Research On Theory,Method And Application Of Multi-Hierarchy Collaborative Modeling For Component-Based Digital Mock-up

This paper researches the theory and method of multi-hierarchy collaborative modeling for component-based digital mock-up. Mechanism model is retrieved automatically based on assembly model and design semantics. The interactive and real-time characteristics during simulation are promoted through the hierarchical composite simulation modeling. The network oriented application services of collaborative assembly and simulation are setup through the component-based representation of the digital mock-up unit. A digital mock-up simulation prototype system is developed. The theory and method suggested have been successfully applied to some research projects, good results have been achieved.Chapter one first summarizes the status in quo of component-based and multi-level modeling technique, product collaborative development technique, and digital mock-up modeling technique, then discusses the existent problem. The research's significance and the contents are discussed.Chapter two discusses the product basic model representation for digital mock-up. The hierarchical part model is established in order to satisfy the different analysis requirement for digital mock-up. The organization and management of assembly model provide the information source for disassembly of digital mock-up and the mechanism extraction. The mechanism model is setup automatically based on the assembly model and engineering semantics information. A basic information model for digital mock-up is produced by integration of hierarchical part information, assembly model and mechanism model.Chapter three sets up a geometry-based solution algorithm for digital mock-up consisting of closed kinematics loops. The kinematics geometric expression for primary and second joints is established using the Lie group geometric concept and exponential product formulation. The acceleration constraint equation is obtained based on the six DOF model of secondary joint. Using the Baumgarte constraint stabilization method and articulated body algorithm the geometry-based solution algorithm for digital mock-up consisting of closed kinematics loops is founded.Chapter four researches the hierarchical composite simulation modeling technique for digital mock-up. A kinetic simulation method based on solid-skeleton composite simulation model is suggested. The combination expression of simulation model is adjusted according to the interactive requirement and the analysis of the complexity of thedigital mock-up, the composite simulation model consisting of solid model, joint skeleton model and part skeleton model is produced. This method can realize the interactive and real-time characteristics of the simulation.Chapter five carries out the research of collaborative assembly for component-based digital mock-up unit. To set up integrated digital mock-up model rapidly, a component-based collaborative assembly method is presented. In this method a component-based representation of digital mock-up is established using the port-based modelling method. Based on the representation, collaborative assembly architecture is built. In this architecture the assembly process is divided into three basic steps: connection element grasp and drag, assembly pre-processing, component assembly. This method simplifies assembly process and improves the efficiency of assembly modelling. In the end the solution space of collaborative assembly is analysed.Chapter six researches collaborative simulation model technique for component-based digital mock-up. The simulation primary component is setup using the port-based modeling method based. The full connection between simulation components is established rapidly based on the configuration semantics as a configuration template. A simulation-oriented service architecture is setup based on the simulation component, configuration semantics and simulation collaborator. In this architecture two simulation mode are established: network collaborative simulation and local collaborative simulation.Chapter seven develops the prototype system for component-based digital mock-up simulation system and applies it into the practical product design. Based on the multi-hierarchy collaborative modeling theory and method for component digital mock-up the DMUSim system is developed, the shaft-piston mechanism of car engine, moon buggy, and Mini baja as the application examples are experimented on DMUSim.Chapter eight summarizes the research results of this paper, and gives the way for further research.