YH—MCS可重构容错多机EMS单元控制系统的设计和实现

随着ＦＭＳ（柔性制造系统）制造单元的日益复杂，ＦＭＳ单元控制系统也从单机系统发展成多机系统。一多机系统具有更强的数据处理能力，更大的灵活性和更高的容错能力。本文介绍一个基于多机的容错ＦＭＳ单元控制系统ＹＨ—ＭＣＳ，详细讨论了它的体系结构，容错和故障定位的特点以及实现技术，并总结了基于多机的单元控制系统的优点。     

计算机集成制造(生产)系统(CIMS/CIPS)

第３讲　制造（过程）自动化系统与集成１　系统内容与结构ＣＩＭ环境下制造自动化系统主要指５层结构中车间以下的部分。一个典型的机械制造自动化车间采用以柔性制造系统（ＦＭＳ）为基础的柔性制造技术,它可以包括多于２个的柔性制造单元（ＦＭＣ）,还可以由ＦＭＳ与ＦＭＣ及多种计算机直接数控（ＤＮＣ）型数控机床群组合构成。一般来说,对于不同类型的企业,根据企业生产制造过程不同,其制造自动化系统的构成和内容也有较大的不同。可将各种制造企业按主要生产过程的连续性分成三大类：（１）离散制造业：包括各种机床、汽车、飞机…     

PLC在柔性制造系统托盘交换控制中的应用

１引言物料自动输送与贮运系统是柔性制造系统（ＦＭＳ）的重要组成部分，其主要任务是通过物料小车完成在装卸站、托盘库和加工中心三者之间工件的自动存贮运送和交换，它担负着使ＦＭＳ物流畅通、高速运行的重任，本文就ＦＭＳ物料系统托盘自动交换采用ＰＬＣ控制进行讨...     

柔性制造系统运行控制软件测试环境的模型

本文讨论了柔性制造系统运控软件的测试环境建立问题，提出ＦＭＳ驼控软件测试区别于一般计算机应用软件测试的特点，并建立了ＦＭＳ运控软件测试环境的硬件模型。     

模糊Petri网在FMS故障诊断中的应用研究

针对柔性制造系统（ＦＭＳ）故障诊断的特点，将模糊Ｐｅｔｒｉ网扩展为模糊行为Ｐｅｔｒｉ网（ＦＢＰＮ）．并应用于知识的表示中，讨论了ＦＭＳ系统、ＦＢＰＮ及产生式规则之间的对应关系，提出一种模糊反向推理机制，给出了利用ＦＢＰＮ进行知识表示和推理的实例．     

柔性制造系统中的信息采集系统研究

为了有效地控制和管理柔性制造系统（ＦＭＳ）,制造过程信息采集对系统来说显得至关重要。本文从信息采集的角度,讨论了ＦＭＳ底层设备运行的功能模型,提出了以工业控制实时局域网为基础的ＦＭＳ信息采集系统的结构。并对工业控制实时局域网的硬件和软件构成进行了详细的描述。最后以西门子３Ｍ数控系统为实例,介绍了底层设备ＦＭＳ网络通信接口的设计与开发。该数据采集系统在一个实际的ＦＭＳ中使用取得了令人满意的效果。     

FMS动态调度软件自动生成研究

本文针对软件自动化方法在ＦＭＳ运控软件设计中的应用，介绍了由ＦＭＳ布局自动生成系统，ＦＭＳ动态调度软件自动生成系统，ＦＭＳ动态调度软件的仿真系统３个基本部分组成的ＦＭＳ运控软件自动生成系统。系统以输入的加工零件信息和生产计划作为推理的基础，并进行优化，自动产生较为合理的布局，在此布局的基础上，通过调用相应的调度规则，自动产生ＦＭＳ动态调度软件，通过ＦＳｉｍｕ仿真器来仿真验证，这样开发一个动态调度软件的时间大大缩短，降低了ＦＭＳ开发成本，还提高了软件的质量。     

一种用于柔性制造系统仿真的图形Petri网软件工具

本文致力于图形Ｐｅｔｒｉ网软件工具—ＧＰＮＳＴ软件包的设计与实现。首先介绍了ＧＰＮＳＴ的结构和功能，分析了它在Ｐｅｔｒｉ网图形编辑和网结构分析方面的能力；其次正式定义了Ｐｅｔｒｉ网的扩展—赋时着色Ｐｅｔｒｉ网（ＴＣＰＮ），并且使用ＴＣＰＮ建立了柔性制造系统（ＦＭＳ）的简化仿真模型。利用这个模型，能基本实现ＦＭＳ的动态仿真，同时显示整个仿真的过程；最后将调度算法、启发式规则、ＴＣＰＮ模型和仿真结合起来，构成一个基于专家系统的调度器，产生出虽非最优，但是具有比较好结果的可行调度，有效地解决了动态仿真中的ＦＭＳ调度问题。     

