KR101953985B1 - Method for designing porous structure automatically - Google Patents

Abstract

A method for automatically designing a porous structure is a method for automatically designing a porous structure to be performed in a designing apparatus for generating a three-dimensional printing model, comprising: generating a transparent three-dimensional object model by receiving numerical values of a three- Generating a mesh of polygons on the target surface of the polygon, automatically creating a cylinder or prism along the edge of the polygon, and connecting the cylinder or prism to each other to produce an integrated three-dimensional printing model.

Description

[0001] METHOD FOR DESIGNING POROUS STRUCTURE AUTOMATICALLY [0002]

The present invention relates to a method of generating a three-dimensional model that can be output from a three-dimensional printer, and more particularly, to a method of automatically designing a porous structure to automatically and rapidly generate a porous structure.

BACKGROUND ART [0002] In recent years, demand for three-dimensional printing or three-dimensional printing has been rapidly increasing due to the development of related technologies as a manufacturing technique of forming a three-dimensional object by forming and laminating a two-dimensional cross section by various methods. Also, the 3D printer refers to a device for generating a 3D three dimensional output from a 3D mesh model implemented on a computer.

Such a three-dimensional printing technique can be used to manufacture various products, and it is possible to produce complex shapes that are difficult to manufacture by conventional processes. Among these products, 3D printing techniques can be used to make porous structures, porous structures include apertured electronics and porous casts used to treat fractures.

Although a three-dimensional model model generation technique (see Korean Patent No. 10-1676576) to be applied to conventional three-dimensional printing is used, it is not a method used for manufacturing a porous structure, and a conventional porous structure creation The method is a method of generating a hole in a planar shape, and there is a limitation that it is not a method of forming a hole in a three-dimensional object, and there is a limitation that only a regular shape hole can be generated. There is a problem that it takes time and effort.

In order to solve such a problem, there is a need for an automatic design method of a porous structure capable of automatically forming holes on a three-dimensional curved surface and adjusting the arrangement, distribution density, and position of holes to be formed.

A problem to be solved by the present invention is to provide an automatic design method of a porous structure capable of automatically and easily forming holes in a three-dimensional curved surface as well as a planar shape, and also capable of adjusting the arrangement, distribution density and position of holes to be formed I have to.

The problems to be solved by the present invention are not limited to the above-mentioned problems, and other matters not mentioned can be clearly understood by those skilled in the art from the following description.

According to another aspect of the present invention, there is provided a method for automatically designing a porous structure in a design apparatus for generating a three-dimensional printing model, Creating a three-dimensional target model, creating a polygonal mesh on the virtual target surface defined by the numerical value, automatically generating a cylinder or prism along the edge of the polygon, and connecting the cylinder or prism And generating an integrated three-dimensional printing model.

According to another aspect of the present invention, there is provided a method for automatically designing a porous structure in a design apparatus for generating a three-dimensional printing model, Creating a mesh of polygons on the target surface of the feature, automatically creating a column or prism in the vertical direction at the vertex or center of the polygon, And forming a hole on the target surface through a Boolean operation to generate a three-dimensional printing model.

According to the present invention, it is possible to provide a method of automatically designing a porous structure capable of easily forming holes in a three-dimensional object and adjusting the arrangement, distribution density, and position of holes to be formed.

1 is a block diagram of an apparatus for automatically designing a porous structure according to an embodiment of the present invention.
2 is a flowchart of a method for automatically designing a porous structure according to an embodiment of the present invention.
FIGS. 3 to 5 are diagrams illustrating respective steps of a method for automatically designing a porous structure according to an embodiment of the present invention.
FIG. 6 is a view illustrating a method of determining the diameter of a cylindrical body along the corners of the mesh in the method for automatically designing a porous structure according to the present invention.
7 is a flowchart of a method for automatically designing a porous structure according to another embodiment of the present invention.
FIGS. 8 and 9 are diagrams illustrating respective steps of a method for automatically designing a porous structure according to another embodiment of the present invention.
10 is a view illustrating a method of determining a direction perpendicular to a mesh structure in the method for automatically designing a porous structure according to the present invention.
11 and 12 are views showing a modification of the automatic method for designing a porous structure according to another embodiment of the present invention.
13 is a view showing a method of determining the hole diameter generated perpendicularly to the mesh structure in the method for automatically designing a porous structure according to the present invention.
14 to 16 are views showing a modification of the automatic method for designing a porous structure according to another embodiment of the present invention.
17 is a view showing a modification of the automatic method for designing a porous structure according to another embodiment of the present invention.
18 to 20 are views showing a modification of the automatic method for designing a porous structure according to another embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The advantages and features of the present invention and the manner of achieving them will become apparent with reference to the embodiments described in detail below with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout the specification.

