Computer-aided design of experiments: an enabler of agile manufacturing

The generation of feature curves or curve network from the digitized points of an object is very important for successful surface reconstruction. Owing to the shape complexity of industrial parts and the random nature of scanned points, the feature curves detected are generally not smooth or accurate enough for the subsequent use. The purpose of this study was to present an algorithm for extracting geodesic or feature lines on triangular meshes provided that the initial and final points of the path are given. The proposed algorithm is essentially developed from a heuristic search algorithm where a cost function composed of distance and curvature information is employed to guide the search of the optimized path. When the distances between the points dominate the cost function, it will result in a geodesic path between the initial and final points. On the contrary, when the curvature cost dominates, the optimized path will track the feature edges or rounded edges appropriately. Successful examples are presented to illustrate the feasibility of the proposed algorithm.     

基于多Agent的敏捷制造单元控制系统

针对敏捷制造的需求,本文提出了一种基于多Agent制造单元控制系统的总体结构,并对各Agent的功能与单元控制系统的实现过程进行了详细描述,简单介绍了Agent之间的通信机制.     

An integrated model of dynamic cellular manufacturing and supply chain system design

In a global dynamic environment, there is a need to develop organizations and facilities significantly more flexible and responsive. This work proposes an integrated model of dynamic cellular manufacturing and supply chain design with consideration of various issues such as multi-plant locations, multiple markets, multi-time periods, reconfiguration, etc. The model objective was to minimize the sum of various costs such as facility/plant to market transportation cost, part holding cost at a facility/plant, part outsourcing cost, machine procurement cost, machine maintenance overhead cost, machine repair cost, production loss cost due to machine breakdown, machine operation cost, setup cost, tool consumption cost, inter-cell travel cost, intra-cell travel cost, and system reconfiguration cost for the entire planning time horizon. To study the model, three procedures—LINGO, artificial immune system, and hybrid artificial immune system—are used to perform computational experiment on some problems from existing literature. The best result generally is found by the hybrid artificial immune system algorithm.     

An adaptive agile manufacturing control infrastructure based on TOPNs-CS modelling

In this paper, an infrastructure for adaptive production control in an agile manufacturing environment is proposed. With this infrastructure, Virtual Production Systems (VPSs), each of which takes care of the production of a specific customer ordered product, can be dynamically and flexibly constructed. This can be achieved logically by product workflow and physically by the resources in one or more manufacturing systems, e.g. job shops. To respond to changes and disturbances to a VPS, architecture for the adaptive controller of a VPS is designed based on adaptive control principles and Temporised Object-Oriented Petri Nets with Changeable Structure (OPNs-CS) modelling. A case study is used in this paper to illustrate how adaptive production control of VPS functions can be conducted to cope with changes and disturbances to the production system.     

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 .     

An integrated planning approach for a nanodeposition manufacturing process

This paper deals with the planning problem in a nanodeposition manufacturing process, in which a toolbit that consists of a multilayer grid of micro/nanofluidic channels is used to deposit nanoscale liquid materials to desired positions on workparts to form solid patterns. The objective is to obtain a planning procedure that achieves efficient throughput for the studied nanodeposition manufacturing systems. We break down the studied problem into several sub-problems as design pattern decomposition, nanopore assignment, liquid material routing in the multilayer grid fluidic network, and toolbit path planning. Efficient algorithms are proposed to solve these sub-problems individually, and then finally integrated into a framework that systematically plans the nanodeposition manufacturing process. A software tool that plans, simulates, and controls the nanodeposition manufacturing process by implementing the proposed algorithms is reported in this paper.     

