A simulation framework for assembly/disassembly process modelling
Résumé
Simulations of Assembly/Disassembly (A/D) processes covers a large range of objectives, i.e. A/D sequencing, path finding, ergonomic analysis …, where the 3D shape description of the component plays a key role. In addition, the A/D simulations can be performed either from an automated or interactive point of view using standard computer equipment or through immersive and real-time simulation schemes. In order to address this diversity of configurations, this paper presents a simulation framework for A/D analysis based on a new simulation preparation process which allows a simulation process to address up to two types of shape representations, i.e. B-Rep NURBS and polyhedral ones, at the same time, thus handling efficiently the configurations where 3D shape representations of assemblies play a key role. In order to illustrate the simulation preparation process some specific steps are addressed. To this end, the automatic identification of contacts in a 3D product model and their corresponding list is described. After this first stage of identification, an interpretation of the results is needed in order to have the complete list with the mechanical contacts for a product. During the preparation process, three major stages of the framework are detailed: model tessellation, surface merging and contacts identification. Our framework is based on STEP exchange format. The contacts are related to basic geometrical surfaces like: planes, cylinders, cones, spheres. Some examples are provided in order to illustrate the contributions of the proposed framework. This software environment can assist designers to achieve a satisfactory assembly analysis rapidly and can reduce the lead-time of product development. Further consequences of the present work is its ability to produce models and treatments that improve integration of assembly models in immersive environments taking into account of the haptic and visual models needed.