Accession Number : ADA326085

Title :   On the Complexity of Partitioning an Assembly.

Corporate Author : STANFORD UNIV CA DEPT OF COMPUTER SCIENCE

Personal Author(s) : Wilson, Randall H. ; Latombe, Jean-Claude ; Lozano-Perez, Tomas

PDF Url : ADA326085

Report Date : DEC 1992

Pagination or Media Count : 15

Abstract : We consider the following problem that arises in 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 called the assembly partitioning problem. Polynomial-time solutions have been presented when the motions allowed for the separation are of certain restricted types. We show that for assemblies of polyhedra, the partitioning problem for arbitrary sequences of translations is NP-complete. The reduction is from 3-SAT. The proof applies equally when each part in the assembly is limited to a constant number of vertices; when rotations are allowed; when both subassemblies are required to be connected; and for assemblies in the plane where each part may consist of a number of unconnected polygons.

Descriptors :   *HEURISTIC METHODS, *SYSTEMS ANALYSIS, MATHEMATICAL MODELS, ALGORITHMS, TIME DEPENDENCE, ASSEMBLY, APPLIED MATHEMATICS, COMPUTER AIDED INSTRUCTION, CONTROL SEQUENCES.

Subject Categories : Operations Research
      Computer Programming and Software

Distribution Statement : APPROVED FOR PUBLIC RELEASE