WO2015019428A1

WO2015019428A1 - Analysis data transmission/reception system and saving system

Info

Publication number: WO2015019428A1
Application number: PCT/JP2013/071306
Authority: WO
Inventors: 子賢張; 一朗片岡; 昌幸針谷; 益祥馮
Original assignee: 株式会社日立製作所
Priority date: 2013-08-07
Filing date: 2013-08-07
Publication date: 2015-02-12
Also published as: JPWO2015019428A1

Abstract

Provided is an analysis data saving and transmission/reception system capable of three-dimensional mesh compression and restoration of tetrahedral, hexahedral, triangular, and quadrilateral meshes. A conventional low-complexity three-dimensional mesh compression device and method using shared vertices information can be applied in the compression of triangular meshes, but there is a problem in that they are not compatible with compression of a tetrahedral mesh. Furthermore, although the size of the analysis data can be reduced with a multiresolution tetrahedral mesh generation method, there is a problem in that the analysis data cannot be restored. This analysis data transmission/reception system is characterized in that a mesh group having shared vertices (a spherical pattern) is extracted from analysis data, and is expressed with a boundary mesh (a boundary shell mesh) and a center point, thereby eliminating duplicate data expressions and compressing data. When compression is performed only duplicate data expressions are eliminated, so the analysis data existing before the compression can be restored.

Description

Analysis data transmission / reception system and storage system

The present invention relates to a transmission / reception system that transmits or receives analysis data, and a storage system that performs storage.

In recent years, analysis data compression technology including mesh data has advanced. With respect to this analysis data compression technique, for example, Patent Document 1 is characterized in that the complexity of data compression for a triangular mesh model is improved and the compression ratio is improved by simplifying the notation of shared vertex information.

Further, Patent Document 2 discloses a method of generating a tetrahedral mesh for finite element analysis by performing a simplification process that reduces the number of meshes of a solid model mesh. It has become.

Special table 2011-528452 JP2006-72531

Although the low-complexity three-dimensional mesh compression apparatus and method using shared vertex information described in Patent Document 1 can be applied to compression of a triangular mesh, there is a problem that it cannot cope with compression of a tetrahedral mesh. Moreover, although the size of analysis data can be reduced by the multiresolution tetrahedral mesh generation method described in Patent Document 2, it is difficult to restore the analysis data to the original state.

In response to these problems, the present invention can deal with tetrahedron, hexahedron, triangle, and quadrilateral mesh, and can perform mesh compression and restoration capable of restoring the same mesh as before compression at the time of restoration. Provide a preservation system.

To achieve the above object, the present invention provides an analysis data transmission / reception system in which an analysis data reading unit for reading analysis data, an analysis data display unit for displaying the read analysis data, and a sharing from the read analysis data An extraction unit that extracts a boundary mesh of a mesh group having vertices, a boundary mesh display unit that displays a boundary mesh extracted by the extraction unit, a boundary mesh compression unit that compresses the extracted boundary mesh, and the boundary mesh compression An analysis data transmitting unit for transmitting the analysis data compressed by the unit, an analysis data restoring unit for restoring the transmitted analysis data, and a network for transferring the transmitted analysis data to the receiving unit. It is a feature.

Further, the present invention is characterized in that in the analysis data transmission / reception system, a boundary mesh of a mesh group having a shared vertex is extracted from the analysis data.

Furthermore, in the analysis data transmission / reception system, the present invention is characterized in that the size of a transfer file is reduced by deleting a mesh that can be restored by a rule and transferring only the mesh that cannot be restored.

Furthermore, the present invention is characterized in that in the analysis data transmission / reception system, the mesh data size is reduced by changing the mesh data format.

Further, the present invention is characterized in that, in the analysis data transmission / reception system, the analysis data compressed by the rule is combined with the received analysis data to restore the compressed analysis data.

To achieve the above object, the present invention provides an analysis data storage system, an analysis data reading unit for reading analysis data, an analysis data display unit for displaying the read analysis data, and the read analysis data. An extraction unit that extracts a boundary mesh of a mesh group having a shared vertex from the boundary, a boundary mesh display unit that displays the boundary mesh extracted by the extraction unit, a boundary mesh compression unit that compresses the extracted boundary mesh, and the boundary An analysis data storage unit for storing analysis data compressed by the mesh compression unit is provided.

