Recent trends in flexible automated manufacturing

In recent years, an important change in developing and implementing manufacturing systems can be observed in all industrialized countries. Due to intense international competition and the growth of personnel costs, companies are forced to use systems with a higher level of automation. At the same time, an increasing number of product variation—caused by adapting the products to customer requirements—demand more flexibility of machine tools and manufacturing systems.Basic types of computer-controlled flexible automated manufacturing systems will be shown and characterized by their special ranges of application. A planning procedure is presented which includes selecting a suitable systems structure such as; transfer line or flexible manufacturing system or automated manufacturing cell, and for determinating every single machine tool within the system. Examples of several new computer-controlled manufacturing systems which have been planned by the above planning procedure are presented with special regard to the evaluation of the system's economic performance.Finally, some rules are given for measuring the economic performance of automated manufacturing or assembly systems including automation of the handling functions.     

Design of flexible transfer lines: A case-based reconfiguration cost assessment

Shortening product life cycles leads competing companies to continually release new products or modifying the existing ones; this is one of the major issues in production systems design. According to the changes in product features, production systems need to be properly configured or reconfigured to efficiently tackle new production requirements. A configuration approach for multi-product flexible transfer lines is presented which aims at minimizing the equipment cost. The approach is applied to a manufacturing case in the automotive sector. The robustness of the solution is tested against changes that affect the products to highlight reconfiguration costs and the penalty associated to the lack of a pro-active configuration approach.     

Development of holonic manufacturing execution systems

Rapid changes of market demands and pressures of competition require manufacturers to maintain highly flexible manufacturing systems to cope with a complex manufacturing environment. To meet these requirements, this work adopts the concepts of holon and holarchy to design manufacturing systems. Holon and holarchy are derived from the studies of social organizations and living organisms and possess the properties of intelligence, autonomy, cooperation, reconfigurability, and extensibility. Moreover, advanced manufacturing systems also require the properties of security certification and failure recovery. Based on the requirements of these properties, a systematic approach is proposed to develop a holonic manufacturing execution system (HMES) for the semiconductor industry. This systematic approach starts with a system analysis by collecting domain requirements and analyzing domain knowledge. The HMES Holarchy is designed by the procedure of constructing an abstract object model based on domain knowledge, partitioning application domain into functional holons, identifying generic parts among functional holons, developing the Generic Holon, defining holarchy messages and the holarchy framework of HMES, and finally designing functional holons based on the Generic Holon. It is believed that this proposed systematic approach provides a novel and efficient way to design HMES.     

Technical investment planning of flexible manufacturing systems—The application of practice-oriented methods

Flexible manufacturing systems (FMS) exhibit a high degree of automation of the machining system and of the workpiece, and for the information flow systems. Therefore, these systems are amongst the most complex production installations and their technical investment planning must be undertaken with great care.This paper introduces a strategic planning procedure and describes auxiliary aids for the selection of the components and for structuring of the overall system. Computer programs for the selection of machine tools and for the simulation of the manufacturing process sequence are part of this procedure. The application of the methods is illustrated by means of several problem situations arising from industrial production companies; the examples show the practical usefulness of the developed auxiliary techniques. The planning accuracy possible by these methods reduces the investment risk associated with the use of these complex manufacturing systems.Also described is an integrated system for the technical investment planning of flexible manufacturing systems which comprises both existing methods and new auxiliary means for planning the machining systems and the technical/organizational overall concept.     

Expanding bottleneck management from manufacturing to product design and engineering processes

Bottlenecks inhibit the performance of companies. Up to now, bottleneck management research has concentrated on manufacturing processes, while neglecting product design and engineering processes. This research fills this gap through developing and testing of a new bottleneck management concept for product design and engineering processes. The new concept is developed using a system theory modelling approach and comprises of four bottleneck management counter measures. Two propositions were developed to test the concept through an event-discrete simulation model. The simulation is grounded on empirical data from three design-driven companies and tests the impact of the four bottleneck management counter measures on the performance of product design and engineering processes. The findings from the simulation confirm the applicability of the newly developed bottleneck concept to improve the performance of product design and engineering processes. In doing so, this research study expands bottleneck management for the first time from manufacturing to product design and engineering processes.     

