支持网络化制造的车间MES与CAPP集成研究

网络化制造已成为现代制造业的主要发展趋势,制造执行系统(MES)和计算机辅助工艺规划(CAPP)是企业实施网络化制造的重要技术。本文首先分析网络制造环境下MES与CAPP的新特征,然后研究网络制造环境下的MES和CAPP集成的必要性和实现集成的关键技术,最后给出基于W eb系统集成的数据库设计。     

Development of a generative CAPP system for axisymmetric components for a job shop environment

Process planning is a function in a manufacturing organization that selects the manufacturing processes and parameters to be used to transform a part from its initial state to the final form according to the design specifications. It is a bridge between product design and product manufacturing. The activities of process planning include understanding the part specifications or product design data, selection of job material and tool, setup planning, sequencing the operations within a setup, determination of process parameters for each operation, and generation of process sheets. This paper outlines a method to develop a generative computer-aided process planning system for axisymmetric components for a job shop environment. A decision support system is used to perform semi-structured tasks such as setup planning and establishing precedence relationship among various operations.     

Object-oriented and fuzzy-set-based approach for set-up planning

Set-up planning is not only a key element of computer-aided process planning (CAPP), but also a key factor for the integration of CAPP with computer-aided fixture planning (CAFP) and production planning and scheduling (PPS). In this work, an object-oriented and fuzzy-set-based approach is developed for set-up planning. Object-oriented technology is employed to represent set-up planning knowledge and generate alternative set-ups which can respond to the dynamic manufacturing resource and facilitate the CAPP/PPS integration. Based on fuzzy-set theory, a fuzzy evaluation function is proposed to produce optimal set-ups. Combined with a real project, a set-up planning system is developed to generate alternative and optimal set-up plans for the machining of prismatic parts.     

线缆制造CAPP系统的开发研究

简述了线缆制造业应用CAPP的重要性，分析了线缆制造工艺过程设计的特点，给出了线缆制造CAPP系统的实现方案，对提高线缆制造行业的工艺设计水平和效率能够起到积极的促进作用。     

现代CAPP技术及其发展研究

企业信息化工程推动了CAPP技术的发展和应用，本文通过CAPP的发展过程、信息技术的发展以及企业信息化工程对CAPP的需求等进行深入分析，从体系结构、系统功能、信息组织、工艺设计模式、系统性能等方面分析了现代CAPP技术的发展趋势。(1)CAPP系统的体系结构由单机模式、C／S模式向C／S模式与基于Web技术的B／S模式相结合、组件化、层次结构化方向发展；(2)CAPP系统的功能覆盖企业整个工艺领域，向集成化制造数据管理方向发展；(3)工艺设计模式向基于知识的分布协同决策的综合智能化设计技术发展；(4)CAPP的应用更加强调系统的集成性和开放性等。文中还简要介绍了相关关键技术。     

Automated tolerance analysis for CAPP system

Various computer-aided process planning (CAPP) systems can produce different process plans, but few of them can deal with the specified design tolerances that have a significant influence on the process selection, machine selection, set-up and datum selection, operation sequencing, cutting condition decisions, and time and cost calculations; nor can they provide exact information on fixture/datum and the coordinates of the tool movements that are the necessary data for automated NC programming. The focus of this paper is on the discussion of an automated tolerance based analysis approach of CAPP systems.     

SMT-TAB: A process planning system for PCB assembly using TAB and SMT

Process planning is a critical function in any manufacturing domain. This is especially true in the electronics manufacturing area where substantial heuristic and experiential knowledge is commonly used during process plan development. While research in computer-aided process planning (CAPP) has tended to concentrate in the machining realm, few CAPP systems have been developed for electronics manufacturing applications and more specifically for the printed circuit board (PCB) assembly domain. Besides, the CAPP systems that have been developed for this area have dealt with either insertion mount or surface mount PCB assembly processes only.Tape automated bonding (TAB), though a relatively new technology, is gaining importance in electronics assembly owing to its inherent advantages. The advent of fine pitch technology together with the ever increasing need for more inputs/outputs and greater pin counts in integrated circuit applications has enhanced the use of TAB technology in electronics manufacturing. This trend has been further augmented by the increasing need for compactness in consumer electronics.This research designed and developed a prototype CAPP system for the PCB assembly domain. The system developed generates a process plan for PCBs populated with surface mount and/or TAB components. An artificial-intelligence based expert system approach has been used in the design and development of the CAPP system. Outputs generated by the system are presented along with ideas for future research.     

