Design And Control Strategy Of AGV-based Logistics Sorting System

The sorting process of logistics is basically in the stage of manual sorting,which has the problems of high error rate and low sorting efficiency.Automatic guided vehicle(AGV)instead of manual sorting and transportation of parcels can achieve a series of sorting operations in a small area,which has attracted more and more attention in modern logistics center.However,when the scale of the system is large,how to ensure the continuous and efficient operation of AGVs in the sorting system is still not well solved.Therefore,the AGV-based logistics sorting system is studied in this paper.On the basis of the overall design of the sorting system,the control strategy is analyzed in depth.The research work of this paper mainly includes four parts:(1)The overall design of AGV-based logistics sorting system.In this paper,an AGV-based logistics sorting system is designed in a discrete grid environment,and centralized control is adopted to the system.The regional function of the sorting platform is analyzed,and the operation network of AGV is constructed.The path planning of AGV is based on this network.(2)Simulation model of sorting system without control at intersections.According to the characteristics of the sorting system,the AGV movement rules and traffic control strategy are formulated.The weight of arc in AGV operation network is determined by considering AGV moving time,path update interval and other factors.The simulation results show that the path update interval has little effect on the efficiency of sorting system when the system capacity is small.When the system capacity is greater than200,the effect of the smaller path update interval on the sorting system is obviously better than that of the larger path update interval.(3)Simulation model of sorting system without stopping at intersections.According to the difference of route planning algorithm and platform simulation algorithm in the model,this simulation model can be divided into four types: improved label correcting-no prediction model(LCNP),improved label correcting-prediction model(LCP),subnetwork-no prediction model(SNNP)and subnetwork-prediction model(SNP).Simulation results show that the four models can be applied to large-scale logistics sorting system.The models using prediction algorithm are better than the models without prediction algorithm in system efficiency,and the subnetwork path planning method is better than the improved label correcting method when the path update interval is small.(4)This paper compares and analyzes the performance of sorting system without control at intersections and the sorting system without stopping at intersections.LCP and SNP model are the best in the system sorting efficiency.The LCP model is used to study the influence of sorting entrance distribution and parcel delivery area on the sorting system efficiency.The simulation results show that the sorting efficiency of the system with uniform distribution of sorting entrances is better than that with centralized distribution.The sorting entrances are distributed on both sides,and the efficiency of the sorting system is higher than that of the sorting entrances only on one side.When the density of parcel delivery area is small and the distribution is uniform,the sorting efficiency and stability of the system are higher.