基于模糊理论的半导体制造系统时变多目标生产调度研究

针对半导体晶圆制造系统(SWFS)调度中的多目标优化和目标时变性问题,提出了一种时变多目标(TVMO)调度算法.基于模糊理论研究了时变模糊集合与多目标重要程度的复杂非线性量化关系,进而研究了SWDS的优化调度方法.所提出的方法兼顾最大产品交期率、最大生产移动量和瓶颈机台最大产能利用率三个目标,根据时变目标权重计算出在制品的加工优先权序列号.大量的仿真实验数据证明,该调度算法能够改善系统多个绩效目标,可为大规模复杂重入型制造系统的科学生产控制与调度提供有效支持.     

Research on a DPN-based production-energy consumption coupling type dynamic dispatching system for continuous process enterprises

针对企业的生产和能源调度需求,采用模块化方法建立并研究了连续型企业生产-能耗耦合式动态调度系统的微分Petri网(DPN)模型,以解决当前能源调度与生产调度脱节的问题.该模型由总体架构模型、带遥调或遥信阀门的系统传输管网模型、检测预警模型、带协同约束弧的调度预警器模型和备用设备模型组成.采用DPN仿真算法,通过调整遥调、遥控和遥信阀门实现了系统DPN模型的动态调度仿真.该生产与能耗耦合的动态调度系统的软件已实现了从工艺界面到调度界面的转化.该系统对企业生产和能源管理具有重要的辅助作用.     

基于并行处理的EPA通信调度算法研究与实现

针对目前工业以太网(EPA)通信调度算法软件实现方法存在的内存资源耗费多,通信调度表搜索效率低的问题,提出了一种基于现场可编程逻辑门阵列(FPGA)的硬件实现方法.该实现方法采用了一种报文集中存储,通信调度表分别构建的策略,并基于该策略设计了一种并行处理的调度表搜索方法.在以Altera Cyclone II FPGA为主控芯片的开发平台上的测试结果表明,与软件实现方法相比,该设计方法减少了内存资源的占有率,将报文搜索效率提高了9倍,通信调度性能提高了1倍.     

An integrated scheduling algorithm with device dependence deferred constraint

针对目前综合调度中没有考虑设备有关延迟约束(DDC)影响调度效果的问题,提出了存在设备有关延迟约束的综合调度的算法.该算法在标准工序、设备有关延迟工序(DDP)和包含设备有关延迟约束的加工工艺树等概念的基础上,将等待延迟时间转化为设备有关延迟工序,使存在DDC的调度问题转变为较易解决的一般综合调度问题,再用拟关键路径法( ACPM)确定工序的调度次序,最后用前沿贪心规则确定工序的开始时间.为了使设备有关延迟工序影响的工序尽早开始,进一步提出了设备有关延迟工序配合调整的策略.实验表明,该调度算法能够有效解决存在设备有关延迟约束的综合调度问题,可在不提高算法复杂度的前提下,提高调度结果的精度并减少产品总的加工时间.     

Multi-radio packet scheduling for real-time packet traffic on general link layer

提出了一个能够为在通用链路层(GLL)上的实时分组业务提供QoS保障的多接入分组调度算法.首先设计了一个目标是在保障实时业务QoS的同时避免资源浪费的调度效用函数,该函数表示将一个用户数据包调度到一个无线接入链路上进行传输所带来的效用;其次在这个调度函数的基础之上兼顾了公平性,建立一个多接入分组调度模型,值得注意的是该模型是一个NP问题;最后利用Hopfield神经网络来快速有效地为这个调度模型找出优化解.仿真结果表明,与M-LWDF和PLR等典型算法相比,该算法在高系统负载的情况下能够满足实时分组的时延要求,同时提高了频谱效率并降低了丢包率及时延抖动.     

PFS在分布式移动通信系统中的应用研究

为提高分布式移动通信系统的空间资源利用率,在并行调度思想的指导下,提出了并行比例公平调度(PPFS)方法,该方法可在取得多用户分集增益的基础上取得复用增益,进一步提高了系统的吞吐量.仿真结果表明,在分布式移动通信系统中,PPFS不仅能够为用户提供更多的接入机会,获得更高的平均系统吞吐量,并且较好地继承了比例公平调度(P...     

面向混合负载的集群资源弹性调度

针对目前集群资源调度方法难以适应互联网业务多样化、定制化特征的问题,提出了一种面向混合负载的集群资源弹性调度方法.该方法通过构建作业约束描述语言,允许作业基于自身负载特征提出多维度的资源申请和具有负载意识的资源调度算法,实现在同一集群内各类业务统一部署与管理,及时匹配资源需求的变化;通过建立作业的软约束与硬约束之间的转化机制,满足作业在不同执行阶段对资源的定制化需求.实验表明,该方法相比于Hadoop,可允许作业利用较少资源获得更优性能,在实际生产系统中,基于该方法可将集群资源利用率由62％提升到75％.     