运用DBR系统的船舶敏捷制造企业生产计划与控制

基于单一生产系统内部"鼓-缓冲器-绳子"(DBR)生产计划与控制系统的实现机制,通过对其应用范围的进一步扩展,提出船舶敏捷制造环境下DBR系统运作的三条基本原理,并从DBR系统的瓶颈识别、缓冲设置与控制机制三个方面对其实现机制进行探讨。提出支持DBR系统运作的船舶敏捷制造企业瓶颈识别、时间缓冲大小的设置方法和控制机制。     

集成激光制造系统的开放式控制研究

针对激光制造系统的发展要求,提出了一种开放式集成激光制造系统,该系统将激光器控制模块、测量模块、机器人模块和计算机控制模块等进行集成,采用模块化设计方法,各模块功能独立,实现了主控计算机对各控制模块的协调控制.其中激光器由PROFIBUS-DP现场总线控制,机器人由运动控制器控制.解决了传统激光制造系统结构封闭,专用性强,难于实现柔性化制造的难题.通过实际应用,进一步证明了该系统的开放性和可控性.     

面向家电敏捷制造的PLM系统实施

从敏捷制造现状出发,分析了面向敏捷制造的PLM(Production Lifecycle Management,产品生命周期管理)价值和功能,指出了家电企业实施PLM技术的必要性,并结合海尔实例分析了海尔集团PLM系统执行情况,对于提升家电企业生产效率,降低生产成本,增强企业竞争力有重要意义.     

An integrated bevel gears manufacturing system

Wholly automated forging systems are still comparatively rare. This paper summarizes the principles of integrated manufacturing systems and reviews the state-of-the-art. The problems associated with the application of automatic loading equipment to the handling of forgings to insure continuous operation of the integrated manufacturing system, object of this research study, are examined by arguments and various types of handling devices are considered. The manufacturing system is under direct numerical control (DNC) and is centered on chipless forming which, as a final product, yield bevel gears and similar parts with ready-to-mount teeth. However, the ultimate solution to automation in such systems seems to lie neither in copying of human skills nor in applying sophisticated industrial robots. Therefore, the synthesis technique of a simple manipulator which is adaptable to transfer/handling tasks in this billet stock metering, forming, cutting, and measuring integrated system aimed at the production of ready-to-mount parts is discussed. The manipulator can be adjusted to handle forgings from the last engraving stage of the installed multistage forging press, attended by a multi-positions inter press transfer manipulator for hot components, to the cutting machine, and then to the conveyor of the automatic measuring line. A hot machining technique is considered as an interesting possibility to increase the cutting operation rates.     

An integrated fuzzy approach for the selection of manufacturing technologies

In this paper, an integrated decision support system is developed, which employs fuzzy techniques to assist decision-makers in choosing an optimal solution from alternative manufacturing options in an uncertain environment. The integrated approach incorporates different justification methods (e.g., strategic, economic, and analytic evaluations) for assessing tangible benefits, like cost, and intangible benefits, like quality, of different alternatives by a fuzzy multi-criteria decision-making method. As an illustrative example, selection of different advanced manufacturing technologies has been demonstrated by using the proposed methodology. The proposed concept will greatly reduce conflicts between tangible and intangible factors, and enhance the process of identification, interpretation, and diagnosis of the value of complex manufacturing and engineering systems.     

制造/再制造集成物流网络模糊优化设计方法

为提高制造/再制造物流管理绩效,提出了合理设计制造/再制造闭环物流网络结构.将废旧产品回收量、新产品或再生品需求量、物流设施的生产或处理能力等看成三角或容差模糊参数,建立了单周期、单回收产品、有能力限制、同一物流设施备选地点对应多种可选物流设施类型的集成物流网络设计的模糊混合整数线性规划模型.为求解该模型,利用模糊机会约束规划方法将其转换成等价清晰模型.介绍了模糊混合整数线性规划模型针对同类型不同规模的物流设施选择的扩展应用,阐述了置信水平重要程度的分析方法,通过算例验证了模糊优化设计方法的有效性.     

An integrated approach to design for manufacturing and assembly based on reduction of product development time and cost

Time and cost reduction during product development is important to meet the competitiveness in the market. Design for Manufacture and Assembly (DFMA) plays a key role in product development, especially in industries like aerospace, wherein variety in component geometry is more. Parts count reduction is one of the basic principles of DFMA. Design for Manufacture (DFM) considerations lead to simplification and standardization of design and manufacturing processes. It also facilitates integration of function and form and optimizes the workflow. This paper outlines the DFMA considerations to sheet metal parts considering factors such as standardization of geometric shapes and integral part design through parts count reduction. A methodology for integration of parts is presented, which is partly interactive, to evolve an integral design from a multipart sub-assembly. The method proposed is applied to a sheet metal parts sub-assembly, and it also compares the time and cost of manufacture and assembly.     

