Computer-aided Engineering System Research Articles

Development of a lightweight CAE middleware for CAE data exchange

Computer-aided engineering (CAE) analysis is considered essential for product development because it decreases the simulation time, reduces the prototyping costs, and enhances the reusability of product parts. The reuse of quality-assured CAE data has been continually increasing in order to shorten the product development cycle and to improve the product quality. However, less attention has been paid to systematic research on the interoperability of CAE data because of the diversity of CAE data and because the structure of CAE data is more complex than that of CAD data. In this paper, we suggest a CAE data exchange method for the effective sharing of geometric and analysis data. The method relies on heterogeneous CAE systems, a virtual reality system, and our developed lightweight CAE middleware for CAE data exchange. We also designed a generic CAE kernel, which is a critical part of the CAE middleware. The kernel offers a way of storing analysis data from various CAE systems, and, with the aid of a script command, enabling the data to be translated for a different system. The reuse of CAE data is enhanced by the fact that the CAE middleware can be linked with a virtual reality system or a product data management system.

A conceptual framework for computer-aided ubiquitous system engineering: architecture and prototype

Ubiquitous computing technology has been rapidly advanced and applied to diverse domains. This paper proposes a new approach, called CAUSE (Computer-Aided Ubiquitous System Engineering), for implementing ubiquitous manufacturing systems. This method has great potential compared with the conventional ones that rely on physical implementation and human experience through trial-and-error correction. Specifically, this paper develops a framework for the software supporting the ubiquitous system engineering based on requirement analysis, functional details, and implementation issues including enabling technology. The usefulness of the proposed method is shown by developing a prototype system for a ubiquitous manufacturing system with radio frequency identification (RFID).

An experimental approach to RFID system performance prediction model

Radio frequency identification (RFID) is increasingly applied for advanced manufacturing systems as part of ubiquitous systems, implementation of which is the task of the ubiquitous system engineer. The present method, used by almost all the ubiquitous system engineers, is based on trial-and-error methods. To reduce costs, prediction of RFID performance in ubiquitous systems is a promising approach. Our previous research has proposed a Computer-Aided Ubiquitous System Engineering (CAUSE) framework by which a ubiquitous system can be designed, analysed and verified on the computer. By developing an architecture and prototype, we showed its usefulness in the ubiquitous system engineering task. In order to be practically effective, however, the accuracy of the CAUSE needs to be improved. For such a purpose, however, the conventional model-based approach is hard to apply because only a few factors have been taken into consideration. In this paper, we investigate a heuristic approach for dealing with realistic problems based on experiments, by proposing a procedure for the experiments and neural network methods. Experimental results show the effectiveness of the experimental method compared with the conventional model-based approach.

Development of an intelligent CAE system for auto-body concept design

The concept design phase is a critical step in auto-body design, as it has a great effect on later design work. This paper describes the implementation of an auto-body structure design in the early stages of a new auto-body developing program. In order to reduce the long design period and analysis error that plagues traditional auto-body concept design, an intelligent CAE system has been successfully developed and implemented based on the UGS NX/API opening platform. This system, the so-called ACD-ICAE (Auto-body concept design-intelligent computer aided engineering) System that means concept design-intelligent computer aided engineering system, employs a fully parametrized template method to build the conceptual auto-body geometry model and FEM model quickly and easily. It also integrates auto-body modeling, analysis and optimization on only one CAD platform via a parametric variables database. Moreover, all parametric variables are shared and updated in different phases of the ACD-ICAE System. A wizard User Interface (UI) based on knowledge of auto-body engineering was developed and used in this system. The procedures implementing the functional diagram of the ACD-ICAE system are also provided. A typical example of a car body concept design with four doors shows that the ACD-ICAE system is efficient and accurate.

Review of research and development of computer-aided Kansei Engineering

Kansei Engineering is an important research approach and has become the hotspot of research in design fields. The concept of Kansei Engineering is introduced based on the investigation of related literatures. The working process and the key technology of computer-aided Kansei Engineering systems are discussed. Finally, the development trend of Kansei Engineering is outlined according to the development of computer and networking technology.

Design for manufacture: the case of concurrent mould and part design in injection moulding

In the current context, efficient DFM relying on the ability to manage simultaneously the definitions of the shape, the material and the process, is crucial. The aim of this article is to illustrate, for plastic injection moulding, how to tackle such a situation. To reach our target, computer aided engineering systems should enable to manage the mutual links between the product properties and the product and process parameters. Such a system integrated to conventional computer aided design (CAD) environment and its supporting design process are detailed. The main idea consists in checking systematically the mutual influences between the part and mould CAD models. The design process has two main design sequences: the part driven one and the mould driven one. The proposed architecture is implemented into the commercial CAD environment PTC ProEngineer. The use of the computer system is illustrated on a real study case dealing.

