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This paper aims to investigate a CAD model simplification method with appearance and assembly feature preservation in order to demonstrate and interact with the virtual assembly process of complex product efficiently. Firstly, the invisible features of current-assembled-state assembly model are detected and removed by pre-rendering the assembly model from multiple view directions to reduce data volume and preserve the appearance. Subsequently, the notion of 'conjugation' is incorporated into the definition of assembly features to guide assembly feature recognition. The attributed adjacency graphs (AAGs) of the simplified current-assembled-state assembly model and to-be-assembled components are established. Then, the assembly features on currently selected to-be-assembled component are automatically recognized by searching conjugated subgraphs between the AAG corresponding to currently selected to-be-assembled component and other AAGs based on improved subgraph isomorphism algorithm. After that, simplified CAD model of the to-be-assembled component with its assembly features preserved is constructed by suppressing the common form features, so that it can complete assembly process fluently with the current-assembled-state assembly model. Finally, this method is applied successfully to several cases and the result shows its feasibility and superiority. [ABSTRACT FROM AUTHOR]

This paper gives a brief introduction to establishing a knowledge-based system for intelligent stamping process planning. Studies on the system’s framework, knowledge model and reasoning mode are introduced. Some key technologies such as the feasibility of the stamping process, an optimal algorithm for blank layout, intelligent strip layout and force calculation are researched. The efficiency of stamping process planning can be improved by the system. [ABSTRACT FROM AUTHOR]

Geometric feasibility (GF) of components is the precondition for assembly/disassembly sequence planning (ASP/DSP), and interference matrix is an important assembly relation model for GF discrimination. Extended interference matrix (EIM) is proposed to determine GF in the slanting directions, whose descriptive directions are extended to axes of a local coordinate system in each component. Turning interference matrix (TIM) is proposed to analyze the GF of the component that must be assembled with a multidirectional path, with the structure compact enough to describe the interference information from a turning point. The methods for acquiring EIM and TIM rapidly and automatically are proposed, including the stepping precise detection, the rough detection, and the accelerated detection based on bounding box. The measures for restraining static hard interference automatically are studied. An algorithm for discriminating GF comprehensively based on EIM and TIM is then presented. An ASP system 'AutoAssem' is developed, with two instances illustrating the effectiveness of each interference detection method. EIM and TIM are testified to enrich the variety and variability of assembly directions, which provide great universality to the GF determination of large-scale assemblies, together with an effective foundation to ASP/DSP algorithms. [ABSTRACT FROM AUTHOR]

In order to realize automation and intelligence of product disassembly process in a virtual maintenance environment, an improved max-min ant system based methodology for product disassembly sequence planning was proposed. The feasibility graph for product disassembly process was defined and the mathematic model of product disassembly sequence planning problem was set up. Thus, the problem of product disassembly sequence planning was transformed into the problem of searching optimal path on a feasibility graph. Moreover, an improved max-min ant system based on the strategy of sorting elite ants was presented and the flowchart of the improved algorithm was designed. Finally, by simulation examples, the robustness and outperforming others of the improved algorithm were verified. [ABSTRACT FROM AUTHOR]