基于故障树的FMS可靠性分析

本文通过对柔性制造系统的故障树的建立及定量的分析，讨论了通过故障树获取ＦＭＳ的各可靠性指标的方法。     

基于关联预测法的递阶生产计划与控制*

本文在研究实现有多种递阶生产计划和控制模型的基础上，提出用关联预测法来解决柔性自动化车间（ＦＡＷ）的最优递阶生产计划与控制问题。文中首先建立ＦＡＷ生产控制的数学模型，然后推导ＦＡＷ递阶生产计划的关联预测算法，编写了基于该算法的ＩＰＡ软件包并进行了算例研究，同现有的计划分解方法相比，这里的方法更适于将ＣＩＭＳ／ＭＲＰⅡ下达给ＦＡＷ的中期计划最优分解成由ＦＡＷ中各ＦＭＳ执行的短期计划。     

A modeling technique for loading and scheduling problems in FMS

In recent years, due to highly competitive market conditions, it has become necessary for manufacturing systems to have quick response times and high flexibility. Flexible manufacturing systems (FMS's) have gained attention in response to this challenge. FMS has the ability to produce a variety of parts using the same system. However this flexibility comes at the price, which is the development of efficient and effective methods for integrated production planning, and control.In this paper, we analyze the production planning problem in flexible manufacturing systems. We address the problems of part loading, tool loading, and part scheduling. We assume that there is a set of tools with known life and a set of machines that can produce a variety of parts. A batch of various part types is routed through this system with the assumption that the processing time and cost vary with the assignment of parts to different machines and assignment of various tool sets to machines. We developed a mathematical model to select machines and assign operations and the required tools to machines in order to minimize the summation of maximum completion time, material handling time, and total processing time.We first integrate and formulate loading, and routing, two of the most important FMS planning problems, as a 0–1 mixed integer programming problem. We then take the output from the integrated planning model and generate a detailed operations schedule. The results reported in this paper demonstrate the model efficiency and examine the performance of the system with respect to measures such as production rate and utilization.     

Taguchi's Method Analysis of an FMS Under Review-Period-Based Operational Controls: Identification of Control Periodicity

Flexibility of flexible manufacturing systems (FMSs) has been considered as an effective tool to compete in the present manufacturing environment. Enormous research efforts have been made to harness the benefits of flexibility through superior control strategies. While modeling flexibility and control strategies, researchers have mostly assumed an information system that can provide real-time control. Literature qualitatively reports that the real-time control can be highly capital intensive and difficult to achieve. This paper focuses on FMS operating under review-period (RP)-based control and presents a combined study of routing flexibility (RF), control strategies, and information system under Taguchi's method using simulation. RP-based control for FMS has been compared with real-time control. This paper contributes an approach for the decision maker to study the performance of an FMS operating under RP control and to identify the periodicity (time interval) of RP that will not deteriorate its performance in comparison to real-time control. It also helps the decision maker to reach a tradeoff between RP-based control and real-time control. The results show that RP-based control can be effectively implemented on an FMS having lower RF level. RP-based control can outperform real-time control with a superior control strategy and smaller RP size. The results under Taguchi's method suggest that the RF and control strategy should have maximum relative percentage contributions in FMS performance, whereas contribution of the RP (information system) should be minimum. Increasing the relative percentage contribution of the information system may deteriorate the performance of FMS. The information system is needed as a catalyst to facilitate the contributions of other factors in improving the FMS performance and not its own contribution     

The effect of responsiveness of the control-decision system to the performance of FMS

In Flexible Manufacturing System (FMS), decision-making process is one of the key aspects for its performance enhancement, particularly for shop-floor control, where operation managers need to make a large number of control decisions. A term called ‘response-time’ in decision-making process has been defined in this study, which refers to a lead time in decision-making and its implementation. This paper contributes a methodology for decision-maker to study the decision-making process and identify a suitable decision-making approach, while considering critical factors such as decision automation levels, routing flexibility levels, and control strategies. Considering the complexity in modelling an FMS with routing flexibility levels, control strategies (sequencing and dispatching rules), and decision-making process with information system, computer simulation modelling has been employed to study the makespan performance. The results show that decision-making process with response-time for FMS control performs as good as with the real-time control when routing flexibility level is low. Furthermore, under some specific situations, it even outperforms the real-time control. This research gives insight to decision-maker to identify whether a decision system with response-time will be more suitable and economically justified, or real-time decision-making system is more appropriate.     

A parametric fuzzy logic approach to dynamic part routing under full routing flexibility

Manufacturing flexibility is a competitive weapon for surviving today’s highly variable and volatile markets. It is critical therefore, to select the appropriate type of flexibility for a given manufacturing system, and to design effective strategies for using this flexibility in a way to improve the system performance. This study focuses on full routing flexibility which includes not only alternative machines for operations but also alternative sequences of operations for producing the same work piece. Upon completion of an operation, an on-line dispatching decision called part routing is required to choose one of the alternatives as the next step. This study introduces three new approaches, including a fuzzy logic approach, for dynamic part routing. The fuzzy part routing system adapts itself to the characteristics of a given flexible manufacturing system (FMS) installation by setting the key parameters of the membership functions as well as its Takagi-Sugeno type rule base, in such a way to capture the bottlenecks in the environment. Thus, the model does not require a search or training for the parameter set. The proposed approaches are tested against several crisp and fuzzy routing algorithms taken from the literature, by means of extensive simulation experiments in hypothetical FMS environments under variable system configurations. The results show that the proposed fuzzy approach remains robust across different system configurations and flexibility levels, and performs favourably compared to the other algorithms. The results also reveal important characteristic behaviour regarding routing flexibility.     