The terminology used herein is for the purpose of illustrating embodiments and is not intended to be limiting of the present invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. It is noted that the terms " comprises " and / or " comprising ", as used herein, do not exclude the presence or addition of one or more other elements, steps and operations.

Referring to FIG. 1, an apparatus for automatically designing a porous structure according to an embodiment of the present invention will be described. 1 is a block diagram of an apparatus for automatically designing a porous structure according to an embodiment of the present invention.

1, an apparatus for automatically designing a porous structure 100 according to an embodiment of the present invention includes a porous structure automatic designing apparatus 100 (FIG. 1) equipped with a design software (program) for generating a three- And includes a shape input module 110, a mesh generation module 120, and a porous structure generation module 130.

The shape input module 110 receives a numerical value or a shape of a three-dimensional object and generates a three-dimensional object model 10. The user can acquire the numerical value and shape of the three-dimensional object to be subjected to three-dimensional printing through a three-dimensional scanner or the like, and the obtained numerical value and shape information can be transmitted to the shape input module 110. Or information of the numerical value and shape of the three-dimensional object created without using a three-dimensional scanner or the like can be transmitted to the shape input module 110. [

On the other hand, when a numerical value of a three-dimensional object is input, a transparent shape of a virtual three-dimensional object model 10 defined by a numerical value appears on the operator's screen. In this transparent shape, have. On the contrary, when the shape of the three-dimensional object is input, the shape of the three-dimensional object model 10 in which the surface exists may be displayed on the screen of the operator (see FIG. 3).

Here, the three-dimensional object of the three-dimensional object model 10 is not limited to any kind, and can be any product or object. Particularly, the present invention can be applied to an article having a hole on its surface, A three-dimensional object can be a case where a porous structure is applied to an electronic product in which a hole is formed on the surface thereof or a cast (cast) used for fracture treatment for the purpose of improving the breathability.

The mesh generation module 120 is a module for generating a polygonal mesh 20 on a virtual target surface defined by the numerical value of the three-dimensional target model 10 or a target surface of the shape of the three-dimensional target model 10. That is, the 3D object model 10 may be configured as a 3-dimensional mesh model through the mesh generation module 120 (see FIG. 3).

The 3D mesh model is one of various methods for describing a three-dimensional object, and the surface of the 3D object model is formed into a plurality of polygonal shapes. The three-dimensional mesh model includes coordinates of a vertex constituting each polygon and an edge which is a connecting line segment between vertices. The coordinate of the vertex describes the position of the vertex in the three-dimensional space, and the vertex-to-vertex connection information indicates the connection relationship between the vertices. These two factors combine to form a 3D mesh model.

Generally, a three-dimensional mesh model is a triangular mesh 20 used as a basic unit constituting the surface of a model in a triangular shape. However, the triangular mesh 20 is not necessarily limited to the triangular mesh 20, Available.

The mesh generation module 120 generates the mesh 20 on the target surface of the 3D target model 10. When the triangle mesh 20 is applied, a plurality of triangles The mesh 20 can be generated. Or a plurality of triangular meshes 20 can be created on the target surface of the shape of the three-dimensional target model 10.

On the other hand, the mesh 20 may be formed on a part of the target surface, not all of it, and the size of the hole formed by each mesh 20 and the distribution density of the mesh 20 on the target surface may be adjusted. We will discuss this in more detail later.

