毕业设计（论文）
外文翻译
多媒体工程数据库管理系统 1
梁允荣 郭贵锁 宋翰涛 冯希 高春雷 郭胜
（北京理工大学计算中心，北京 100081）
摘 要：在以工程数据库为核心的发动机 CAD 系统中，工程数据库管理系
统（ECAD-EDBMS）除管理图形和数据外，还能提供文字、声音、图像、影像
等信息媒体的管理操作功能，为 CAD 系统中多个子系统开发和发动机设计者提
供多媒体支持环境，提高工作效率。
关键词：数据库管理系统；多媒体技术；工程 CAD
Multimedia Engineering Database Management System
Liang Yunrong Guo Guisuo Song Hantao Feng Xi Gao Chunlei Guo
Sheng
(BIT Computing Center,Beijing Institute of Technology,Beijing 100081)
Abstract: In the Engine CAD application system engineering database
management system (ECAD-EDBMS) is the kemel. ECAD-EDBMS can manage and
process the multimedia such as graphics, data, text, sound, image and video. It
provides the integrated environment and more functions for many subsystems of
ECAD and engine designers. So it improves the design efficiency.
Keywords: Database Management Systems; multimedia technology; engineering
CAD
近年来，多媒体技术发展迅速。工程设计人员可以通过友好用户界面来有效
地管理并处理多媒体。所以计算机应用领域也随之扩展。在一些传统的应用领域
中，多媒体技术的应用使普通用户能更容易地掌握计算机的使用。
1 Journal of Beijing Institute of Technology,1996,,
多媒体技术已经成功地应用于许多领域中，如：娱乐产业，教育业，广告业，
培训业，指挥和咨询业等。在 CAD 工程领域中，多媒体的应用是一种新的尝试，
它可以提高 CAD 系统的应用水平和扩充作用。如今的机械设计师不仅需要有强
大的二维和三维图形的处理能力，而且还需要会综合管理图表和非图表的数据。
许多研究人员为实现开发工程数据库管理系统（EDBMS）这一目标尽了很大的
努力。EDBMS 和 EDB 将会成为 CAD 的核心部分。这表示多媒体技术以全新的
面貌应用于 EDBMS 中，将会大大提高 EDBMS 的功能。我们的研究小组一直致
力于 EDBMS 的 CAD 应用系统发动机这一项目（ECAD-EDBMS），ECAD 系统
需要用到 EDBMS 的多媒体。在我们不断发展的过程中，一些问题已经逐步解决
了。本文讨论的是这种需求和解决办法。
1 ECAD-EDBMS 对多媒体的要求（设计 CAD-EDBMS）
ECAD 应用系统包括了大约 20 个子系统，例如一般设计的发动机（GD），
活塞组设计（PD），汽缸设计(CD) ，曲轴设计（CRD）和供油系统（OSD）等
等。ECAD 是将以太网网络连接到工作站和微机上工作的。ECAD-EDBMS 是整
个 ECAD 应用系统的核心。那些被 EDBMS 管理控制的 EDBMS 和 EDB 是上文
中所说的 CAD 子系统之间交换信息的中心。EDBMS 应具备综合管理图表和工
程数据并从图表数据中提取转化几何参数给 EDB 的能力。ECAD 系统中的 EDB
可分为综合数据库和局部数据库两种数据库。例如：在设计如何将发动机投入
到 GDB 中时，要考虑到它的性能参数，几何大小和经济目标，因此每个 CAD
子系统可以从这个 GDB 中恢复初始参数。当然，像标准参数库（SPPL），包括
文字和数字显示的技术参考扫描图像库（TRMSIL）的标准部分，图表生成程序
库（GGPL）的标准部分和材料库（ML）都属于 GDB。每一个 CAD 子系统都有
其自己的工作 EDB 和许多包含图标和参数数据库的代表性产品库，其中大多属
于 LDB。LDB 存储在本地工作站中并常被 CAD 子系统应用于运行这个工作站。
这种布置可以提高系统的工作效率。GDB 和 LDB 可以相互传递到对方所需要的
位置。
ECAD-EDBMS 提供给综合多媒体环境 GD,PD,OSD 等子系统，如图 1 所示，
EDBMS 应满足以下需要。
综合管理图表和工程数据的必要条件
每个 ECAD 的 CAD 子系统需要多种操作管理图表的功能和能从 GDB 和
LDB 方便获取大量工程数据的能力。EDB 必须引入大量的工程图纸和代表性产
品的参数，引擎设计师也常常需要这些图纸和参数。有时候，有些数据应从图表
提取出并传递到 GDB 或 LDB。ECAD-EDBMS 是所有 CAD 子系统的基础。
对图像的需求
当使用标准部分库和材料库时，设计者需要做两件事情。首先是提取出需要
的那部分参数并将它们转发给相应的图表生成程序（2D 和 3D）从而将部分图表
绘制到设计图纸上。第二件事就是查找需要的技术文本，例如技术指标，进程说
明，包含了大量汉字和图表的机械零件图纸。要深入到这些材料中是非常困难的。
以下是关于标准件和发动机的三种技术材料。
(1) 把参数表放进 GDB 中，再通过设计者将其恢复传递给图标生成程序。
