A two-level advanced production planning and scheduling model for RFID-enabled ubiquitous manufacturing

Radio frequency identification (RFID) technology has been used in manufacturing industries to create a RFID-enabled ubiquitous environment, in where ultimate real-time advanced production planning and scheduling (APPS) will be achieved with the goal of collective intelligence. A particular focus has been placed upon using the vast amount of RFID production shop floor data to obtain more precise and reasonable estimates of APPS parameters such as the arrival of customer orders and standard operation times (SOTs). The resulting APPS model is based on hierarchical production decision-making principle to formulate planning and scheduling levels. A RFID-event driven mechanism is adopted to integrate these two levels for collective intelligence. A heuristic approach using a set of rules is utilized to solve the problem. The model is tested through four dimensions, including the impact of rule sequences on decisions, evaluation of released strategy to control the amount of production order from planning to scheduling, comparison with another model and practical operations, as well as model robustness. Two key findings are observed. First, release strategy based on the RFID-enabled real-time information is efficient and effective to reduce the total tardiness by 44.46% averagely. Second, it is observed that the model has the immune ability on disturbances like defects. However, as the increasing of the problem size, the model robustness against emergency orders becomes weak; while, the resistance to machine breakdown is strong oppositely. Findings and observations are summarized into a number of managerial implications for guiding associated end-users for purchasing collective intelligence in practice.     

RFID-enabled real-time wireless manufacturing for adaptive assembly planning and control

Wireless Manufacturing (WM) is emerging as a next-generation advanced manufacturing technology (AMT). WM relies substantially on wireless devices (e.g. RFID—Radio Frequency Identification or Auto ID—Automatic Identification, and on wireless information/communication networks (e.g. Wi-Fi and Bluetooth), for the collection and synchronization of manufacturing data. This paper proposes a WM framework where RFID devices are deployed to workstations, critical tools, key components, and containers of WIP (Work In Progress) materials to turn them into so-called smart objects. The study is based on a simplified product assembly line. Smart objects are tracked and traced and shop-floor disturbances are detected and fed back to decision makers on a real-time basis. Such real-time visibility closes the loop of adaptive assembly planning and control. A facility called assembly line explorer is provided for the line manager to oversee the status of the entire assembly line, and a workstation explorer facility for operators to monitor the status of their operations at corresponding workstations. These facilities improve the effectiveness of managerial decisions and operational efficiency.     

Development of an agent-based system for manufacturing control and coordination with ontology and RFID technology

Integrating physical objects with the corresponding enterprise applications any time any where is the essential issue for a real-time enterprise. This study proposes a multi-agent system framework called agent-based manufacturing control and coordination (AMCC) system, a agent-based framework using ontology and RFID technology to monitor and control dynamic production flows and also to improve the traceability and visibility of mass customization manufacturing processes. The capabilities offered by multi-agent systems to respond to RFID events in real-time and a broad class of agent design and coordination issue regarding just in time (JIT) and just in sequence (JIS) manufacturing processes are also exploited in this study. To validate the proposed framework, case study of a bicycle manufacturing company is used to demonstrate how the proposed framework can benefit its JIT production. Finally, an example prototype system is implemented to demonstrate the concept of the proposed framework.     

Toward a cloud-based manufacturing execution system for distributed manufacturing

This paper illustrates the needs and challenges for the management of distributed manufacturing in a multi-company supply chain and processes these further as features of new IT systems. Requirements are collected from manufacturing companies and combined with insights from literature in the field of current ERP/MES system drawbacks, advantages, needs and challenges. The findings show that the needs and challenges in data integration inside SME networks are closely related to the limitations of current supply chain solutions. Current ERP-solutions lack extended enterprise support and a shared cloud-based approach. On the other hand, current MES solutions can operate the manufacturing process, but not for distributed manufacturing. As an answer to the requirements, we made a proposal for the core of architecture for next generation of MES solution in this position paper. Moreover, a pilot software tool has been developed to support the needs related to real time, cloud-based, light weight operation.     

RFID-enabled automation in support of factory integration

In recognition of the need for more effective and efficient factory system integration solutions, this paper improves the method proposed in our previous work, focusing on new mechanisms to bridge the gap between shop floor automation and factory information systems. As one of the mainstream identification technologies, radio frequency identification (RFID) technology makes possible all products uniquely identifiable across factories. By taking advantage of data capacity stored in an RFID tag, critical manufacturing information on a product can be locally stored with the product. RFID technology provides a means for a product to rapidly retrieve its needed information as it advances through shop floors. A corresponding framework to enable the instant delivery of pertinent data and information on a uniquely identifiable job/product at point-of-need across factories is proposed. A small-scale manufacturing application is presented to show how the proposed approach can be implemented on the shop floor.     

