Neutral representation of tolerance information for process planning using STEP AP 224

The focus of CIM is on information as it is the crucial element for integrating all the manufacturing activities. CAPP, as one of the key elements in CIM, needs to extract the manufacturing information such as machining features and precision specifications like surface roughness and tolerances from a geometric model in order to link CAD and CAM. However, these data are not real attributes of the geometric model in most of the current CAD systems. Therefore, human interpretation is inevitable for further processing of CAD model for downstream application like process planning or inspection. This paper proposes a scheme to represent the manufacturing information in a neutral format using STEP technology in order to enable downstream users such as process planner and inspection planner to make correct decisions on process selection, processing conditions, etc. It is shown that by using STEP AP224 manufacturing information encompassing machining features, surface roughness, dimensional and geometric tolerances can be completely represented together with part geometry, which certainly contributes to successful implementation of CIM.     

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.     

基于用户的CAPP零件编码系统的研究

介绍了一个基于用户的面向多品种零件机械加工的ＣＡＰＰ系统及其中零件信息处理方法，讨论适于品种零件的信息编码系统和工艺设计系统的信息集成问题     

Computer-aided process planning for NC tool path generation of complex shoe molds

This paper presents a computer aided process planning (CAPP) system for numerical control tool path generation of complex shoe molds. This CAPP system includes both the automation of auxiliary boundary curve generation and machining strategies. The automation of auxiliary boundary curve generation and machining strategies make tool path generation more accurately and efficiently. Traditional shoe mold making is a very tedious process. Even with the utilization of computer-aided design and computer-aided manufacturing (CAD/CAM), the CAM process requires long hours of tool path programming and debugging. It would also take a long time to calculate (sometimes several hours) the tool path for complex athletic footwear. In order to reduce the tool path editing and programming time, this paper proposes the use of CAPP to reduce processing time and increase efficiency. It is difficult, if not impossible, to develop a generic CAPP system that can generate a process plan to solve general production problems. However, it is quite possible to capture the domain knowledge of a certain production process and embed that knowledge into a CAPP system. We prove, by using such a system, that a very complicated process planning problem can be overcome by a knowledge-based CAPP approach. With such an approach, the traditional manufacturing process of shoe molds can be converted to an automatic manufacturing process with the CAPP system. In fact, shoe molds for real production have been created using the developed CAPP system, demonstrating the effectiveness of this approach. In this paper, we show that several complex and different shoe molds and their machining strategies were automatically planned by the proposed CAPP system. The result of a comparison between the CAPP system with the traditional approach is presented and discussed.     

An intelligent process planning system for prismatic parts using STEP features

This paper presents an intelligent process planning system using STEP features (ST-FeatCAPP) for prismatic parts. The system maps a STEP AP224 XML data file, without using a complex feature recognition process, and produces the corresponding machining operations to generate the process plan and corresponding STEP-NC in XML format. It carries out several stages of process planning such as operations selection, tool selection, machining parameters determination, machine tools selection and setup planning. A hybrid approach of most recent techniques (neural networks, fuzzy logic and rule-based) of artificial intelligence is used as the inference engine of the developed system. An object-oriented approach is used in the definition and implementation of the system. An example part is tested and the corresponding process plan is presented to demonstrate and verify the proposed CAPP system. The paper thus suggests a new feature-based intelligent CAPP system for avoiding complex feature recognition and knowledge acquisition problems.     

CAPP在现代企业生产作业计划中的集成应用

重点介绍CAPP(计算机辅助工艺设计管理系统)及其在现代企业中的运用创新情况.通过对CAPP强大功能和机加工市场对企业工艺生产管理变革需求的分析阐述,明确了CAPP的发展趋势,CAPP进一步工具化和加强与生产作业计划的紧密结合才能发挥出CAPP在机加工行业中的综合边际功效。     

基于用户的CAPP零件编码系统的研究

介绍了一个基于用户的面向多零件机械加工的ＣＡＰＰ系统，主要介绍了其中零件信息处理方法，讨论了适于多种零件的信息编码系统和工艺设计系统的信息集成问题。     

基于共同进化算法的多工艺路线决策研究

针对传统单种群进化算法(ConventionalEvolutionaryAlgorithm,CEA)求解CAPP中多工艺路线决策与生产调度集成的不足,提出利用共同进化算法(SymbioticEvolutionaryAlgorithm,SEA)来实现单件小批量生产和面向定单生产的柔性工艺设计和生产调度的集成。并对共同进化中工艺子种群和调度子种群的基因编码、染色体的交叉、变异和共同进化个体的选择做了探讨。最后以算例验证了基于动态资源条件下,共同进化算法能够实现系统的全局优化,表明此算法能够较好地解决CAPP和生产调度的集成。     

多模式CAPP系统的过程数据协同管理模型研究

文中在分析传统CAPP系统不足的基础上,建立了工艺设计过程协同模型;分析了工艺设计过程中的流程管理及多人、多任务协同问题;构建了面向不同设计主体和不同设计对象的工艺过程数据管理体系,以增强工艺数据的重构性、重用性及扩展性,从而使CAPP系统的可定制性和灵活性得到有效的拓展;这个模型和体系为工艺设计者共享和管理异质异构系统的信息提供了有效的途径.     