The porous structure generation module 130 is a module for generating a final three-dimensional printing model in which a porous structure is formed on a target surface. Specifically, when a numerical value of a three-dimensional object is input and a transparent shape of a virtual three-dimensional object model 10 defined by a numerical value is used, a plurality of polygonal meshes 20 are formed in a transparent shape, The printer 130 may automatically generate a cylinder 30 or prism along the edge of the polygon and connect the generated cylinders 30 to one another to produce an integrated three dimensional printing model 50 Reference).

Alternatively, when the shape of the three-dimensional object is input and the shape of the actual three-dimensional object model 10 having the surface is used, a plurality of polygonal meshes 20 are formed on the shape surface, (60) or prism (60) perpendicular to a virtual plane including a corresponding vertex or center point at a vertex or center point of the polygon (which may be the center of gravity) A plurality of holes 70 may be formed on the target surface through a Boolean operation with the target surface (i. E., A curved surface or plane that includes the vertex or center point) to produce a three-dimensional printing model 80 Reference).

As described above, the apparatus for automatically designing a porous structure 100 according to the present invention can be applied to any three-dimensional model beyond the automatic design of a regular shape in a two-dimensional to a 2.5-dimensional shape range within the same plane or the same radius of rotation And it is also possible to form irregular holes in the formation of the holes and to control the distribution density of the holes.

Particularly, when a hole is formed on a curved surface of a cast (cast) used for treatment of fracture for ventilation, conventionally, a hole position is selected, a sketch surface contacting the curved surface based on the hole position is created, And a hole is formed in the curved surface while performing a boolean operation. Therefore, much time and effort were required. However, in the case of the present invention, by applying a polygonal mesh model and automatically generating a cylinder at the vertex of the polygon and applying a Boolean operation, holes can be formed on the curved surface with a very short time and little effort. Actually, it takes 5 hours or more to use a conventional method for forming a hole in a cast, but 5 minutes is enough to apply the present invention.

The apparatus for automatically designing a porous structure 100 according to an embodiment of the present invention has been described, and a method for automatically designing a porous structure according to the present invention will be described below.

A method of automatically designing a porous structure according to an embodiment of the present invention will be described with reference to FIGS. 2 is a flowchart of a method for automatically designing a porous structure according to an embodiment of the present invention. FIGS. 3 to 5 are diagrams illustrating respective steps of a method for automatically designing a porous structure according to an embodiment of the present invention. FIG. 6 is a view illustrating a method of determining the diameter of a cylindrical body along the corners of the mesh in the method for automatically designing a porous structure according to the present invention.

The automatic method of designing a porous structure according to an embodiment of the present invention can be applied when a numerical value of a three-dimensional object is input and a transparent shape of a virtual three-dimensional object model 10 defined by a numerical value is used.

2, a method for automatically designing a porous structure according to an embodiment of the present invention is a method for automatically designing a porous structure performed in a designing apparatus for generating a three-dimensional printing model, Generating a transparent three-dimensional target model (S10), generating a polygonal mesh on the virtual target surface defined by the numerical value (S20), automatically generating a cylinder or prism along the edge of the polygon (S30), and creating a three-dimensional printing model (S40) by connecting the cylinders or prisms together to form an integrated three-dimensional printing model.

In the step S10 of generating a transparent three-dimensional object model by receiving the numerical values of the three-dimensional object, the shape input module 110 receives the numerical values of the three-dimensional object acquired through the three-dimensional scanner, You can enter a known value. The transparent three-dimensional object model 10 can be generated through the inputted numerical information.

The step S20 of creating a polygonal mesh on a virtual target surface defined by a numerical value is performed by generating a transparent three-dimensional object model 10 defined by numerical values through input numerical information, Creates a mesh 20 on the target surface of the three-dimensional target model 10. When a triangle mesh 20 is applied, a plurality of triangle meshes 20 are created on a virtual target surface defined by a numerical value .

In step S30 of automatically creating a cylinder or prism along a corner of the polygon, the porous structure generation module 130 automatically creates a cylinder 30 or prism along the corners of the triangle along each corner .