An asymmetric multileveled symbiotic evolutionary algorithm for integrated FMS scheduling

This paper considers the integrated FMS (flexible manufacturing system) scheduling problem (IFSP) consisting of loading, routing, and sequencing subproblems that are interrelated to each other. In scheduling FMS, the decisions for the subproblems should be appropriately made to improve resource utilization. It is also important to fully exploit the potential of the inherent flexibility of FMS. In this paper, a symbiotic evolutionary algorithm, named asymmetric multileveled symbiotic evolutionary algorithm (AMSEA), is proposed to solve the IFSP. AMSEA imitates the natural process of symbiotic evolution and endosymbiotic evolution. Genetic representations and operators suitable for the subproblems are proposed. A neighborhood-based coevolutionary strategy is employed to maintain the population diversity. AMSEA has the strength to simultaneously solve subproblems for loading, routing, and sequencing and to easily handle a variety of FMS flexibilities. The extensive experiments are carried out to verify the performance of AMSEA, and the results are reported.     

Analysis of dynamic due-date assignment models in a flexible manufacturing system

This paper investigates the effects of dynamic due-date assignment models (DDDAMs), routing flexibility levels (RFLs), sequencing flexibility levels (SFLs) and part sequencing rules (PSRs) on the performance of a flexible manufacturing system (FMS) for the situation wherein part types to be produced in the system arrive continuously in a random manner. The existing DDDAMs considered are dynamic processing plus waiting time and dynamic total work content. A new model known as dynamically estimated flow allowance (DEFA) has also been developed and investigated. The routing flexibility of the system and the sequencing flexibility of parts are both set at three levels. A discrete-event simulation model of the FMS is used as a test-bed for experimentation. The performance measures evaluated are mean flow time, mean tardiness, percentage of tardy parts and mean flow allowance. The statistical analysis of the simulation results reveals that there are significant interactions among DDDAMs, RFLs, SFLs and PSRs for all the performance measures. The proposed DEFA model provides the minimum percentage of tardy parts in all the experiments. Regression-based metamodels have been developed using the simulation results. The metamodels are found to provide a good prediction of the performance of the FMS within the domain of their definition.     

Semi-heterarchical control of FMS: From theory to application

This paper presents both a model and a real implementation of a semi-heterarchical control system for flexible manufacturing systems (FMS). After presenting the concepts of heterarchical and semi-heterarchical control, a product-based control structure, composed of a dynamic allocation process (DAP) and a dynamic routing process (DRP), is proposed. Though the associated control processes (DAP and DRP) are hierarchically dependant, each is managed heterarchically, with no supervisor. The dynamic allocation algorithms are presented, and our highly distributed approach to routing control is then explained in detail. A real distributed application of the active entities and the control architecture was implemented in the AIP-PRIMECA pole at the University of Valenciennes, and this implementation is described in detail. A mixed-integer linear model of the FMS was used to compute lower bounds. The flexibility and robustness of our approach are highlighted through several real experiments.     

Modelling for flexible manufacturing systems and structural properties of optimal work routing policy

We consider flexible manufacturing systems (FMSs) which are composed of a set of workstations linked together with a material handling system (MHS). Each workstation consists of an input buffer, a single machine and an output buffer. The MHS consisting of a single cart routes work among the workstations according to the process paths required by the work. We deal with an optimal control problem in this FMS. We model the FMS as a closed queueing network. In the model, the cart routes the work to the workstations in accordance with a Markov routing with exponentially distributed routing time, and the machines process work with exponentially distributed processing time. An objective is to find a work routing policy that maximizes the total expected reward earned by operating machines. This optimal control problem is formulated as an undiscounted semi-Markov decision process. Structural properties of an optimal policy are analysed. Moreover, a sufficient condition is derived for the optimal policy to be of control limit type. An example is given to illustrate the result.     

Flexible job-shop scheduling with routing flexibility and separable setup times using ant colony optimisation method

This paper proposes an ant colony optimisation-based software system for solving FMS scheduling in a job-shop environment with routing flexibility, sequence-dependent setup and transportation time. In particular, the optimisation problem for a real environment, including parallel machines and operation lag times, has been approached by means of an effective pheromone trail coding and tailored ant colony operators for improving solution quality. The method used to tune the system parameters is also described. The algorithm has been tested by using standard benchmarks and problems, properly designed for a typical FMS layout. The effectiveness of the proposed system has been verified in comparison with alternative approaches.