A Conceptual Framework for Computer-Aided Ubiquitous System Engineering: Architecture and Prototype

Ubiquitous computing technology has been rapidly advanced and applied to diverse domains. This paper addresses the problem of how to implement ubiquitous manufacturing system by proposing a new approach, called CAUSE (Computer Aided Ubiquitous System Engineering). This method has great potential compared with the conventional ones relying on physical implementation based on human experience followed by trial-and-error correction. Specifically, this paper develops a framework for the software supporting the ubiquitous system engineering based on requirement analysis, functional details, and implementation issues including enabling technology. The usefulness of the proposed method is shown by developing a prototype system for a ubiquitous manufacturing system with RFID.

6.1.2 Better use of Design Descriptions to embrace complexity and creativity in Systems Engineering

AbstractMost Systems Engineering practitioners now have access to Computer Aided Systems Engineering (CASE) tools that greatly assist with the engineering of complex problems. However, the productivity of these tools is often offset by the inability to effectively manage the large amounts of data associated with the system models offered by these engineering tools. As well as better CASE tools to improve productivity and success, we must not forget the role of innovation and creativity as a means of progressing solutions to engineering problems. This paper examines the use of the long standing practice of using ‘design descriptions’ and advocates that we formalize this approach by using Systems Engineering Design Descriptions to manage the engineering complexity and to embrace engineering creativity.

How Industry Concepts of Concurrent Engineering Enhance Aircraft Design Education

Two student projects are described including the intended goals, the approaches taken, the tools used, and what was learned from the exercises. An international collaborative teaching protocol between Ecole Polytechnique de Montreal and the Royal Institute of Technology (KTH) was exercised in aircraft design education. Poignantly, a novel instructive design process using the analogue of contemporary concurrent engineering practices in industry was implemented. The idea was to strategically assign multi-disciplinary design tasks to each Partner University in accordance with their respective competencies. The university-industry coupling was initiated by request for proposals and corresponding marketing requirements and objectives produced by Bombardier Aerospace in Montreal, Canada. Two MATLAB TM-based tools were prominent in facilitating the capstone aircraft design projects. They included: Quick Conceptual Aircraft Research and Design, a computer-aided conceptual design engineering system; and TORNADO, a Vortex-Lattice code for computing aerodynamic characteristics. The result of the two exercises was found to benefit the participating industry, the educational establishments involved, and the students carrying out the projects.

Triangular and Quadrilateral Finite Element Mesh Generation on Poorly Parameterized Free-Form Surfaces

The non-uniform rational B-spline (NURBS) surfaces are widely employed for the exchange of geometric models between different computer aided design and computer aided engineering systems. However, if the input surfaces are poorly parameterized, surface meshing algorithms may fail or the constructed meshes could be ill conditioned. This paper presents a new method that can generate well-conditioned meshes, even on poorly parameterized freeform surfaces, by regenerating NURBS surfaces. At the outset, adequate points are sampled on the poorly parameterized original surfaces. New surfaces are then created by interpolating these points. Finally, mesh generation is performed on the new surfaces. By employing this method, models with poorly parameterized surfaces can be successfully meshed.

Distribution and synchronisation of engineering information using active database technology

Today, work collaboration is normal practice in developing modern products. Engineering collaborative work involves a number of team members that need to share and exchange design ideas while working with engineering analysis tools such as mechanical computer aided engineering systems. This work presents the M-Sync prototype system that uses an active database approach to enable exchange of engineering information among distributed team members in a timely manner. The distributed data is fully accessible by the local member and is automatically synchronised between different places using a database management system that support event-condition-action (ECA) database rules. Only updates introduced at one location are distributed to other locations, thereby minimizing information transfer and enhancing performance. Members working at different locations can therefore work in a peer-to-peer (P2P) manner and interactively manipulate the same set of information at the same time.

Reworking with a Legacy Financial Accounting System: Lessons from a Pharma Company

