Research On Configuration And Task Scheduling Of Tier-to-tier Shuttle-based Storage And Retrieval System

As an advanced type of automatic storage solution,the tier-to-tier shuttle-based storage and retrieval system has been widely used in scenarios with high storage requirements and low sorting requirements due to its advantages of flexibility and stability.However,due to factors that include the rack design,equipment selection and its number,it's difficult to design a storage system perfectly.In addition,the lift and the shuttle undertake the vertical and horizontal movement respectively,higher requirements are put forward for the cooperative scheduling of the shuttle and lift to improve the system's efficiency.Therefore,the tier-to-tier shuttle-based storage and retrieval system is taken as the research object in the thesis,and the research goal is to optimize the storage resource allocation and the task scheduling problem.The main research contents are as follows:(1)Research on the operation of the tier-to-tier shuttle-based storage and retrieval system.Based on the study of the storage layout of the tier-to-tier shuttle-based storage and retrieval system in engineering practice and the operating characteristics of the main equipment,the workflow of the system executing the single command cycle and the compound command cycle are analyzed to summarize and decompose the operation processes.(2)Research on the configuration of the tier-to-tier shuttle-based storage and retrieval system.A multi-objective optimization model for storage resource allocation is proposed.The number of shelves and columns,the number of shuttles,the maximum speed and acceleration of the shuttle,and the maximum speed andacceleration of the lift consist of the decision variables of the optimization model.The objectives of the model are maximizing the warehouse throughput,minimizing the initial construction investment and the operating energy consumption.A NSGA-? algorithm is designed to solve the problem,and non-inferior solution set is obtained and analyzed,which can be used as a reference for the design of the tier-to-tier shuttle-based storage and retrieval system.(3)Research on task scheduling of the tier-to-tier shuttle-based storage and retrieval system.A task scheduling model is built to minimize the order task completion time based on the analysis of operation process of the system's compound command cycle and the idea of the hybrid assembly line model of irrelevant parallel machines.And an improved artificial fish algorithm is designed to solve the problem.(4)Model and algorithm verification.A practical case of a domestic cooker company is analyzed and solved through the algorithm designed by Matlab,which verifies the validity of the multi-objective storage resource allocation model and task scheduling model.