An approach to collaborative assembly design modification and assembly planning

Abstract

Product assembly design and assembly planning are two important steps in product development. The research presented in this thesis investigates a collaborative assembly design modification and assembly planning approach to improve the efficiency of product assembly design and assembly planning in a collaborative design environment. In order to realize effective collaborative assembly design, the design modification issues are first addressed, and a methodology to support the effective design modification in collaborative assembly design is developed. A co-assembly representation model is proposed and a design modification propagation control mechanism is developed, upon which a system framework that is suitable for realizing the design modification in collaborative assembly design is proposed and developed. To realize effective assembly planning, an enhanced assembly planning approach using a multi-objective genetic algorithm is developed. Firstly, a tolerancing approach is proposed to conclude the relative assemblability of different assembly sequences, and this relative assemblability is used as a constraint in the assembly planning. Secondly, a genetic algorithm with multiple search directions is proposed. Using this algorithm, more non-dominated solutions can be found while the experience of the decision maker is considered. To evaluate the product assembly design and modification, a set of redesign guidelines is proposed through the evaluation of the assembly planning results. Considering the detailed assembly process in the design stage, the design modification or redesign should be more practical and feasible. The aforementioned GA-based assembly planning approach is extended for collaborative assembly planning. This enables several planners to carry out the assembly planning collaboratively, and speed up the assembly planning process.