Further, the present invention is characterized in that in the analysis data storage system, a boundary mesh of a mesh group having a shared vertex is extracted from the analysis data.

Furthermore, the present invention is characterized in that in the analysis data storage system, the size of the transfer file is reduced by deleting the mesh that can be restored by the rule and transferring only the mesh that cannot be restored.

Furthermore, the present invention is characterized in that in the analysis data storage system, the mesh data size is reduced by changing the mesh data format.

In response to the above problem, according to the present invention, by extracting a mesh group (spherical pattern) having a shared vertex from analysis data and expressing it with a boundary mesh (boundary shell mesh) and a central point, duplication of data description The problem is solved by a storage and transmission / reception system for analysis data characterized by deleting and compressing the analysis data. At the time of compression, only duplicate data descriptions are deleted, so that the same analysis data as before compression is restored.

According to the present invention, it is possible to provide an analysis data storage and transmission / reception system that enables mesh compression and decompression that can handle tetrahedral, hexahedral, triangular, and quadrilateral meshes.

It is an example regarding the compression / decompression apparatus block diagram of the Example of this invention. It is an example regarding the detail of the compression / decompression apparatus block diagram of the Example of this invention. It is an example regarding the spherical mesh and boundary mesh of the Example of this invention. It is an example regarding the spherical mesh extraction part flowchart of this invention Example. It is an example regarding the data format conversion method of the boundary mesh of the embodiment of the present invention. It is an example regarding the boundary mesh data format conversion method flowchart of an Example of this invention. It is an example regarding the boundary mesh compression by the rule of the Example of this invention. It is an example regarding the boundary mesh compression flowchart by the rule of this invention Example. It is an example of the figure regarding the data display part of the Example of this invention. It is an example regarding the boundary mesh compression by the rule of the Example of this invention. It is an example regarding the boundary mesh compression part by the data format conversion of an Example of this invention.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of a system configuration according to an embodiment of the present invention. A compression device 103 including an analysis data storage unit 101 and a data compression unit 102, and a restoration device 105 including a data restoration unit 104 and an analysis data storage unit 106 are provided. The analysis data stored in the analysis data storage unit 101 is input data. The data compression unit 102 reads the analysis data from the analysis data storage unit, reduces the data size by the data compression unit 102, and transmits it to the network 106 such as the Internet. The restoration device 105 receives analysis data compressed by the data compression unit from the network 106 such as the Internet, restores the analysis data by the data restoration unit 104, and registers the analysis data in the analysis data storage unit 106.

FIG. 2 shows details of the compression / decompression apparatus configuration shown in FIG.

The compression device 103 includes an analysis data storage unit 201, an analysis data reading unit 202, an analysis data display unit 203, a spherical mesh extraction unit 204, a boundary mesh extraction unit 205, a boundary mesh display unit 206, and a data format conversion A boundary mesh compression unit 207 according to the above, a boundary mesh compression 208 based on a rule, a compression rate display unit 209, and a data storage unit 210 are included. Here, in order to confirm the compression process, the analysis data display unit 203, the boundary mesh display unit 206, and the compression rate display unit 209 are included, but these are not essential components in the compression process. It is good also as a structure remove | excluding.

The restoration device 105 includes a restoration unit 213 by data format conversion, a restoration unit 212 by rules, and an analysis data storage unit 214.

Hereinafter, the details of each processing unit will be described by taking compression of tetrahedral mesh data as an example.
1. About the compression device 103
(1) Analysis data reading unit 202, analysis data display unit 203
The analysis data reading unit 202 receives the tetrahedral mesh data stored in the analysis data storage unit 201 as input. The vertex information and tetrahedron information of the analysis mesh data are read and stored in two lists of the tetrahedron list for storing the vertex list and the vertex connection information. The format of the vertex list is as follows. x, y, and z are the coordinates of the vertex, and are in a “double float” format in C language.
x1 y1 z1
......
xn yn zn

The format of the tetrahedron list is as follows, and the ID is the vertex ID, which is an integer format.
ID11 ID12 ID13 ID14: 1st line ID21 ID22 ID23 ID24: 2nd line ......
IDn1 IDn2 IDn3 IDn4: nth line

