Catálogo de publicaciones - libros

With the similarity between the evolution of living beings and the development of manufactured products, gene-engineering techniques have been applied to develop a systematic design theory and methodology for product innovation. This innovation method is different from the conventional one as it innovates products via artificial differentiation of the virtual product chromosomes. It provides a logically structured process, which can reduce blindness to innovation. Since products have no physical chromosomes, their virtual chromosomes must be reverse-deduced according to their function requirements so that the new innovation method can be applied. This paper introduces the gene engineering based innovation method, discloses the contents and data structure of virtual product chromosomes and applies database techniques to edit and store product chromosomes.

Three families of methods coexist for managing ( representing and propagating) uncertainty of product data during the preliminary design, namely: fuzzy methods, probabilistic methods and Constraint Programming (CP) methods. CP methods over reals are, up to now, the less frequently used approaches, but they are worth further study for use in design engineering thanks to a number of good properties and recent significant advances. They may be roughly considered as a collection of methods that are sophisticated evolutions of interval analysis. The objective of this paper is to assess four of these major methods; namely the {Hull, Box, 3B-weak, 3B}-consistency methods in the context of the preliminary design of mechanical products where large variable domains are considered and a representation of the remaining consistent design space turns out to be of practical interest to support the designers’ understanding and decision making. A measure for comparing the level of consistency of the methods is then proposed in the context of engineering design. It consists of a pairwise comparison of the overlapping part of the remaining design spaces for a given splitting grain size. Numerical results are established for an example of a combustion chamber design with 6 variables and 12 constraints. Next, a sensitivity analysis of the consistency of the previous methods is performed in regards to a variable splitting grain size. Experiments have been performed on a research platform including up-to-date NCSP methods. The paper concludes that NCSP methods are not easy-to-use and that the designer must be aware of a number of concepts so as to select the best choices in the resolution strategies.

The digital modelling of technical systems and physical phenomena and their environment forms the basis for design and development in the future. Based on models and visualisation technologies, the appearance and behaviour of a technical system can be studied, simulated and viewed for different purposes, in different disciplines, and at different detailing levels. It forms the base for human communication and interaction to meet the goals of all stakeholders in their study and development. Adding new technologies for man-model interaction and for the dynamic change of models and their viewing will further increase human possibilities for interaction and communication in the same co-located environment as well as in a virtual co-located environment. The paper will focus on a stereo interaction table environment as an important vehicle for integrated human-to-model and human-to-human interaction and some future possible developments.

Increasing competition forces companies to put products on the market as soon as possible, hence the need for research in concurrent engineering. Invention is the second main issue: since today products must be cheaper and better than the competition’s. This requires technological invention, which in turn necessitates research in creativity and problem solving theories. Our research interests are within these two academic domains: concurrent engineering processes and inventive solutions to technical problems. Starting from the specific situation of injection molding design, we identified the need to develop a new modeling approach for product and manufacturing molds that could link the powerful OTSM-TRIZ theory with concurrent engineering. We build our contribution on the parametric design model and cause-effect relationships; we propose guidelines to analyze and synthesize the resulting complex contradiction network in a single inventive redesign task. A plastic valve stem design is used for validation of the proposed approach.

From a generic point of view, the engineering design process can be considered as the transformation of needs into a complete product definition. Besides the needs, designers have to take into account some constraints. In this sense, the design process can be seen as a problem solving process, with some specific properties. Several models of the design process exist that consider this problem and its expression differently. We will question the consideration of the design problem in the classical approaches, and identify the relevance of co-evolutionary models to describe the design process, including its cognitive aspects. An activity-based co-evolutionary model of the design process is thus proposed, which defines and situates the objects implicated in evaluation and problem expression. A well-established design corpus is used to evaluate the relevance of the proposed approach to fit a real design process. The objective of the work described in this paper is to use this model as a basis to investigate the support of problem expression, and the activities that refer to it, in a concurrent engineering context.

