An experience-based assembly sequence planner for mechanical assemblies

Abstract

This paper presents an approach to the assembly sequence planning problem based on a "plan reuse" philosophy. Most of assembly planning research in the past has attempted to completely plan each problem from scratch. This research shows that stored cases of basic assembly configurations can be applied to a given assembly problem. It is observed that the number of such basic assembly configurations is quite small. In the first phase of planning (EVALUATOR phase), the assembly is divided into a number of constituent configurations, which are called "loops". These act as subgoals in its search for solutions (RETRIEVER phase). Plans retrieved for all the subgoals are fused into a set of plans that are consistent with the constraints implied by each plan (MODIFIER and COMPOSITER phases). Application specific constraints on the assembly are explicitly handled in the final phase of planning (POSTPROCESSOR phase).