COMPUTER ASSISTED METHOD FOR MANUFACTURING A FOLDABLE PARABOLOID ANTENNA

Abstract

A computer assisted method for manufacturing a foldable paraboloid antenna includes election of a two-dimensional radial Origami pattern with triangular cells and election of a paraboloid surface. The Origami pattern is projected from the paraboloid surface focus onto the paraboloid surface to print the Origami pattern on the paraboloid surface, obtaining triangles with curved sides. A pattern with triangles with straight sides on the paraboloid surface is obtained by joining vertices of the projected curved-sided triangles. The method includes scaling and calculating centroids of the triangles, to reduce each triangle referenced on the corresponding centroid and to determine spacing, obtaining a mesh with segments and triangular cells delimited by the segments. The triangular cells have triangles of reflective rigid material. The mesh is flexible, so each segment width is at least the sum of the thicknesses of two adjacent rigid triangles, and periphery cells have a rounded outer edge.

Claims

1. A computer assisted method for manufacturing a foldable paraboloid antenna, the method comprising the following steps: selecting a two-dimensional radial Origami pattern with triangular cells and selecting a paraboloid surface, projecting the two-dimensional radial Origami pattern with triangular cells from the focus of the paraboloid surface on the paraboloid surface in order to print the Origami pattern on the paraboloid surface, and afterwards triangularizing the paraboloid surface to obtain triangles with curved sides, obtaining a pattern with triangles with straight sides on the paraboloid surface by joining vertices of the projected triangles with curved sides, calculating centroids of the triangles and scaling of the triangles with a homothetic operation from the focus, in order to reduce each triangle taking as a reference a corresponding centroid and determining spacing between triangles, obtaining a mesh with a plurality of segments and a plurality of triangular cells delimited by the segments of the mesh, the segments acting as hinges that enable folding of the triangles, the triangular cells are filled with triangles of a reflective rigid material, the mesh of the antenna is manufactured with a flexible material, such that a width of each segment is at least sum of thicknesses of two adjacent rigid triangles, and the cells on the periphery are manufactured with a rounded outer edge.

2. The computer assisted method for manufacturing a foldable paraboloid antenna, according to claim 1, wherein the two-dimensional radial Origami pattern with triangular cells is divided in a plurality of circular sectors, and the steps of the method are repeated for each sector separately.

3. The computer assisted method for manufacturing a foldable paraboloid antenna, according to claim 1, comprising using a tool for support of the paraboloid antenna while being assembled.

4. The computer assisted method for manufacturing a foldable paraboloid antenna, according to claim 1, wherein the flexible mesh is made of PEEK.

5. The computer assisted method for manufacturing a foldable paraboloid antenna, according to claim 1, wherein the flexible mesh is made of kapton.

6. The computer assisted method for manufacturing a foldable paraboloid antenna, according to claim 1, wherein the flexible mesh is made of a metallized material.

7. The computer assisted method for manufacturing a foldable paraboloid antenna, according to claim 1, wherein the triangles of a reflective rigid material are made of CFRP.

8. The computer assisted method for manufacturing a foldable paraboloid antenna, according to claim 7, wherein the thickness of the triangles made of CFRP is 1 mm.

Description

DESCRIPTION OF FIGURES

[0019] FIG. 1 is a view of a known Origami pattern.

[0020] FIG. 2 is a view of an Origami pattern with triangular cells.

[0021] FIG. 3 is a view of the two-dimensional radial Origami pattern with triangular cells and the paraboloid surface used in an embodiment of the method of invention.

[0022] FIG. 4 is a view of the projection of a circular sector of the Origami pattern of FIG. 2 on the paraboloid surface of FIG. 3.

[0023] FIG. 5 is a detail of the triangularization of the paraboloid surface.

[0024] FIG. 6 is a view of the triangles and their centroids.

[0025] FIG. 7 is a plan view of the pattern for the foldable paraboloid antenna.

[0026] FIG. 8 is a view of one sector of the support tool for the assembly of the foldable paraboloid antenna

[0027] FIG. 9 is a plan view of the assembled foldable paraboloid antenna.