The assessment of mechanical performances, in the automotive engineering domain, is mainly at present time, the result of late finite element analysis processes (FEA) which remain computationally expensive, limiting their use to the analysis of a limited number of design alternatives. But, in the conceptual design stage, the quality depends on the comprehension and on the exploration capabilities of the design space. This paper describes a strategy for building and more systematically exploring mechanical conceptual models, in the case of non-trivial expected mechanical performances. This strategy consists of a series of consistent stages: simplification of the parameterized structural model, choice of a subset of determining design parameters, computation of a limited number of approximate models of performances (metamodels obtained after a design of experiments and a model fitting) and a concept exploitation stage (deterministic exploration, optimization, non-deterministic exploration). This strategy has been successfully applied to assess vibro-acoustic performances of an automotive sub-frame. In this example, we show that designers have obtained useful information from the graphical and the numerical exploitation of this conceptual model. Moreover, this is now possible to take vibro-acoustic performances into account since the determining stage of envelope volumes allocation for sub-systems, a stage that is necessary in concurrent engineering for the automotive architecture deployment. Before, acousticians were not even able to negotiate with architects for a given volume allocation in regards to the possible consequences on the performances of which they were in charge.

Incorporating manufacturing flexibility into product styling is the next challenge of mass customisation. Fashionable or preferable style is widely accepted to visually enhance a product and satisfy the demands of today’s consumers. Considerable work remains to be done to integrate product styling (the process used to enhance visual aesthetics of a product) with manufacturing flexibility, platform approach. The initial findings from an exploratory study that consists of interviews and a research on “ look” style are reported. It examines the relationships between product style/styling and fashion trends on consumer’s preferences. The findings indicate that style can be manipulated by a proposed set of complex attributes. A particular style plus its application method(s) function together as an intangible module to refresh ordinary products. A framework of case-based indexing device is developed to support the above product styling platform approach. This study has opened up a wealth of interest towards the understanding and applying of the visual aesthetic aspects in meeting product styling challenges in the dynamic marketplace.

The evolution of manufacturing systems is triggered by the dynamic customer environment of its time. The main characteristics of today’s customers’ environment are mass customization and responsiveness to market demand and thus the reconfigurable manufacturing system was suggested for such environment. This paper presents a systematic approach for the design of reconfigurable manufacturing systems and how to control that design process through developing an open mixed architecture for that purpose. The architecture prescribes the different design activities starting from capturing market demand to the system-level configuration and finally the component-level implementation, and also provides some performance measures that are used to control the design process. An example of a reconfigurable automatic PCB assembly line is used to illustrate an application of the developed architecture in real world manufacturing system design.

Design of electronic-mechanical assemblies involves many disciplines, tasks, and a disparate set of CAD/CAE tools. The problem is to facilitate collaboration between them by increasing the interoperability between these tasks and their respective tools while maintaining the integrity of the designs, including constraint management. This paper will present the requirements envisioned for a ME-EE co-design environment called CrossTalk. It is hoped that the knowledge gained from this bottom approach will be used to design a framework for commercial ECAD-MCAD-CAE collaboration and communication that is specific to this cross-domain design but independent of proprietary file formats and software.

Recently, 3D CAD systems have been rapidly improving. However, the principal improvements have been focused on the geometric modeling and developing user-friendly operational improvements, while neglecting improvements to the treatment of the design information and the intention generated in the design process, especially to support the design process flow. In this process, it is important to transmit the design information and intention, considered by each design phase, to the downstream process. In this paper, we explain the framework to handle the design information including designers’ intention, and we discuss the architecture that supports the design process flow. First, we describe the integrated model of the geometric model and the design information. We propose the framework to treat various kinds of design information and the intention and present a typical example. Next, we describe the methodology to extend the proposed integrated model and also the architecture to support the design process flow. We define what design information should be handled and explain how to extend the integrated model to support the design process flow. Finally, we describe an application example of design process flow. The result shows an immediate specification of the design information and intention at the downstream process. The system supports the designers creating and modifying the geometric model correctly to satisfy the designers’ intention as the design progresses.