Generating test sequences using symbolic execution for event-driven real-time systems

Real-time software, often used to control event-driven process control systems, is usually structured as a set of concurrent and interacting tasks. Therefore, output values of real-time software depend not only on the input values but also on internal and nondeterministic execution patterns caused by task synchronization. In order to test real-time software effectively, one must generate test cases which include information on both the event sequences and the times at which various events occur. However, previous research on real-time software testing focused on generating the latter information. Our paper describes a method of generating test sequences from a Modechart specification using symbolic execution technique. Based on the notion of symbolic system configurations and the equivalence definitions between them, we demonstrate, using the railroad crossing system, how to construct a time-annotated symbolic execution tree and generate test sequences according to the selected coverage criteria.     

基于射频识别技术的装备维修器材管理信息系统设计

本文简要介绍了射频识别技术的基本原理，着重叙述了基于射频识别技术的便携式维修器材管理信息系统的组成、功能和特点。该系统运行可靠，操作方便，提高了装备维修器材保障的效率。     

Design and development of a mobile EPC-RFID-based self-validation system (MESS) for product authentication

The increase in the number of counterfeits penetrating into the open market has created the need for a product authentication approach in tracing and tracking the product anytime, anywhere. Owing to the vague concepts frequently represented in flow of products, this paper presents a self-valuation and visualization system by integrating the RFID technology and EPC concept to protect products from counterfeiting by the means of mobile platform. In this paper, a system architecture is proposed which is capable of integrating mobile technology and EPC-RFID applications. The implementation roadmap of such system architecture is examined and explained in the context of a case study. The aims of the system are to provide greater visibility of the product logistic flow data and to improve the anti-counterfeit process, from traditional physical identification to self-validated location-based authentication. The case study illustrates the capability, benefits and advantages of using the proposed system, particularly its support of product authentication and supply chain activities in countering the global counterfeit problems.     

Agent learning in autonomic manufacturing execution systems for enterprise networking

In enterprise networks, companies interact on a temporal basis through client–server relationships between order agents (clients) and resource agents (servers) acting as autonomic managers. In this work, the autonomic MES (@MES) proposed by Rolón and Martinez (2012) has been extended to allow selfish behavior and adaptive decision-making in distributed execution control and emergent scheduling. Agent learning in the @MES is addressed by rewarding order agents in order to continuously optimize their processing routes based on cost and reliability of alternative resource agents (servers). Service providers are rewarded so as to learn the quality level corresponding to each task which is used to define the processing time and cost for each client request. Two reinforcement learning algorithms have been implemented to simulate learning curves of client–server relationships in the @MES. Emerging behaviors obtained through generative simulation in a case study show that despite selfish behavior and policy adaptation in order and resource agents, the autonomic MES is able to reject significant disturbances and handle unplanned events successfully.     

Application of an artificial immune system-based fuzzy neural network to a RFID-based positioning system

Due to the rapid development of globalization, which makes supply chain management more complicated, more companies are applying radio frequency identification (RFID), in warehouse management. The obvious advantages of RFID are its ability to scan at high-speed, its penetration and memory. In addition to recycling, use of a RFID system can also reduce business costs, by indentifying the position of goods and picking carts. This study proposes an artificial immune system (AIS)-based fuzzy neural network (FNN), to learn the relationship between the RFID signals and the picking cart’s position. Since the proposed network has the merits of both AIS and FNN, it is able to avoid falling into the local optimum and possesses a learning capability. The results of the evaluation of the model show that the proposed AIS-based FNN really can predict the picking cart position more precisely than conventional FNN and, unlike an artificial neural network, it is much easier to interpret the training results, since they are in the form of fuzzy IF–THEN rules.     

复杂生产过程计划调度级联模型在选矿MES中的应用研究

针对大型选矿生产线运行和管理特点,分析了选矿企业生产成本、原矿处理量、精矿品位、金属回收率等综合生产指标在计划层、执行层和控制层间的交互关系;说明了选矿企业计划调度主要特征是将综合指标逐层分解优化为日生产线指标的思想;建立了在保证产品质量合格前提下总成本最小为目标和在保证合理精矿品位的前提下,以减小精矿库存、最大限度地满足设备生产能力为目标的计划与调度两阶段级联优化模型;提出了决策选矿生产线日原矿处理量和精矿品位与尾矿品位等生产指标的生产计划调度优化方法,并应用于某选矿企业制造执行系统(Manufacturing execution system, MES),取得显著应用成效.     