基于MPSO的有限缓冲区多产品厂间歇调度问题的研究

研究了以最小化最大完工时间为目标的有限缓冲区多产品厂间歇调度问题,提出了一种基于多种群粒子群优化(MPSO)的间歇调度算法.该算法采用多种群,增加了种群初始粒子的多样性,在每一代子种群并行进化的过程中引入移民粒子,使子种群之间相互影响和促进,避免算法过早地陷入局部最优,提高了算法的全局搜索能力;每代进化后选出子种群中的优秀粒子作为精华种群,并对其进行变邻域搜索(VNS),进一步提高了算法的收敛精度.通过对不同规模调度问题的仿真,以及与其它算法的对比,证明了该算法解决有限缓冲区多产品厂间歇调度问题的有效性和优越性.     

供应链中生产和运输协调调度问题初探

提出了解决供应链中生产和航空运输协调调度问题的理论框架.基于对生产调度和航空运输调度彼此制约关系的分析,协调调度问题被分解为两个子调度问题.建立了航空运输子调度问题的整数规划模型,并证明了该问题为NP完全问题.提出了基于倒排调度方法(backward scheduling method)的调度算法解单机生产调度子问题.     

基于自适应遗传算法的模具生产调度研究

研究了一种基于自适应遗传算法的模具企业车间作业调度算法,建立了调度问题的数学模型,给出了具体的遗传操作算子设计方法.针对离散型模具生产的工艺特征,设计了生产单元分配方法,将生产单元作为调度对象.该算法改进了传统的基于工序的编码方法,给出了一种动态调整交叉概率和变异概率的计算方法.对实际模具企业的生产调度求解结果表明,该...     

基于时延库所Petri网的动态联盟任务调度研究

针对动态联盟中任务调度的特点,提出了采用时延库所Petri网对动态联盟任务调度进行建模。给出了模型的形式化描述及变迁规则,对动态联盟中的产品加工类型进行了分类,并建立了各种加工类型的时延库所Petri网模型,分析了通过模型中零时差的库所求解关键路径和利用可达图求解合理调度方案的方法。最后,以实例表明了该方法的可行性和有效性。     

Decision-making on multi-mould maintenance in production scheduling

The reliability of a critical tool like a mould on a machine affects the productivity seriously in many manufacturing firms. In fact, its breakdown frequency is even higher than machines. The decision-making on when mould maintenance should be started become a challenging issue. In the previous study, the mould maintenance plans were integrated with the traditional production schedules in a plastics production system. It was proven that considering machine and mould maintenance in production scheduling could improve the overall reliability and productivity of the production system. However, the previous model assumed that each job contained single operation. It is not workable in other manufacturing systems such as die stamping which may contain multiple operations with multiple moulds in each job. Thus, this study models a new problem for multi-mould production-maintenance scheduling. A genetic algorithm approach is applied to minimise the makespan of all jobs in 10 hypothetical problem sets. A joint scheduling (JS) approach is proposed to decide the start times of maintenance activities during scheduling. The numerical result shows that the JS approach has a good performance in the new problem and it is sensitive to the characteristic of the setup time defined.     

A multi-level heuristic search algorithm for production scheduling

This paper introduces a multi-level heuristic search algorithm for identifying the optimal production schedule considering different levels of manufacturing requirements and constraints. The multi-level heuristic search algorithm generates search nodes at different levels. An upper level search node is composed of lower level search nodes, and evaluated based upon the evaluation of these lower level search nodes using a heuristic function. A production scheduling system was developed based upon the multi-level heuristic search algorithm. In this scheduling system, production requirements and constraints are represented at three different levels: task level, process level, and resource level. A task describes a manufacturing requirement. A process defines a method to achieve the goal of a task. A resource, such as a machine or a person, is a facility for accomplishing a required process. The multi-level heuristic search-based scheduling system was implemented using Smalltalk, an object-oriented programming language. Discussions on scheduling quality and efficiency are addressed at the end of this paper.     

Enhancing smart shop floor management with ubiquitous augmented reality

This paper describes a framework for implementing Smart manufacturing Shop floor systems based on the Ubiquitous Augmented Reality technology (SSUAR). The proposed system makes use of data sharing between shop floor resources and a sensor network in order to optimise the production schedules for carrying out projects. The optimisation is performed in real-time and the production scheduling responds to new projects as well as the changing status of resources, such as machines and workers. Ubiquitous augmented reality interface has been developed and utilised as a user interface for the shop floor workers to receive information, instructions and guidance from the experts and manufacturing systems, and to update the systems on task parameters, such as estimated completion times, progress and machine status. A review of related work, methodology and implementation of the proposed system, and a case study are presented in this paper. Using this architecture, real-time scheduling of tasks in the smart shop floor can be achieved. The case study demonstrated the ability of SSUAR to integrate task scheduling with two-way communication between the system and the users.     