6, a method of determining the diameter of the cylinder 30 when the cylinder 30 is automatically generated along the edge of the polygon will be described. 6A shows six neighboring meshes (or elements) (n ₁ , n ₂ , ..., n ₆ ) sharing one vertex (or node) P. FIG. Any of the elements of these plurality of elements (n _i) which is shown in 6 (b) also, after made the repair in each corner of the polygon from the center of gravity (G) of the polygonal element (n _i) of each waterline length (Vertical length) are referred to as C ₁ , C ₂ , and C ₃ . In this case, the radius of the cylinder that is 6, as shown in (c), generated according to a polygonal element, each edge _{(P 1 P 2, P 2} P 3, P 3 P 1) of the (n _i) (r _i) Can be expressed by the following equation.

- r _i < min (C ₁ , C ₂ , C ₃ )

In addition, when the above method is extended to the entire mesh (n ₁ , ..., n _i , ..., n _e elements), the diameter (D ^* ) of the cylinder formed along the edge of the polygon is expressed by the following equation . &Lt; / RTI &gt;

- w _min <D ^* < _{2 min} (r ₁ , r ₂ , ..., r _e ) (where w _{min is the} minimum line width that can be output from the three-

The method of determining the diameter of the cylinder 30 when the cylinder 30 is automatically generated along the edge of the polygon has been described above. This method is also applicable to a method for determining the cross-sectional dimension of a prism Can be similarly applied.

The step (S40) of generating the integrated three-dimensional printing model by connecting the cylinders or the prisms is performed by connecting the cylinders 30 generated through the porous structure generation module 130 after the cylinders 30 are automatically generated An integrated three-dimensional printing model 50 can be generated. On the other hand, since the cylinder 30 is located on the transparent model, the hole 40 can be formed automatically at the portion surrounded by the cylinder.

3, 7, 8, and 9, a method for automatically designing a porous structure according to another embodiment of the present invention will be described. 7 is a flowchart of a method for automatically designing a porous structure according to another embodiment of the present invention. FIGS. 8 and 9 are diagrams illustrating respective steps of a method for automatically designing a porous structure according to another embodiment of the present invention.

The method of automatically designing a porous structure according to another embodiment of the present invention can be applied to a case where a shape of a three-dimensional object is inputted and a three-dimensional object model 10 having a surface is used.

7, a method for automatically designing a porous structure according to another embodiment of the present invention is a method for automatically designing a porous structure performed in a designing apparatus for generating a three-dimensional printing model, A step S60 of generating a three-dimensional target model by receiving a polygon mesh on the target surface of the shape, a step of automatically generating a cylinder or a prism in a vertical direction at the vertex or center point of the polygon, S70), and creating a three-dimensional printing model (S80) by forming a hole on the target surface through a boolean operation between the cylinder or the prism and the target surface.

In the step S50 of inputting the shape of the three-dimensional object and generating the three-dimensional object model, the shape input module 110 receives the shape of the three-dimensional object acquired through the three-dimensional scanner, The shape can be input. The three-dimensional target model 10 can be generated through the input information.

The mesh generation module 120 generates a mesh of the polygon on the target surface of the 3D object model 10 by generating the 3D object model 10 through the inputted information A mesh 20 is created on the target surface where a plurality of triangular meshes 20 can be created on the target surface of the three dimensional object model 10 when the triangle mesh 20 is applied.

In step S70, the porous structure generation module 130 automatically generates vertices or prisms in the vertical direction at the vertex or center of the polygon, vertically or vertically to the vertex or center point of the polygon, A cylinder (60) or a prism can be automatically generated.

10, a method of determining the vertical direction when the cylinder 60 or the prism is automatically generated perpendicular to the vertex or center point of the polygon will be described. First, the case of determining the vertical direction, a normal vector relative to the center point of the triangular elements (n _i), the normal vector (vector Normal) and unit vectors (Normalized normal vector) can be expressed as follows.