The issues of legacy systems become more pronounced at the time of a major IT upheaval such as implementation of ERP or business process reengineering (BPR) exercise. In this changing scenario, there is a need to update the systems and skills and integrate them with the emerging enterprisewide infrastructure. The main problems with a legacy system are that it remains insulated from the update attempt that largely follows market trend thus rendering it outdated and also that its documentation is poor. In this paper, the authors share the experiences of a project undertaken in one of India's leading multinational pharmaceutical companies (MPC) which was to rework on the existing legacy system and design a new application. The legacy system referred to here is the company's financial accounting system which was developed in 1993. Originally designed in COBOL, it was subsequently improved as and when the finance department put forth its requirements. The major downside of the system was that it had virtually no documentation and no one from the original team that developed the system was still working with the company. This made it all the more difficult to understand and document the system. Also, the system had a high response time thus leading to lower productivity of the data entry staff and other users. Further, it had a limited reporting capability and was basically used for storing financial data. When this project was undertaken for rework, the MPC was in the process of implementing an ERP package for its manufacturing and, therefore, it was necessary to bring all its applications to the same database structure. The most obvious question was whether to discard the legacy system and implement ERP's accounting module. The management, however, decided to retain and rework on the legacy system with the intention of integrating the new system with ERP. The driving point in favour of this decision was the realization that the legacy system was regarded as very critical for the accounting function and also that the users had become conversant with the system despite it being not very user-friendly. Also, there was no risk of failure. Incidentally, the review of the legacy system and ERP implementation coincided thereby easing out concerns of managing organizational changes as the company already had its strategy and preparedness in place for the scenario emerging out of ERP implementation. The computer-aided systems engineering (CASE) tool was chosen for designing the new system because of its inherent advantages in handling software projects which are as follows: The well-documented new system simplifies the maintenance jobs and, therefore, fewer people are required for its maintenance (this was the major problem with the previous system). It has removed the dependence of the management on a small set of people who specialized in the maintenance of an undocumented system. Financial reporting has become easier and better. The experience on this project made it amply clear that the top management support can make or mar a project. This is one of the most popular hypotheses in the information systems literature which has been found to be true in the case of the MPC.

Contouring Medial Surface of Thin-Plate Structures Using Local Marching Cubes

This paper describes a new algorithm for contouring a medial surface from CT (computed tomography) data of a thin-plate structure. Thin-plate structures are common in mechanical structures, such as car body shells. When designing thin-plate structures in CAD (computer-aided design) and CAE (computer-aided engineering) systems, their shapes are usually represented as surface models associated with their thickness values. In this research, we are aiming at extracting medial surface models of thin-plate structures from their CT data for use in CAD and CAE systems. Commonly used isosurfacing methods, such as marching cubes, are not applicable to contour the medial surface. Therefore, we first extract medial cells (cubes comprising eight neighboring voxels) from the CT data using a skeletonization method to apply the marching cubes algorithm for extracting the medial surface. It is not, however, guaranteed that the marching cubes algorithm can contour those medial cells (in short, not “marching cubeable”). In this study, therefore we developed cell operations that correct topological connectivity to guarantee such marching cubeability. We then use this method to assign virtual signs to the voxels to apply the marching cubes algorithm to generate triangular meshes of a medial surface and map the thicknesses of thin-plate structures to the triangle meshes as textures. A prototype system was developed to verify some experimental results.

Model transfer among CASE tools in systems engineering

Systems engineering as a core discipline of technical product development uses a variety of different Computer-Aided Systems Engineering (CASE) tools. Very often the need arises for data transfer between such tools. Currently, due to insufficient interface formats, a labor-intensive manual transfer of data is necessary. A step towards improving data exchange between systems engineering tools along the process life cycle is the definition of standard interface formats such as the application protocol (AP) framework of ISO Standards for the Exchange of Product Data (STEP). The aim of this paper is to analyze and evaluate the implementations of the Systems Engineering Data Representation and Exchange Standard (SEDRES/AP233) information model with regard to supporting data exchange, to propose improvements for the emerging modular AP233 ISO standard and to provide solutions for the observed problems. The solutions proposed in this paper were developed while designing, developing, and using a STEP ISO 10303–SEDRES conformant import and export interface for the tools Teamwork, Statemate, and the requirement management tool DOORS. The developed interfaces demonstrate that the SEDRES information model is an efficient medium for tool and vendor independent transfer of systems engineering information. © 2004 Wiley Periodicals, Inc. Syst Eng 8: 41–50, 2005

Model-based Concurrent Systems Design for Safety

This article describes a model of concurrent systems design for developing safety-critical systems. The developed model integrates system design, system safety analysis, and human factors. The model is able to develop the specifications for safety-critical systems easily. System safety analysis is a crucial part of the system effectiveness analysis for safety critical systems that require a concurrent systems design for safety (SDFS). This concurrent engineering approach is important during the early phase of the systems engineering process. The results of SDFS must be established during the early phase of the development life cycle to yield the architecture option satisfying the safety requirements. Evolution of computer technology has enabled engineers to perform more productive model-based systems engineering. A computer-aided systems engineering (CASysE) tool, CORE, is used to carry out the SDFS. The proposed method can provide the insight and traceability among requirements, functions, components, and the potential hazards. The application of the method to a commercial aircraft, one of the safety-critical systems, demonstrates utility of this model for concurrent SDFS. The method shows the concept of concurrent engineering during the system design while a specialty engineering analysis must be integrated. System engineers can efficiently develop the system specification considering system safety using this approach.

