Imre Horváth

The evolution, challenges, and future of knowledge representation in product design systems

Product design is a highly involved, often ill-defined, complex and iterative process, and the needs and specifications of the required artifact get more refined only as the design process moves toward its goal. An effective computer support tool that helps the designer make better-informed decisions requires efficient knowledge representation schemes. In todays world, there is a virtual explosion in the amount of raw data available to the designer, and knowledge representation is critical in order to sift through this data and make sense of it. In addition, the need to stay competitive has shrunk product development time through the use of simultaneous and collaborative design processes, which depend on effective transfer of knowledge between teams. Finally, the awareness that decisions made early in the design process have a higher impact in terms of energy, cost, and sustainability, has resulted in the need to project knowledge typically required in the later stages of design to the earlier stages. Research in design rationale systems, product families, systems engineering, and ontology engineering has sought to capture knowledge from earlier product design decisions, from the breakdown of product functions and associated physical features, and from customer requirements and feedback reports. VR (Virtual reality) systems and multidisciplinary modeling have enabled the simulation of scenarios in the manufacture, assembly, and use of the product. This has helped capture vital knowledge from these stages of the product life and use it in design validation and testing. While there have been considerable and significant developments in knowledge capture and representation in product design, it is useful to sometimes review our position in the area, study the evolution of research in product design, and from past and current trends, try and foresee future developments. The goal of this paper is thus to review both our understanding of the field and the support tools that exist for the purpose, and identify the trends and possible directions research can evolve in the future.

Editorial: Fundamentals of next generation CAD/E systems

Since the 1960’s, computers have been playing more and more important roles in engineering practices. The evolution of Computer-Aided Design and Engineering (CAD/E) systems has been driven by both the needs for efficient design processes and high quality representation of products, and the advancement of computing technologies andmethodologies related to design practices. The computing (software) technologies that have greatly impacted on CAD/E systems include geometric modeling, finite element analysis, manufacturing process planning, human factor assessment and optimization algorithms, data base technologies, artificial intelligence, web search technologies, as well as networking and communication technologies. The paradigm behind current CAD/E systems can be characterized by the following features: (i) artifact geometry, structure and process modeling, (ii) displaysbased graphical visualization, (iii) numeric data-based behavioral analysis and simulation, (iv) network-hosted remote collaboration, (v) data base-level functional integration, and (vi) product/process life cycle data management. The market of commercial CAD/E systems is dominated by a number of large software developers who intend to offer complete solutions for the industry. Though academic research is still very active in the field of CAD/E systems, there are indications that the conventional system development resources will sooner and later become exhausted. A new paradigmmight be necessary to provide additional support for the industry, to cope with the complexity of products, processes, and data/knowledge, and to open up new opportunities for researchers, innovators, systemdevelopers, system integrators, and end users. Many recent technological developments, for instance, smart and ubiquitous technologies, cloud computing, semantic web, cyber-physical systems, molecular computing, social networking and brain interfacing, are stimulating the discussions and the research towards a new paradigm. This is the first of a series of special issues targeting the functionality, implementation, integration and application issues, approaches and solutions of next generation of CAD/E systems that will be used by designers and engineers around and after 2020. Special issues on Ubiquitous Computing-Based Design Tools and Systems and Application of Brain–Computer Interfaces in CAD/E Systems are already in development by other guest editors and authors. The objective is to explore new ideas, theories, methodologies, concepts, functionalities, forms of interaction, technologies and implementations that offer themselves to more efficient systems and applications. It is expected that novel information and knowledge mining technologies, mobile communication and ad hoc networking, semantic network technologies, air borne visualization technologies, smart reasoning and agent based computing, ubiquitous sensing and computing technologies, knowledge ontologies, natural interaction techniques will have a say in the formation of the paradigm of next generation CAD/E systems and environments. The objective of this special issue is to provide an overview and to investigate the fundamental theories and techniques that may underlie the new paradigm. One major criterion that we applied at selecting the published papers was if they addressed one or more fundamental issues that might have a significant impact on future CAD/E systems. Based on the recommendation and review comments of the invited peer reviewers, out of twenty-one submissions, ten papers have been selected for publication in this special issue. Most of the submitted papers have gone through three rounds of review. They address issues such as understanding, analysis, synthesis, representation, search and communication in computer aided design and engineering. The papers selected for this special issue can roughly be divided into three categories. The first category includes papers that concentrate on the understanding of design problems and design knowledge (including meaning based information search). The papers belonging to the second category deal with various different aspects of creative design synthesis, while those belonging to the third category address design expression and representation. They indicate a shift from product orientation to designer and environment orientation. Obviously, the contributed papers could cover only a part of this very complex and challenging problem, and raise many more fundamental questions than they could answer. In the first paper, entitled ‘‘Cognitive, collaborative, conceptual and creative — Four characteristics of the next generation of knowledge-based CAD systems: A study in biologically inspired design’’, Goel et al. proposed four characteristics (referred to as four C’s) for the next generation knowledge-based CAD systems. These systems are conceived to be supported by CAD technologies other than computational geometry and computer graphics. They argued that the next generation knowledge-based CAD systems will be (i) cognitive, (ii) collaborative, (iii) conceptual, and (iv) creative. The first C refers to a specific methodology for developing CAD systems, namely, grounding the design, development and deployment of CAD systems in cognitive studies; whereas the other three C’s define the characteristics of design that CAD systems may support. The second C indicates that design is collaborative in at least four dimensions: (i) time; (ii) space; (iii) discipline; and (iv) culture. Communication between systems, between system and human, and between humans is the core for the collaborative process. The third C refers to conceptual design, which mainly focuses on the understanding of the design problem and the synthesizing of design information into solution concepts. The fourth C represents creativity, and indicates that the next generation of CAD systems will support design creativity and creative designs. Based on this framework and by using the SBF (Structure–Behavior–Function) model, the authors introduced in