基于设计模型的信息系统自动测试方法

针对当前自动测试领域存在的问题,提出了一种基于设计模型的自动测试方法（Model Based Automated TestIng System,MATIS）。该方法利用用户界面自动生成方法,把设计模型中的类属性定义和实现中的控件属性组织在一起,构建描述界面的逻辑对照表,辅助测试脚本引擎执行自动测试脚本。借助设计模型中扩展的类定义,MATIS方法可以自动生成测试用例和测试数据。MATIS方法是一个较轻量级的方法,更贴近于实际的软件开发过程,可以有效地降低自动测试成本。     

Automated knowledge acquisition for design and manufacturing: The case of micromachined atomizer

In order to remain competitive in the global market, original equipment manufacturers (OEMs) are developing a process-based, knowledge-driven product development environment with emphasis on the acquisition, storing, and utilization of manufacturing knowledge. This is usually achieved by using the symbolic artificial intelligence (AI) approach. Specifically, knowledge-based expert systems are developed to capture human expertise, mostly in terms of IF–THEN production rules. It has been recognized that the development of symbolic knowledge-based expert systems suffers from the so-called knowledge acquisition bottleneck. Knowledge acquisition is the process of collecting domain knowledge and transforming the knowledge into a computerized representation. It is a challenging and time-consuming process due to the difficulties involved in eliciting knowledge from human experts. This paper presents an automated approach for knowledge acquisition by integrating neural networks learning ability and fuzzy logics structured knowledge representation. Using this approach, knowledge is automatically acquired from data and represented using humanly intelligible fuzzy rules. The approach is applied to a case study of the design and manufacturing of micromachined atomizers for gas turbine engine. The influence of geometric features on the performance of the atomizers is investigated. The results are then compared with those obtained using traditional regression analysis approach (abstract mathematical models). It was found that the automated approach provides an efficient means for knowledge acquisition. Since the fuzzy rules extracted are easy to understand, they can be used to allow more clear specification of manufacturing processes and to shorten learning curves for novice manufacturing engineers.     

Automated setup and reconfiguration for modular fixturing

Current trends in manufacturing have identified the need for automation and flexibility in fixture design. The majority of flexible fixturing systems, however, are not well suited for automation. Modular fixtures can be designed to meet the requirements for traditional fixtures in addition to those for modern automation. This paper discusses the issues involved in the automation of modular fixtures with emphasis on automated planning. These issues include proper design, determination of layout requirements, feasibility and automatic reconfiguration. Requirements and guidelines for each issue will first be presented in a general format, and then applied specifically to sheet-metal fixturing.     

Interoperability requirements for automated manufacturing systems in construction

Multi-disciplinary software interoperability in the Architecture, Engineering, Construction and Operations industry is becoming a new and widely adopted business culture. Technical advances in interoperability architectures, frameworks, methods and standards during the last decade resulted in higher maturity of product and process models. Mature models, in effect, enable data exchange by an increasing number of software applications in the industry. This establishes trust in data exchange and results in the lower cost impact of inefficient interoperability. The negative cost impact increases with advancing life-cycle phase, from planning and design phase to construction phase and to operation and maintenance phase. Interoperability in the planning and design phase is most mature and well published, while interoperability in the construction phase and for automated manufacturing is less researched. This paper reviews state-of-the art automated manufacturing systems in construction and researches interoperability requirements for automated construction in context of the entire building lifecycle. Our research is based on experimental free-form clay building, designed with embedded simple HVAC components, and manufactured with additive layer technology. Conclusions provide valuable results for interoperability research and practice in construction projects with automated manufacturing systems in place.     

Guest editorial

Attention has recently focused on improving the information and knowledge flow between design and manufacturing. Interfacing Computer Aided Design (CAD) with Computer Aided Manufacturing (CAM) systems has helped this information flow while also improving both processes. Once CAD and CAM systems were introduced the obvious next step to (1) decrease a product's time-to-market and its costs, while (2) increasing the product's quality, has been to utilize knowledge based system technology during both the design and the manufacturing phases of a product. Unfortunately, the knowledge based systems that we have developed have been designed as stand-alone components. These have been built using a variety of implementation philosophies, styles of reasoning and are deployed over distributed computing environments. The companies with large investments in design and manufacturing automation, as well as in expert system technology have come to realize that achieving the two goals stated above will require the integration of such diverse systems in ways that will allow their coordination and cooperation. This special issue of theJournal of Intelligent Manufacturing has brought together reports of recent research whose goal was this type of integration.     

An expert system for aided design of ship systems automation

The paper presents a structure and functions of an expert system for aided design of ship systems automation. The system was developed on basis of a detailed analysis of the design process of ship systems automation. The system includes: knowledge bases regarding methods and procedures of ship systems automation design, databases of automated objects, control devices and elements, requirements of classification societies, and a subsystem for simulation investigations co-operating with the Matlab Simulink package and a knowledge base. In the creation of the system the shell expert system Exsys Developer was used. This system is characterised by a rule-oriented representation of knowledge, backward and forward chaining inference methods, various confidence modes to handle uncertain reasoning including fuzzy logic, and possibility of co-operation with other software and databases. The databases were made using the MS Access software.     

