Research On Task Scheduling Optimization Of Four-Way Shuttle System

With the deepening of Industry 4.0 and "Made in China 2025",more logistics enterprises are accelerating transformation to intelligence,and various automated warehousing systems emerge in endlessly.As a new type of automated intensive warehousing system,the four-way shuttle system has received widespread attention and application due to its advantages of good flexibility,strong flexibility,and high space utilization.This paper takes the four-way shuttle system as the research object,and conducts research on the task scheduling optimization problem of the four-way shuttle system under two different operation modes:the tier-captive operation and the tier-to-tier operation.The specific research content is as follows:(1)Analysis of the tier-captive and the tier-to-tier operation process of the four way shuttle systemClassify the operation modes of the four-way shuttle system and analyze the system operation processes under different operation modes.By studying the composition of the hardware equipment and software system and characteristics of the four-way shuttle system,analyze and study the inbound,outbound,and compound operation processes under two operation modes of the tier-captive operation and the tier-to-tier operation.(2)Establishment and solution of task scheduling model for the tier-captive operationPropose and establish the task scheduling models for single operation and compound operation in response to the optimization problem of task scheduling in the tier-captive of the four-way shuttle system.Analyze the motion characteristics of the four-way shuttle and the cargo lift,taking into account factors such as the maximum running speed and acceleration of the four-way shuttle in the main lane and storage lane under empty and loaded conditions,the reversing time,and the loading(unloading)time of the four-way shuttle,with the goal of minimizing the total inbound and outbound operations time,and separately constructing the task scheduling models of single operation and compound operation under the tier-captive operation mode.Combining the advantages of ant colony algorithm and particle swarm algorithm,an ant colony-particle swarm fusion algorithm is designed for optimization and solution.The resulting task scheduling scheme can effectively improve the system’s operation efficiency under both operation modes,with single operation efficiency increasing by 8.36%to 13.49%and compound operation efficiency increasing by 13.33%to 16.91%.Meanwhile,compared to ant colony algorithm and particle swarm algorithm,the ant colony-particle swarm fusion algorithm proposed in this paper has higher average optimization efficiency and more stable performance.(3)Establishment and solution of task scheduling model for the tier-to-tier operationPropose and establish the tier-to-tier operation task scheduling models for single operation and compound operation.In the tier-to-tier operation mode,the number of four-way shuttle is less than the number of shelves in the system.A shuttle lift is installed at the end of the main lane to complete the tier-to-tier action of the shuttle.Analyze the tier-to-tier operation process of the shuttle,divide the movement process of the shuttle and the shuttle lift into three stages,consider factors such as the maximum speed and acceleration of the cargo lift and the shuttle lift,the difference in the speed of the four-way shuttle under empty and loaded conditions,and before and after reversing,constrain the uniqueness and continuity of tasks,as well as the collaborative operation of four-way shuttle,cargo lift,and shuttle lift,establish the tier-to-tier operation task scheduling models of single operation and compound operation with the goal of minimizing the total time of inbound and outbound operations in sequence.Design the hybrid particle swarm optimization algor-ithm to obtain the optimal task scheduling solution.Compared with random results,the optimization results obtained by using hybrid particle swarm optimization algorithm can effectively achieve the tier-to-tier operation task scheduling optimization for four-way shuttle under single operation and compound operation modes,with single operation efficiency increasing by 8.18%to 9.56%and compound operation effi ciency increasing by 15.00%to 19.24%.Based on the analysis of the tier-captive and tier-to-tier operation processes and equipment motion characteristics of the four-way shuttle system,this paper studies the optimization problem of task scheduling under two operation modes.The optimal task scheduling scheme obtained can improve the system’s operation efficiency under different operation modes and reduce enterprise costs.It has theoretical guidance significance for providing task scheduling modeling and practical significance for providing the optimal task scheduling solution for the four-way shuttle system.