加工仿真系统中弯管类零件加工工艺信息的自动提取

在加工仿真系统中 ,加工工艺信息的自动生成对于提高仿真系统的自动化、实用化水平 ,减少工艺人员的工作负荷至关重要。该文针对弯管零件加工仿真系统 ,提出了加工工艺信息自动提取方法。该方法根据弯管零件的数字化模型 ,自动判断曲面的类型 ,生成各曲面间的拓扑关系 ,提取每个曲面的几何参数及相关曲面的位置关系信息 ,并将这些信息转为工艺参数 ,输入工艺知识库 ,再根据相应的工艺知识 ,生成加工工艺信息。     

面向移动终端的三维CAD模型面片生成方法

为提高三维CAD模型在移动终端的显示效率,提高模型细节的显示精度,提出了一种基于类型层次结构及对象体元的三维CAD模型面片生成方法。依据模型的数据库表示形式,抽取其必要的类型和图形信息,将三维CAD模型用图形分类树表示;对交互选择的分类树节点,使用基于离差标准化的方法估算所选节点的模型规模系数;依据规模系数确定模型的显示精度,以此进行三维CAD模型面片的生成。在移动终端开发了三维CAD显示系统并进行了三维CAD模型面片生成实验,通过实验证明了所提三维CAD模型面片生成方法的可行性和有效性。     

由薄壁类零件直接制造模具的自动编程的研究

CAD/CAM技术的发展,使得在数控加工中直接利用CAD的设计数据成为可能.特别是微机与数控机床的连接,使得设计、工艺规划及编程的整个过程全部在计算机上完成,而不需要输出专门的工艺文件.现在,许多CAD/CAM软件包都提供自动编程功能,这些软件一般是在编程界面中,提示工艺规程的有关问题.近10多年来,MasterCAM一直是数控加工中自动编程优先选用的软件之一,它提供了刀具选择、加工路径规划、切削用量设定等功能.编程人员只要掌握了刀具选择和切削用量确定的基本原则,设置了相关参数,就可以自动生成加工程序并传输至数控机床完成加工.     

基于Pro/ENGINEER平台的液压机数控加工程序的自动生成

一、引言Pro/ENGINEER、UG、IDEAS等CAD/CAM系统将产品的设计与制造以及NC代码生成功能集成在统一的平台下，具有很强的设计和加工功能。但这些系统均缺乏与CAPP的信息集成，使CAD/CAPP/CAM的信息集成出现断流。CAPP产生的工艺信息无法直接、自动地为CAM模块所使用。在这些系统     

面向装配的飞行器超大模型实时可视化技术

针对飞行器大数据量CAD模型实时绘制困难的问题,提出一种LOD自动批处理生成以及实时自适应绘制方法.以零部件为处理对象以保留装配树信息,结合模型分割完成超大模型简化,并根据计算机存储能力、实时绘制能力以及CAD模型特点,实现了定量的LOD自动批处理生成;以精确遮罩查询为基础,根据计算机实时绘制负载和CAD模型面片密度,动态地调整LOD精度等级,使得各个模型的精度基本一致,避免了传统算法的弊端,实现了LOD实时自适应绘制,并进行了优化.实验结果表明:采用文中技术处理千万级三角面片的模型约1h完成LOD生成,并可在普通计算机上实现实时的自适应绘制.     

集成于CAD系统的数控线切割自动编程系统

本文以具体例子说明了从CAD系统的零件描述中自动生成数控线切割程序系统的设计方法。读系统从提取CAD数据转换文件中的信息开始,自动识别零件的内外轮廓,确定切割方向和走刀路线,最终生成通用的数控程序,并利用后处理程序转换成特定数控加工程序。     

数控加工中刀具的选择与切削用量的确定

刀具的选择和切削用量的确定是数控加工工艺中的重要内容,它不仅影响数控机床的加工效率,而且直接影响加工质量。CAD/CAM技术的发展,使得在数控加工中直接利用CAD的设计数据成为可能,特别是微机与数控机床的联接,使得设计、工艺规划及编程的整个过程全部在计算机上完成,一般不需要输出专门的工艺文件。现在,许多CAD/CAM软件包都提供自动编程功能,这些软件一般是在编程界面中提示工艺规划的有关问题,比如,刀具选择、加工路径规划、切削用量设定等,编程人员只要设置了有关的参数,就可以自动生成NC程序并传输至数控机床完成…     

