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.     

基于Windows平台的插齿刀CAD/CAPP系统

介绍了插齿刀CAD/CAPP系统的设计原理、功能模块和相关技术。以VisualBasic6·0为开发语言,Au-toCADR14为绘图支撑平台,采用基于插齿刀外形特征的零件编码系统和参数化设计绘图方法,实现了一体化的插齿刀CAD/CAPP功能。     

基于Pro/E的插齿刀设计CAD系统开发

以Excel 2003软件为基础,采用Visual C＋＋和Pro/TOOLKIT为开发工具,对Pro/E进行二次开发,研究出插齿刀计算机辅助设计CAD系统。系统采用模块化设计,主要阐述了产品信息输入处理模块、参数选择与计算模块和工程图绘制模块等主要模块及其实现方法。系统能够实现不同结构插齿刀的复杂设计及几何建模,缩短了设计周期,提高了刀具设计的精度和效率,是计算机应用技术与工艺设计相结合的一个典型实例。     

基于经验的刀量具选择系统的研究

计算机辅助刀量具选择在计算机辅助工艺设计系统(CAPP)乃至计算机集成制造环境(CIM)中是一个至关重要的元素。通过对刀量具查询的特点和方法的研究,对刀量具基础数据库进行了优化和整合,建立了合理并且无冗余的刀量具数据库,并运用Delphi60及MicrosoftSQLServer2000开发了刀量具选择系统。     

A Surface Area Calculation and CAPP System for Non-Axisymmetric Deep Drawing Products

In this paper a surface area calculation for non-axisymmetric deep drawing products of elliptical shape was constructed for the design of blank shapes of deep drawing products by using an AutoLISP function in AutoCAD software. A computer-aided process planning (CAPP) system for rotationally symmetric deep drawing products has been developed. In this study, a CAPP system for non-axisymmetric deep drawing products of elliptical shape was constructed using process sequence design. The system developed consists of four modules. The first is the recognition of shape module for recognising non-axisymmetric products. The second is a 3D modelling module for calculating the surface area for non-axisymmetric products. The third is a blank design module for creating an oval-shaped blank with an identical surface area. The fourth is a process planning module based on production rules that play the most important role in an expert system for manufacturing. The production rules are generated and upgraded by interviewing field engineers. The drawing coefficient, the punch and die radii for elliptical shape products are considered as the main design parameters. The suitability of this system was verified by applying it to a real deep drawing product. This surface area calculation and CAPP system should be very useful for reducing the lead-time for manufacturing and for improving the accuracy of products.     

基于智能体的零件设计制造集成研究

基于并行工程的设计制造集成要求零件及其制造过程的设计同步进行,以求获得零件及其制造过程设计的整体优化。本文叙述的研究系统中,设计和制造过程之间的数据共享及通讯是通过数据库实现的;开发的特征造型模块是在UGII环境中工作的;零件制造性能评价和CAPP模块应用了智能体技术;CAPP和NC模块所需的输入数据也是从数据库中提取的。     

Geometric Feature Recognition for Reverse Engineering using Neural Networks

1. Point data reduction module. 2. Edge detection module. 3. ANN-based feature recogniser. 4. Feature extraction modules. This approach was validated with a variety of real industrial components. The test results show that the developed feature-based RE application proved to be suitable for reconstructing prismatic features such as blocks, pockets, steps, slots, holes, and bosses, which are very common in mechanical engineering products. An example is presented to validate this approach.     

On-line integration of a process planning module with production scheduling

An approach to the on-line integration of process planning and production scheduling is reported. Based on a geometric modeller, a geometric analyser and a knowledge base, the process planner generates alternative process plans and provides automatic tool selection and calculation of the appropriate machining parameters. Time and cost estimations are input to the decision-making module in the production scheduling system that produces optimal scheduling decisions as well as a complete record of the actual state of the factory resources. An information flow, designed as a relational data model, maintains the interaction between the process planning and the production scheduling systems and provides the dynamic feedback to the process planner. Specific geometry features of the blank, the finished part and the cutting tools, and geometry features-based rules are stored in the database of a developed CAPP system by using a separate CAD interface. The integrated production planning and production scheduling system and the CAPP system were validated with rotational parts machining.     

