A Deadlock-Avoidance Dispatching Method for Multiple-Load AGVs Based Transportation System  

基于多载量AGV的运输系统死锁避免调度方法

作　　者：XIAO Haining WU Xing ZOU Ting ZHAI Jingjing 肖海宁;武星;邹婷;翟晶晶(盐城工学院机械工程学院,盐城224051;南京航空航天大学机电学院,南京210016;纽芬兰纪念大学机械工程系,加拿大圣约翰市A1B 3X5)

机构地区：[1]School of Mechanical Engineering,Yancheng Institute of Technology,Yancheng 224051,P.R.China [2]College of Mechanical and Electrical Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,P.R.China [3]Department of Mechanical Engineering,Memorial University of Newfoundland,St.John’s A1B 3X5,Canada

出　　处：《Transactions of Nanjing University of Aeronautics and Astronautics》2021年第1期181-192,共12页南京航空航天大学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.52005427,61973154);the National Defense Basic Scientific Research Program of China(No.JCKY2018605C004);the Natural Science Research Project of Jiangsu Higher Education Institutions(Nos.19KJB510013,18KJA460009);the Foundation of Graduate Innovation Center in Nanjing University of Aeronautics and Astronautics(No.KFJJ20190516)。

摘　　要：In recent years,multiple-load automatic guided vehicle(AGV)is increasingly used in the logistics transportation fields,owing to the advantages of smaller fleet size and fewer occurrences of traffic congestion.However,one main challenge lies in the deadlock-avoidance for the dispatching process of a multiple-load AGV system.To prevent the system from falling into a deadlock,a strategy of keeping the number of jobs in the system(NJIS)at a low level is adopted in most existing literatures.It is noteworthy that a low-level NJIS will make the processing machine easier to be starved,thereby reducing the system efficiency unavoidably.The motivation of the paper is to develop a deadlock-avoidance dispatching method for a multiple-load AGV system operating at a high NJIS level.Firstly,the deadlock-avoidance dispatching method is devised by incorporating a deadlock-avoidance strategy into a dispatching procedure that contains four sub-problems.In this strategy,critical tasks are recognized according to the status of workstation buffers,and then temporarily forbidden to avoid potential deadlocks.Secondly,three multiattribute dispatching rules are designed for system efficiency,where both the traveling distance and the buffer status are taken into account.Finally,a simulation system is developed to evaluate the performance of the proposed deadlock-avoidance strategy and dispatching rules at different NJIS levels.The experimental results demonstrate that our deadlock-avoidance dispatching method can improve the system efficiency at a high NJIS level and the adaptability to various system settings,while still avoiding potential deadlocks.近年来,多载量自动导引车(Automatic guided vehicle,AGV)系统因其交通拥堵率低、车队规模性小等优势,在物流运输领域的应用愈加广泛。实现死锁避免一直是多载量AGV系统调度过程中面临的主要挑战之一。为了避免系统死锁,现有文献普遍采用了低在制品数策略。然而,该策略会使加工机床易于待料停产,最终降低系统效率。为此,提出了一种适用于高在制品数AGV系统的死锁避免方法。首先,在包含4个子问题的调度过程中融入了一个死锁避免策略,该策略根据系统缓存区状态动态识别并临时禁止关键任务运行以避免潜在死锁。其次,为了提高系统的效率,综合考虑输入/输出缓存区状态、行驶距离等属性设计了3条多属性调度规则。最后,开发了一个仿真系统来评估所提出的死锁避免策略和多属性调度规则在不同在制品数上的性能。仿真结果表明,所提出的死锁避免调度方法不仅可以避免潜在的死锁,而且可以在较高的在制品数量上提高系统的效率,具有较高的系统适应性。

关 键 词：automatic guided vehicle(AGV)dispatching deadlock avoidance multiple-load AGV system critical tasks multi-attribute rules 

分 类 号：TP278[自动化与计算机技术—检测技术与自动化装置]