Modelingand Optimization Of Double-load Single-deep Multi-tier Shuttle System

In recent years,with the increasing prosperity of E-commerce,the E-commerce logistics has entered a new stage of rapid development.Against this background,how to process massive orders efficiently,and how to distribute goods quickly become the problems of E-commerce logistics.Multi-tier Shuttle-based Storage and Retrival System(MSS/RS)is a new type of "Parts-to-People" picking system,because of the quick response and the excellent storage capability,MSS/RS gradually become the main storage form of e-commerce enterprise.Aiming at the problem of how to improve the efficiency of the Multi-tier shuttle system,the Double-load Single-deep Multi-tier Shuttle System studied in this paper is configurated with double-load shuttles and single-deep racks,combines shuttles and lifts to complete the outbound tasks.In an ideal case,the shuttle can load the goods on both sides of an aisle in one stop,and there is no need of rearrangement operations.Compared with the traditional single-load single-deep multi-tier shuttle system,outbound efficiency is improved relatively.Firstly,this paper introduces the research overview,system components,storage and retrieval process of the Multi-tier Shuttle System.After analyzing the time-sequence characteristics of the system's outbound operation,the outbound operation model of the Double-load Single-deep Multi-tier Shuttle System was established,which laid the foundation for the design of the system's storage allocation and task scheduling algorithm.Secondly,according to the characteristics of the outbound operation of the Double-load Single-deep Multi-tier Shuttle System,and considering the outbound frequency of the goods and the correlation between the goods,the frequency-correlation storage allocation principle is designed,and simulation experiments are designed to verify this storage principle;at the same time,in order to compare the order delivery time of the Double-load Single-deep Multi-tier Shuttle System and other Multi-tier Shuttle Systems in different situations,the same principle was used to establish the time-sequence model and design the storage allocation principle of the Single-load Single-deep Multi-tier Shuttle System and Double-load Double-deep Multi-tier Shuttle System.Finally,the order of outbound tasks of this system is optimized.This paper takes the shortest order delivery time as the optimization goal,uses the Max-Min Ant Colony algorithm to sort the delivery tasks of the Multi-tier Shuttle System to obtain the optimal operation sequence of the outbound task.And simulation experiment is designed to verify the outbound efficiency of different Multi-tier Shuttle Systems under the optimal order of outbound.By changing the system storage capacity,outbound order structure,the number of shuttles and lifts,the number of storage columns in the aisle,the maximum speed and acceleration of the shuttle and lift and other variables,this paper studies the applicability of different forms of Multi-tier Shuttle Systems under various scenarios,and provides a theoretical basis for enterprises to choose a suitable Multi-tier Shuttle Systems.