Research And Implement Of Several Key Techniques About Product Digital Pre-assembly

As a key technique of the advanced manufacture models such as Agent Manufacture & Virtual Manufacture, the Product Digital Pre-assembly attracts concerns from both academic and industrial circles. The virtual environment of the assembly is builded by data modeling to the product, so that to simulate and analyse the assembly process. Hence, can evaluate the assembly schema conveniently in the product reseach and design process, to find the assembly defaults and revise them as early as possible. Also we can feedback this assembly information to the product design step to optimize assembly design. Using this technology, we can discard the traditional physical prototype and use the digital prototype of the product instead. It is not only can be favourable to the deployment of Concurrent Engineering, but also can great reduce the product's design cost, increase the product's design efficiency, shorten the product's design cycle and so on, so it can improve the product's commercial competitive ability. There has be important theoretical and practical value to research the assembly sequences planning for the implement of Agile Manufacture, Virtual Manufacture and other advanced manufacture model.This dissertation associates with the co-operation project of the National High-technique Research & Development Planning, focuses on the researching and implement of several key technology of the Product Digital Pre-assembly. Which consists of assembly modelling, assembly sequences planning and evaluating etc..In the chapter 1, we briefly summarize the background and the present status of the Product Digital Pre-assembly at first. Then we point out the research emphasis of this dissertation.In the chapter 2, the architecture of the assembly sequences planning is discussed. First, we introduce the Product Digital Pre-assembly system. Then the architecture and development platform of the Digital Pre-assembly is presented.In the chapter 3, we discuss how to establish the Product Digital Pre-assembly model. First, several representative models of Product Digital Pre-assembly system are analysed; Then, we bring forward the discrete patch model, which is used in our Product Digital Pre-assembly system; In the end, the implement of the discrete patch model is discussed in detail.In the chapter 4, we mainly discuss assembly sequences planning. First the representative methods of assembly sequences are analysed and their characteristics are introduced. Then we bring forward the algorithm of the assembly sequences planning: Subassembly identification algorithm for assembly sequences planning. Flow Block Diagram of the assembly sequences algorithm bases on subassembly identification is presentated. Then the key technologies of the algorithm involved are discussed in detail, which include the construction of Attributed Liaison Graph and Weighted Attributed Liaison Graph; subassembly identification; disassemblability check of subassembly; subassembly evaluation and selection and the generation of assembly partial tree.In the chapter 5, a practical use case is given to verificate the validity of the algorithm.In the end, all of the works in this dissertation are summed up, and their futures are prospected.