多媒体工程数据库管理系统

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1、毕业设计（论文）外文翻译多媒体工程数据库管理系统 Journal of Beijing Institute of Technology,1996,Vol.5,No.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CADMultimedia Engineering Databa

2、se Management SystemLiang 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 proces

3、s 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

4、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。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

5、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EDB

6、MS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

7、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。1.1 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。

8、1.2 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

9、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。1.3 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。1.4 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。1.5 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

10、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 4.1.1， 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。2.1 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3.0的环境下用GUL ECAD-E

11、DBMS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

12、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

13、面工具。ECAD-EDBMS为引擎设计师提供了极其方便的综合环境。2.2 多媒体支持的环境在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

14、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。2.3 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 Databas

15、e Management SystemAbstract : 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 ma

16、ny subsystems of ECAD and engine designers. So it improves the design efficiency.Key words : database management systems; multimedia technology; engineering CADIn recent years, the multimedia technology is developing fast. With the help of friendly user interface, engineering designers can manage an

17、d 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, trai

18、ning, 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 o

19、f 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 i

20、n 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 d

21、iscusses 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 s

22、ystem (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

23、 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, t

24、he 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 inc

25、luding 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 w

26、orkstation 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

27、 shown in Fig.1.EDBMS should meet the requirement as follows.1.1 Requirement for Integrated Management of Graphics and Engineering DataEvery 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

28、 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.1.2 Req

29、uirement for ImagesWhen 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 t

30、echnical 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

31、 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 drawi

32、ngs 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 c

33、omputers with pick up cameras in the compressed files. Designers can look up these image files when making decision of selecting solid model.1.3 Requirements for SoundSome sound records of evaluating meetings and speaks of specialists and statements of design experience and product introduction audi

34、o tapes can also be input to computer disk. So designers can replay these audio files for reference.1.4 Requirements for videoSome 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 equipp

35、ed with the engines on different roads and sloping fields.1.5 Requirements for AnimationsThe 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 IMPLEMENTATIONSome p

36、roblems mentioned above have been solved and remain requirements will be realized. Our development environment is SUN SPARC station running SUNOS 4.1.1, ORACLE RDBMS and universal mechanical CAD system which provides powerful functions in 2D and 3D graphics processing. The SUN system is in an Ethern

37、et network including microcomputers. The network software is NFS and PC-NFS.2.1 Integrated Processing Graphics and Engineering DataBased on ORACLE RDBMS and universal mechanical CAD system, we developed the ECAD-DEBMS which links up these two software systems in the open window 3.0 environment using

38、 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

39、processing program works in another window which is divided into three subwindows (e.g. 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 r

40、etrieve 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 file and then moves to the graphics window easily to pre

41、ss the icon desired on the iconsmenu, and the corresponding graphics program uses the medium file to 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 pa

42、ge 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 u

43、sing 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

44、the uniform manner. The ECAD-EDBMS provides the extreme convenience and the integrated environment for engine designers.2.2 Environment Supported by the MultimediaOn SUN work station there are the sound interface and processing software, so the sound information can be easily I/O when the designers

45、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.

46、 A special subdirectory of SUN station is mounted on PC as a logic disk (e.g. G disk), the video file name is passed to PC with a file (so called a postbox) in the logic disk. The display program starts replay with the passed video file name. The format of scanned image files must be translated to t

47、he SUNs 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.2.3 Displaying AnimationTo display the animation of the general layout of the engine

48、 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 CONCLUSIONThe 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.