MODELING AND IMPLEMENTATION OF A DISTRIBUTED SHOP FLOOR MANAGEMENT AND CONTROL SYSTEM

Adopting distributed control architecture is the important development direction for shop floor management and control system, is also the requirement of making it agile, intelligent and concurrent. Some key problems in achieving distributed control architecture are researched. An activity model of shop floor is presented as the requirement definition of the prototype system. The multi-agent based software architecture is constructed. How the core part in shop floor management and control system, production plan and scheduling is achieved. The cooperation of different agents is illustrated. Finally, the implementation of the prototype system is narrated.     

分布式车间管理控制系统研究

制造执行系统（MAS）具有分布性,自主性,互操作性,开放性等特征,这些特征有助于将一个递阶式管理控制方式改造为并行智能方式,目前一些分布式对象计算中间软件也正不断走向商品化,因而采用MAS来改造CIMS环境下的车间管理控制系统能够使之具有快速动态重组生产过程的能力（这是敏捷性的关键）,提出了基于MAS的敏捷化车间管理控制系统的体系结构,并设计了用于任务分配的招标机制和Agent间协作机制,采用面向对象的方法对Agent的构造进行了讨论。     

面向状态的车间控制模型研究

通过对现代车间生产活动控制的功能,目标和现代车间制造系统基本特征的考察,分析,揭示了现代车间控制的根本矛盾,提出了面向状态 的车间控制策略和方法,针对数据加工车间设计了面向状态的控制模型并进行了应用研究。     

A Multi-Agent-Based Agile Shop Floor Control System

The ability of an enterprise to deliver new products quickly and efficiently to market is often the chief determinant of competitive success. The shop floor control system must be an open dynamic system with the capability of adapting and accepting radical unpredictable changes in its structures and industrial practices. This paper presents a new architecture for an agile shop floor control system. The architecture is based on the methodology of multi-agent systems in distributed artificial intelligence (DAI). The multi-agent system has some common characteristics such as: distribution, autonomy, interaction, and openness, which are helpful for transferring traditional architecture to a distributed, cooperative architecture for a shop floor control system. A bidding method based on the required production cost and processing time is also proposed. Using a distributed object-oriented technique, a CORBA-based multi-agent framework for an agile shop floor control system is constructed to integrate all the activity of the shop floor into a distributed intelligent open environment. To implement the framework, a coordination model between agents and behavioural models of some representative agents are established.     

状态控制模型及其在数控加工车间中的应用

通过对现代车间生产活动控制的功能、目标和现代车间制造系统基本特征的考察、分析,揭示了现代车间控制的根本矛盾,提出了面向状态的车间控制策略和方法,针对数控加工车间设计了面向状态的控制模型并进行了应用研究。     

适应性的递阶式车间层控制系统ALSYS

适应性的递阶式车间控制系统ALSYS具有相对控制层次的独立性、相对应用过程的独立性和相对于计算机的独立性,基本上能满足适应性的要求。本文论述了该系统新颖的体系结构和功能模型,并介绍了以上海交通大学生产系统与控制技术研究所的CIM示范系统实例所进行的系统开发和实现。     

基于Flexsim仿真的FMS车间级控制系统开发

在研究车间级控制系统与仿真控制理论的基础上,构造了基于仿真的FMS车间级控制系统模型,并结合北京交通大学教学型FMS,在Flexsim中进行系统建模,完成了该FMS的车间控制系统的设计与开发,实现了仿真和实际控制逻辑的共用.     

A Cascading Auction Protocol as a Framework for Integrating Process Planning and Heterarchical Shop Floor Control

A new contract net-style auction protocol is proposed as a framework for integrating process planning and shop floor control in heterarchical manufacturing systems. Process planning is partitioned into on-line and off-line activities; off-line process planning decisions are represented in a graph format and used as input for on-line process planning activities performed by machine controllers. Triggered by the opening round of an auction, the final on-line stages of process planning are dovetailed with the resource allocation process in the shop floor control system. The auction process allows final process planning decisions to be based on timely information, relying on the distribution of static process planning information rather than the distribution of a model of dynamic shop floor status and allowing a controller to identify all the primary and secondary resources and operations that must be provided for the incremental processing of a part.     

