Abstract: The freights loading based on balancing constraints aims to improve the utilization rate of the available capacity of the car and the balance level of the center of gravity as well. It is important for the safe and high performance of the freight transportation. In terms of the optimization of packing multi-category rectangular freights into multi-car, an idea is proposed that the freights are loaded symmetrically from the two sides of the cars. An improved GASP algorithm is designed to fulfill the freights loading process and two strategies are introduced to improve the initial result of the placement. Through moving parts of the freights in the intermediate positions, the optimization of the center of gravities for each loaded cars is realized. The instance demonstrates that the algorithm can quickly generate the balancing packing plan, by which the higher utilization rates of the cars and the safe requirements for the transportation are all well met.

Key words: freights loading, layout optimization, balancing constraints, heuristic algorithm