C-space cell defragmentation for general translational assembly planning

We present an exact and practical incremental method for general translational assembly planning. In practical cases, an exact and complete representation of the relevant free regions in the high-dimensional assembly configuration space becomes amenable by incrementally computing an arrangement of cells in d-dimensional space. Here we introduce a novel reduction scheme, D-node reduction, that allows for online defragmentation of the computed cell decomposition and thus significant speedup and reduction of storage requirements. Experimental results for both two- and three-dimensional assemblies show the practicality of the proposed approach and illustrate the impact of the new reduction scheme.