Design synthesis of machining systems using co-platforming

Modern manufacturing environment is characterized by frequent product design changes in order to satisfy evolving customer requirements. Various strategies are implemented in order to efficiently manage the consequences arising from the product design changes starting from product design to planning and manufacturing. This paper focuses on synthesizing manufacturing system using the co-platforming concept which maps product platform features and components to the manufacturing system candidate platform machines. A matrix-based mapping model is proposed in order to determine the candidate platform and non-platform machines. Product-related characteristics including manufacturing features, feature orientation, dimensional and geometrical tolerance, cutting power requirements, workpiece volume and surface finish are considered. Characteristics of machines in the manufacturing system include machining axes, accuracy, working envelop and available power. A case study adopted from an automotive engine cylinder block manufacturer is used for demonstrating synthesizing manufacturing systems, based on co-platforming, which are capable of adapting to new products variants without changes to the platform machines. This prolongs the life of the manufacturing system and reduces costs associated with retooling and replacing it.     

Design of expert systems for integrated production automation

An approach to the design of expert systems for integrated production automation is presented. The major components in an integrated manufacturing system consist of corporate planning, marketing planning, research and development, engineering design, production planning, manufacturing, warehousing, and product distribution. These components are linked by management information flow, technology information flow, as well as materials flow. An intelligent computer is used to integrate information flow and to control materials flow. This paper discusses characteristics of the future factory, elements of knowledge based systems, and the design of computer based expert systems for production planning, for engineering design, and for integrated manufacturing.     

过程系统体系结构及信息集成

体系结构是指导大型复杂综合自动化系统的原则和框架,信息集成是分布式综合自动 化系统成功运行的基础.以石化企业为背景,综合研究了过程企业体系结构和信息集成问题.提 出了包含信息、功能、组织、产品和资源等五个视图及需求分析,初步设计和详细设计三个主要 阶段的体系结构.进一步探讨了过程企业方法库、管理数据库、实时数据库和装置模型库的构建 方法,提出了基于C0RBA标准的分布式信息集成模型.     

Supporting connectivism in knowledge based engineering with graph theory,filtering techniques and model quality assurance

Mass-customization has forced manufacturing companies to put significant efforts to digitize and automate their engineering and production processes. When new products are to be developed and introduced the production is not alone to be automated. The application of knowledge regarding how the product should be designed and produced based on customer requirements also must be automated. One big academic challenge is helping industry to make sure that the background knowledge of the automated engineering processes still can be understood by its stakeholders throughout the product life cycle.The research presented in this paper aims to build an infrastructure to support a connectivistic view on knowledge in knowledge based engineering. Fundamental concepts in connectivism include network formation and contextualization, which are here addressed by using graph theory together with information filtering techniques and quality assurance of CAD-models. The paper shows how engineering knowledge contained in spreadsheets, knowledge-bases and CAD-models can be penetrated and represented as filtered graphs to support a connectivistic working approach. Three software demonstrators developed to extract filtered graphs are presented and discussed in the paper.     

Applications of microcomputers in automated process planning

Two microcomputer based computer aided process planning systems are developed to assist small- to medium-sized companies implement automated process planning (APP). Micro-CAPP is a variant process planning system used to manipulate a large manufacturing knowledge database. Micro-GEPPS is a semigenerative process planning system which simulates a process planner's experience in order to automatically generate operation sheets. The operation and structures of both systems are discussed and a perspective direction for the development of APP is also presented.     

Automated tool management in flexible manufacturing

The need for automated tooling in flexible machining, assembly, and sheet fabrication systems is reviewed. The various methods of implementing these systems, their benefits and drawbacks are discussed. The basic modules of automated tool transfer, storage, loading/unloading, and management are described together with the appropriate level of automation for each module. The advantages and prerequisites for unmanned machining systems, the current sensing methods and the tool replacement strategies are also reviewed. The importance of a tool database, its uses and structure are highlighted. Finally, the design and evaluation of automated tooling systems and operating strategies, with the aid of discrete events computer simulation are discussed. An existing computer package which is capable of simulating automated tooling systems for flexible manufacturing systems is presented.     

Implementation of rule-based information systems for integratedmanufacturing

Focuses on the development of a methodology within a software environment for automating the rule-based implementation of specifications of integrated manufacturing information systems. The specifications are initially formulated in a natural language and subsequently represented in terms of a graphical representation by the system designer. A new graphical representation tool is based on updated Petri nets (UPN) that we have developed as a specialized version of colored Petri nets. The rule-based implementation approach utilizes the similarity of features between UPN and the general rule specification language used for the implementation. The automation of the translation of UPN to the rule specification language is expected to considerably reduce the life-cycle for design and implementation of the system. The application presented deals with the control and management of information flow between the computer-aided design, process planning, manufacturing resource planning and shop floor control databases. This provides an integrated information framework for computer integrated manufacturing systems     

制造执行系统的功能模型

制造执行系统是企业信息集成的关键技术之一,而制造执行系统的功能建模是设计制造执行系统的基础。文章分析制造执行系统的功能需求,并利用IDEF0方法建立面向制造过程集成的制造执行系统的功能模型。这些功能模型是制造执行系统软件开发的基础。