Method for discriminating geometric feasibility in assembly planning based on extended and turning interference matrix

摘要

Geometric feasibility (GF) of components is the precondition for assembly/disassembly sequence planning (ASP/DSP), and interference matrix is an important assembly relation model for GF discrimination. Extended interference matrix (EIM) is proposed to determine GF in the slanting directions, whose descriptive directions are extended to axes of a local coordinate system in each component. Turning interference matrix (TIM) is proposed to analyze the GF of the component that must be assembled with a multidirectional path, with the structure compact enough to describe the interference information from a turning point. The methods for acquiring EIM and TIM rapidly and automatically are proposed, including the stepping precise detection, the rough detection, and the accelerated detection based on bounding box. The measures for restraining static hard interference automatically are studied. An algorithm for discriminating GF comprehensively based on EIM and TIM is then presented. An ASP system "AutoAssem" is developed, with two instances illustrating the effectiveness of each interference detection method. EIM and TIM are testified to enrich the variety and variability of assembly directions, which provide great universality to the GF determination of large-scale assemblies, together with an effective foundation to ASP/DSP algorithms.