Disassembly sequence planning identifies physically viable plans to disassemble an assembly of parts. It is often used in end-of-life product design to verify the future ability to disassemble the product for recycling or repairs. This field is crucial towards a more automated product design and manufacturing process.
We use motion planning to generate disassembly sequences. Our approach treats the parts in the assembly as robots and operates in the composite configuration space of all the individual parts. It then searches in this composite configuration space for a valid disassembly sequence using popular sampling-based motion planning techniques. We tackle the challenges of high dimensional composite configuration spaces and narrow passages arising from parts in close contact by biasing the sampling along potential movement directions. These potential movement directions are based on the geometric characteristics of configurations known to be reachable from the assembled configuration, such as the face normals of the parts. We also develop a method for subassembly identification based on collision information.
We propose a new general framework for disassembly sequence planning. This framework is a flexible method for the complete disassembly of an object; versatile in its nature, allowing different types of search schemes (exhaustive vs. preemptive), various part separation techniques, and the ability to group parts, or not, into subassemblies to improve the solution efficiency and parallelism. This gives the new ability to approach the disassembly sequence planning problem in a truly hierarchical way. By simply changing the definitions of the framework’s subroutines, a wide spectrum of disassembly search strategies may be achieved.