EDBMS 必须要为这种参数表指南创建并管理 SPPL。
(2) 满足这种技术指标、进程说明和图纸要求的材料可以通过使用扫描仪以
页码的形式很容易地投入到 TRMSIL 中。设计者可以使用 EDBMS 逐页查询这
些图像档案。被扫描过的图像压缩后能节省磁盘空间。
(3) 关于整个发动机或装配零部件的产品照片可以用扫描仪扫描或者也可以
使用相机拍照后压缩文件存入计算机中。当需要决定选择哪种实体模型时，设计
者就可以查阅这些图像文件。
对声音的要求
一些评估会议的录音记录、专家谈话发言、有关设计经验的报告和产品介绍
的录音带也可以输入到计算机磁盘中。这样设计者就可以使用这些音频文件作参
考。
对视频的要求
有些视频文件需要存储在计算机磁盘中。这些文档记录了运行到饱和状态的
内部或外部发动机或装配零部件和汽车引擎装备在不同路段、坡地的状况。
对动画的要求
一般的发动机设计需要从不同的角度来设计规划装配零部件和各种企划。设
计者希望运动系统的动画具备动作效果。
2 ECAD-EDBMS 的实现
上述提出的问题有一部分已经得到了解决，目前还依然存在的问题需要我们
继续研究得以改善。我们的发展环境是 SUN SPARC 站运行可以提供用二维和三
维图形处理这一强大功能的 SUNOS ， ORACLE RDBMS 和通用机械 CAD
系统。SUN 系统是一种适用于包括微型计算机在内的以太网网络。网络软件是
指 NFS 和 PC-NFS。
综合处理图表和工程数据
根 据 ORACLE RDBMS 和 通 用 机 械 CAD 系 统 ， 我 们 开 发 设 计 了
ECAD-DEBMS，此 ECAD-EDBMS 能够在开放式窗口 的环境下用 GUL
ECAD-EDBMS 的主题连接两个软件系统，使其在一个窗口上运行。它的菜单条
有 GDB，LDB，GDB 和 LDB 之间的相互转换，图表数据的提取，SPPL，TRMSIL
和 ML 按钮。当设计者按动每一个按钮时,子菜单将会弹出，然后设计者可以用
鼠标按钮从菜单中选择一项。图表处理程序在另一个被分为三个子窗口（如：图
表，指令和列表区域）的窗口工作，这样设计者就可以在这个窗口做交互式的设
计。大多数的设计工作是在这也图表窗口完成的。在 ECAD-EDBMS 的帮助下，
设计者可以按 SPPL 键取回参数数据库放入一个新的窗口，这样设计者就能够在
窗口边缘使用标准件的数量和滚动条查找记录。设计者可以通过简便地按下在图
标菜单中的图标请求来选择其中一个需要的记录并把它保存到中间文件中在将
其移到图像窗口，相应的图表程序用中间文件在图形窗口的指针位置制作出理想
的图表。当然设计者也可以选择用 TRMSIL 菜单选项打开另外一个窗口来逐页
显示技术参考材料。标准部分的数量和上述内容是相同的。工作程序将扫描好的
图像文件解压缩，然后在窗口中显示出来。设计者可以根据说明提示来选择所需
要的那部分参数。所以用鼠标按钮完成这些窗口的相互交换既方便又快捷。其实，
部分参数是从 ORACLE 数据库中取回的，而部分图表又是又通用 CAD 系统形
成的。但是这一过程对于设计者来说是透明可见的。所以，ECAD-EDBMS 是唯
一 一 种 能 以 同 一 种 方 式 操 作 图 表 ， 工 程 数 据 和 扫 描 图 像 的 界 面 工 具 。
ECAD-EDBMS 为引擎设计师提供了极其方便的综合环境。
多媒体支持的环境
在ＳＵＮ工作站上有声音界面和处理软件，因此当设计者想要记录或重新播
放这个声音文件是可以很容易地输入、输出声音信息。有价值的声音资源都会被
搜集起来做好记录，而且必须重新播放。但是在我们的 SUN 站上没有图像界面，
所以我们要用微机连接上 SUN 站才能输入、输出视频以及输入扫描过的标准件。
SUN 站有一个特殊的子目录是设置在 PC 机上作为一个逻辑磁盘的（如：G 盘），
视频文件名连同一个逻辑磁盘里的文件（所以称为邮箱）一起传递给 PC 机。显
示程序是同已经传递的视频文件名一起开始重新播放的。扫描过的图像文件的格
式必须翻译成 SUN 的格式并将其从邮箱传递到 SUN 的磁盘上。在 SUN 站上，
扫描后的图像文件会从每页 500kB 压缩到每页 30kB。
所以这成功地解决了多媒体支持环境的问题。
动画展示
要展示一般布局的发动机需要用到很多子系统的绘制结果，但是要绘制出装
配上活塞，汽缸还有机轴的运转机理的动画，就需要借助通用的 CAD 系统的帮
助才能做到。这个动画是一个仿效运动学的议案。设计者可以根据这个议案分析
运动学的特征。
3 结束语
ECAD-EDBMS 正处于发展进步中。它将会把多媒体整合为一个系统并为其
他 ECAD 系统的 CAD 子系统和引擎设计师提供扩展功能，这样可以提高设计的
效率。
Multimedia Engineering Database Management System
Abstract : In the Engine CAD application system engineering database management
system (ECAD-EDBMS) is the kemel. ECAD-EDBMS can manage and process the
multimedia such as graphics, data, text, sound, image and video. It provides the
integrated environment and more functions for many subsystems of ECAD and
engine designers. So it improves the design efficiency.