The application of PDA as mobile computing system on construction management

This paper reports a development of mobile computing system with personal digital assistants (PDA) for construction managers on construction sites. First, this paper describes the aim, the concept based on end user computing (EUC), and the essential element of the mobile system. This also shows the necessary functions for the mobile computing, and the concept of this computer-aided engineering system. Secondly, this paper describes the structure of the system and the outline of subsystems: Inspection System, Checklist and Reference System, Position Check System, and Progress Monitoring System. The system has two programs: the data input program in PDA and the output program in PC. – Inspection System assists architects and construction managers to inspect the result of construction especially for finish works. – Checklist and Reference System assists construction managers to access the checklist and the reference such as drawings and specifications. – Position Check System assists construction managers to check and correct the position of structural members such as the steel column and the form. – Progress Monitoring System assists construction managers to monitor the progress of projects. Finally, this paper indicates the development of more refined process of construction management with the mobile computing device on construction sites.

What Do You Know?

This article focuses on the fact that when the time comes for mechanical engineering students to look for their first professional jobs, how much does it count which computer-aided design system they learned in college. In the 1980s, when most engineering organizations were newly acquainted with CAD and computer-aided manufacturing technologies, employers emphasized their need for engineers with very specific knowledge of a particular computer-aided engineering system. Mechanical engineering majors should understand the methods behind solid modeling, such as the principle of orthographic projection. The method of representing objects does not include the viewer’s perspective and can take a bit of practice to pick up. Eifel maintains the CAD programs UGS and I-deas from EDS, and Catia from Dassault Systemes of Paris. Engineers use ICEM Surf from ICEM Ltd. of Southampton, England, for surface design, and Power mill from Delcam Plc of Birmingham, England, for CAM.

Using UML to facilitate the teaching of object-oriented systems analysis and design

This paper discusses how UML, with the aid of a CASE (Computer Aided Systems Engineering) tool, can help teach an Object-Oriented Systems Analysis and Design (OOSAD) course. Today's students need to be actively involved in the learning process and must be able to apply a concept while it is being taught. Most OOSAD real-world problems are to complex to deal with in the classroom, so we have chosen a simpler problem - consisting of a university setting - that all students are familiar with. By using a CASE tool to draw UML diagrams students can visualize the object-oriented concepts and see the relevance of what is being taught. UML can help simplify OOSAD problems and at the same time actively engage students in the learning process thus increasing the general interest level of the student. The author's basic approach to teaching OOSAD material is to have the students emulate the instructor when working through a problem. With enough concrete practice like this, students soon build a strong foundation in UML diagrammatics and in the process gradually abstract out the underlying OOSAD concepts. The aim is to reach a point where students can make their own interpretation, apply OOSAD concepts independently, and ultimately devise their own extensions to UML to solve a problem.

Nanofractal Analysis of Material Surfaces Using Atomic Force Microscopy

The surface structures of four materials (a pure aluminum sheet, an aluminum alloy sash, a thickness gauge and a magnetic tape) are observed on the nanometer scale by atomic force microscopy (AFM) and analyzed by one-dimensional fractal analyses. It is confirmed for all the surfaces that they have a self-affined fractal property under a resolution of 1 nm. The two-dimensional fast Fourier transformation (2D-FFT) analysis is also applied to these surfaces and their characteristics are clarified. The power spectrum model for surface simulation is proposed and its validity is confirmed by experimental results. A method for simulating the surface structure of any materials is presented, and its validity is shown on some materials whether in-plane isotropic or anisotropic. A computer-aided engineering (CAE) system composed of 2D-FFT and inverse FFT (IFFT) for quantitative estimation of surface nanostructures is advanced and applied to various surface problems. It enables the mass data of a material surface to compress into only three parameters. This compressed information includes all surface waviness, complexity, irregularity, roughness and in-plane anisotropic properties.

Towards computer-aided reverse engineering of heavy vehicle parts using laser range imaging techniques

We present an integrated system to automatically generate computer-aided design (CAD) models of existing vehicle parts using laser range imaging techniques. The proposed system integrates data acquisition, model reconstruction, and post processing to generate a set of models from real-world automotive parts. This range image-based, computer-aided reverse engineering (CARE) system has potential for faster model reconstruction over traditional reverse engineering technologies. As part of this system, we also propose a novel crease detection algorithm, which segments the surfaces of reconstructed models along smoothness discontinuities. We present results for both the CARE system and the proposed crease detection algorithm for a set of automotive parts.