基于协商的Multi-Agent生产计划与调度系统

目前企业使用的ERP系统中由于计划与能力计算的分离以及调度信息不能及时反馈 ,已很难适应敏捷制造的需要。Agent技术是进行分布式制造系统建模的一种主要方法之一。工作中心是各种生产能力单元的通称 ,也是发生加工成本的实体 ,各工作中心Agent之间通过协商与协作 ,形成一个基于能力与成本的Multi Agent集成生产计划与调度系统 ,使企业具有实时应变性。     

基于Petri网的多工艺方案优化

以扩展的 Petri网模型 PP- net为工具确定可行工艺方案的制造成本 ,PP- net的每个变迁中含有加工时间、准备时间、搬运时间和更换刀具时间 ,由此可以得到工序制造成本评价函数。利用启发式搜索算法对 PP- net的可达树进行搜索 ,得到制造成本最低的工艺方案。     

智能制造系统的多Agent模型研究

提出了一个智能制造系统的多Agent模型，其中Agent代表基本的处理实体，Agent的特性用Petri网来表示。由于Agent具有自主性、社会交互性、反应能力和预动能力的特点，使得能够进行分布式决策，而系统的合作是通过通讯和协商解决的。Agent在交互的过程中被赋予角色，从而能够满足智能制造中复杂过程建模灵活性的需求，并能够构建一个可重用部件的扩展框架。     

Intelligent networking architecture: AI in integrating the enterprise

Achieving manufacturing efficiency requires that many groups that comprise a manufacturing enterprise, such as design, planning, production, distribution, field service, accounting, sales and marketing, cooperate to achieve their common goal. The concept of intelligent networking (IN) is introduced as the element to facilitate the integration of distributed heterogeneous functions of a manufacturing enterprise. The integration is supported by having the network first play a more active role in accessing and communicating information, and then provide the appropriate protocols for distribution, coordination and negotiation of tasks and outcomes. The IN is divided into six layers: network; data; information; organization; coordination; and market. Each of these provides a portion of the elements, functions and protocols to allow the integration of a manufacturing enterprise. The first three layers of this architecture are presented. These layers mainly support the management of a distributed knowledge base.     

Chaotic neurons for on-line quality control in manufacturing

Given today's trend towards globalisation of markets, on-line quality control of manufacturing processes is deemed essential. We describe the use of neural networks and chaos theory to implement the idea of intelligent integrated diagnostics (IID) for this purpose. Our efforts are specifically concentrated on implementing IID in the turning process — a ubiquitous manufacturing process. We propose and develop two types of chaotic neurons — neural network architectures trained to capture the underlying chaotic dynamics of the turning process — to address the common problems of tool wear and chatter. The first, called the fractal estimation continuously estimates tool wear; the second, called theCOPAVAS, initiates optimal chatter control.     

柔性制造系统中OPN模型的建立

针对敏捷制造单元的特点 ,提出了一种面向对象的知识Petri网的建模方法。一方面 ,此方法建立的实时控制模型可采用数学分析手段进行模型的死锁分析 ;另一方面 ,此方法将控制 /决策知识融入到面向对象Petri网中 ,使控制系统具有一定的智能性     

A distributed architecture for automated manufacturing systems

The concept of distributed architectures for automated manufacturing systems is presented here. A modular architecture for a logical cell-controller is proposed where shopfloor level modules are incorporated in the cell control system so as to allow active co-operation for distributed decision making and control. Two examples illustrating distributed formulations for specific planning and control are presented. These examples demonstrate the feasibility and potential for distributed architectures for automated manufacturing. This work has been supported by a grant from the Institute of Manufacturing Research, Wayne State University, USA.     

基于时间Petri网的实时并行设计过程建模研究

分解与重组基于特征的零件设计与工艺设计的并行过程 ,实现了基于特征的零件设计与工艺设计的实时并行 ;通过增加设计小循环次数来减少设计大循环次数 ,从而减少设计的反复过程和缩短产品开发周期。建立了基于时间Petri网零件设计与工艺设计的实时并行过程模型 ,通过计算设计循环时间 ,定量分析了实时并行过程的时域性 ,理论分析与实际基本一致 ,为实施产品实时并行设计方法提供了可靠的理论依据。     

Planning and Sequencing Heuristics for Feature-Based Control of Holonic Machining Equipment