飞机结构件加工特征定义方法研究

根据飞机结构件几何形状和加工工艺特点,对其加工特征进行了划分,并用分层式方法对特征几何拓扑进行描述;同时根据工艺规划和刀轨计算对特征信息的需求,提取加工特征的属性参数,并采用几何拓扑和属性参数相结合的方式来完整表达特征信息,从而满足飞机结构件数控编程过程中不同应用领域对特征信息的需求。     

汽车覆盖件模具CAPP系统的开发研究

汽车覆盖件模具ＣＡＰＰ系统是单小批生产方式下的一种无编码的“广义ＣＡＰＰ”系统，现已用于微型轿车和轻型车的覆盖件模具工艺设计，并实现了工艺设计工作的全盘计算机作业化。该系统具有不同的工艺方案用于对不同的重要零件的工艺设计。     

面向生产调度的柔性CAPP系统

这里重点分析了工艺规划对生产调度的影响，并提出了面向生产调度的工艺规划方案。在理论研究的基础上，设计出柔性CAPP的系统结构及功能模块。     

RESEARCH ON CAPP／SCHEDULING INTEGRATION MULTI-AGENT SYSTEM MODEL AND IMPLEMENTATION

A design methodology fOr multi-agent systems is proposed. The systemic framework ofCAPP and scheduling integrated multi-agent system according to design methodology is researched.Agent model, composition model and cooperation model are discussed respectively in the multi-agentsystem.Static composition model and dynamic running model of CAPP and scheduling integrated     

集成环境下特征基工艺过程设计系统

介绍集成环境下的飞机结构件数控加工的工艺过程设计系统ＦＡ－ＣＡＰＰ，包括ＦＡ－ＣＡＰＰ系统同ＣＡＤ、ＣＡＭ系统的集成，层次化零件特征模型，工艺设计专家系统，系统的结构等。     

一种实用的单件小批量生产计划调度方法

结合某模具公司生产实际，以应用为出发点，提出了一种生产计划调度方法，该方法采用2层计划，第1层是基于MRP思想将任务分解到工序级，第2层进行车间作业计划，采用基于一组规则的启发式调度方法，将任务下达到各车间，由人工最后确认。     

基于集成的CAPP系统的研究

提出一种集成环境下的基于DFM的CAPP系统以及适用于工艺设计的零件信息模型。介绍基于零件主框架特征的工艺路线和加工特征的工序的分级的自动工艺设计方法 ,并初步探讨零件的工艺性分析     

面向用户的CAPP系统中工序图的生成

介绍一个机械加工的CAPP系统，主要介绍其中零件信息处理方法，讨论零件的工序图CAD系统和工艺设计系统的信息集成问题。     

基于过程集成的闭环动态工艺规划系统

描述了一个在过程上实现工艺规划与车间规划集成的闭环动态工艺规划系统,建立了实用化CAPP系统的新模型,丰富了动态CAPP的概念。它能根据车间环境的状态,充分利用制造工艺和车间环境的柔性产生优化的工艺方案。系统在车间环境约束下采用专家系统技术进行非线性工艺规划,产生可选工艺路线和工序可选设备。在一个由工艺路线选择、设备动态优化选择和车间优化规划构成的闭环系统中,以高生产效率为目标,根据推广的关键路线分析的结果和一系列启发式知识动态地选择工艺路线和设备,最后获得有较高实践意义的结果。     

面向产品快速开发的几何推理和虚拟原型

计算制造旨在解决制造系统和制造过程的计算复杂性问题，以实现产品快速开发，探讨了计算制造的基本概念、研究内容和典型问题，对计算制造的理论基础和体系结构进行了有益探索。详细讨论了支持产品快速开发的几个关键使能技术：几何推理、反求工程和虚拟原型，并扼要介绍了在这些方面的有关研究成果，为产品快速开发的研究提供了一些新的思路和方法。     

基于几何与公差信息的加工特征识别方法

为实现计算机辅助设计与计算机辅助工艺规划系统的有效集成,提出了一种同时利用几何信息和公差信息的加工特征识别新方法。建立了加工资源、加工表面和加工方法三类信息模型。提出了切削模式的概念及以之为基础的表面加工方法生成原理和过程。建立了表面加工方法优化选择模型。采用多目标模糊优化结合蚁群算法求解该模型,为每个加工表面选择最优加工方法,并将在同次装夹中采用同一刀具类型和加工条件进行加工的表面聚为加工特征。最后,通过实例测试,验证了该方法的正确性和有效性。