Learning the methods and the skills of global product realization in an academic virtual enterprise

This paper reports on and draws conclusions about the international course called European Global Product Realization. It was organized to provide university students with knowledge about distributed product development in virtual enterprises. The philosophy of the course is discussed together with its structure, contents, organization, infrastructure, deliverables and the experiences. Necessitated by globalization, the principles of operation of virtual enterprises were used in organizing the course. The knowledge accumulated in global product realization by the participating companies and academic sections provided the basis for the course and for the student projects. The organizers put the students of three European universities into the position of evolving young professionals who act as both knowledge producers and knowledge consumers. The design and engineering students took part in academic lectures and industrial case studies in a virtual classroom and practised collaborative product development in the emulated virtual enterprise. The academic virtual enterprise framework has been confirmed to be a solution for opening the conventional educational institutions. Our future work will concentrate on how to exploit disciplinary and operational research as the engine behind academic learning and teaching.

Tool profile and tool path calculation for free-form thick-layered fabrication

Abstract In several application fields, large sized, free-form objects of various soft materials are widely used. Available layered prototyping technologies cannot be applied for fabrication of these kinds of objects due to size limitations. The authors have developed a novel approach of layered manufacturing that is the most appropriate for physical concept modeling. This paper presents the algorithms for geometrically-based modeling of the profile curve of the flexible blade tool. It also describes the algorithm for direct slicing of the CAD model. The second part of the paper deals with the algorithms for slicing, tool positioning and tool path calculation. On the front surfaces of the layers G2, quasi G1 continuity can be implemented at the transition from one layer to another. In the circumferential direction G0 continuity exists.

