A correct and complete algorithm for the generation of mechanical assembly sequences

Abstract

An algorithm for the generation of all mechanical assembly sequences for a given product is presented. It uses a relational model of assemblies. In addition to the geometry of the assembly, this model includes a representation of the attachments that bind parts together. The problem of generating the assembly sequences is transformed into the problem of generating disassembly sequences in which the disassembly tasks are the inverse of feasible assembly tasks. The problem of disassembling one assembly is decomposed into distinct disassembly subproblems. The algorithm returns the AND/OR graph representation of assembly sequences. The correctness of the algorithm is based on the assumption that it is always possible to decide correctly whether two subassemblies can be joined, based on geometrical and physical criteria. An approach to computing this decision is presented. An experimental implementation for the class of products made up of polyhedral and cylindrical parts with planar or cylindrical contacts among themselves is described. Bounds for the amount of computation involved are presented.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>