PCB设计系统中CAD数据库的研制

本文描述一个新型CAD数据库系统的设计。在设计过程中,采用了将索引顺序文件管理系统与一般商用关系数据库相结合的方法,针对复杂PCB实际分层设计的需要,提出一种关系和网状混合数据模型,并根据这种数据模型实现了CAD数据库系统的操作,从而使得该数据库系统有效地支持各种CAD工具的集成,为PCB设计提供了一个集成和有效的环境。     

基于组件的工业过程数据仓库

工业企业自动化系统所产生的过程数据,分散在异构系统上,不能统一的存储、调用和管理,造成数据资源浪费.基于组件和分布式应用技术,设计和实现了工厂级的工业过程数据仓库,包括:集成各类自动化软件的过程数据,数据压缩存储,可视化分析工具开发.通过该系统,可集成和开发工业过程历史数据资源,从中挖掘对生产有用的知识.     

REDAC系统的PCB设计

<正> 一、引言 REDAC系统是一个快速自动和交互操作的计算机辅助工程化设计工作站,是设计印制电路板的有力工具。它主要用于进行印制电路板的布线设计和逻辑图设计。它既可以独立工作站方式工作,也可与VAX机联机工作。 REDAC系统独立工作站硬件配置如图1示。     

印制电路板设计

本文阐述了印制电路板设计时在元件布局、布线、电磁兼容与抗干扰方面应注意的事项,在印制电路板设计时遵循这些原则将为印制电路板设计带来很多方便,减少印制电路板设计中的错误,提高印制电路板设计的成功率。     

Using ObjectARX to Realize Feature Modeling

为了满足中小企业实施CAD/CAM集成过程中对产品特征模型的需要,基于特征设计的建模理论,建立了特征的信息模型。研究了在AutoCAD系统上实现特征建模的方法,阐述了特征的参数输入、定位、生成及存储等特征建模的主要步骤。以齿轮泵泵体特征建模为例,证明了基于ObjectARX实现特征建模的可行性,为中小企业实施CAD/CAM集成提供了一种简单而有效的方法。     

电子制作中印制电路板设计

印制电路板是电子制作中的重要组成部件,它的首要工作就是PCB图纸的绘制。印制电路板的设计不单是元器件、线路的简单布局安排,它是集成元件、有源元件、无源元件,信号线,电源线的高密度集合体,还必须符合抗干扰的设计原则。其抗干扰性能直接影响到整机的稳定性、可靠性,所以印制电路板的抗干扰是设计中至关重要的一环。我们就绘制电路板PCB图纸工作中的几点经验总结如下。     

基于ObjectARX实现特征建模的方法

为了满足中小企业实施CAD/CAM集成过程中对产品特征模型的需要,基于特征设计的建模理论,建立了特征的信息模型。研究了在AutoCAD系统上实现特征建模的方法,阐述了特征的参数输入、定位、生成及存储等特征建模的主要步骤。以齿轮泵泵体特征建模为例,证明了基于ObjectARX实现特征建模的可行性,为中小企业实施CAD/CAM集成提供了一种简单而有效的方法。     

手工焊接印制电路板的焊点缺陷与建议

在电子产品的生产设计以及加工制造的过程中,焊接工艺是重要的一个部分,电子元器件焊接的质量直接影响到了产品的可靠性和安全性。其中,印制电路板在各个电子元件当中起到了重要的作用,因此焊接质量对印制电路板有着重要的影响,需要不断的提高手工焊接印制电路板的质量,从而确保整个产品的质量。本文主要对印制电路板的设计过程进行分析,然后说明了手工焊接印制电路板的焊点缺陷及产生原因,最后提出了手工焊接印制电路板焊点缺陷的解决方法,从而在根本上提升手工焊接的质量。     

印制插件板自动布线

<正> 在计算机设计过程中,完成逻辑设计后,紧接着就是考虑它的工程实现,而印制电路板(包括扦件板和底板),布线,则是其中最重要而又最困难的环节。一台计算机的研制周期和制造精度,与它的印制电路板的设计和制造有很大关系,因此,使印制板设计和制造自动化,是缩短计算机研制周期、减少设计差错、提高制造精度的有效手段之一。 在研制DJS—8000系列计算机中,我们在HP-1000计算机上,实现了对DJS-8000系列印制扦件板的自动布线系统。该系统输入扦件逻     

基于CORBA的CAX信息集成系统设计

由于企业在采用CAD、CAE、CAM、CAPP等软件时所用的操作系统和硬件平台的差异,因此不可避免地要产生大量的分布式异构数据和冗余数据。该文提出一种新的基于CORBA软总线和CAX信息集成系统结构,它包括CAX信息集成功能模拟软总线和集成工具软总线,并研究了功能软组件的实现和集成工具接口的实现。该集成系统结构可实现跨网络、跨平台的协同设计。     