The intelligent manufacturing system program was proposed by Japan in 1989. Five participating regions—Australia, Canada, the European Community, Japan, and the United States—currently are involved in developing 21st century manufacturing technology through an investment of US $1.2 billion over 10 years. Korea joined the program and will start work on one of the six ongoing projects, holonic manufacturing systems (HMSs). The objective of the paper is to develop the control architecture of the holonic machining unit (HMU) for construction of the HMSs and to present some planning and sequencing heuristics for feature-based control of the HMU. Further, the paper provides the HMU's functionality using the IDEF0 function modeling method. The basic operation of the decision maker among the HMU's functions is to determine an efficient feature sequence in real time from the nonlinear feature graph used to represent a process plan. To this end, two methodologies are applied sequentially to managing a nonlinear process plan: removal of the OR nodes and then grouping and sequencing the features in the feature graph. Markov chain theory is used to compute the path preference indicator for removing the OR nodes, that is, for selecting the best path among those surrounded by OR nodes. The resulting graph is the AND graph, from which the feature type nodes are formed into sequenced groups. The CNC codes associated with the features in each group are combined and downloaded to the CNC machine. The development of the methodologies can help manufacturers efficiently cope with unexpected failures encountered during computer-automated machining.     

The development of an object-oriented Petri net cell control model

This paper presents an object-oriented Petri net cell control (OPNCC) model for scheduling and controlling the operations of a flexible manufacturing cell. The development of the OPNCC model includes three phases:

1. Static analysis.
2. Dynamic analysis.
3. Integration.

The dynamic analysis, the most important phase in developing the OPNCC model, will first construct the object-oriented Petri net (OPN) for each physical object and connect all the related “encapsulated” OPNs to be a complete OPN model to represent the dynamic behaviour or control logic of shop floor operations. Then, the control logic of the complete OPN model must be analysed through an object behaviour analysis, an inter-object message passing analysis and a conflict analysis. The OPNCC model not only possesses the characteristics of object-oriented method (e.g. inheritance, encapsulation and a higher degree of flexibility and reusability) and Petri nets (e.g. graphical representation and mathematical analysis capabilities), but also incorporates scheduling/dispatching knowledge in the control logic specified by the OPN model. The practical significance of the OPNCC model is that practitioners may apply it to develop both a real-time cell controller and an off-line shop floor scheduling simulator.     

基于最大时间约束的零部件供应商价格谈判模型

为了控制基于网络谈判过程中的谈判成本,提出了一种基于最大时间控制策略的零部件供应商谈判方法。首先研究了谈判成本的构成问题,分别为显性谈判成本和隐性谈判成本。为了满足谈判过程中对零部件供货期的不同要求,提出了异步非实时谈判策略和同步实时谈判策略。通过设定最大谈判时间,给出了供应商价格谈判的离散数学模型。在该模型中,既考虑了谈判双方对价格问题的一致性要求,也考虑了谈判双方所必须满足的最大谈判时间约束。最后,基于该模型,给出了谈判双方所开展的谈判流程的具体分析。     

Integrated metrology systems

The integration of quality into future manufacturing planning is an essential part of the factory of the future, one specific area of quality assurance — metrology or dimensional inspection — plays a key role in guiding, coordinating, and approving manufacturing efforts. The advances in modern industrial production towards greater precision and more reliable function of products have created the need for a continuing, parallel improvement in dimensional measurement and inspection technologies. Selecting, justifying, and integrating these technologies into manufacturing operations requires careful planning and the consideration of alternative approaches for implementation. An overview is presented of a programme recently completed for the US Army Tank and Automotive Command (TACOM) with the purpose of assisting TACOM vendors in the integration of metrology into future operations to improve quality and reduce overall costs.     

网络化制造环境下质量协同保证的关键技术

在分析网络化制造环境下过程分析理论基础上,基于工作流技术提出了质量协同保证的关键技术,突出了质量保证的过程控制特点.文中给出了通过广义随机Petri网对质量保证系统进行分析和论证,依据ISO9000标准,在网络化制造企业间构造协同质量保证流程的方法,为网络化制造中过程质量的重构优化找到有效手段.最后通过实例说明结论的应用.     

A systems approach to fixture planning and design

Within the last decade, the manufacturing research community has addressed many of the micro issues of automating the fixture design process using computers. Most of this research has concentrated on the geometric and kinematic factors that determine the configuration of a computer-aided fixture design (CAFXD) system. However, before the implementation of any of the researched micro issues can be accomplished, a systematic approach to fixture planning and design must be recognised that considers the macro issues (process planning and fixture design) of the complete design to manufacturing process. In order to improve the effectiveness and implementation of researched micro issues in fixture design, a generic model of the functional activities can provide an understanding of the process and information exchanged between process planning and fixture design. This paper presents such a generic IDEF working model that promotes the functional integration of these two functions — developed from a systems perspective.     