(여기서,

,

)- Normal vector:

(here,

,

)

- Unit vector:

를 구한 후, 아래 수식을 사용하여 꼭지점의 평균 법선 벡터를 계산한다(

: i번째 삼각형 요소의 면적).Next, when a normal vector is determined based on the vertex (node) of the triangular element n _i , which is not the center point (see FIG. 6A), all the elements including the vertex P (elements of n ₁ , ..., n _i , ..., n _e ) with respect to the center point of each element,

, The average normal vector of the vertices is calculated using the following equation (

: the area of the ith triangle element).

-

As described above, a method of determining the vertical direction when automatically generating the cylinder 60 or the prism perpendicular to the vertex or center point of the polygon has been described.

In the step S80 of forming a three-dimensional printing model by forming holes on the surface of the target through a boolean operation between the cylinder or prism and the target surface, the porous structure generation module 130, after automatically generating the cylinder 60, A three-dimensional printing model 80 can be created by forming a plurality of holes on the target surface through a boolean operation between the generated cylinder 60 and a target surface (i.e., a curved surface or a plane including the corresponding vertex).

11 to 13, a modification of the automatic method for designing a porous structure according to another embodiment of the present invention will be described. 11 and 12 are views showing a modification of the automatic method for designing a porous structure according to another embodiment of the present invention. 13 is a view showing a method of determining the hole diameter generated perpendicularly to the mesh structure in the method for automatically designing a porous structure according to the present invention.

In this modification, the density of the mesh 20 formed on the specific surface on the target surface of the three-dimensional object model 10 is higher than the density of the mesh 20 formed on the other surface. In this case, the number of holes generated through the mesh 20 is larger than that of the other portions, and the size of the holes may be different from the holes of other portions (see FIGS. 11A and 12B).

That is, in the case of the present invention, the distribution density of the mesh 20 can be adjusted, thereby adjusting the hole number density and hole size on the target surface. In this regard, referring to FIG. 13, a method of determining the diameter of the hole in the porous structure will be described. 13 (a) shows a case where there is no interference between adjacent holes due to a proper size of the hole, Fig. 13 (b) shows a case where the hole is too large and interference occurs between neighboring holes, It is too small and the gap between neighboring holes is too wide.

First, in order to determine the initial hole diameter, a minimum distance L _i between a vertex (node) and a vertex neighboring the vertex is calculated. Considering that the radius R _i of the hole should be less than 1/2 of the minimum distance between vertexes in order to avoid interference between holes, the initial hole diameter (D ^* ) is determined as follows (that is, the mean concept of the minimum distance between nodes) .

-

Next, as shown in Figs. 13 (b) and 13 (c), if the holes are too large to cause superposition between holes, and conversely if the holes are too small to reduce the aeration effect of the porous structure, And can be adjusted locally.

-

- if the hole is large (ie, the mesh is small):

- Small holes (ie large mesh):

Due to these characteristics, various types of porous structures can be manufactured by adjusting the number and size of holes on the target surface for various reasons including aeration.

14 to 16, a modification of the method for automatically designing a porous structure according to another embodiment of the present invention will be described. 14 to 16 are views showing a modification of the automatic method for designing a porous structure according to another embodiment of the present invention.

In the case of this modification, the mesh 20 is formed only on a part of the target surface, not all of the target surface, so that the hole is formed only on a part of the three-dimensional printing model. For example, as shown in the figure, in the case of an ankle cast, a mesh 20 is not formed on a part of a target surface in order to maintain the strength and rigidity of the cast. As a result, a vent is formed in a portion where the mesh 20 is not formed (See FIG. 16C).

That is, according to the present modification, the durability of the porous structure can be maintained and the service life of the product can be increased. Further, the automatic design can be easily performed by forming the ventilation holes only at desired portions.

A modification of the porous structure automatic designing method according to another embodiment of the present invention will be described with reference to FIG. 17 is a view showing a modification of the automatic method for designing a porous structure according to another embodiment of the present invention.

This modification may create a reinforcing structure 90 (e.g., reinforcing rib) around the hole to prevent strength and stiffness degradation around the hole formed in the porous structure (see Fig. 17D). Such a reinforcing structure 90 can be automatically formed around the hole at the same time as the hole is generated in the process of generating the three-dimensional printing model.

