Dual-objective optimization of compound operations in tier-to-tier shuttle-based storage and retrieval system

Abstract Considering the characteristics compound operations in tier-to-tier multi-shuttle system, the different sequence of warehouse tasks will lead to different working paths of the shuttles and the lifts, which will affect the operating time and energy consumption of the system. In order to reduce the operation time and energy consumption of the tier-to-tier multi-shuttle system, the dual-objective model with the shuttle operation time and energy consumption is established according to the system process compound operations scenario. According to the characteristics of the model, a hybrid particle swarm optimization-genetic simulated annealing two-level algorithm, is put forward. Then, the numerical example is calculated to verify the validity of the model and the algorithms. The experimental results show that the dual-objective model can reduce energy consumption and shuttle travel time better than the single time objective model, and can reduce time and improve work efficiency more effectively than the single energy consumption objective model.