Research On Performance Comparison And Configuration Optimization Of Automated Vehicle Storage/Retrieval System Based On Mobile Charging And Fixed Charging

With the rapid development of the logistics industry in the direction of intelligence and wisdom,the automated storage retrieval system is prompted.There are various forms of automated warehouses:Automated Storage/Retrieval System(AS/RS)and Automated Vehicle Storage/Retrieval System(AVS/RS),etc.Among them,AVS/RS has been widely used due to its high stability and good system performance in recent years.According to the different charging methods of the shuttles,AVS/RS can be divided into two types:mobile-charging AVS/RS and fixed-charging AVS/RS(hereinafter referred to as mobile charging systems and fixed charging systems).The two systems differ in terms of performance indicators and costs,but both have a certain market in practical applications.At present,there is little literature on the comparative analysis of the two systems,so at the stage of equipment selecting in early system construction,there is no corresponding theoretical basis to guide enterprises in the selection of equipment,resulting in difficulties in the selection of the two systems,which brings great inconvenience to enterprises.This paper analyses the performance differences and configuration selection of the two systems,with a view to providing theoretical guidance on system selection for enterprises in the early stages of logistics and distribution construction.For the above reasons,the following work is carried out in this paper:1.The system layout and operational process of the mobile charging system and the fixed charging system are analyzed;the mechanical structure and functional role of the individual hardware devices in the system are introduced;and the differences between the two systems in terms of structural layout and task process are investigated.2.Open Queuing Network models are developed for each of the two systems,and the system performance metrics including throughput and order completion cycle are obtained through model solving;the accuracy of the proposed models is verified through simulation experiments.On this basis,the performance differences between the two systems are investigated under various scenarios with different shelf layouts;by calculating the performance indicators of the two systems under the same configuration,the results show that the throughput of the fixed charging system is lower than that of the mobile charging system,while the order completion cycle is higher than that of the mobile charging system.3.A heuristic algorithm based on a greedy algorithm is proposed to solve the configuration optimization problem for a single mobile charging system or a fixed charging system.The algorithm allows the calculation of the optimal configuration of both systems for a given requirement with the lowest cost as the objective.In addition,a sensitivity analysis of the throughput,number of cargo spaces,shuttle cost ratio and capacitance ratio of customer demand on the system cost is carried out.The data analysis shows that a fixed charging system is preferred when the number of spaces is larger,the throughput is smaller,the shuttle car cost ratio is smaller and the capacitance ratio is smaller,while a mobile charging system is preferred when the number of spaces is smaller,the throughput is larger,the shuttle car cost ratio is larger and the capacitance ratio is larger.4.For a hybrid charging shuttle system containing both mobile charging shuttles and fixed charging shuttles,the optimal configuration of the two different charging types of shuttles in the system is investigated,with the objective function being the lowest cost under the constraints of throughput and order completion time;a system configuration optimization algorithm based on an ant colony algorithm is proposed to solve the problem,and finally the effectiveness of the configuration algorithm is verified through experiments.Finally,the effectiveness of the configuration algorithm was verified experimentally.The results show that the cost of the hybrid charging system decreases by about 5%compared to the cost of a single charging system under the same throughput and order completion cycle requirements.This paper designs different configuration algorithms to solve the optimal configuration problem of different types of AVS/RS,starting from the selection requirements of different AVS/RS,completes the calculation of the optimal configuration scheme of the system under the condition of satisfying the customer’s needs,and provides guidance in the selection of the system for the subsequent construction of the logistics center.The research in this paper can reduce the customer’s investment in the early stage of warehouse construction,and has certain theoretical significance for the development of enterprises and the logistics field.