| At the same time as the global economy is developing rapidly,the intelligent manufacturing industry plays a key role in this development process.At the same time,the research on the composition system related to material management has also drawn special attention from domestic and foreign researchers.Automated Storage/Retrieval System(AS/RS)plays a major role in the current social intelligent material management system,which integrates all aspects of material information and has an impact on the development of the entire material storage system in terms of intelligence,data and information.Among them,the output efficiency of AS/RS directly affects the production efficiency and benefit of the demand side.In the AS/RS with a circular track system,the Rail Guided Vehicle(RGV)system is a key link in the material handling system.Improper scheduling can cause blockages or deadlocks,resulting in inefficient access to the entire AS/RS.Therefore,how to optimize the dispatching of the circular rail RGV delivery operations to improve the output efficiency of the warehouse system,bring greater benefits to the enterprise,improve customer satisfaction,and bring greater challenges to the logistics industry.This paper studies the scheduling problem of circular 2-RGV system during AS/RS delivery process.The paper first discusses the relevant research background,significance and main research content of AS/RS and RGV;then reviews the domestic and foreign research results of AS/RS,RGV system scheduling,and related scheduling algorithms;second,it has a circular orbit during the AS/RS output process of the 2-RGV system,two rail guided vehicles are prone to collision or deadlock during the transportation process.To avoid this situation,the shelf access area and the delivery station are divided into two the overlapping areas,and the task instructions issued in the two non-overlapping areas are assigned to the two shuttles,establishing constraints such as the order of output,the order of picking the goods by the stacker,and RGV collision avoidance.The mixed integer programming model of RGV output job scheduling problem,the goal is to minimize the total output time of all goods;again,combined with the regional circular 2-RGV delivery job scheduling feature,a variable neighborhood search algorithm is designed to solve the problem.The design of the algorithm mainly includes:(1)The initial solution is constructed by combining the characteristics of the ring rail shuttle and the picking sequence of the stacker.(2)In the process of designing the neighborhood,this paper uses the advantages of three feasible neighborhood structures to broaden the depth of the variable neighborhood search algorithm in the feasible neighborhood.(3)When performing local search,the local search is performed based on the characteristic that the circular track RGV has a common working area when performing tasks in combination with the designed algorithm.Finally,taking a company's ring-shaped track automated three-dimensional warehouse as an example,the improved variable neighborhood search algorithm designed according to the characteristics of the research problem is compared with CPLEX to evaluate the calculation performance of the algorithm.The results of the example prove that the improved variable neighborhood search algorithm is better than CPLEX in terms of solution performance,especially in the case of a large number of delivery samples,the algorithm has better solution effect and more stable solution time the constructed models and algorithms can effectively solve this research problem. |
PDF Full Text Request