立体仓库多机器人协同路径规划与冲突消解

针对立体仓库中多机器人协同路径规划问题,建立了一个具有最优作业时间和能耗的多目标路径规划模型.采用分治-协作策略将多机器人路径规划问题分解为多个单机器人路径规划子问题.在路径规划中,采用改进的蚁群算法对每个机器人的初始路径进行规划.基于时空协同约束,采用协同迭代优化策略,提出了多蚁群协同进化算法.针对路径冲突问题,设计了一种动态优先级冲突消解策略,有效地解决了多机器人冲突问题,找到了最优路径组合.仿真结果表明,该方法能有效提高多机器人的协同搬运效率,降低能耗并缩短搬运时间.     

柔性作业车间多自动导引小车和机器的集成调度

针对含有AGV的柔性作业车间调度问题,提出基于时间窗和Dijkstra算法的混合遗传算法。建立了AGV/机器的双资源调度数学模型;采用3种解决策略处理多AGV路径规划冲突和碰撞;为了将机器和AGV调度集成考虑,设计了三链式编码结构及AGV编码链的交叉、变异算子,同时在遗传算法的解码操作中将Dijkstra算法与时间窗原理相结合,以精确地为任务小车规划出一条无碰撞无冲突的最短路径;算例对比验证了该算法的可行性、有效性和优越性。     

多AGV定位和路径规划方法研究

针对多AGV小车在实际应用中出现的路径冲突问题,提出一种基于时间窗的多AGV路径规划改进方法。以AGV实时定位和无线通信技术为基础,将时间窗算法和dijstra算法相结合,依次规划各AGV的路径,并采用实时更新位置信息和时间窗排布的方法对冲突路段进行路径动态规划,有效地避免了AGV之间的路径冲突,提高了系统运行效率。     

带AGV开放车间调度的析取图模型与求解

随着AGV小车在制造系统的广泛应用，其路线规划与生产调度集成可大大提高生产效率，降低运输能耗。这里以开放车间为研究对象，考虑AGV的物料搬运特性，提出了一种考虑最大完工时间和AGV能耗的双目标析取图模型，剖析问题特征，提取问题的关键弧特性；其次，设计了基于关键弧的多种邻域结构，融合遗传算法的全局搜索能力和变邻域结构的局部探索能力实现问题的寻优。最后，标杆案例测试结果表明，所提出算法可有效解决带AGV开放车间调度问题，多种邻域结构设计显著地提升了算法求解性能。     

数字孪生驱动的车间自动导引车路径规划

针对车间物流配送中的自动导引车(AGV)路径规划问题，以某企业自动化总装车间为研究对象，提出一种数字孪生驱动的AGV路径规划方法。建立了车间数字孪生环境模型，设计了基于环境地图孪生模型的无冲突路径规划算法。对于车间内实时到达的配送任务订单，采用改进的A^*算法结合环境地图孪生模型中的动态邻接矩阵和时间窗矩阵，按任务优先级顺序为相应的AGV规划无冲突路径，并实时更新孪生模型中的数据。所提方法使AGV配送的任务完成时间和冲突调整时间分别平均减少13.4%和17.54%。     

带时间窗约束的AGV集配货绿色路径规划问题研究

针对柔性制造车间背景下带时间窗约束的自动化导引运输车（automated guided vehicle,AGV）集配货绿色路径规划问题,以最小化AGV集配货过程能耗及时间偏离能耗作为组合优化目标,构建AGV绿色车辆路径规划模型,根据所研究问题特性,提出了一种改进变邻域搜索的混合遗传算法（GA-VNS）对其进行求解,并设计了5种邻域结构来提高算法寻优能力。通过对Solomon算例测试集进行求解,并与国际已知最优解进行数据对比,验证文章所提算法的可行性;进一步以某柔性制造车间某一生产时段的AGV物流运输任务作为实验案例,分别使用所设计的算法、GA和VNS算法对问题进行求解,数值实验结果表明了文章所提模型及算法的优化、适用性,为车间实现节能减排的发展目标提供一种可行方案。     

多自动导引车路径规划的时空冲突约束A*算法

针对自动导引小车(AGV)在仓储物流搬运系统中的路径冲突问题,提出一种基于时空冲突约束的A*算法.先在拓扑栅格地图的基础上加入时间轴建立时空地图模型,再针对时空地图的特点和冲突约束条件重新设计A*算法的子节点扩展规则和节点评估函数.利用改进后的A*算法按照优先级顺序为各个AGV规划路径,规划完成一条路径后,用mark表记录其在时空地图中的节点信息,再利用改进后的A*算法结合mark表搜索新路径.通过仿真实验证明了该算法的有效性.     