10 shows details of an operation screen related to the analysis data reading unit in FIG. The operation screen consists of buttons for data reading, spherical pattern extraction, boundary mesh extraction, compression by rules, compression in a new format, and data storage. In accordance with the user's data reading button 901 selection, the “Open file” screen is displayed. As the user selects mesh data on the “file open” screen, the analysis data display unit 203 displays the analysis mesh data on the display screen 902.
(2) Spherical mesh extraction unit 204
A spherical mesh is a group of meshes having shared vertices, and since its shape is generally similar to a sphere, it is defined as a spherical mesh. FIG. 3 shows an example of a spherical mesh, which corresponds to all tetrahedron groups 301 including the vertex IDo. The spherical mesh extraction unit uses the analysis data read from the analysis data reading unit as input data.

In this embodiment, a process for extracting a spherical mesh from a tetrahedral mesh will be described with reference to a spherical mesh extraction unit flowchart shown in FIG.

(Step 401: hereinafter referred to as S401) In “select first vertex from vertex list”, the vertex having the smallest ID number in the vertex list is selected.

In (S402) “Is it a boundary vertex?”, It is determined whether or not the vertex is a boundary vertex of tetrahedral mesh data. The boundary vertex is a vertex belonging to the boundary mesh. The boundary mesh is a surface triangle belonging to only one tetrahedron among the surface triangles constituting the tetrahedral mesh.

(S403) In “whether the tetrahedron including this vertex has been extracted as a spherical mesh”, it is determined whether the extraction has been performed with reference to a mark list having the same length as the tetrahedron list created in advance. The mark list is initialized without being extracted at first, and when the tetrahedron is extracted as a spherical mesh, the extracted mark is assigned to the list position corresponding to the tetrahedron. In this way, it can be easily determined whether it has been extracted or not extracted.

(S404) “Extract tetrahedron including this vertex as a spherical mesh” expresses the extracted spherical mesh in the following format. ID11 to IDn3 indicate vertices, and IDo is the ID of the shared vertex. Therefore, all tetrahedrons belonging to this spherical mesh group include IDo.
ID11 ID12 ID13 IDo
ID21 ID22 ID23 IDo
......
IDn1 IDn2 IDn3 IDo

The output data is all the extracted spherical meshes. A tetrahedron that has not been extracted as a spherical mesh is listed at the end of the list of extracted tetrahedron groups.

The format is as follows.
ID11 ID12 ID13 IDo1
......
IDm1 IDm2 IDm3 IDo1
A spherical mesh including the shared vertex IDo1 is described from shared vertex IDo1 to IDm1. Subsequently, a spherical mesh including the shared vertex IDo2 is described.
IDn1 IDn2 IDn3 IDo2
......
IDp1 IDp2 IDp3 IDo2
All the spherical meshes extracted in this way are described.
After this, the tetrahedral mesh that was not extracted is described.
IDq1 IDq2 IDq3 IDq4
......

In (S405) “Select next vertex in vertex list”, the vertex immediately after the processed vertex is selected in the vertex list.

In (S406) “Last vertex”, it is determined whether it is the last vertex in the vertex list.

With this process, one or more spherical meshes are extracted from the input analysis data.
(3) Boundary mesh extraction unit 205, boundary mesh display unit 206
The triangular boundary mesh of the spherical mesh group extracted by the spherical mesh extraction unit is called a boundary mesh.

The input data of the boundary mesh extraction unit is mesh data of the spherical mesh group extracted by the spherical mesh extraction unit. The components of the tetrahedron (tetrahedron ID11, ID12, ID13, IDo in FIG. 3) are a triangle (triangle ID11, ID12, ID13) and one node other than this triangle (point IDo in FIG. 3). . All tetrahedrons including the node IDo are composed of the node IDo and a triangular shell mesh (boundary mesh) surrounding the node. By compressing the boundary mesh data, the tetrahedral mesh data is compressed.

The output data is a triangular shell mesh extracted from the boundary mesh extraction unit. The format of the extracted boundary mesh is as follows. Finally, vertices (shared vertices of the mesh of the spherical tetrahedron group) included in this boundary mesh are described.
ID11 ID12 ID13
ID21 ID22 ID23
......
IDn1 IDn2 IDn3
IDo

Here, a configuration may be adopted in which the extracted boundary mesh is displayed on the boundary mesh display unit 206 for confirmation.