Work organization,integrated manufacturing,and CIM system design

This paper is based on ESPRIT project 1199: ‘Development of a Human-Centred CIM System’. The idea of human-centredness is discussed in relation to flexible integrated manufacturing and to the development and use of computer systems in individual and cooperative work. The paper discusses systems development techniques for individual users and cooperative work. The integration of computer systems is reshaping work organization darmatically, and a method for addressing problems of work organization during the development of integrated computer systems is described.     

An integrated manufacturing information system for mass sheet metal cutting

In order to reduce manufacturing cost and to improve the operational efficiency, some factories in the sheet-metal-related manufacturing industry centralize the production and management of sheet metal cutting. To support the centralized mass manufacturing paradigm, this paper presents an integrated manufacturing information system to achieve the high utilization of raw sheet material, lower the manufacturing cost, as well as to improve the operational efficiency and production management. The system architecture and some key technologies to implement this system are investigated, based on which, the whole information system is developed. This system integrates the functions of sheet metal part modeling and unfolding, nesting planning, automatic and interactive nesting, cutting process planning, NC-programming, off-line processing simulation and on-line monitoring. The system has been successfully utilized in industry, and an example of its application is described in the paper.     

An integrated approach to the design and management of a supply chain system

In the modern competitive business environment, the design and management of supply chains is one of the most important and critical problems facing managers of multinational companies operating worldwide. There are three levels of decisions in a supply chain: strategic, tactical, and operational levels. The literature generally treats these decisions separately. This study defines a conceptual framework for the development of new modeling approaches for the Production Distribution Logistic System Design (PDSD) problem. In particular, the authors introduce the initial basis for the development of an innovative decision support systems platform capable of integrating the design, management, control, and optimization activities for a supply chain system.     

面向敏捷制造的PDM系统的分析与UML建模

分析了面向敏捷制造的PDM系统的功能需求,构建了面向敏捷制造的PDM系统的体系结构和功能模型,并采用UML(统一建模语言)提出了系统的业务用例模型。     

面向敏捷化可重构制造系统的产品分类方法

通过对敏捷制造联盟内产品的模块化结构、技术和市场需求等的分析,提出了模块化产品族的若干特征属性,构建了产品族的属性关联量化矩阵,运用层次分析和聚类分析得到产品间相似值,为敏捷虚拟企业制造系统重构提供了依据.     

基于多色集合的敏捷制造系统重构方法

为了在满足客户需求的同时降低制造系统的生产成本,以敏捷制造系统的资源重构为研究对象,提出了基于多色集合理论的系统重构建模与重构方案评价方法。利用元素、个人颜色、统一颜色等概念,建立制造资源与系统功能的映射关系,通过搜索围道布尔矩阵获得系统重构方案。以此为基础,给出了基于系统功能冗余度的重构方案评价指标计算方法。实例验证结果表明,该建模方法简便易行,便于形式化表述和软件实现。     

An integrated methodology for operations analysis of computer integrated manufacturing systems: Application to an FMS for manufacture of medical instruments

This paper contributes a novel methodology for operations analysis of computer integrated manufacturing systems. The methodology employs an integrated set of personal computer-based manufacturing systems modelling software, and is conducted in three stages. The methodology is illustrated in detail for analysis of materials flow and staffing for a flexible manufacturing system (FMS) installed at a medical instruments manufacturing plant. First, a rough-cut capacity and materials flow analysis was performed using a queueing model. Second, a detailed analysis of FMS system characteristics was conducted by creating and analysing a discrete-event simulation model. Finally, a graphical animation package was used to verify previous results and provide visual feedback on FMS system performance. Analysis results were obtained rapidly and conveniently, and were used to advise manufacturing managers regarding FMS operating policy. This analysis methodology can be applied to a wide range of computer integrated manufacturing systems and manufacturing cells.