基于图形软件CADtool的冷冲模CAD系统

本文介绍了一套基于国产绘图软件的冷冲模CAD系统。分析了对典型冷冲压模具进行智能设计时软件应具有的功能模块及其逻辑结构；探讨了智能生成模具加工工艺过程卡的查询生成法和工步拼装生成法。     

应用Matercam铣削轴类键槽的方法探讨

正随着数控技术和CAD/CAM技术的发展,数控加工在机械加工中拥有了越来越重要的地位。在数控加工中经常会遇到加工轴类键槽的情况,通常我们会应用CAD/CAM软件首先绘制出零件的三维实体模型,然后选择机床、毛坯、加工方法、刀具以及加工参数后生成刀具路径,在验证正确后再自动生成数控加工程序。本文应用美国CNC Software公司的CAD/CAM软件Mastercam加工如图1所示的键槽,进行铣削轴类键槽的方法探讨。     

基于CAPP系统的浮空器囊体工艺设计

本文针对目前浮空器囊体制造领域存在的工艺繁琐、信息共享困难等问题,在分析生产业务流程和管理现状的基础上,阐述了浮空器囊体制造辅助工艺(CAPP)系统的设计框架和设计思路。该系统通过设计功能模块的划分和生产数据库的建立,实现了浮空器囊体生产数据的有效存储和管理。可以根据导入数据,自动生成工艺过程文件及囊体装配工艺规程,极大地促进了浮空器囊体加工生产的自动化,提高了工艺设计效率。     

A feasible approach to the integration of CAD and CAPP

Although current CAD systems are declared to be feature-based, in fact, the so-called feature is just a modeling macro or menu name such as Protrusion, Revolution, Cutout, Block, etc., instead of a design feature or manufacturing feature in accordance with engineering practice. Consequently, product model data insufficiency and incompatibility between varieties of application systems are still the major barriers to system integration, especially the integration of design and process planning. This paper proposes a practical solution for a bi-directional integration of CAD and CAPP on the platform of commercial CAD systems. The key techniques such as feature recognition and conversion, feature parameter and constraint extraction, feature tree reconstruction, technical information processing, process planning, automatic process drawing marking and 3D material stock CAD model generating are discussed. And the extracted features and their related technical information and knowledge are encapsulated together with the geometry-oriented CAD model to form an integrated product information model to facilitate effective integration with the downstream activities. The integrated CAD/CAPP system is implemented on a commercial CAD package, UGS/SolidEdge. A case study and industry implementation illustrate the feasibility of the approach proposed.     

An integrated manufacturing planning assistant — IMPA

In this paper, we describe our development of a fully integrated manufacturing planning assistant (IMPA) system, which is able to: (1) interpret the finished part requirements directly from the designer's CAD systems or solid modelers without user intervention or special feature coding; (2) check the machinability of a designed part; (3) automatically generate a process plan, a tool path and an NC (numerically controlled) code, and (4) support interactive user modification of the resulting plans, tool paths and NC code. A demonstration version of the system was designed to provide automated assistance for the planning of machining processes on three-axes NC machine tools. The underlying architectural concepts and reasoning algorithms can be extended to more complex machines such as four-or-more-axes NC machines. CAD, CAE, and CAM including robotic, FMS (flexible manufacturing system) and NC machines are widely used in industry today. There is increasing interest in automation of factory control software Merchant, (1988); this includes automating the generation of the control programs — that is, in developing systems which will automatically produce the NC code for machining the part, given a model of the part, the shape of the raw material, and the machine specifications. With such systems, there are several difficulties in the manual preparation of an NC program code such as, long and tedious calculations, high risk of error in data preparation, etc., which need to be eliminated. This is a critical step toward the integration of CAD and CAM into a truly concurrent engineering and manufacturing environment.     

Product design logic for an intelligent product modelling system

Recent research in CAD systems has been conducted to realize intelligent processing. Several CAD systems and product modelling systems have been developed using AI techniques. However, in order to develop more intelligent CAD systems, the design logic which connects the functional requirement to the geometric and the technological information of the designed product must be evaluated.

A product model used in such intelligent CAD systems has to include not only the geometric and the technological information of the product but also the designer's thought process which explains the design logic.

