Research On The Configuration And Optimization Of Multi-tier Shuttle-based Storage And Retrieval System With Double I/Os

With the increasing demand for logistics efficiency in the e-commerce industry,the mismatch of equipment utilization and low overall efficiency in the traditional single-IO automatic vehicle storage and retrieval system(MSS/RS)have become increasingly prominent.New MSS/RS models,such as MSS/RS with cross-layer operation,can solve the resource waste caused by service rate mismatch between service providers,but the inefficiency of access and storage is still the bottleneck restricting its wide application in e-commerce environment.This paper presents an MSS/RS system with double I/Os.At the same time,the efficiency of warehouse throughput is greatly improved,which has good engineering application value.Firstly,a new model of automatic vehicle storage and retrieval system with double I/Os is designed.Through the decomposition of the system structure,the characteristics of the automatic vehicle storage and retrieval system with double IOs are shown.Based on the system physical model,the work logic and complete work flow of the out-bounding and in-bounding operations are further explained.It lays a physical foundation for the establishment of system model and performance analysis.Secondly,aiming at the characteristics of the MSS/RS with double I/Os,kinematics model,the MSS/RS job sequencing model and the system queuing network model are established.Based on the above mathematical model,the sensitivity of the system is analyzed,and the effects of different rack structures and I/Os’locations on the system performance are studied.The model is verified by experiments,which shows the accuracy of the mathematical model established in this paper.Thirdly,with the lowest order throughput time and the lowest total system cost as the optimization objectives,the multi-objective optimization model is established with the constraints of customer requirements for storage capacity,storage efficiency and order delay time.The decomposition-based multi-objective optimization algorithm(MOEA/D)is used to solve the problem,and the multi-objective optimization results of the system are obtained under the premise of limited resources.Finally,the simulation results show the effectiveness of the optimization algorithm.