APPLICATION OF IMPROVED PRODUCTION ACTIVITY CONTROL ARCHITECTURE FOR SHOP FLOOR INFORMATION SYSTEM IN DIGITAL MANUFACTURING

Shop floor control (SFC) is responsible for the coordination and control of the manufacturing physical and information flow within the shop floor in the manufacturing system. Weaknesses of the production activity control (PAC) architecture of the shop floor are addressed by the Maglica's new system architecture. This architecture gives rise to unlimited number of movers and producers thus evolving more complex but decentralized architecture. Beijing Institute of Technology - production activity control (BIT-PAC) architecture introduces an idea of sub-producers and sub-movers thus reducing the complexity of the architecture. All the equipments including sub-producers and sub-movers are considered to be passive in the proposed shop floor information system. The dissemination of information from sub-producers and sub-movers is done manually through a PC. Proposed BIT-PAC SFC architecture facilitates the information flow from shop floor to the other area of the organization. Effective use of internet information services (IIS) and SQL2000 is done along with the ASP.NET technology to implement the application logic. Applicability of the software based on BIT-PAC architecture is checked by running application software on a network PC that supports the dynamic flow of information from sub-producers and sub-movers to the other parts of the organization. Use of software is also shown at the end for BIT training workshop thus supporting the use of SFC architecture for similar kind of environments.     

可重构车间管理系统的关键设计技术研究

介绍了一个基于组件的可重构车间管理系统,分别从建模方法、体系结构和组件设计等角度描述了系统的设计思想,并阐述了系统涉及的组件分类、组件粒度划分及XML的应用等关键设计技术。开发的可重构车间管理系统已经用于沈阳第一机床厂两个不同类型生产车间的管理,应用效果良好。     

Hybrid shop floor control system for Computer Integrated Manufacturing (CIM)

A shop floor can be considered as an important level to develop Computer Integrated Manufacturing system (CIMs). However, a shop floor is a dynamic environment where unexpected events continuously occur, and impose changes to the planned activities. To deal with this problem, a shop floor should adopt an appropriate control system that is responsible for the coordination and control of the manufacturing physical flow and information flow. In this paper, a hybrid control system is described with a shop floor activity methodology called Multi-Layered Task Initiation Diagram (MTD). The architecture of the control model contains three levels: i.e., the shop floor controller (SFC), the intelligent agent controller (IAC) and the equipment controller (EC). The methodology behind the development of the control system is an intelligent multi-agent paradigm that enables the shop floor control system to be an independent, an autonomous, and distributed system, and to achieve an adaptability to change of the manufacturing environment.     

Controlling flexible manufacturing systems based on a dynamic selection of the appropriate operational criteria and scheduling policy

This study presents the development of a multi-criteria control methodology for flexible manufacturing systems (FMSs). The control methodology is based on a two-tier decision making mechanism. The first tier is designed to select a dominant decision criterion and a relevant scheduling rule set using a rule-based algorithm. In the second tier, using a look-ahead multi-pass simulation, a scheduling rule that best advances the selected criterion is determined. The decision making mechanism was integrated with the shop floor control module that comprises a real-time simulation model at the top control level and RapidCIM methodology at the low equipment control level.A factorial experiment was designed to analyze and evaluate the two-tier decision making mechanism and the effects that the main design parameters have on the system’s performance. Next, the proposed control methodology was compared to a selected group of scheduling rules/policies using DEA. The results demonstrated the superiority of the suggested control methodology as well as its capacity to cope with a fast changing environment.     

基于无线传感器网络的自治制造车间控制

为应对制造环境不可预知和动态的变化,基于无线传感器网络的自治车间控制系统,通过在制造车间中的各种物理对象（产品、设备等）上嵌入无线传感器节点,赋予其通信、计算和决策能力,实现了基于信息素的自治控制。该算法模拟蚁群觅食过程,将复杂的车间控制问题变为多个产品自治地寻找最佳加工路径的过程。原型系统实验证实了该方法能有效地适应动态变化的制造环境,获得了满意的控制效果。     

