Research On Assembly Sequence Modeling And Planning For Collaborative Assembly

As one of the key technologies of product design, collaborative assembly can be adopted to improve the efficiency of assembly design and reduce the cost of assembly. It is highly needed to study the collaborative assembly design.Firstly, a system framework for collaborative assembly design that includes model representation, information modeling, conflict resolution and assembly optimization is presented, and the collaborative assembly sequence planning method for complex products is investigated.Secondly, based on analysis of general assembly design process for function and assembly relation among components, a two-layer assembly sequence planning model is proposed for assembly sequence planning. Furthermore, several principles based on function features of non-core component to simplify the assembly tree model are yielded. In order to make the planning of assembly sequence, a precedence relation matrix is yielded from precedence relation directed graph and the detailed processes are described. An assembly cost evaluation criteria in which total cost of assembly is based on change times of assembly direction during assembling process and motion uncertainty of assembled component is proposed.Thirdly, based on the proposed assembly model, genetic arithmetic is adopted to conduct the assembly sequence planning. And the assembly sequence is yielded and optimized. An inference method based on the assembly precedence relation matrix is used to verify the feasibility of the assembly sequence and calculate the assembly intervene numbers in the assembly sequence.Lastly, an assembly of automobile rear floor is used as an example to verify the validity of proposed model and genetic arithmetic of assembly sequence planning. In the end of the dissertation, summary and future trends of research are outlined.