A genetic algorithm for automatic packing in rapid prototyping processes

Rapid prototyping (RP) is an emerging technology for creating physical prototypes from three-dimensional computer aided design models by using the additive process with layers. The loading multiple parts into the building space of RIP machines, which is a packing optimization problem, is considered as the most important factor to maximize the utilization of space in the building cylinder and reduce building time. To obtain optimized packing result, a genetic algorithm (GA) Is developed and implemented. In this paper, chromosomes consist of two segments: one represent the sequence of parts packing by transposition expression, the other represent the rotation mode of parts. This paper will detail the development of a specific algorithm to solve the conversion between the scanning sequence and part layout in two-dimension packing and three-dimension packing of RP processes. Experiments show that the building space is to be used more productively by this packing method for multiple parts.