Hierarchy transformation method for repetitive manufacturing system specification,design, verification and implementation

The hierarchy transformation method consists of a series of transformations through functional, controllable, dynamic, commanding hierarchies for CIM implementation. Here a functional hierarchy is initially constructed from a manufacturing system specification. Then a controllable hierarchy at the design stage is constructed after the functional hierarchy. Subsequently, a dynamic hierarchy and a commanding hierarchy are constructed through transformations at the verification and implementation stages, respectively. After invariant analysis at the verification stage, the controlled objects at the implementation stage are generated by computation. After deadlock analysis, their behaviours are monitored and predicted by verified rules. This provides not only a systematic method, but also a formal approach for CIM implementation.     

A specification language for planning and fault recovery in manufacturing systems

This paper presents the syntax and semantics of a component-oriented rule-based language for specifying the formal models of manufacturing systems. A model captures the state of a component of the system in a set of first-order logic predicates, and it captures the semantics of the operations performed by this component in a set of rules that determine the preconditions and postconditions of an operation. The models are then used to plan the sequence of operations of each class of jobs to be manufactured by these systems. A plan-oriented fault detection and correction strategy is proposed. This strategy can automatically handle any combination of faults that may occur when monitoring the operations of manufacturing systems. A fault-tree is consulted prior to executing the scheduled operations of a plan, and the faults that affect the execution of these operations are handled subsequently. Resuming the original cyclic schedule is attempted, whenever feasible. As a proof of concept, a prototype implementation of both the main constructs of the component-oriented rule-based language and the planning and fault-recovery algorithms presented in this paper have been completed. This prototype is implemented on a Unix-based system in the Ada programming language. The specification of a manufacturing system is first expressed in the proposed language. These statements are then translated into Ada code. This code is next compiled by a Verdix Ada compiler and is executed in order to create and populate the model data structure of the system. A detailed plan of execution and a set of fault-recovery plans may then be derived for a job to be manufactured on this system.     

可重构制造系统集成设计框架研究

提出了基于可重构制造单元的可重构制造系统集成设计框架.在该框架中,从规划和运行方面阐述了可重构制造系统的设计目标、设计流程及采用的关键技术,建立了支持可重构制造系统实施的计算机辅助设计系统的功能模型和体系结构,并讨论了系统的内部集成和外部集成问题.根据该设计框架,开发了集重构、布局规划、生产调度和仿真优化为一体的软件系统,该系统现已应用于航天、船舶和兵器部门.     

A multi-material part design framework in additive manufacturing

Additive manufacturing (AM) technologies provide more freedom to functional part design in various industries. One of the unique capabilities of AM is that multi-material parts can be produced with material compositional and geometric complexity. Multi-material parts have the advantage of achieving multiple performance requirements. In the research, we propose a framework for designing multi-material parts using AM processes. The proposed framework is composed of four interacting modules, including design requirement identification, primary material selection, AM process selection, material composition, and part geometry determination. Rules and guidelines for AM are integrated into the proposed framework with AM processes’ capabilities and constraints compiled in databases. We also introduce databases to assist in decision-making and ensure manufacturability of the designed multi-material part in various product design phases. The proposed framework is applied to a case study involving a conceptual design of a multi-material battery pack cooling plate.     

Object-oriented approach to the specification of manufacturing systems

This paper proposes an object-oriented approach to the specification of manufacturing systems. The specification model is built around a set of concurrent cooperating objects whose behaviour is described using communicating finite state machines. One of the interesting features of this approach is that the system's environment can be included in the model. This allows for rapid prototyping of the system through realistic simulations.     

A loop layout design problem for flexible manufacturing systems

The interconnection pattern of the processing modules of a computerized manufacturing system affects its performance. In this article, we discuss a set of requirements that the interconnection network should satisfy. Subsequently, we concentrate on a simple and popular architecture, the loop network. The problem we address is to design the layout of the system so that the number of machines that the part types cross in their manufacturing process is minimized. We formulate the problem mathematically and solve it by a heuristic that obtains consistently better results than an earlier popular method.     

An integrated control framework for flexible manufacturing systems

This paper presents the design, development, and implementation of an integrated control framework that provides a real-time supervisory control model with limited look-ahead capability for flexible manufacturing systems. Control goals and policies are modeled and characterized by a fuzzy rule base, which is integrated with the control model. The framework consists of a finite state machine generator and a controller. The generator model is equipped with an output function and output sets. The controller model has a four-stage decision-making structure. The controller monitors performance measures of the manufacturing system and reacts according to the changes in the system states in order to keep the performance measures at desired levels. The integrated framework has been implemented on a software platform in order to validate its effectiveness. The performance of the framework has been tested on a hypothetical flexible manufacturing system using a simulation .     