Rule-based process planning by grouping features

A macro-level CAPP system is proposed to plan the complicated mechanical prismatic parts efficiently. The system creates the efficient machining sequence of the features in a part by analyzing the feature information. Because the planning with the individual features is very complicated, feature groups are formed for effective planning using the nested relations of the features of a part, and special feature groups are determined for sequencing. The process plan is generated based on the sequences of the feature groups and features. When multiple machines are required, efficient machine assignment is performed. A series of heuristic rules are developed to accomplish it.     

内嵌于UG的基于特征的CAPP系统

介绍了一个内嵌于UG的CAPP系统,着重研究了基于特征的工艺规程决策机制。在内嵌于UG的特征库 的支持下进行特征设计,并通过UG提供的产品定义和几何公差模块建立了零件的信息模型,用UGAPI实现了特 征的识别、提取、匹配以及到CAPP系统的特征映射,据此开发了一个完整的内嵌于UG的CAPP系统,该系统采用 两种类型(派生式和创成式)、三种模式(编辑模式、检索模式和推理模式)的综合式工艺生成机制,已在多家企业得 到了较好的运行。     

基于AutoCAD的CHC型少齿差减速器参数化CAD系统

以Visual Basic 6.0为开发工具,对AutoCAD进行二次开发,研制CHC型少齿差减速器CAD系统。该系统主要包括两大功能模块:设计计算子系统和参数化绘图系统,两者之间通过产品数据库实现有效连接。参数化绘图系统采用ActiveX技术从外部操作AutoCAD的对象,利用开发的底层函数读取零件库中的零件参数,实行零件图的绘制。结合ObjectDBX技术和对象的扩展词典技术实现装配图的绘制,最终实现设计计算和参数化绘图一体化。     

面向STEP-NC的特征CAD/CAPP系统

将特征建模技术与STEP及STEP-NC标准相结合,为实现CAD/CAPP/CAM及CNC的集成,探索了一条有效的途径。建立基于STEP AP224的特征模型,它包含工艺设计所需要的产品管理、材料、精度等信息。另外,将特征与加工方法链相对应,并建立相应的数据库,同时讨论了工步排序的若干规则。在Pro/ENGINEER软件平台上,实现了CAD/CAPP/CAM高层次的集成。以三轴数控加工的棱柱体零件为例,阐述了工步的产生以及排序,最终生成符合STEP-NC标准的加工文件。     

利用用户定义特征实现的冲压CAD/CAPP集成系统

提出了利用CAD系统的用户定义特征实现面向CAPP的特征设计的方法，在归纳定义常用冲压特征的基础上，建立了冲压特征信息模型，介绍了用Visual C 6．0在参数化三维特征CAD软件平台上开发的冲压CAPP系统，实际应用证明，用户定义特征是在商品化CAD系统中实现集成化CAD／CAPP系统的一种有效方法。     

带式输送机设计软件系统设计及实现

以功能强大的VisualBasic为工具,将Access数据库和ADO数据库编程技术应用于带式输送机系统的设计,开发了基于CEMA标准的带式输送机设计系统。系统采用模块化结构,由数据库模块、设计选型模块、结果输出模块组成。能够实现原始参数输入、设计计算、部件选型、自动生成设计说明书和绘制线路图,对于减轻技术人员的劳动强度,加快开发速度,缩短设计周期具有现实意义。     

板材的步冲CAPP系统研制

在VB环境下开发了柔性冲裁装置下的步；中CAPP系统，实现了与CAD系统、NC加工系统的数据交换，并重点介绍了系统的功能、主要组成模块及解决的主要问题。     

An Object Oriented Planner for Inspection of Prismatic Parts – OOPIPP

Coordinate measuring machines (CMMs) have been widely accepted and are increasingly used for carrying out inspections. With the increase in complex designs and tighter tolerances, the inspection process involving a CMM has become critical and there is a need to plan it effectively. In the present work, an object oriented planner for the inspection of prismatic parts (OOPIPP) has been developed. It incorporates interactive feature recognition and carries out all the essential steps of inspection planning, that is, selection of the most stable part orientation, arriving at number and distribution of inspection points, feature accessibility analysis, sequencing of probe orientations, removal of duplicate faces, and, finally, sequencing of faces. Various relationships between different entities of the system and distinct features of OOM have been used to develop the algorithms of different modules. Fuzzy logic for decision making has also been applied and a suitable method of combining fuzzy sets has been used for the selection of part orientation and for sequencing probe orientations.     

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.     

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。