Java-based computer-aided process planning

This investigation addresses distributed environments for computer-aided process planning (CAPP) over a network. The Java 2 Enterprise Edition (J2EE) standard using Java is applied to implement cross-platform and distributed computing architecture, thus reducing the system loading during manufacturing process planning. The product-oriented standard, standard exchange of product (STEP), model data is applied to define a robust data model that associates product, shape, and feature definitions and provides the mechanisms for data exchange, sharing, and integration with other engineering systems, such as computer-aided design (CAD) and computer-aided manufacturing (CAM). STEP AP224 is engaged to define the machining features of machined products in the proposed CAPP system. The life cycle of a product from design to sale, and especially the period of manufacturing, can be greatly shortened; the cost of manufacturing can be reduced and the quality of the product can be improved using the proposed CAPP system.     

A Generative Computer-Aided Process Planning System for Prismatic Components

This paper deals with design and development of a generative computer-aided process planning (CAPP) system for prismatic components and named PSG-CAPP. The proposed CAPP system has been divided into three modules. The first module is concerned with feature extraction. The second and third modules deal with planning the set-up, machine selection, cutting tool selection, cutting parameter selection, and generation of process plan sheet. The whole CAPP system is developed using Visual Basic 6.0 as front end and Oracle 7.3 as back end. The SolidWorks98 plus has been used for modelling, and feature extraction has been implemented using a program written in Visual Basic 6.0. The speciality of the developed CAPP system is that it is linked with the CAD module and it extracts the majority of features automatically prior to process planning. The developed CAPP system has been tested with aerospace components. The main feature of the proposed CAPP system is its ability to handle a variety of prismatic components and generate process plans for them. A case study has been included to highlight the potential of the CAPP system. ID="A1"Correspondance and offprint requests to: Professor P. V. Mohanram, Department of Mechanical Engineering, PSG College of Technology, Peelamedu, Coimbatore 641004, India. E-mail: msadaiah@yahoo.com     

基于多代理的智能CAPP系统体系结构研究

为了提高CAPP系统的柔性、可扩展性、可重用性和动态适应性,基于并行工程理念,采用多代理技术,提出了一种智能CAPP系统体系结构,研究了智能CAPP系统的工作机理,并对智能CAPP系统中各Agent的结构、功能以及相互之间的通讯机制进行了研究。     

面向CAPP/PPC集成控制的工艺优化模型研究

为了提高工艺规划在实际生产中的执行性，得到优化的制造资源配置，提出了一种基于动态工艺、以制造资源为核心的计算机辅助工艺设计／生产计划控制并行集成模式，研究了计算机辅助工艺设计／生产计划控制集成过程中的动态工艺优化和制造资源优化配置问题。在讨论动态工艺描述方式的基础上，提出了动态工艺优化分级求解策略。在求解过程中，首先将动态工艺进行分解；然后以成本和交货期为优化目标对分解的工艺进行资源优化配置，从而实现全局的工艺优化和制造资源优化配置；最后，以齿轮轴为例说明了工艺优化模型的正确性和可行性。     

Selecting optimal tools for arbitrarily shaped pockets

As a result of slicing a 3D part into 2D pockets for generating tool paths, pockets are becoming more commonly used. When a pocket is machined, the question of which of the many feasible tools for cutting the pocket is best always arises. Will cutting be more efficient if multi-tools are used? Will the algorithm to choose the optimal tools be timesaving enough? This paper presents a method in which an upper bound O(N) is used to choose the optimal cutting tool combination, where N is the number of feasible tools available. The proposed method is quick and sufficient for computer-aided process planning (CAPP) and computer-aided manufacturing (CAM) environments.     

面向工艺设计的制造过程建模

基于工艺设计对产品制造成本、质量和效率的重要影响，提出了一种基于工艺设计的制造过程建模方法，以通过对过程模型的仿真，预测、分析和优化工艺设计效果。基于对制造过程的特征分析，采用面向对象的方法，首先将制造过程定义为一组成对象，并划分为制造活动、过程控制和制造资源3类成分对象，建立了制造过程类结构模型和动态过程模型。分别定义了工序类、制造资源类和过程控制类的类结构模型，以及各类对象的方法和属性。基于这些模型开发了一种计算机辅助工艺设计系统，可快速、自动地构建工艺设计定义的制造过程模型，并对过程参数（成本、时间）、切削加工、工件物流进行计算和仿真。     

A blackboard-based process planning system for the surface mount manufacture of PCBs

This paper describes a real-time computer-aided process planning (CAPP) system for printed circuit board (PCB) assembly using surface mount technology. The prototype, dynamic, realtime CAPP system described uses a blackboard to integrate multiple knowledge sources (knowledge bases) in implementing the process planning procedure. The CAPP system is implemented using the expert system environment (ESE) and structured query language (SQL). The system uses two subsystems (knowledge bases). They are a planning subsystem which performs the static process planning task and a dynamic information processing subsystem which considers the real-time changes on the shop floor and routes the PCB assembly flow. The integrated system developed generates process plans that can be implemented in real time. The use of the blackboard concept for CAPP architecture is unique and well suited for this task.     