Knowledge-based tool for manufacturing systems design

Knowledge engineering technology has been applied to the construction of a tool which aims to provide support during the complicated process of manufacturing system desing. Based on the ‘controllability engineering’ method, this knowledge-based system is directed towards the analysis and redesigning of manufacturing systems. The approach used in the construction of the CENT system is based on accumulated case experiences which have been implemented on hypermedia tools. Building problems associated with the project are described, alternative solutions to the problems encountered are explored, the project's current status is outlined, and the knowledge-based system's use is detailed.     

A model management systems approach to manufacturing systems design

Manufacturing systems design involves the solution of a complex series of interrelated problems. This complexity will increase in the future as manufacturing practices change to meet increased global competition. Research within manufacturing systems design has mainly been focused on finding improved models for solving particular problems, or extending existing modeling techniques. This has resulted in numerous modeling tools being available to support manufacturing systems design. However, little research work has been carried out into consolidating the existing theories and models. As a result, a large body of this work has not been applied in industry.Model management has evolved as a research area which investigates methods for storing, modifying, and manipulating models. This article describes a prototype model management system for manufacturing systems design. The objective here is not to develop another decision support system for manufacturing design, but to illustrate, through the development of a prototype system, a number of key ideas of how concepts from the area of model management systems can be used to support manufacturing systems design. The prototype model management system utilizes the structured modeling framework and uses an extended version of the structured modeling language. An important aspect of the prototype model management system is the incorporation of the model development task, thus allowing the system to be easily updated and adapted. The prototype system was evaluated using a range of queueing network models for manufacturing systems design.     

A decision-making framework model for evaluating flexible manufacturing systems using digraph and matrix methods

In the present work, a methodology based on digraph and matrix methods is developed for evaluation of alternative flexible manufacturing systems. A ‘flexible manufacturing system selection index’ is proposed that evaluates and ranks flexible manufacturing systems for a given industrial application. The methodology is illustrated by an example.     

Utility of design methodology for advanced manufacturing systems

A methodology is presented for the design of advanced manufacturing systems (AMSs). Following an introduction to the problems of specifying AMSs, a survey and classification of methodologies is presented. The classification is further illustrated in discussing some existing methodologies, namely, decisional (graphe à résultats et activités interreliés (GRAI)), informational (structured system analysis design (SSAD)) and physical (graphe de commande etape-transition (GRAFCET)).     

Sandglass-type product specification management method for supporting modular design of semiconductor manufacturing equipment

The product life cycle for semiconductor manufacturing facilities has been significantly reduced as a result of the technological advancement of the semiconductor manufacturing process and the expansion of its demand. To ensure long-term market competitiveness under this environment, many companies attempt to convert their systems into mass customization production systems. In general, the specification management for semiconductor manufacturing equipment has adopted the method of making the bill of materials structure of the existing equipment into a new one based on the same physical structure and then customizing it according to a customer’s demands in the detail design phase. However, this method results in longer lead times and difficulties maintaining data consistency due to frequent design changes in connection with various derived products. We suggest a sandglass-type product specification management method to efficiently reflect varying and versatile requirements in product development and shorten the design lead time. In addition, we propose a method to support the modular design of semiconductor manufacturing equipment by classifying the standard specifications for a final product into product component and part component specifications. Finally, we develop a closed-loop product specification management system called NEXUS using our method, and apply this system to semiconductor manufacturing processes.

     

A systematic approach for the sequence controller design in manufacturing systems

This paper presents a systematic approach for the design and implementation of the sequence controller in manufacturing systems. By employing the IDEF0, we construct the simplified Petri net controller (SPNC) through the material flow diagram and the information flow diagram. Then, the ladder logic diagram (LLD) can be transformed from the SPNC through the token passing logic (TPL). The proposed approach, including the IDEF0, SPNC, and TPL tools, leads to the standard IEC1131-3 LLD for PLC implementation. Finally, an application of a stamping process is provided to illustrate the design procedure of the developed approach .     

A distributed internet-based framework for manufacturing planning

Manufacturing organizations worldwide are re-inventing their product development practices in an effort to satisfy changing customer requirements. In the context of these changes influencing the manufacturing community, there is a need to develop frameworks, architectures, and methods to facilitate the creation, implementation, and functioning of virtual enterprises (VEs). This paper presents an Internet-based framework, which supports distributed process planning activities in the context of a VE. Typically, in a VE, the enterprise partners are distributed, and possess diverse skills and heterogeneous software resources, which employ heterogeneous computing platforms. Using the developed approach, physically distributed product development partners can collaborate virtually via the Internet and integrate their life-cycle product development activities through seamless information exchange. In this framework, the distributed manufacturing resources communicate with each other via the Internet inter-ORB protocol (IIOP) using an object request broker (ORB) at each distributed site.     

