Automated disassembly sequence planning and optimization

Disassembly is an important activity which directly governs the cost of products. Literature reveals that much of the research has been focused on assembly sequence planning. The disassembly planning problem, however, needs a separate consideration on account of the need for partial disassembly and other constraints. This paper reports the seamless design and implementation of a software system which automatically determines how to disassemble a product completely, given only a geometric description of the assembly. The system is conceptually divided into two stages. The first stage takes the CAD model of the product assembly as input, which generates interference matrices for principal directions (±x, ±y, ±z). A precedence relationship is determined from these interference matrices to aid in the generation of disassembly sequences. In the second stage a user defined fitness function is proposed with the objective of minimizing the number of reorientations and tool changes during disassembly. An enhanced Genetic Algorithm was designed and implemented to generate optimum solution(s) with the help of this function. A module was implemented to visually simulate the optimum disassembly sequence generated by above algorithm. The system was found to efficiently generate logical, optimum disassembly sequences.