DESIGN COMPETENCE DEVELOPMENT IN AN ACADEMIC VIRTUAL ENTERPRISE

Development of competence has been one of the major issues and goals of modern academic design and engineering education. Nevertheless, our literature study revealed that we are still far from a common interpretation of design competence. There are different views on it which we called reductionist and holistic. In the reductionist view, design competence is considered to be not else than a set of low level competencies such as drawing skills, spatial vision, specialized knowledge, intuitiveness and creativity, verbal communication, and technical writing, which have been typically addressed disjointedly. In the holistic view, design competence is a synergetic construct of some generic capacities. We followed this latter view in our work. We studied the implementation opportunities and manifestation of holistic design competence at the development and conduct of our recent European Global Product Realization course. Based on our past experiences and the information from the literature, we assumed that holistic design competence is a construct of five generic capacities: capabilities, attitude, knowledge, skills, and experiences, and can be efficiently developed by concurrently focusing on each of these, respectively. The professional content and didactic approach of the course were designed accordingly. An academic virtual enterprise was formed with the involvement of an industrial company and universities of five countries. The course included two instructional streams, which have been called professional navigation and industrial project. This paper presents our interpretation of holistic design competence, the didactic aspects of developing the underpinning generic capacities, and their manifestation in the European Global Product Realization course. A qualitative research has been completed with the involvement of 46 students to make out how our approach contributed to the development of the elementary design competencies. The conclusion has been that our approach equally well supports the development of both the holistic design competence and the elementary design competencies that are needed by product designers to be able to successfully operate in geographically dispersed virtual enterprises. The students’ opinion has been that the course was challenging but rewarding from the point of view of their future carrier as product designers.Copyright

Free-form thick layer object manufacturing technology for large-sized physical models

Abstract Large-sized free-form objects of different materials are widely used in various industrial applications. Currently, layered rapid prototyping technologies are not suitable for the fabrication of this kind of objects, due to the necessity of a large number of layers and the limitations in size. This paper reports a novel approach of layered manufacturing that is more appropriate for the fabrication of these large objects. A method of thick-layered object manufacturing is presented, which is based on a higher order approximation of the shape and application of a flexible curved cutting tool. The method allows the production of physical prototypes, which need little or no finishing. In order to meet the designers intend, as closely as possible, some feasible system characteristics are introduced. The process is ordered in a sequential way and provides a highly automated process. A hierarchical decomposition of the CAD geometry takes place into components, segments, layers and sectors, based on morphological analysis. This method enables the manufacturing and the re-assembly of the parts to produce the physical prototypes without affecting the requested functionality. Due to the possibility of obtaining multiple solutions in the physical model, much attention must be paid to the efficiency of the process.

Testing shape manipulation tools using abstract prototypes

Abstract Research in computer support to industrial design typically involves much experimentation. Proposals for new modeling methods are commonly evaluated using pilot software implementations. The experimentation tends to be lengthy and therefore expensive. We propose a faster way to evaluate the functionality of design tools. This evaluation method, called abstract prototyping, can be used in a very early stage of the development of a computer tool, prior to any software implementation. The evaluation focuses on how potential users appreciate new modeling functions by simulating their basic properties. The method aims at decreasing the risk of building a useless tool. We have applied abstract prototyping to make a selection among different candidate shape modeling techniques. The method proved to be feasible, fast and inexpensive,

Merging deformable and rigid body mechanics simulation

We present an interface between a deformable-body mechanics model and a rigid-body mechanics model. What is novel with our approach is that the physical representation in both the models is the same, which ensures behavioral correctness and allows great flexibility. We use a mass–spring representation extended with the concept of volume, and thus contact and collision. All physical interaction occurs between the mass elements only; thus there is no need for the explicit handling of interaction between rigid and deformable bodies or between rigid and rigid bodies. This also means that bodies can be partially rigid and partially deformable. It is also possible to change dynamically whether part of a body should be rigid or not. We present a demonstration example and possible applications in conceptual design engineering, geometric modeling, as well as computer animation.

Navigated active learning in an international academic virtual enterprise

Active learning is an educational paradigm that has been reinvented and methodologically underpinned many times in order to intensify learning in various forms. This paper presents a complex approach to active learning in a design-centred academic course with international participation. Research and design were considered as vehicles of active learning in the academic virtual enterprise environment established for the course. The former provided a methodological framework for exploring and structuring dispersed information and knowledge, and for constructing new ones. The latter supported the further development of the creative design capabilities, skills and experiences of the students by involving them in a project presented by the problem-owner partner company. The students formed international design teams, collaborated with industrial and academic experts, managed their own work, acquired information and knowledge in a systematic way, conceptualized and prototyped products according to real-life expectations, and persuaded the partner company to buy their concept products. The course proved to be an excellent active learning environment also for the educators, who could verify new pedagogical concepts and gained experience with the daily management of an academic virtual enterprise.

Collaborative Shape Conceptualization in Virtual Design Environments

Vague discrete modeling is a flexible and adaptable means for designers to express and shape ideas in a collaborative environment.