(4) Boundary mesh compression unit 207 by data format conversion, compression rate display unit 209
The input data of the boundary mesh compression unit by data format conversion is the boundary mesh extracted by the boundary mesh extraction unit. As processing, the data size is reduced by deleting the overlapping element side in the boundary mesh notation. First, a triangle group 501 having a shared vertex is extracted from the boundary mesh. In general, the boundary mesh describes three integer vertex IDs in one line. Therefore, the triangle group 501 in FIG. 5 includes six triangles, and is described by six lines 502. On the other hand, in the method of the present invention, nodes ID11 to ID16 on the outer periphery of meshes e1 to e6 attached to shared vertex ID17 are extracted and described with shared vertex ID17 and one line 503. Such a description is called a deduplication format. Using such a description, the data size is reduced by reducing the overlapping description of the boundary mesh.

FIG. 6 shows a flowchart of the method of the embodiment of the present invention. The output data is the boundary mesh compressed in the deduplication format, the boundary mesh not compressed, and the shared vertex ID of the spherical tetrahedron group.

The format is shown below. The first to m-th rows are compressed boundary meshes, the n-th to p-th boundary meshes are not compressed, and the last IDo is a shared vertex of the spherical tetrahedron group.

FIG. 11 illustrates an operation screen related to the boundary mesh compression unit by data format conversion. When the “compress with new format” button is pressed, the boundary mesh is compressed, the boundary mesh before compression and the boundary mesh after compression are displayed side by side, and the compression rate is displayed. The format conversion reduces duplicate analysis data information and reduces the data size.
(5) Boundary mesh compression unit 208 by rules, compression rate display unit 209
The input data of the boundary mesh compression unit according to the rule is the boundary mesh extracted by the boundary mesh extraction unit, and the processing procedure will be described with reference to FIG. A reference element side 702 is extracted from the boundary mesh 701, and when connected to the reference element side 702, two nodes close to an equilateral triangle are searched to generate a triangular mesh. Triangular meshes are repeatedly generated using the newly generated triangle element side as a reference side. The mesh 703 generated by this rule is compared with the analysis mesh 701, and the triangular mesh existing only in the analysis data mesh is extracted as the difference mesh 705. By transferring only the difference mesh 705, the node information 704 of the analysis data mesh, and the reference side 702, the capacity of the transfer file can be reduced.

Fig. 8 shows a flowchart of the boundary mesh compression unit according to the rule. The boundary mesh is read as input data (step 801, hereinafter referred to as S801), and the shortest side of the boundary mesh is extracted as a reference element side (S802). When connected to the reference element side, the coordinates of a node close to an equilateral triangle are calculated, and in the case of three dimensions, the obtained coordinate values are circular (S803). A node closest to the obtained coordinate value is searched for in the boundary mesh (S804), a triangular mesh is generated by connecting to the reference element side, and it is determined whether or not it exists in the analysis data (S805). If it exists in the analysis data, it is determined that it can be restored by the rule, and the corresponding triangular mesh is deleted (S807). If it does not exist, it cannot be generated by the rule, and is recorded as it is (S806). The newly generated triangle side is used as the next reference side (S808). The output data is triangle information recorded from S806. Eventually, a mesh that cannot be restored remains, but transferring only this can reduce the data size to be transferred.

FIG. 10 illustrates an operation screen related to the boundary mesh compression unit according to the rule of the present invention. All the spherical patterns of the analysis data read from the reading unit are extracted, and the boundary mesh extraction unit extracts the boundary mesh from the spherical pattern. When the “compress by rule” button is pressed, the boundary mesh is compressed according to the rule, and the boundary mesh before compression and the compressed mesh after compression are displayed side by side, and the compression rate is displayed.
(6) Data storage unit 210
The data storage unit stores the analysis data compressed by the boundary mesh compression unit 207 by data format conversion and the boundary mesh compression unit 208 by rules in a storage device.
2. About restoration device
(1) Restoration unit 213 by data format conversion
The restoration unit 213 based on the data format conversion is the analysis data compressed by the boundary mesh compression unit 207 based on the data format conversion, and is restored by the inverse method of the compression method. The output data is analysis data having the same node information and connection information as the analysis data stored in the analysis data storage unit on the compression device side. First, the compressed boundary mesh is restored. Since the last ID of the numbers in one line is a shared ID, the next ID is extracted from the previous ID and is combined with the shared ID (last ID) to be restored to a triangle (restoration process shown in FIG. 5). . For example, as shown in FIG. 5, there are seven numbers in one line in the format after compression, and when it is expanded into a triangular shape as in the restoration process of FIG. 5, the specific format is as follows.
ID11 ID12 ID13 ID14 ID15 ID16 ID17
=>
ID11 ID12 ID17
ID12 ID13 ID17
ID13 ID14 ID17
ID14 ID15 ID17
ID15 ID16 ID17
ID16 ID11 ID17

