Research On The Techniques Of Information Integration For Digital Assembly And CAD

The information integration from the initial design of the product to assembly planning is an important foundation to realizing automatic and flexible assembly. Study on feature information conversion from design domain to assemble domain not only enriches and prefects feature technology, but also presents a general way to acquire assembly feature in assembly process analysis. Applying assembly features, the assembly planning is studied. Based on the introduction of the project background and an overview of interrelated research, these problems are researched such as features classification and expression , the mathematical model of feature mapping, the mapping approach, and assembly sequence planning in this thesis.Analyzing engineering activity in design domain and assembly domain, the features classification and representation in design domain and assembly domain are discussed. The product's design features express as part's design information and an information of assembly intention, and the product's assembly features express as the set of part's feature, liaisons' feature and technological feature. An integration system based on feature mapping is proposed.By the set theory, the principle of features mapping is studied. Through the features' multiple mapping, the mathematical model of feature mapping from design domain to assembly domain is constructed. The conversion of feature information in different levels has been described systematically. The feature mapping is implemented through a direct feature mapping system.On the basis of the feature mapping model, the classification and representation of feature facets are described. Parts' form feature mapping is proposed by a constraint matching approach. And some key issues of part's feature mapping and practical steps of feature mapping are studied.By the geometric test and geometric reason, the constraint relation and liaison relation between parts are determined. From this, the reason rules are studied, and the mating type between parts and the operation to assemble these parts are determined. The mapping approach of liaison' features and technology features are research.Applying assembly features information, the precedence constraint for parts' connection is described by three classes: geometrical precedence constraints, special component precedence constraints, and technological precedence constraints. Thefeasible of assembly tools is discussed preliminarily. Combining the advantages of the decomposition method and precedence constrain method, a generation of assembly sequence in concurrent engineering is proposed and verified by the example.The project is supported by Robotics Laboratory, Chinese Academy of Sciences foundation (No: RL199905).