A Dynamic Programming Based Process Planning Selection Strategy Considering Utilisation of Machines

Computer-aided process planning (CAPP) has been recognised as a key element in computer-integrated manufacturing (CIM). Despite the fact that tremendous efforts have been made to develop CAPP systems, the benefits of CAPP in real-life manufacturing environments are not obvious. One of the main difficulties in applying CAPP in real manufacturing settings is the missing link between generated process plans and shop-floor activities. The assumptions that the shop floor remains static and there are unlimited resources available have caused a typical CAPP system to make a repetitive selection of the same most desirable machines for manufacturing different parts. When process plans for various parts are finally sent to the shop floor, process bottlenecks normally arise, making the generated plans ineffective. Some efforts have been made in the integration of process planning and shop floor activities; however, the problems associated with the lengthy time and impractical attempts at the generation of process plans, remain unsolved. Since in most cases, it is possible that several alternatives exist for machining a part by using different equipment, a stage-type network structure can be constructed. This paper introduces a dynamic programming based process plan selection strategy, enabling the efficient solution of this stage-type network prob-lem. In this proposed strategy, the use of workstations is also taken into consideration so that the resulting plan is valid for the conditions that exist on the shop floor at the time an order is released. A case study has been provided to substantiate the effectiveness of this proposed strategy.     

A clustering-based modeling scheme of the manufacturing resources for process planning

Process planning determines how a product is to be manufactured and, therefore, is one of the key elements in the manufacturing process. The basic crux of computer-aided process planning (CAPP), however, is the diversity of manufacturing background and the complexity of process planning. Since the process plans are generated on demand with the manufacturing resources on a shop floor, modeling method of the manufacturing resources is one of most important issues in computer-aided process planning. Hence, the major objective of this research is to create a clustering-based modeling scheme of the manufacturing resources for process planning. This modeling scheme combines clustering method with averaging method so as to reasonably partition and classify the manufacturing resources on a shop floor. The proposed approach provides one of search strategies of machine tools for process planning, especially for the selection of machine tools. Finally, an illustrative example is applied to describe the clustering-based modeling scheme.     

Agent technology for collaborative process planning: a review

Agent technology has been considered as a promising approach for developing process planning systems and optimizing process plans in a distributed environment. A number of researchers have attempted to use agent technology in process planning for the purpose of integrating systems, tools and algorithms which are geographically distributed. In this paper, the historical background of agent technology is systematically reviewed. A comprehensive review of agent technology and its applications in manufacturing is presented including the applications of agent in scheduling, control, and enterprise integration and supply chain management. The focus of the paper is on how agent technology can be further developed in the support of collaborative process planning as well as its future research issues and directions in process planning. The current research directions in computer aided process planning (CAPP) and issues in traditional CAPP approaches are also discussed. Three agent-based approaches for process planning are presented. Finally, the key issues in developing agent-based collaborative process planning systems are summarized.     

Computer aided manufacturing planning for mass customization: part 2, automated setup planning

Setup planning plays a crucial role in CAPP to ensure product quality while maintaining acceptable manufacturing cost. The tasks of setup planning include identifying manufacturing features and corresponding manufacturing processes, determining the number of setups, part orientation, locating datum and process sequence in each setup, and selecting machine tools and fixtures. An automated setup planning technique and system has been developed based on not only the tolerance analysis, but also the manufacturing resource capability analysis. The automated setup planning is divided into two levels: setup planning in single part level and in machine station level. Algorithms for setup generation and process sequencing have been developed and a case study of setup planning is presented.     

基于网络制造环境的机床刀具动态选择模型的研究

计算机辅助机床和刀具选择(CATS)是计算机辅助工艺设计(CAPP)系统中的一个至关重要的环节。本文讨论了在基于网络的制造环境下机床和刀具的动态选择。它能帮助现有的CAPP系统进行具体的、经济的工艺规划,并且让设计者有效地进行产品的可制造性评估。特别是将选择机床与选择刀具相结合能对经济生产进行优化决策。     

基于PDM的工艺管理研究

工艺是连接产品设计与制造的桥梁，是实现产品信息集成与管理的关键。在研究工艺设计及工艺信息管理的基础上，分析了工艺管理的功能需求，建立了面向产品全生命周期集成的工艺信息模型，提出了基于PDM的两级工艺管理方案，有效地简化了CAPP系统的设计，有利于真正实现CAD、CAPP、CAM、PDM、ERP的全面集成。