidistant from the second object portion; a derivation step of deriving an intersection portion where the first isodistant surface generated by the first generation step and the second isodistant surface generated by the second generation step intersect; a third generation step of generating a protection surface that is equidistant from the intersection portion derived in the derivation step; a curve generating step of generating a curve that connects, on the protection surface, a point at which the protection surface generated in the third generating step and the first target portion contact with a point at which the protection surface generated in the third generating step and the second target portion contact with each other in the shortest distance; a range generating step of generating a shape of a lightning protection range using the curve generated by the curve generating step; A program for executing the above.

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