On the other hand, the reinforcing structure 90 may be a protruding structure in which protrusions are formed in both directions or one direction while maintaining a certain thickness based on the perimeter of the holes formed in the porous structure, but the present invention is not limited thereto.

A modified example of the method for automatically designing the porous structure will be described with reference to FIGS. 18 to 20. FIG. 18 to 20 are views showing a modification of the automatic method for designing a porous structure according to another embodiment of the present invention.

Figs. 18 to 20 show holes formed in part or all of the rear surface of the cellular phone case to improve air permeability and appearance aesthetics. 18, when generating a three-dimensional printing model of the cellular phone case, the triangle mesh 20 is formed on the rear surface of the case, but the density of the mesh 20 around the hole of the camera is set high to compensate for the decrease in strength See E of FIG.

19 and 20 are to form holes only in a specific rear part of the cellular phone case (for example, a logo part), in order to create meshes 20 only at a specific rear part thereof, A hole may be formed only in a specific portion (see F in Fig. 19 and H in Fig. 20). Particularly, in the case of FIG. 19, the method of FIG. 2 in which a circular cylinder or a prism is automatically formed along the edge of the polygon to form a hole is applied. In the case of FIG. 20, a vertex or a prism The method of FIG. 7 is applied to automatically generate and form holes.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, You will understand. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

10: 3D Target Model 20: Mesh
30, 60: cylinder 40, 70: hole
50, 80: Three-dimensional printing model 90: Reinforced structure
100: automatic design apparatus for porous structure 110: shape input module
120: Mesh Generation Module 130: Porous Structure Generation Module

Claims (5)

A method for automatically designing a porous structure in a design apparatus for generating a three-dimensional printing model of a thin structure,
Selecting a surface on which a mesh is to be generated by receiving a numerical value of a three-dimensional object;
Generating a mesh having a plurality of polygons on the selected virtual target surface;
Automatically generating a plurality of cylinders along all corners that are connecting line segments between respective vertexes of the plurality of polygons; And
Dimensional printing model having a plurality of polygonal holes passing through the thin structure by connecting the plurality of cylinders to each other,
The step of automatically generating a plurality of cylinders along all corners, which are connecting line segments between respective vertexes of the plurality of polygons,
Determining the radii of the cylinders to a value less than the smallest of all the lengths of the waterline from each center of gravity of the polygon to each corner; And
Determining a diameter of a cylinder formed along an edge of the polygon to be a value smaller than a minimum line width that can be output from a three-dimensional printer and smaller than a value obtained by multiplying a smallest value among the radiuses of the determined cylinder by 2; Automatic structure design method.
A method for automatically designing a porous structure in a design apparatus for generating a three-dimensional printing model of a thin structure,
Selecting a surface on which a mesh is to be generated by receiving a shape of a three-dimensional object;
Creating a mesh of a plurality of polygons on a target surface of the selected shape;
Automatically generating a plurality of cylinders protruding in a vertical direction from all the vertices constituting the plurality of polygons; And
Dimensional printing model having a plurality of cylindrical holes passing through the thin structure by forming holes corresponding to the plurality of cylinders on the target surface through a boolean operation between the plurality of protruding cylinders and the target surface, Comprising:
Wherein the step of automatically generating a plurality of cylinders protruding in a vertical direction from all the vertexes forming the plurality of polygons comprises:
Automatic structure design for calculating the minimum distance between any one vertex and the vertex adjacent to the vertex to determine the initial hole diameter and determining the average value of the minimum distance as the initial hole diameter of the cylinder based on the vertex Way.
3. The method according to any one of claims 1 to 3,
The method comprising the step of adjusting at least one of the number, density and size of the holes to be formed or the distribution density of the mesh when the mesh formed on the target surface of the three-dimensional target model is higher than the density of the mesh formed on the other surface. Design method.
3. The method according to any one of claims 1 to 3,
Wherein the mesh is formed on a portion of the target surface and no porous structure is formed in a portion where no mesh is formed.
3. The method of claim 2,
Further comprising the step of creating a reinforcing structure having a protruding structure in which protrusions are formed in both directions or in one direction while maintaining a predetermined thickness around the perforations formed in the porous structure around the perforations.

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