Key words : database management systems; multimedia technology; engineering
CAD
In recent years, the multimedia technology is developing fast. With the help of
friendly user interface, engineering designers can manage and process multimedia
effectively. So computer application fields are extended. In some traditional
application fields, multimedia technology has made computers easy to be used by
ordinary users.
Multimedia are applied successfully in many fields such as entertainment [1],
education, advertisement, training, command and consultative. In the field of
engineering CAD, it is a new attempt to apply multimedia to improve the application
level and extend the functions of CAD system. Nowadays mechanical designers have
not only the need of powerful 2D and 3D graphics processing ability but also the need
of integrated management of graphics and nongraphics data. Some researchers have
made great efforts to develop engineering database management systems (EDBMS) to
attain this goal. EDBMS and EDB will become the kernel of some CAD application
systems. It is a new aspect to apply multimedia technology in EDBMS, which will
greatly enhance the functions of EDBMS. Our research group has been working on
the project of EDBMS of the engine CAD application system (ECAD-EDBMS),
ECAD system demands multimedia of EDBMS. Some problems have been
progressively solved in our developing environment. This paper discusses this kind of
requirements and solutions.
1 REQUIREMENTS FOR MULTIMEDIA TO ECAD-EDBMS (ENGINE
CAD-EDBMS)
The ECAD application system includes about 20 subsystems, for example
general design of engine (GD), piston group design (PD), cylinder design (CD),
crankshaft design (CRD) and oil supply system (OSD) and so on. ECAD will work in
an Ethernet network connecting some workstation and microcomputers.
ECAD-EDBMS is the kernel of the whole ECAD application system. EDBMS and
EDB managed by EDBMS are the centre to exchange information between these
CAD subsystems mentioned above. EDBMS should meet the requirement for
integrated management of graphics and engineering data, and have the ability to
extract and transfer geometry parameters from graphics data to EDB. EDB of ECAD
system can be divided into two kinds of database, global databases (GDB) and local
databases (LDB). For example, the performance parameters, geometry size and
economy targets of the designed engine are put into GDB, so each CAD subsystem
can retrieve design parameters from this GDB. Of course the standard parts parameter
Lib. (SPPL), technical reference material scanned image Lib. (TRMSIL) of standard
parts including text and figure shows, graphics generation program Lib. (GGPL) of
standard parts, and material Lib. (ML) belong in GDB. Every CAD subsystem has its
own working EDB and a lot of typical products Lib. (TPL) including graphics and
parameter databases which belong in LDB. LDB is stored in local workstation and
used frequently by local CAD subsystem running on this workstation. This
arrangement can improve the systems working efficiency. GDB and LDB can be
transferred each other as needed.
The ECAD-EDBMS provides the integrated multimedia environment for the
GD, PD, OSD subsystem and so on as shown in should meet the
requirement as follows.
Requirement for Integrated Management of Graphics and Engineering Data
Every CAD subsystem of ECAD needs many functions of graphics operation
and management and the ability to access easily a vast amount of engineering data
from GDB and LDB. A large number of engineering drawings and parameters of
typical products must be entered into EDB and referenced frequently by engine
designers. Sometimes some data should be extracted from graphics and transferred to
GDB or LDB. The ECAD-EDBMS is the foundation for all CAD subsystems.
Requirement for Images
When using standard parts Lib. And material Lib. the designer can do two things.