基于融合任务规则优先级蚁群算法的多AGV路径规划实现研究

蚁群算法所具备的合作搜索能力被广泛用于寻找单台AGV最短路径,却不适用解决现实情况中多台AGV同时使用的问题,为此提出了融合任务规则优先级的蚁群算法实现多AGV路径规划,用于解决现实问题中多台AGV同时使用而且存在多种碰撞冲突的情形。通过将AGV运行的路径环境进行建模等针对性措施,把蚁群算法引入到AGV路径规划的现实问题中,然后考虑多AGV路径规划可能存在的不同碰撞冲突类型,并考虑不同AGV拥有不同的任务优先级的现实情况,提出了避免AGV碰撞的策略,形成了基于融合任务规则优先级蚁群算法的多AGV路径规划算法。通过仿真实验结果,证实所提出的算法可以避免多台AGV之间的路径冲突,同时利用了蚁群算法寻求最优路径的能力,改进后的蚁群算法能够用于多AGV路径规划的实际场景中。     

基于多智能体系统的自动化码头多AGV无冲突路径规划

针对自动化码头中自动导引车(AutomatedGuidedVehicle,AGV)数量增加会导致AGV之间冲突更频繁的问题,以最小化AGV在岸桥和堆场之间的作业堵塞率为目标,考虑AGV行驶速度、作业时间和冲突距离,建立多AGV的无冲突路径规划模型。设计基于多智能体系统(Multi-Agent System,MAS)的多AGV系统的体系结构,采用基于黑板模型的交互协议作为AGV的通信方式,将改进速度控制方法和基于时间成本确定AGV优先级的方法作为AGV的协商策略,改进Dijkstra算法计算每台AGV的无冲突路径。通过不同控制方式的对比实验,结果表明基于MAS的控制方式比任务优先级的控制方式的系统平均堵塞率降低0.22%,AGV平均等待时间减少7.8s,平均完成时间减少8.9s,基于MAS的控制方式更加适合30台以上AGV的无冲突路径规划问题。     

基于差分进化与块结构邻域的作业车间调度优化

作业车间调度问题是一类非常重要的生产调度问题,具有广泛的工程应用背景.针对优化最大完成时间指标,研究通过交换或插入关键路径块结构中的工序产生可行解的方法,提出基于块结构的交换邻域和插入邻域.结合问题的结构特点和基本差分进化算法的原理,提出一种解决作业车间调度问题的离散差分进化算法.该算法采用基于操作的编码方式,设计了离散的变异算子和交叉算子,能够直接产生可行调度解.进而提出一种自适应的多邻域局部搜索算法,并将其嵌入离散差分进化算法中来改善优化质量;基于典型算例的仿真试验验证了所提算法的有效性和优越性.     

Development of an intelligent agent-based AGV controller for a flexible manufacturing system

Automated guided vehicles (AGVs) are the most flexible means to transport materials among workstations of a flexible manufacturing system. Complex issues associated with the design of AGV control of these systems are conflict-free shortest path, minimum time motion planning and deadlock avoidance. This research presents an intelligent agent-based framework to overcome the inefficacies associated with the aforementioned issues. Proposed approach describes the operational control of AGVs by integrating different activities such as path generation, journey time enumeration, collision and deadlock identification, waiting node location and its time estimation, and decision making on the selection of the conflict-free shortest feasible path. It represents efficient algorithms and rules associated with each agent for finding the conflict-free minimum time motion planning of AGVs, which are needed to navigate unidirectional and bidirectional flow path network. A collaborative architecture of AGV agent and its different modules are also presented. Three complex experimental scenarios are simulated to test the robustness of the proposed approach. It is shown that the proposed agent-based controller is capable of generating optimal, collision- and deadlock-free path with less computational efforts.     

自动导向小车与加工设备多目标集成调度的聚类遗传算法

针对AGV与加工设备的集成调度问题,在考虑AGV无冲突路径规划的情况下,建立了以最大完工时间、AGV运行时间及机器总负荷为优化目标的调度优化模型,提出一种基于时间窗和Dijk-stra算法的多目标自适应聚类遗传算法.根据算法在不同迭代时期的特点,提出一种包含自适应个体交叉概率的交叉重组策略;设计了自适应种群变异概率;引...     

考虑双联卡箍约束的航空发动机多管成束敷设优化方法

为解决航空发动机多管路成束敷设问题,提出了一种基于双联卡箍约束和改进NSGA-Ⅱ的管路敷设优化方法。提出一种基于混沌反向学习机制和Levy变异算子的改进NSGA-Ⅱ算法,以改善算法收敛性和非支配解分布性。为解决管路和卡箍的装配约束和设计耦合关系,建立了基于双联卡箍约束的路径模式,生成卡箍和路径控制点,综合考虑管路敷设与卡箍布置规则,基于改进NSGA-Ⅱ设计管路-双联卡箍敷设算法,对卡箍位姿参数和管路路径同时求解。根据多管端口相对位置,提出基于聚类分析的管路分组及敷设序列规划方法,调用管路-双联卡箍敷设算法完成多管成束规划。所提敷设方法在管路设计阶段即考虑卡箍布置问题,实现了双联卡箍布置和多管成束敷设的同时自动规划,最后通过测试函数和敷设算例验证了所提方法的有效性。     