制造企业生产计划调度与控制集成策略研究

传统的生产系统中,生产计划、调度与控制是分开进行的,生产信息的反馈周期长,生产调度缺乏必要的现场信息。通过分析生产系统的功能模型和信息模型,结合我国制造企业的实际情况,建立了生产管理系统的层式模块化结构。按照这种结构,构建企业的集成化生产管理系统,将会实现生产计划的实时调度以及生产过程的实时控制。实例证明,本文提出的方案是行之有效的。     

An efficient heuristic for scheduling batches of parts in a flexible flow system

Flexible manufacturing systems (FMSs) are a class of automated systems that can be used to improve productivity in batch manufacturing. Four stages of decision making have been defined for an FMS—the design, planning, scheduling, and control stages. This research focuses on the planning stage, and specifically in the area of scheduling batches of parts through the system.The literature to date on the FMS planning stage has mostly focused on the machine grouping, tool loading, and parttype selection problems. Our research carries the literature a step further by addressing the problem of scheduling batches of parts. Due to the use of serial-access material-handling systems in many FMSs, the batch-scheduling problem is modeled for a flexible flow system (FFS). This model explicitly accounts for setup times between batches that are dependent on their processing sequence.A heuristic procedure is developed for this batch-scheduling problem—the Maximum Savings (MS) heuristic. The MS heuristic is based upon the savings in time associated with a particular sequence and selecting the one with the maximum savings. It uses a two-phase method, with the savings being calculated in phase I, while a branch-and-bound procedure is employed to seek the best heuristic solution in phase II. Extensive computational results are provided for a wide variety of problems. The results show that the MS heuristic provides good-quality solutions.     

虚拟制造组织中协作关系建模的研究

由于虚拟制造环境下分布式制造过程间的相互协作缺少有效的理论支持，为此，提出了一个盟员企业相互协作的关系模型，基于赋时有色Petri网和工作流技术，对盟员企业内部制造过程以及相互之间协作关系进行了数学定义和图形建模，分析了面向对象技术在协作关系建模中的应用，并对模型的有效性并进行了验证，为虚拟制造组织的协作与控制提供了一个模型框架。     

面向网络化车间制造的工序质量智能控制系统

针对分布式企业复杂的车间制造环境,如何进行实时有效的质量波动监控、异常波动的诊断分析以及过程中适时的工序调整,是进行工序质量控制面临的问题。提出了集质量监控-异常诊断-工序调整为一体的工序质量控制模式,构建了系统功能体系结构。综合运用相似制造、统计学习、神经网络、统计过程控制等理论,开发了面向网络化车间制造的工序质量智能控制系统。采用针对多品种、小批量过程的基于相似工序的工序质量控制技术和针对多变量过程的基于混合自组织映射模型的控制方法,应用B/S五层架构,完成了工序质量控制系统的开发,验证了系统的可行性,为网络化车间制造提供有效工序质量控制。     

Behavioural analysis of a complex system

Recent works have shown that well-known models used for the analysis of human behaviour, in economics and in production—distribution contain unsuspected regimes of deterministic chaos. This paper is intended to study and analyse such behaviour in manufacturing and assembly shops.We have shown how deterministic chaos could be produced by human decision making: the equations built from decision rules generally applied in a complex manufacturing system, lead to chaotic behaviour in a realistic region of parameter space. Also, we have implemented a methodology with associated tools to verify the nature of a production system and to highlight the above assumptions. Such target systems concerned by a deterministic chaos cannot be controlled through conventional management systems.Dynamic modelling analysis of different production systems including delays, multiple-feedback loops, environmental and intrinsic disturbances, enables the induction of the management rules to be implemented for improving the control of such complex and chaotic systems.Glossary AGV Automatic guided vehicle - AI Artificial intelligence - BAT Bond assembly and test - BM Bill of material - CRP Capacity requirement planning - DM DeMand - DSS Decision support system - FCS Floor control system - FFT Fast Fourrier transform - FMS Flexible manufacturing systems - GA Genetic algorithm - KBS Knowledge-based system - LMA Line manager advisor - MAQ Maximum allowable quantity - MCS Manufacturing control system - MRP Material requirements planning - NC Numerical control - NO Numerical optimisation - PLOOT Plant layout optimisation - RESQ Research queuing package - SMS Shop management system - TAT Turn around time - TCM Thermal control module - WIP Work in process - WMS Workstation management system     

一种基于Petri网的顺序共享资源AMS＊s

Ｐｅｔｒｉ网控制器自动设计及控制程序自动生成方法的研究是自动制造系统ＡＭＳｓ和柔性制造系统ＦＭＳｓ领域研究的热点问题之一〔２～６〕。本文以ＡＭＳｓ计划和调度产生的生产序列ＰＳ和资源需求序列ＲＲＳ为基础，为顺序共资源ＡＭＳｓ设计了一种规格说明语言，以自动生成ＡＭＳｓＰｅｔｒｉ网模型的矩阵形式，并给出了转换步骤。由于引入了资源状态反馈，故生成的Ｐｅｔｒｉ网模型是无死锁的。最后，用一个实例说明了设计过程。