Frédéric Noël

Dynamic data sharing in a collaborative design environment

Based on expert engineering and collaborative work tools, the digital modelling of product development should now be realized in the context of life-cycle management. The objective is to develop a collaborative engineering design system and this paper focuses on the support of the dynamic sharing of design information as the main structuring element of collaboration. To enable information multi-representation, granularity expression, semantic encapsulation, updating and reuse, the design environment connects existing engineering tools and the specifically developed missing element able dynamically to share the data among designers.

The PPO design model with respect to digital enterprise technologies among product life cycle

The product–process–organization model, PPO, provides efficient assistance to collaboration during innovative design project. This model is dedicated to the development phase of new products for which product architecture is indeed not a priori defined and tasks will be set dynamically during the product development process. In an integrated design perspective, product behaviours must also be forecasted; that is achieved by assessing PPO behaviours. This paper presents the PPO model and the open IPPOP framework that instantiates this model. It investigates how such a model with such a digital platform may interact with other services used to assist other phases of the product life cycle.

A data structure dedicated to an integrated free-form surface meshing environment

A data structure is described, making available an efficient mesh adaptivity dedicated to free form surfaces. It relies on a link between the surfacic mesh and its corresponding geometric model, and ensures the preservation of the topologic compatibility between the mesh and the geometric model. Geometric compatibility, however, is discussed as a free constraint on the mesh. Finally, illustrations of the interest of this data structure in relation to the graph theory are presented through nodes sliding and mesh refinement techniques (i.e. a basic tool for r-adaptivity of a mesh).

Generation of quadrilateral meshes on free-form surfaces

Abstract Meshing is one of the main steps of the finite element method. Free-form surfaces are widely used but their meshing process is still not straightforward. Moreover, quadrilateral elements are less used because quadrilateral meshes are generated with more difficulty than triangular ones. Here, a new method is introduced to mesh free-form surfaces with quadrilateral elements. At first, a triangular mesh is used to generate each quadrilateral element by merging two adjacent triangles. For this purpose, a frontal method is used. Then the remaining triangles are eliminated by moving one of them towards another one in order to create a quadrilateral element. Next, the mesh is optimized by topologic operators which eliminate mesh singularities. A specific node repositioning scheme is used to further improve the shape of the elements. Ultimately, the goal is to obtain a mesh with the largest number of nodes belonging to four adjacent elements. Various topological operators are described. Some of them are complex and effectively move singularities across the quadrilateral mesh to improve it. Finally, examples illustrate the behaviour and the efficiency of the approach described.

A generic architecture to synchronise design models issued from heterogeneous business tools: towards more interoperability between design expertises

Product development involves many experts collaborating to the same design goal. Every expert has his own formalisms and tools leading to a high heterogeneity of information systems supporting design activities. Interoperability became a major challenge to avoid information incompatibility along the product life cycle. To synchronise heterogeneous representations of product will be a major step to integrate expert activities. In this paper, the authors propose a meta-model framework to connect together heterogeneous design models. This meta-model framework is used to formalise possible interactions between heterogeneous representations. Interaction formalisation is considered as a key point to synchronise heterogeneous models and to provide more interoperability between various computer assisted systems. The synchronisation loop is also presented as a major sequence of activities to manage collaborative design. Tools to support synchronisation are proposed. However, through a basic case study, authors highlight what can be automated and where human intervention is still expected.

Development of control mechanisms to support coherency of product model during cooperative design process

Product development became an increasingly collaborative and distributed activity. Collaborative design process gathers experts from different backgrounds and areas for a common objective about product development. An effective exchange support is expected to share and integrate design knowledge avoiding conflicts between designers. The management of heterogeneous product representation is a major step to integrate expert activities. To successfully manage this process, this paper proposes: (1) A research experimental platform for cooperative design in product development processes. (2) A new constraint based model to maintain complex relationships in multi-disciplinary cooperative design. (3) A model differentiation technique, which identifies differences and conflicts between models. (4) A Meta-rule concept, which controls the constraint network in design process, leading to a new notification mechanism to present conflict to all corresponding actors.

A collaborative platform architecture for coherence management in multi-view integrated product modelling

The increasing competition and complexity of product design require the collaboration of experts with different skills and from many disciplines who often work in a distributed environment and do not use the same description for the same object. Every expert having his own formalisms and tools, integration and collaboration of the expert tools has become a challenge to avoid design conflict along the product lifecycle. The synchronisation of heterogeneous representation of product will be a major step to integrate expert activities. In this paper, the authors propose 1) a constraint-based model to maintain complex relationships in multi-disciplinary collaborative design during synchronisation process, 2) a meta-rule concept to control the constraint network in design leading to a new notification mechanism for presenting conflict to all corresponding actors. These results should contribute to the improvement of collaborative design.

Tools for Dynamic Sharing of Collaborative Design Information

The development of Internet technologies supports the design of more efficient collaborative tools. This paper defines a collaborative environment based on theses technologies. It sets the conditions of use of this environment and points out the needs in information sharing. From this analysis we define tools whose functions complete currently available. Two new specific pieces of software illustrate the starting point of this environment development. The first tool, CoDVS, offers functions to archive data shared for the collaboration between actors. The XML format is used to achieve this goal while other functions give opportunities to update project data in a CVS fashion mode. The second tool, CoDISS, allows the dynamic definition of concepts shared by several actors, together with the connection of these data with the working parameters of each actor. Actors collaborate together by accessing this shared database that they can edit. They also automatically update their skill oriented models to reflect changes decided by their colleagues. Updates are automated with an API using the CORBA protocol.

Toward a Framework for Effective Collaborative Product Development

Collaborative product design is an approach for supporting designers connected by network, to participate in distributed and dynamic product development environment. Communication, negotiation, coordination and cooperation became essential for effective preparation and to follow-up design changes and conflicts. A collaborative environment requires a mechanism allowing the project actors to recognize and to resolve the interdependence-conflict among their respective terms. We suggest the use of constraint based system to facilitate and support the conflict resolution through synchronization process. This paper presents: (1) a framework to improve asynchronous as well as synchronous collaboration (2) a constraint based model for detecting design conflicts (3) a new notification mechanism for presenting conflict to all corresponding actors. These results should contribute to the improvement of collaborative design.

Shape optimization of three-dimensional parts based on a closed loop between structure analysis and geometric modelling

Optimization of three-dimensional parts is viewed here as optimization of the real design parameters found in geometric modellers, thus ensuring a part is usable in any further CAD treatment. Use of such a technique within the industrial design process is discussed. The B-Rep modelling technique forms the basis for the part geometry parameters. Design parameters are chosen or built up from these. A bi-directional link between surface description and location of nodes is described and provides good compatibility between the boundary geometry and the mesh throughout the optimization loops. Thus, objective and constraint functions both come from structure analysis and geometry implications. The necessary gradient computation of a mechanical criterion with respect to node location is processed by a method using an adjoin equation and a material derivative approach. An existing industrial mechanical solver can then be used, without any change being necessary: each development is performed using CAD software.