Environment for rapidly creating interactive design tools

The Garnet toolkit was specifically designed to make highly interactive graphical programs easier to design and implement. Visual, interactive, user-interface design tools clearly fall into this category. At this point, we have used the Garnet toolkit to create three different interactive design tools: Gilt, a simple interface builder for laying out widgets; Lapidary, a sophisticated design tool for constructing application-specific graphics and custom widgets; and C32, a spreadsheet interface to constraints. The features of the Garnet toolkit that made these easier to create include use of a prototype-instance object system instead of the usual class-instance model, integration of constraints with the object system, graphics model that supports automatic graphical update and saving to disk of on-screen objects, separation of specifying the graphics of objects from their behavior, automatic layout of graphical objects in a variety of styles, and a widget set that supports such commonly used operations as selection, moving and growing objects, and displaying and setting their properties.     

原理图自动审查系统中的协同技术

该文提出了一种原理图级电路设计自动审查系统协同设计实现方案。这种技术的关键就在于将设计和测试向量融为一体,即当设计和测试单独进行时,能够根据设计资料生成标准的测试向量,依据测试向量实现原理图的自动测试。该文介绍了此协同设计体系的系统结构、集成框架结构及扩展EDA内置的测试功能。     

A Graphical User Interface for Formal Proofs in Geometry

We present in this paper the design of a graphical user interface to deal with proofs in geometry. The software developed combines three tools: a dynamic geometry software to explore, measure, and invent conjectures; an automatic theorem prover to check facts; and an interactive proof system (Coq) to mechanically check proofs built interactively by the user.     

The role of expert systems in producing log interpretation software

Abstract: Log interpretation science is a controversial and rapidly changing domain. Designing interpretation models is a highly experimental process which involves trials with a computer program as an integral part of the design. Therefore conventional software engineering techniques, which require a complete specification of the problem before the program is written, are often not applicable or fail to produce high quality software. The development of expert systems has provided the techniques, tools, and capabilities to let us seek alternate methods to produce log interpretation software: exploratory programming environments and automatic programming systems. An exploratory programming environment combines the power of interactive graphics and programming tools to merge the design and programming tasks into a single process where model and program develop together. An automatic programming system will embody the knowledge of the programming process and of some log interpretation heuristics to produce log processing programs from interactive specifications expressed in familiar terms. These facilities will allow log interpretation model designers, who are non-computer specialists, to produce high quality software as the end result of a model design.     

Selection assistant system for gate array user

The problem of selecting the most suitable gate array for a design simply arises from the abundance of choices and the lack of commonly adopted and well defined criteria. This is a particularly difficult problem for an inexperienced gate array user. The selection assistant system described resorts to expert-system techniques to make the selection process transparent to a user. The system establishes user requirements either through interactive dialogue or automatic extraction from a schematic. Selection criteria are divided into electrical and technical aspects. Examples of the former are delay, gate count, etc., whereas those of the latter are computer facilities, price, etc. As the system is designed to be adaptive, the knowledge base can be modified and fine-tuned. It is suggested that the system should be tailored to a specific working environment in practical use.     

Softing software engineering system

An integrated production system covering the phases specification, design, programming, documentation, test and integration—as well as project and configuration management is described. The system is built upon a unified development methodology supported by interactive tools. It encompasses a quality assurance procedure based on the automatic control of all intermediate products. It also provides a development database for project planning and control. The system is presently under development in Budapest, Hungary. Three of the planned seven subsystems are already operating in West Germany.     

一个交互式的Fortran77并行化系统

并行化编译器可以把现有的串行程序自动或半自动地转换为并行程序.现有并行化系统的自动并行化效果与手工并行化的效果相比还有一定的差距,这是由于并行化工具的分析能力不足以及程序中所固有的语义信息无法被并行化工具所理解而造成的.TIPS(Tsinghua interactive parallelizing system)系统通过提供一些友好的交互式工具,使用户与编译器紧密协作,是提高并行化系统的能力和效率的一条有效途径.     

基于TestDirector的软件自动化测试系统的设计

针对国内软件测试自动化程度较低的现状,介绍了软件自动化测试技术和Mercury Interactive公司的3个测试工具:TestDirector、WinRunner和LoadRunner.然后以全国短波监测网络系统为例详细阐述了用TestDirector做测试管理,用WinRunner和LoadRunner做自动测试的整个测试系统的设计.从实践中证明了测试系统的可用性,并将自动控制理论融入到测试问题中,以求用控制理论的方法来指导软件测试.     

基于飞思卡尔MC9S12XE系列单片机的汽车电子车身控制器硬件自动化设计

旨在介绍一种汽车电子行业的硬件自动化设计软件,主要用于汽车车身控制系统。使用者只要明确系统需求,按照要求填写输入输出信息表,就可以自动生成满足功能的电路原理图。根据汽车电子行业的特点,将自动化硬件设计向更为专业化的方向进一步尝试,目标是能创建一个能够满足各种实际负载和功能需求,并且在成本上较为优化的专业性平台型软件。