Agile manufacturing system control based on cell re-configuration

The control of an agile manufacturing system (AMS) is expected to be flexible, open, scalable and re-configurable so as to tackle the more complex and uncertain information flows. To meet these requirements, we propose agent-based control architecture for AMS, under which the functions of task planning, scheduling and dynamic control are integrated seamlessly. First of all, this paper introduces the concept of RMC (re-configurable manufacturing cell), based on which, we construct the control architecture for AMS in compliance with multi-agent system (MAS). The whole control process under the architecture comprises two hierarchies, i.e. the upper one for order planning and RMC forming and the lower one for task scheduling within each RMC. For the upper hierarchy, we establish a linear integer programming (LIP)-based mathematical model and a MAS-based dynamic process model, and present a two-step approach to order planning and RMC forming. For the lower hierarchy, we develop the scheduling model, a method based on the bidding mechanism from contract net, and describe the rescheduling mechanism in the control system. To illustrate the methodology proposed in the paper, a simulation study is thoroughly discussed. Our studies demonstrate that the RMC-based control architecture provides an AMS with an optimal, dynamic and flexible mechanism of responding to an unpredictable manufacturing environment, which is crucial to achieve agility for the whole manufacturing system.     

基于多项目关键链的ETO型企业计划管理方法

在ETO型制造企业计划管理中存在着多项目环境、工期不确定性、项目延迟以及人为因素影响等问题.根据多项目关键链原理,提出了包含以计划模板建立、计划编制、控制三个部分的计划管理流程;每个部分又划分为若干个步骤;针对步骤分别详细设计了具体应用方法.最后构造了以某大型变压器制造企业为背景的3个产品并行的多项目环境,并采用Crystal Ball软件模拟了该环境,评估结果显示优化后产品平均周期时间比优化前缩短了2.7d.     

Look ahead job demanding for improving job shop performance

In this paper a new coordination approach for decentralized job shop scheduling rules is presented and analyzed in a simulation study. The coordination is based on look ahead information and contains a mechanism for demanding and supplying jobs. The simulation experiments show that the performance of conventional scheduling rules is significantly improved using the coordination mechanism.     

A hybrid control architecture and coordination mechanism in virtual manufacturing enterprise

The concept of Virtual Enterprise (VE), a special organization of manufacturing units and enterprises, has attracted considerable attention in recent years. Unlike traditional enterprise, VE is most suitable in production environments that experience frequent changes in product mix. To complete a complex task composed of some sub-tasks, traditional control architecture is not versatile enough to coordinate and schedule multi-site and multi-type resources, especially in resolving resource conflicts during operations. Using hybrid control architecture, VE can execute the effective control on multi-site enterprises to support the rapid response to customer demands. Coordination mechanism running through the total life cycle of VE is applied to coordinating and scheduling the requests from different tasks and resources, which make VE flexible, adaptive and robust. In this paper, the hybrid control architecture based on multi-agent technology that supports the cooperation of enterprises is presented. Coordination mechanism and the corresponding optimal models are discussed. Finally a case study is used as an illustration to present the detailed coordination mechanism.     

Servitization of manufacturing in the new ICTs era: A survey on operations management

Servitization of manufacturing has become one of the main pathways for transition and upgrade in the manufacturing industry. New information and communication technologies (ICTs), such as the Internet of Things, Big Data, and Cloud Computing have enabled the servitization of manufacturing in terms of value creation, resource management, and supply chain management. This study presents a comprehensive review on the servitization in operations management in the era of new ICTs. A new value chain framework is proposed under the business model that revolves around servitization, which showcases the new activities and ways of implementation in the era of new ICTs. The virtualization, configuration, and evaluation of integrated manufacturing and service resources are analyzed. In particular, the methods used in new ICT-supported resource management platforms are surveyed. Problems in the supply chain management in manufacturing services (including the selection of partners, as well as the coordination, planning, and scheduling among members) are presented. This study concludes with a discussion on state-of-the-art servitization in operations management in the era of new ICTs.     

考虑资源需求差异的印包设备网络协同制造资源匹配方法

目的 包装印刷装备行业存在制造资源分散、产业协同不足和效率低等问题,针对网络协同制造中的制造资源匹配问题提出一种有效方法。方法 从不同子任务资源需求差异视角出发,构建基于TQCS制造资源评价指标体系及制造任务约束体系,通过层次分析法计算不同子任务的权重,以资源与任务的匹配度最大为目标函数,提出基于莱维飞行–遗传算法的网络协同制造资源匹配方法。结果 改进的资源匹配方法相较于传统方法,能够得到成本更低、时间更短的方案,并且改进的遗传算法的寻优能力更高。结论 相较于传统方法,改进的制造资源匹配方法的目标函数更合理、权重取值更客观、寻优能力更好,能够得到更为合理的制造资源匹配方案。