DETAILED DESCRIPTION OF THE INVENTION

[0028] In this description the simplest subdivisions that can be made in an Origami folding pattern will be called a “unitary cell”

[0029] FIG. 1 shows a known Origami pattern being able to fold and unfold radially and comprising unitary cells with four sides. FIG. 2 shows an Origami pattern being able to fold and unfold radially with unitary cells of triangular shape (in this figure it is shown in its unfolded state). Both patterns are able to unfold into a planar circular shape.

[0030] In order to be able to obtain a foldable paraboloid antenna, a computer assisted method is performed, which can use a software such as CATIA.

[0031] A two-dimensional radial Origami pattern with triangular cells (such as the one shown in FIGS. 2 and 3) is chosen, and also a desired geometry is chosen (in this case, a paraboloid surface as a non-planar surface for the antenna, as shown in FIG. 3).

[0032] FIG. 4 shows the projection of the two-dimensional radial Origami pattern with triangular cells from the focus of the paraboloid surface on the paraboloid surface. The projection is generated to print the Origami pattern on the paraboloid surface. After this step, a triangularization of the paraboloid surface is made, obtaining triangles with curved sides.

[0033] The next step consists in transforming the triangles with curved sides into triangles with straight sides. For this purpose, the vertices of the projected triangles with curved sides are selected, and then they are joined to form a pattern with triangular cells with straight sides, as shown in FIG. 5.

[0034] Once defined the pattern, it is necessary to design the hinges that can make the triangles fold. In order to do that, the centroids of the triangles are calculated to make a progressive scaling of each triangle with a homothetic operation from the focus (see FIG. 6)

[0035] Once each triangle has been reduced locally taking as a reference the centroid (which avoids the displacement of the corresponding triangle), we can obtain a surface with a parametrized spacing between triangles. A mesh with a plurality of segments and a plurality of triangular cells delimited by the segments of the mesh is obtained by computer, as shown in FIG. 7.

[0036] It is important to take into account that the above process can be made by circular sectors, i.e., the two-dimensional radial Origami pattern with triangular cells can be divided in several circular sectors (for instance, 12 circular sectors), and the steps of the method are repeated for each sector separately (for instance, FIG. 4 shows the projection of a circular sector of the two-dimensional radial Origami pattern).

[0037] Afterwards the antenna is assembled (see FIG. 9). The triangular cells are filled with triangles of a reflective rigid material, and the mesh with segments is manufactured with a flexible material. As the periphery of the paraboloid surface is rounded, the cells on the periphery are manufactured with a rounded outer edge.

[0038] In order to avoid the contact between two adjacent triangles when the antenna is folded, the width of each segment of the mesh is at least the sum of the thicknesses of the two adjacent rigid triangles.

[0039] A tool for support of the paraboloid antenna while being assembled can be used. This tool can be divided in circular sectors, as shown in FIG. 8.

[0040] The mesh of the paraboloid antenna (shown in FIG. 9) has to be made in a flexible material. For example, it can be made of PEEK or Kapton, or a metallized material.

[0041] The triangles have to be made in a reflective rigid material (for example, CFRP). In an embodiment, the CFRP used has a thickness of 1 mm, so in that case the distance between adjacent triangles is at least 2 mm, to avoid the contact or overlapping between the adjacent triangles when the antenna is folded.

[0042] Once the foldable paraboloid antenna has been manufactured, it is placed on the tensegrity structure and is joined to it through pins. Accordingly, the foldable paraboloid antenna is held by a tensegrity structure being able to fold radially. When unfolded, a triangularization of a non-flat structure (a paraboloid) is obtained.

[0043] Although the present invention has been fully described in connection with preferred embodiments, it is apparent that modifications can be made within the scope, not considering this as limited by these embodiments, but by the content of the following claims.

NUMBER REFERENCES

[0044] 1—Foldable paraboloid antenna [0045] 2—Two-dimensional radial Origami pattern [0046] 3—Paraboloid surface [0047] 4—Focus [0048] 5—Vertices [0049] 6—Triangles [0050] 7—Centroids [0051] 8—Mesh [0052] 9—Segment [0053] 10—Triangular cells [0054] 11—Triangles of a reflective rigid material [0055] 12—Cells on the periphery [0056] 13—Tool