Subsequently, all the developed triangles are combined with the shared vertices of the spherical tetrahedron group to restore a tetrahedral mesh. The specific format is as follows.
ID11 ID12 ID17 IDo
ID12 ID13 ID17 IDo
ID13 ID14 ID17 IDo
ID14 ID15 ID17 IDo
ID15 ID16 ID17 IDo
ID16 ID11 ID17 IDo

When the compressed tetrahedron data is restored, the format is as follows.

The restored analysis data is registered in the analysis data storage unit 214.
(2) Restoring unit by rule 212
The input data of the restoration unit 212 by the rule is analysis data compressed by the boundary mesh compression unit 207 by the rule, and is restored by a reverse method of the compression method. The output data is analysis data having the same node information and connection information as the analysis data stored in the analysis data storage unit on the compression device side.

The restored analysis data is registered in the analysis data storage unit 214.

As described above, the system includes a compression unit that reduces the data size of the analysis data and a restoration unit that restores the data to the state before compression, thereby reducing the data transfer time and the data storage area. There is.

Note that although compression of tetrahedral mesh data has been described in the present embodiment, the data size can be reduced by the same method for analysis data composed of other types of meshes such as hexahedral mesh, quadrilateral mesh, and triangular mesh.

101 analysis data compression unit 102 transmission system 103 analysis data restoration unit 104 reception system 201 shared vertex 202 tetrahedron group 307 including shared vertex Boundary mesh compression unit 308 by data format conversion 308 boundary mesh compression unit 705 by rule Difference mesh

Claims

An analysis data reading unit for reading analysis data;
An analysis data display section for displaying the read analysis data;
An extraction unit for extracting a boundary mesh of a mesh group having a shared vertex from the read analysis data;
A boundary mesh display unit for displaying the boundary mesh extracted by the extraction unit;
A boundary mesh compression unit that compresses the extracted boundary mesh;
An analysis data transmission unit for transmitting analysis data compressed by the boundary mesh compression unit;
An analysis data restoration unit for restoring the transmitted analysis data;
An analysis data transmission / reception system comprising a network for transferring transmitted analysis data to the receiving unit.
The analysis data transmission / reception system according to claim 1, wherein a boundary mesh of a mesh group having a shared vertex is extracted from the analysis data.
The analysis data transmission / reception system according to claim 1, wherein the size of a transfer file is reduced by deleting a mesh that can be restored by a rule and transferring only the mesh that cannot be restored.
In the analysis data transmission / reception system according to any one of claims 1 to 3,
An analysis data transmission / reception system that reduces the size of mesh data by changing the data format of the mesh.
In the analysis data transmission / reception system according to claim 3,
An analysis data transmission / reception system which restores compressed analysis data by combining analysis data generated by a rule and received analysis data.
An analysis data reading unit for reading analysis data;
An analysis data display section for displaying the read analysis data;
An extraction unit for extracting a boundary mesh of a mesh group having a shared vertex from the read analysis data;
A boundary mesh display unit for displaying the boundary mesh extracted by the extraction unit;
A boundary mesh compression unit that compresses the extracted boundary mesh;
An analysis data storage system comprising an analysis data storage unit for storing analysis data compressed by the boundary mesh compression unit.
The analysis data storage system according to claim 6,
An analysis data storage system, wherein a boundary mesh of a mesh group having a shared vertex is extracted from the analysis data.
The analysis data storage system according to claim 6,
An analysis data storage system that reduces the size of a transfer file by deleting meshes that can be restored by rules and transferring only meshes that cannot be restored.
In the analysis data storage system according to any one of claims 6 to 8,
An analysis data storage system that reduces the size of mesh data by changing the mesh data format.