Complexity reduction in geometric selective disassembly using the wave propagation abstraction

Disassembling a subset of components from an assembly, defined as selective disassembly, often occurs during product de-manufacturing (recycling, reuse and maintenance). Selective disassembly analysis of a product enables quick assessment of the design for de-manufacturing. This paper presents an approach to solve the following selective disassembly problem: given an assembly of n components and s (<n) selected components, automatically determine a disassembly sequence for s components with minimal component removals. In general, this analysis is computationally expensive, and typically exponential. In order to reduce the complexity for optimal sequencing, we propose a wave propagation (WP) approach of computational complexity O(sn/sup 2/). The WP approach defines: (i) disassembly waves, to topologically arrange the components and (ii) intersection events between the waves, to determine the selective disassembly sequences. The intersection events are prioritized and an optimal sequence is determined in polynomial time by evaluating only the candidate events for optimal sequencing, and in the order in which the events occur. The WP approach analyzes selective disassembly from the geometric perspective and is applicable for both 2D and 3D assemblies.