Assembly Sequence Planning Based on Contact-Relation Analysis

This paper presents an assembly sequence planning method with a capability to automatically select non-orthogonal assembling directions based on part contact-relation analysis.First,motion constraints for a part are created according to part contact-relations extracted from assembly model and instantaneous movable directions of the part are identified by solving the inequality constraints.Second,currently removable parts are determined by checking the existence of feasible disassembly paths constructed along the instantaneous movable directions.Finally,different layers of removable parts in an assembly are obtained by repeating the above two steps and the reverse order of the layers is regarded as the assembly sequence.The experimental results are presented and they show that the method is effective and efficient.