Integrated tasks assignment and routing for the estimation of the optimal number of AGVS

A fundamental problem in the management of an automated guided vehicle system (AGVS) is the determination of the load to be transported and the vehicle to transport it. The time for the loading and unloading of pallets must be specified as soon as possible. Typical objectives are minimization of travel times and costs by the reduction of the number of vehicles required to fulfill a given transportation order. This article presents a methodology for the estimation the minimum number of AGVs (considering all the available ones at the shop floor level) required to execute a given transportation order within a specific time-window. A comparison is made between the algorithms Shortest Job First and meta-heuristic Tabu Search (applied to an initial solution) for a task assignment. An enhanced Dijkstra algorithm is used for the conflict-free routing task. The number of vehicles is estimated so as to provide an efficient distribution of tasks and reduce the operational costs of the materials handling system. Simulation results of two typical industrial warehouse shop floor scenarios are provided. Although the study focuses on pre-planning of order fulfillment of materials handling, the proposed methodology can also be utilized as an important tool for investment analysis of the warehouse layout design and for estimating the ideal number of AGVs.     

Dispatching, routing, and scheduling of two automated guided vehicles in a flexible manufacturing system

This article presents a new approach for planning the dispatching, conflict-free routing, and scheduling of automated guided vehicles in a flexible manufacturing system. The problem is solved optimally in an integrated manner, contrary to the traditional approach in which the problem is decomposed in three steps that are solved sequentially. The algorithm is based on dynamic programming and is solved on a rolling time horizon. Three dominance criteria are used to limit the size of the state space. The method finds the transportation plan minimizing the makespan (the completion time for all the tasks). Various results are discussed. A heuristic version of the algorithm is also proposed for an extension of the method to many vehicles.     

考虑任务行程时间的多载量自动导引车系统防死锁任务调度

针对多载量自动导引车（AGV）系统的任务调度和缓冲区死锁问题,提出了考虑任务行程时间的防死锁任务调度方案。以最小化延迟率和交通负荷不均衡度为目标,建立了任务调度模型;分析了任务调度中的实际约束,并在任务行程时间约束下构建了预测模型;针对任务调度模型,提出了一种基于人工免疫-灰狼优化（AI-GWO）算法的多目标防死锁任务调度方法,利用死锁避免规则禁止即将引发工位缓冲区死锁的任务运行,并融合AI-GWO算法对任务执行顺序进行多目标优化;最后,根据AGV负载均衡度进行AGV任务分配。仿真结果表明,上述任务行程时间预测模型具有较高的准确率,任务调度模型及防死锁调度方法具有较好的优化性能和计算效率,从而显著提高了物流系统的任务准时率和路径网络的交通负荷均衡度。     

汽车发动机滚子链的疲劳可靠性试验研究

根据ISO15654-2004（传动用精密滚子链疲劳试验方法）中规定的链传动疲劳试验规范,分别利用成组法和升降法对汽车发动机机油泵滚子链06BT-1进行了疲劳可靠性试验,研究了高速汽车链的疲劳寿命分布规律,建立了与不同可靠度相对应的疲劳寿命和载荷水平之间的关系曲线。通过试验结果的对比分析,探讨了成组法和升降法的“谐应”关系,提出了实用的高速汽车链的疲劳试验方法。     

An improved artificial bee colony algorithm for the blocking flowshop scheduling problem

This paper presents an improved artificial bee colony (IABC) algorithm for solving the blocking flowshop problem with the objective of minimizing makespan. The proposed IABC algorithm utilizes discrete job permutations to represent solutions and applies insert and swap operators to generate new solutions for the employed and onlooker bees. The differential evolution algorithm is employed to obtain solutions for the scout bees. An initialization scheme based on the problem-specific heuristics is presented to generate an initial population with a certain level of quality and diversity. A local search based on the insert neighborhood is embedded to improve the algorithm's local exploitation ability. The IABC is compared with the existing hybrid discrete differential evolution and discrete artificial bee colony algorithms based on the well-known flowshop benchmark of Taillard. The computational results and comparison demonstrate the superiority of the proposed IABC algorithm for the blocking flowshop scheduling problems with makespan criterion.     

Disassembly sequence planning approach for product virtual maintenance based on improved max–min ant system

In order to realize automation and intelligence of product disassembly process in a virtual maintenance environment, an improved max–min ant system based methodology for product disassembly sequence planning was proposed. The feasibility graph for product disassembly process was defined and the mathematic model of product disassembly sequence planning problem was set up. Thus, the problem of product disassembly sequence planning was transformed into the problem of searching optimal path on a feasibility graph. Moreover, an improved max–min ant system based on the strategy of sorting elite ants was presented and the flowchart of the improved algorithm was designed. Finally, by simulation examples, the robustness and outperforming others of the improved algorithm were verified.