Interlocking Problem in Automatic Disassembly Planning and Two Solutions

In remanufacturing, disassembly is the first step to dismantle the end-of-life products into components, which is labour-intensive due to the variability of returned products. Compared to manual disassembly, robotic disassembly is a promising technique to automate remanufacturing processes, which liberates the human labours from the repetitive disassembly operations. However, it requires predesigned disassembly sequences which are planned manually. Several planning methods have been proposed to remove removable parts sequentially. However, those methods can fail in the disassembly sequence planning task if the product has interlocked components. This paper first explains the interlocking problem and then proposes two solutions. One solution is to identify subassemblies by using ‘separable pairs’. It complements conventional sequential disassembly planning methods and enables automatic detection of subassemblies online. Another method is based on a divide-and-conquer disassembly strategy which allows subassemblies to be detected before disassembly. This approach generates disassembly sequence plans that are hierarchical to avoid interlocking problems and reduce computational complexity.