Aspects of a knowledge-based tool for manufacturing systems design

In the face of increasing worldwide competition, many manufacturing companies are reassessing their operations. Systematic design of manufacturing systems increasingly requires the adoption of a multidisciplinary approach involving all aspects of a company's activities. In carrying out this task, well structured knowledge-based systems can act as a useful tool for supporting the work of trained manufacturing systems engineers. This is due to the complex and iterative nature of the systems design process which requires the integration of knowledge from a number of application domains. User acceptance of the resulting knowledge-based system is critically dependent on the human-computer interface which, in this case, must be adaptable to the varied requirements of users with different levels of expertise and specialist skills. This paper describes the facilities provided in one such knowledge-based tool developed to help redesign existing manufacturing systems.     

A modular simulator for design,planning, and control of flexible manufacturing systems

Flexible manufacturing systems are designed to produce a variety of different part types with high machine utilisation, short lead times and little work-in-progress inventory. Simulation is an efficient tool to verify design concepts, to select machinery, to evaluate alternative configurations and to test system control strategies of an FMS. This paper discusses a general-purpose, user-oriented discrete simulator (the Modular FMS Simulator) which can be used for design as well as for operation and scheduling of FMSs. The package can be implemented in different hierarchical steps of FMS production planning. It is also a useful tool in validating the results of analytical models or heuristic procedures developed for FMS problems. This package contains features for the system hardware and the control hierarchy. The model can study multiple part families, various station types, different number of work-in-process buffers and carts and almost any system layout. It is also possible to analyse the performance of the system. The package contains a set of decision rules from which the user can make his choice.     

可重构制造系统工艺路线与系统布局设计研究

为使可重构制造系统的重构过程更加快速有效,提出了一种工艺路线和系统布局设计的方法.首先,基于图论构建了可重构制造系统工艺路线的有向网络模型,并采用Dijkstra算法和双向扫视算法,进行最优工艺路线和备选工艺路线的选择;然后,以工艺路线为基础,依据排队论中的相关理论,对制造系统的布局进行优化设计,以获得可重构制造系统布局方案.实例表明,该设计能够适应可重构制造系统快速多变的特征,提高对制造系统已有资源的利用率.     

符号学视角下的智慧制造系统集成框架

为了从社会和技术两个方面探讨智慧制造系统中的建模问题,从符号学的视角出发,建立和分析了由社会系统、信息系统和物理系统组成的智慧制造系统洋葱模型和阶梯模型,并用阶梯模型诠释了现有集成制造系统,指出现有集成制造系统的不同在于达到符号学的层次或包含符号学的层数,而智慧制造系统则是包括了符号学所有层次的集成模式。所提出的阶梯模型为制造系统集成与建模提供了一个系统清晰、根基牢固的理论框架。     

Reconfigurability consideration design of components and manufacturing systems

A manufacturing system should be able to produce a variety of components at a low cost and in a short period of time. In this paper, manufacturing system reconfigurability in agile manufacturing is discussed. The reconfiguration of a manufacturing system is analysed based on the relationship of component routes, material handling costs, reconfiguration cost, and so on. Components with similar routes are selected in an early design stage in order to minimise the number of machines to be relocated. The variety of resources required is reduced by a proper selection of components and manufacturing processes for system reconfiguration. An algorithm for selection of components and manufacturing resources is developed.     

An intelligent concurrent design task planner for manufacturing systems

Product design is an integral component of manufacturing systems. This paper presents a prototype intelligent concurrent design task planner, which combines the strength of genetic algorithms and an iterative design analyser for the scheduling of a complex design process of a manufacturing system. It accounts significantly for shortening the time-to-market of a product, and hence, improves the agility of a manufacturing system. The proposed prototype attempts to schedule the design process inherently containing iteration, which is caused by the interdependencies among tasks and leads to prolonged lead-time and increased cost on the whole time-span of introducing a product. Genetic algorithm (GA), as one of the effective optimisation techniques, is embodied in the prototype to search for the optimal schedule for a design process for the goal of satisfying the managerial objective under resource constraints. The iterative design analyser, which is basically an analytical tool for design iteration, is utilised to estimate the time and engineering cost spent on the design process for each candidate schedule. Considering the unpredictable length of a schedule for iterative design process, a novel chromosome representation scheme and unique crossover and mutation operators have been introduced. A case study conducted on a burn-in system of a manufacturing company has illustrated the effectiveness of the proposed prototype.