A Model Based Approach to Assembly Sequence Planning

This paper presents a systematic approach for automatic assembly sequence planning (ASP) by using an integrated framework of assembly relational model (ARM) and assembly process model (APM), which are established by object-oriented method. ARM, consisting of assembly, components and liaisons, is used to describe the geometric relationships between components in terms of contact, constraint and interference matrixes. And APM, containing states and sub-processes, is to represent all potential alternatives in assembly process. An algorithmic procedure is also presented, by which APM of an assembly can be constructed systematically by analysing states from lower levels to higher levels. Through the procedure, all feasible sequences of a product can be generated, and the optimum one can be determined by further evaluating each sequence. To explain the approach, a sample assembly with 4 components is always used throughout the paper.