流程工业生产执行系统的软件基础设施

结合流程工业环境苛刻,生产过程复杂等特点,针对传统MES存在的环境适应性低、研发和维护成本高和应用效果不理想等问题,提出基于模型驱动架构软件开发方法的软件基础设施,用于构建下一代柔性MES。其总体目标是使MES在满足流程工业普适性需求的同时,也能适应特定的企业环境。基于层次化设计,系统分为CIM、PIM和PSM。在PIM软件基础设施之上,CIM又包括3个领域模型:功能模型分析需求并描述功能,逻辑模型使用自描述的建模方法,定义工厂对象模型、用户接口和工作流程,科学计算模型将工厂对象模型转换为数学模型,最终实现数据协调和生产优化的闭环管理。原型验证及工程实践表明,系统能够实现与传统MES相一致的领域模型,并显著缩短产品交付时间,降低项目成本。本文将领域建模过程和软件开发过程彻底分离,提高了软件抽象层次和复用度。与之前的MDA相比,系统更具运行时动态特征,领域模型能够在编译期后被方便地修改,使UML等设计工具的输出不再仅仅是文档,而成为可执行的产物。     

基于广度优先动态二进制的RFID抗碰撞的搜索算法

射频识别技术(RFID)在超高频段的应用将成为物流商业开发的主流,对于排除阅读器识别多个电子标签发回信号的电磁波干扰,实现快速、准确地信息识别,抗碰撞的搜索算法是最为关键的因素.研究了基于广度优先动态二进制搜索算法,并进一步提出优化方案,从技术上切实提高了射频识别系统的效率.     

RFID在候机室管理系统中的应用研究

通过RFID技术、新RFID中间件工具Oracle Sensor Edge Server和Stream Dispatcher,CAVIP系统实时以非接触方式获取旅客位置信息,定位旅客在候机室中的位置,进而提高服务质量。CAVIP系统通过RFID中间件可以做到及早过滤采集到的无效RFID数据,有效保护RFID网络的投资,协调不同来源的RFID设备,而且通过创新性地使用Oracle Stream 和触发器可以做到使企业应用系统不知道RFID的存在,使企业实施RFID高效快速且易于实现。     

流程工业MES中的数据集成研究及应用

MES是流程工业综合自动化系统的关键环节。数据集成是MES中的基础。如何实现在异构网络、异构操作系统、异构数据库等异构环境中的数据集成是系统集成中的难点。该文提出了一种基于实时数据平台的集成模型,并应用于实际系统集成中,取得了比较满意的效果。     

RFID室内实时定位系统的数据滤波方法

在射频识别室内实时定位应用中,由于场景的复杂性和定位系统的精度有限,定位系统报告的物品的连续两个位置可能出现在不同的区域内,物品的运动轨迹可能出现穿过墙壁等异常。为此,提出了一种避免这种异常的室内定位系统的数据滤波方法。首先,将场景离散化为一幅“灰度图像”,图像像素表示场景中的点,图像像素的灰度表示不同的区域/房间、墙壁或房门;在定位过程中,将物品的连续两个场景坐标分别映射到两个图像像素,利用连接这两个像素的线段上的像素的“灰度”来判断是否出现穿墙等异常,并修正物品当前在图像上的位置;最后,将图像中的位置映射回场景坐标。实验表明,所提方法快速且高效,能有效避免物品运动轨迹中的异常。     

有源RFID标签安全文件系统的设计

针对有源RFID标签应用中对微型文件系统的需求,围绕标签内存小和大量标签盘点过程中要求文件读写速度快的特点,展开对有源RFID标签安全文件系统的研究。最终通过选用高速存储器件和对FAT文件系统进行改进（实现灵活的数据缓冲层、精简文件目录项、增加文件访问控制）,实现了简洁高效安全的文件系统设计,并在实验中展现了文件系统良好的性能。     

对钢铁业自动化发展策略的思考

预测中国钢铁自动化的发展趋势,可借鉴国外钢企的发展历史、参考离散制造业的发展思路,同时必须结合国情和行业特色。钢铁自动化未来的主要发展方向应该是与信息技术深度融合,推动智能化制造和绿色生产。     

基于Activiti工作流的玻璃盖板生产业务流程设计与实现

为实现玻璃盖板行业的智能化生产及网络化的管理和运营,提出采用Activiti工作流技术。结合当前主流的Spring、SpringMVC、Mybatis软件系统开发框架,设计玻璃盖板行业生产的主要业务流程,实现ERP任务单到生产工单的在线业务处理。通过Activiti的流程定义功能,结合PDM工艺信息,实现玻璃盖板行业生产任务的线上管理与分配及生产工艺的在线指导。根据广东某玻璃盖板生产企业的运营试用,证明了其具有很高的实用性。