Applying an Integrated Analysis Method to Develop a Shop Floor Control System

The fundamental concept of computer integrated manufacturing is to integrate the information flow, material flow and control flow of the whole manufacturing enterprise. One major task, which might be required during the integration process, is to model the related enterprise activities. Currently, the most common method of modelling automatic manufacturing systems is to describe the system from organisational, functional, information or process points of view. Many tools or methods have been developed to support those modelling processes. However, most of those methodologies are focused only on one viewpoint. There is very little connection among various viewpoints. Therefore, gaps might exist among those models which may need extra work to bridge them while implementing the developed model. In this research, an ARIS^™ based framework to assist shop floor controller development is proposed. The major merit of using ARIS is that an integrated model containing the organisation, function, information and process entities of the shop floor can be achieved. In addition, a set of rules was developed to transfer the logic of this integrated model to the control codes of the controller during the implementation stage. The main objective of this framework is to reduce the gaps among various models and hence to shorten the system modelling and development time.     

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.     

三维图形实时协同评估中发言权控制策略的研究

研究和分析现有的发言权控制策略，介绍了基于,JAVA和VRML技术的分布式产品协同评估系统。针对本三维图形实时协同评估系统的特点，采用特定的发言权控制策略。进行并发控制。在借鉴已有的发言权控制策略的基础上，提出将请求和时间周期相结合的控制策略，即平等发言权和多重队列轮换法的协同发言权控制策略，对不同的参与人员数量，采用不同的策略，并对其在该系统中的实时性、公平性进行分析。     

Real-time control and scheduling of flexible manufacturing systems: An ordinal optimisation based approach

A unique real-time control and scheduling framework for flexible manufacturing systems (FMS) is presented in this paper. The framework enables the adoption of different scheduling policies for short-term intervals when responding to the dynamic changes of the FMS shop floor status. Each time when rescheduling is called for, standard clock (SC) simulation is first employed to evaluate the performance of a set of scheduling policies for a short planning horizon. The ordinal optimisation concept is then used to choose quickly the most desirable scheduling policy. Owing to the use of the standard clock technique and the ordinal optimisation concept, this framework accomplishes a dramatic reduction in the time needed for decision making, the essential requirement for real-time control. It is also found that as the scale of the problem increases, the decision-making time increases linearly rather than exponentially. These two important features indicate that this framework has the potential for being successfully implemented in real FMS settings. Although the framework cannot always guarantee the global best performance, the case study indicates that satisfactory performance results are always achieved by using this framework.     

敏捷制造车间任务规划系统的设计与开发

敏捷制造车间任务规划作为联系敏捷制造车间计划与敏捷制造车间调度与控制的纽带，是计划任务在敏捷制造单元层上的动态分配。对敏捷制造车间任务规划系统进行了设计，构造了基于多Agent的体系结构，定义并描述了敏捷制造车间任务规划问题，并在分析敏捷制造车间各个智能体行为的基础上，提出了基于知识和联盟形成算法的敏捷制造车间任务规划方法。该方法。是敏捷制造车间任务规划系统的核心。介绍了开发的敏捷制造车间任务规划系统。     

An economic and reliable tool life estimation procedure for turning

The conventional methods of tool life estimation take a long time and consume a lot of work piece material. In this paper, a quicker method for the estimation of tool life is proposed, which requires less consumption of work piece material and tools. In this method the tool life is estimated by fitting a best-fit line on the data falling in the steady wear zone and finding the time till tool failure by extrapolation. Neural networks are used to predict lower, upper and most likely estimates of the tool life. Comparison between neural networks and multiple regression shows the superiority of the former. The paper also proposes a methodology for continuous monitoring of tool use in the shop floor and updating/obtaining the tool life estimates based on the shop floor feed back.     

生产车间混合式控制结构模型和协商机制研究

为了提高车间控制系统的柔性、开放性和全局优化性能,在分析现有车间控制体系结构的基础上,融合Agent技术,提出了一种适应性混合式车间控制系统体系结构模型。该模型利用递阶结构将控制功能设计成系统优化Agent、单元协调Agent和单实体Agent三层结构,并允许同层Agent及上下层Agent之间的协商。为了进一步提高协商效率,集成分布式协商和全局控制,设计了基于招投标机制和示例学习方法的协商机制,详细分析了包括时间约束算法和基于示例的学习方法的协商机制核心算法。在JADE(Java Agent development framework)平台上构建了原型系统。