Optimizing data transfer between different integrated design systems using UML architectures.

Bucur, Carmen Cristiana ; Cazacu, Dragos Alexandru ; Aurite, Traian 等

1. INTRODUCTION

From at least 10 years the researchers have been studying the problem on CAD/CAM integration and trying to optimize data transfer between different IDS Systems.

The implementation of a supporting infrastructure for Virtual Enterprise can be based on a number of component technologies and paradigms, the most important are: interoperability and integration of standards (STEP, EDI, etc.) and integration of legacy systems (CAD, CAM, CAE, etc) (Camarintha-Matos, 1999).

In our documentation we discovered barriers in product data transfer produced by: different users operating in a different manner Integrated Design Systems (IDS); number of different organizations involved in the definition and manufacture of products, each having their own distinct set of rules; the development of the second IDS, which used different data to represent the same information as the first system, providing some new functions and types of information; the information created in one system cannot be read and processed by the other system; from the lifecycle of many products, which extends far beyond the effective working life of one particular IDS and its hardware; product support must extend until the last product is scrapped (Barata, 1999).

The options discovered until now to solve these problems are: the simplest option would be to enforce the use of the same IDS system throughout a project; the second approach is to recognize the need for multiple IDS, and to build translators between the various systems; the third approach is to develop a neutral form of data with which each system can communicate (Barata, 1999).

Data exchange problems are caused by the CAD/CAM/CAE process. Such things as dissimilar software systems, lost data, inconsistent product versions and poor communication between design, engineering and manufacturing can impede success (Popa & Bucur, 2004).

Solving some problems which appear in virtual enterprise from industrial organizations using different IDS from one department to another is important for the industrial partners involved in such architecture as well as for the software developers.

One problem is the discordance which appears after the data transfer between one Integrated Design System to another, and the bigest problem is that the part can't be edited anymore.

2. CASE STUDY

Based on the main issue presented, we elaborate an SADT frame of an IDS data transfer model in order to improve CAD/CAM communication (Bucur, 2005).

We develop this SADT until the "Generating the 2D or 3D parts/assemblies in CAD Module" activity. There are two ways to elaborate the parts/assemblies in IDS: the first one is to design the parts/assemblies directly in actual IDS and the second is to import the parts/assemblies model built in previous IDS (Bucur et al., 2005).

We considered that the best way to import parts/assemblies from a IDS to another is to create an intermediary software, that will be able to keep the historic of each part in the IDS that is transferred. For the beginning we chose to develop the idea in UML 2.0 architecture. These will allow us to keep track of each item exported from the initial IDS and to make sure that it will be kept in the final IDS.

As you can see in figure 1 this study continues with UML architectures for shafts designed for CATIA made in IBM Rational Software Architect.

CATIA diagram for shaft parts incorporate the PART_name Class which import the Shaft and Pocket commands. In PART_name Class is defined the part_name attribute and operation as String type, witch shall import the real name of the part. The Shaft Class defines the shaft_no attribute, in order to import them in chronological order and operation as Integer type and is associated with Angle, Axis and Sketch options. The Angle Class is characterized by Value attribute and operation defined as Integer type, to import/export the degrees number. Axis Class appeals the 3D Line that uses 3D Point Class. Axis_no parameter is described as Boolean type. The Pocket option is associated with Sketch and Height Class. Pocket_no attribute and operation is described as Integer type. Each of these classes is importing/exporting the values, the coordinates, the elements that are used by the command from the other classes that are reading them from the original model in order to write them in the new one.

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In figure 2 is presented the Sketch or Profile diagram and for both programs is the same. This diagram contains the following classes: Absolute Axis, Constrains and Geometry. The Constrains Class includes the next attributes: Coincidence, Parallelism, Tangency, Offset, Perpendicularity, Angle, Radius and Length. The Geometry Class includes the Point, Line and Circle attribute and options. All of these are supposed to take from the original part sketch the information like: sketch plan coordinates, the axis directions, the geometry, the value attributed to each object, constrains between witch objects and value if necessary, to export them to another IDS. This way we are practically reading each step made by the designer in the IDS that he used and remaking the same steps in a different IDS, like a new part.

SOLID EDGE diagram for shaft parts is presented in figure 3 and incorporate the PART_name Class which import the Revolved Protusion and Cutout commands. The Revolved Protusion Class is associated with Angle, Axis of Revolution and Profile options. The Cutout Class is associated with Profile and Height Class. The attribute and operation type defined in class diagrams are the same like in CATIA diagram to make the import/export operations functionally.

Transposing the UML in C++ Programming language, we obtain the agent source that can be transformed by a programmer in an import/export agent. This agent can be developed in software that will be able to import and export parts with full historic, between CAD software. A sequence of this agent source is shown in figure 4.

This software is going to be able to read the steps made by the designer in the IDS that he is using and to actually redesign the part in the second IDS, making the same moves like the designer, but using the other IDS commands. This way the part will be editable after the transfer.

[FIGURE 3 OMITTED]

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3. CONCLUSION

In present are built numerous translators between the various systems but none of them are able to import the parts with historic. The main focus of this study is to create the UML architectures for the CATIA and SOLID EDGE Software in order to improve the data transfer in a Virtual Enterprise. Solving the problems which appear using different IDS from one department to another is important especially to reduce design and manufacturing time, errors and even blanks rebooting.

Starting from the similarity of design commands in any IDS, we created the UML 2.0 architectures for shafts designed in CATIA and SOLID EDGE in order to transpose the UML in C++ Programming language and to obtain the agent source which can be transformed in import/export software by a programmer. After that the users of different IDS will be able to work on the part with full historic.

In the future researching we intend to extend this UML 2.0 architecture for UNIGRAPHICS and SOLID WORKS Programs. These diagrams may be filled with the entire existing Integrated Design Systems.

The main idea of this architecture is to be the start point of the future professional software that will improve CAD communication between any software.

4. REFERENCES

Barata, J. (1999). Introduction to Modelling and STEP, Available from: http://www.uninova.pt/ ~escn/storage/U2PIUninova.pdf, Accesed on 2009-03-18

Bucur, C.C.; Parpala, R.C., Popa, C.L. & Ciobanu, L.F. (2005). SADT Modelling for Data Transfer using the STEP Format. Proceedings of The 8th Conference on Management of Innovative Technologies. MIT 2005, Chircor, M. & Dragoi, G. (Ed.), pp 193-197, ISBN 961-6238-96-5, Slovenia, September 2005, Fiesa

Bucur, C.C. (2005). SADT Frame of an IDS Data Transfer Model Using STEP Format. Proceedings of The 16th International DAAAM Symposium, Katalinic, B. (Ed.), pp. 47-48, ISSN 1726-9679, Austria, October 2005, Published by DAAAM International, Vienna

Camarintha-Matos, L.M. (1999). Introduction to Virtual Enterprise, Available from: http://www.uninova.pt /~escn/storage/U1PIUninova.pdf, Accesed on 2009-03-18

Popa, C.L. & Bucur, C.C. (2004). Data Transfer between CADCAM-CAE Cooperative Systems. Proceedings of The 7th Conference on Management of Innovative Technologies. MIT 2004, Chircor, M. & Dragoi, G. (Ed.), pp 11-14, ISBN 973-700-028-5, Romania, October 2004, AIUS, Constanta