Assembly partitioning along simple paths: the case of multiple translations

Abstract

We consider the following problem that arises in mechanical assembly planning: given an assembly, identify a subassembly that can be removed as a rigid object without disturbing the rest of the assembly. This is the assembly partitioning problem. Specifically, we consider planar assemblies of simple polygons and subassembly removal paths consisting of a single finite translation followed by a translation to infinity. Such paths are typical of the capabilities of simple actuators in fixed automation and other high-volume assembly machines. We present a polynomial-time algorithm to identify such a subassembly and removal path or report that none exists. In addition, we extend this algorithm and analysis to removal paths consisting of a small number k > 2 of translations. We discuss extending the algorithm to three dimensions and to other types of motions typical in non-robotic automated assembly.