ASSEMBLY-DESIGN-ORIENTED SEMANTIC MODELING AND ASSEMBLY CONFIGURATION SIMULATION IN VIRTUAL ENVIRONMENT

Usually, virtual assembly simulation is based on fixed assembly relationships between parts which are extracted from product's CAD models. And virtual assembly systems is mainly used to evaluate product assemblability. In order to enhance the function of virtual assembly system to more assembly design-oriented, a method of dynamic assembly configuration based on part's semantic modeling is presented. The part's semantic model contains assembly features, semantic attributes and physical properties of a part. The uniformed part semantic information is defined based on part's STEP models and described in XML, format. Assembly process simulation for dynamic assembly relationship configuration is realized by semantic reasoning, such as the reasoning to determine mating parts, mating positions, construction/solving/navigation of geometry constraints, and generation and modification of assembly relationships. The method supports the assembly processes simulation from single parts to produce the entire assembly in the virtual environments and works without predefined associations between parts. A prototype system is developed and demonstrated with an excavator. The results show that different assembly configurations for product assembly design can be obtained and the assemblability can be evaluated during the virtual assembly simulation process.