Design logic is generally divided into two parts. One is the generalized design logic which is commonly used in the conceptual design of mechanical products. The other is the product specified design logic which is used in the fundamental and detailed design phase. Different logic is applied to each product. This type of design logic is often used in modification design and compilation design, where the dimensions of parts have to be modified according to different functional requirements. When the dimensions and accuracies of the products are defined in connection with the functional requirements through design logic, the CAD system can automatically make decisions according to the given requirements. In this paper, suitable presentation formats and processing functions for these two types of design logic are discussed.

The importance of design logic in product modelling is proven through several case studies in this paper. As a conclusion, the intelligent product modelling system is developed, which should expedite the progress of design automation in the near future. In conceptual design, the design logic is processed in the modelling system and the product structure, with the technological information decided automatically from the functional requirement. Automation in the detailed design phase is also facilitated by the modelling system using the product specified design logic in the product model.     

转塔式数控冲床CAD/CAM系统的设计

介绍一种转塔式数控冲床加工代码自动生成的CAD/CAM软件系统设计的实现技术。它可以与AutoCAD、Protel、CAXA等图形文件进行数据交换装入图形,也可以开发系统绘制图形,然后对图元对象进行编辑、分块处理、建立模板,经过加工路线自动排序、干涉检验、基点选定、加工模拟,最后生成数控加工代码。该文论述了系统软件结构、设计模式、模板建立、自动排序、代码生成等技术内容。     

A simple approach for point-based object capturing and rendering

Point-based object representations are a powerful alternative to traditional polygonal object representations. Capturing 3D geometry is a mission-critical content acquisition technique in application domains such as virtual reality, CAD/CAM, and physical asset management. We describe SPOC, a simple, point-based object capturing system we've developed to automatically capture and process 3D geometry for point-based image rendering. We also identify the problems involved and describe the technical solutions we've implemented. Finally, we address several algorithmic issues in capturing point models using a simple digital camera and turntable setup, and in processing and rendering point clouds.     

基于STEP装配特征的BOM信息提取和多视图映射

为了解决企业信息集成过程中CAD文件物料清单提取问题,提出一种基于STEP装配特征辨识的物料清单信息提取方法,该方法以STEP作为中间数据格式,采用统一建模语言建立实体类映射模型,利用模型的装配特征辨识实体的装配关系,实现异构数据物料清单统一提取。同时,在XMLwebServices框架的网络服务平台上,利用扩展样式表语言转换自动映射机制,有效实现物料清单多视图转换过程集成规范化。在此基础上建立了基于STEP产品物料清单信息管理系统,并给出了该系统在工程机械制造企业产品数据管理中的应用实例。     

Development of a CAD-based intelligent manufacturing system

This research proposes a CAD-based manufacturing system that embraces computer-aided design, design for manufacturing and assembly (DFMA), computer-aided process planning (CAPP), computer-aided assembly planning (CAAP), and vision-robot integration. The proposed system starts with the design of products using a commercial CAD software, Autocad. The design data is then extracted from the CAD database and organized into a standardized product model. Interface programs are used to translate the geometrical and topological information in the model into DFMA, CAPP, CAAP and vision image representations. Based on the results generated by the interface programs the applications using artificial intelligence techniques can automatically generate redesign advises, CNC part programs, assembly sequence and instructions for robots.     

THE OBJECT-ORIENTED INTELLIGENT PROGRAMMING IN CAD/CAM

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注塑件CAD建模与CAE智能处理的集成化研究

CAD／CAE技术的集成化研究是当前的一个研究热点，对于注塑件／模而言，CAD信息向CAE传输中存在信息丢失和少智能问题，而CAE的结果向CAD信息的反馈过程中也存在信息缺乏衔接和少智能化的问题，利用CBR（基于事件的推理）对工艺参数进行智能推理，然后结合推理出的参数值以及CAD中过滤出的信息，输入到CAE进行分析，对CAD中的特征信息与CAE后处理的信息进行合理的匹配，建立对后处理结果的缺陷解释专家系统。重点对工艺参数优选的CBR及后处理的专家解释系统和数据流的流动过程进行了深入的研究，提出CAD／CAE并行环思想，从而方便了注塑件特征造型与CAE智能处理的集成。