The first is to retrieve parameters of desired part and transfer them to corresponding
graphics generation program (2D or 3D) to form the part graphics on the designed
draw. The second is to look up technical text about desired part, for example the
technical index, processing explanation [2], drawing of mechanical parts contain a
vast amount Chinese characters and graphics. To enter these materials is very
difficult. There are three kinds of technical materials about standard parts and the
engine as following.
(1)The parameter tables should be entered into GDB and can be retrieved and
transferred to graphics generation programs by designers. EDBMS must create and
manage SPPL for this kind of parameter tables of manuals.
(2)The materials of technical index and processing explanations and drawings can
be simple put into TRMSIL in the page form using the scanner. Designer can use
EDBMS to look up these image files page by page. The scanned images are
compressed to save disk space.
(3)The product photographs of the whole engine or assembly parts can be
scanned with scanners or shooted into computers with pick up cameras in the
compressed files. Designers can look up these image files when making decision
of selecting solid model.
Requirements for Sound
Some sound records of evaluating meetings and speaks of specialists and
statements of design experience and product introduction audio tapes can also be
input to computer disk. So designers can replay these audio files for reference.
Requirements for video
Some video files are needed to be stored in computer disks. These files record
the running saturation of internal or external engines or assembly parts and the vehicle
equipped with the engines on different roads and sloping fields.
Requirements for Animations
The general design of the engine needs the layout of assembly parts and various
of the layout from different view point. Designers have the demand for motion
animation of movement system [3].
2 IMPLEMENTATION
Some problems mentioned above have been solved and remain requirements will
be realized. Our development environment is SUN SPARC station running SUNOS
, ORACLE RDBMS and universal mechanical CAD system which provides
powerful functions in 2D and 3D graphics processing. The SUN system is in an
Ethernet network including microcomputers. The network software is NFS and
PC-NFS.
Integrated Processing Graphics and Engineering Data
Based on ORACLE RDBMS and universal mechanical CAD system, we
developed the ECAD-DEBMS which links up these two software systems in the open
window environment using Motif GUL ECAD-EDBMS runs on one window. It
has menu bar with GDB, LDB, transfer between GDB and LDB, extraction of
graphics data, SPPL, TRMSIL and ML buttons. When designers press each button the
submenus will be pulled out and designers can choose one item from menus with
mouse buttons. Graphics processing program works in another window which is
divided into three subwindows (. graphics, command and list area) and designers
can make interactive design in this window. Most of design work is done in this
graphics window. With the help of ECAD-EDBMS designers can press the SPPL
button to retrieve the parameter databases in a new window, in which designers are
able to look up the records using the standard part number and the scroll bars on the
window borders. The designer can select one record needed and save it into the
medium then moves to the graphics window easily to press the icon desired on the
iconsmenu, and the corresponding graphics program uses the medium form the
desired graphics at the cursor position on the graphics window. Of course designers
can open another window by selecting the TRMSIL menu option to display the
technical reference material page by page. The standard part number is the same one
mentioned above. The working program decompresses the scanned image files, then
displays them in the window. The designer can look at the instruction to select the
desired part parameters. So it is easy and fast to exchange between these windows
using mouse buttons. Actually the part parameters are retrived from ORACLE
databases and the part graphics are formed by the universal CAD system. But this
process is transparent for the designer. So the ECAD-EDBMS is the only interface to
operate graphics, engineering data and the scanned images in the uniform manner.
The ECAD-EDBMS provides the extreme convenience and the integrated
environment for engine designers.
Environment Supported by the Multimedia
On SUN work station there are the sound interface and processing software, so
the sound information can be easily I/O when the designers want to record or replay
the sound files. The valuable sound resources collected by records must be used by
replay. But there is no images interface on our SUN station, so we use the
microcomputer connected with SUN station to input and output video and to input the
scanned images of standard parts. A special subdirectory of SUN station is mounted
on PC as a logic disk (. G disk), the video is passed to PC with a file (so called a
postbox) in the logic disk. The display program starts replay with the passed video .
The format of scanned image files must be translated to the SUN’s format and moved
from the postbox to the SUN disk. On SUN station the scanned image files are
compressed from 500 kB to 30 kB for each page.
So the solution of the multimedia support environment is successful.
Displaying Animation
To display the animation of the general layout of the engine using the design
results produced by many subsystems and the animation of motion mechanism
assembled with the piston, cylinder and crankshaft must be done with the help of the
universal CAD system. The animation is an emulation of kinematics of the motion.
The designer can analyze the kinematics features.
3 CONCLUSION
The ECAD-EDBMS is in progress. It will integrate multimedia into one system
and provide extended functions for other CAD subsystems of ECAD system and
engine designers, so the design efficiency can be improved.
