基于VRML的虚拟实验室框架的研究
摘要
在现代教育中，实验教学占有非常重要的地位。它是教学活动中一个必不可少的过程，尤其是那些实践性较强的学科，同时实验对于培养学生的实际操作能力、创新能力和解决问题的能力也是至关重要的。随着计算机网络技术、多媒体技术和VRML技术的快速发展，特别是远程教育的蓬勃发展，有力地推动了网上虚拟实验及虚拟实验室的发展。
本课题首先阐述了国内外虚拟实验及虚拟实验室的发展，计算机辅助教学的发展及远程教学的发展和应用情况。接着研究了构建虚拟实验室的几种可行方案，着重讨论了基于VRML技术的实现方法，并引出采用此方案的特殊意义。结合当前信息网络技术的实际应用情况，并参考了前人在这方面的经验，提出了应用VRML技术来实现网络虚拟实验室框架的具体方案。在此框架基础上利用VRML、EAI和Java的有机结合实现了对车床基本车削加工方式的虚拟。利用ASP网页技术编写使用者界面与网站管理者界面，并结合Access数据库服务器管理网站资料。在这个虚拟实验室框架平台上，异地的实验者可以通过Internet/Intranet远程访问，完成车床一些车削加工操作实验，基本上达到了远程/本地实验教学的要求。
本课题对以下几个方面作了详尽的探讨：1）应用VRML技术，并巧妙地结合3DS MAX强大功能，对车床及工件进行了3D模型的设计。由于VRML的跨平台性及多种常用浏览器的支持，为满足各种不同的实验用户奠定了坚实的基础；2）研究了用户和VRML世界的交互方法。VRML可以在浏览器环境中为3D实验台模型添加多种感知器，能够良好地感知操作者的各种意图。在VRML和Java技术的接口中，可以利用Java程序代码来完成一些复杂的任务，从而实现了用户与实验的交互。实验者感知实验台的各种仪器，程序完成相应的任务，然后返回相应的结果；3）仔细研究了车床车削加工方式的原理，对车床加工方式建立了相关的3D模型，并实现了动态仿真。4）实验台远程访问的实现。运用VRML和Java语言的跨平台性，特别是Java语言的字节码无需重新编译这一特性，实现了远程的用户可以通过Internet/Intranet在本地浏览器上直接访问。
最后对本课题的发展作了一个总结与展望，本课题所完成只是虚拟实验室的一个基本框架，实现了部分功能。还有一些方面，特别是在协同实验方面有待于深入的研究。
Nowadays, experimental learning and teaching is playing a very important role in modern education. It is an absolutely necessary procedure in education, especially for some practical courses. And it's very important for a student to improve his/her capability of analyzing, innovating and solving problems. The rapid development of the technology of network, multimedia and VRML, especially the distance education, accelerates the step of virtual experiment and virtual laboratory on the Internet.
The first part of this thesis recapitulates the development and application of virtual experiment and virtual laboratory, computer aided construction and distance education at home and abroad. The second part of this paper studies several available projects that establish virtual experiment and virtual laboratory, discusses the method which based on the VRML and puts forward my own project on the virtual experiment based on VRML, referred to other experience in this field. Based on the framework, this paper puts the cutting ways of the lathe into effect, combined VRML, EAI and Java program. And then this paper uses the ASP to develop user's and master's homepages and combines MS Access database to manager the website data. In this virtual laboratory framework, the remote operators can do their experiment through the Internet/Intranet.
This paper makes much detailed study on the follows: 1) With the aid of VRML, combining functions of 3DS MAX, I design a 3D model of the cutting experiment. Due to VRML's compatibility of multisystem and support of multiple browsers, this model can be visited in different users who are in different places. 2) Detailedly study the alteration between operators and the virtual world. Various sensors of operators' behaviors; Java byte codes that are besotted in the interface between VRML and Java through the "script" node can finish difficult tasks. So the alteration can be concluded as follows: Operators touch parts of the shelf, and the Java byte codes execute the relative function, finally results are reported to the operators. 3) Through detailedly studying the working function of the basic cutting ways of the lathe, I construct a 3D model of the lathe and simulate the basic cutting ways of the lathe. 4) Realizing the remote visit through Internet/Intranet. Because VRML and Java are both across operation systems, especially with the compatibility of Java byte codes, the remote users can directly visit the virtual experiment. In one sense, it's just like a 3D website.
At last, a summary and a prospect of this thesis are given. This paper only accomplishes the basic framework of the virtual laboratory and a part of functions. And further researches are also prospected, especially in concurrent working.
本课题首先阐述了国内外虚拟实验及虚拟实验室的发展，计算机辅助教学的发展及远程教学的发展和应用情况。接着研究了构建虚拟实验室的几种可行方案，着重讨论了基于VRML技术的实现方法，并引出采用此方案的特殊意义。结合当前信息网络技术的实际应用情况，并参考了前人在这方面的经验，提出了应用VRML技术来实现网络虚拟实验室框架的具体方案。在此框架基础上利用VRML、EAI和Java的有机结合实现了对车床基本车削加工方式的虚拟。利用ASP网页技术编写使用者界面与网站管理者界面，并结合Access数据库服务器管理网站资料。在这个虚拟实验室框架平台上，异地的实验者可以通过Internet/Intranet远程访问，完成车床一些车削加工操作实验，基本上达到了远程/本地实验教学的要求。
本课题对以下几个方面作了详尽的探讨：1）应用VRML技术，并巧妙地结合3DS MAX强大功能，对车床及工件进行了3D模型的设计。由于VRML的跨平台性及多种常用浏览器的支持，为满足各种不同的实验用户奠定了坚实的基础；2）研究了用户和VRML世界的交互方法。VRML可以在浏览器环境中为3D实验台模型添加多种感知器，能够良好地感知操作者的各种意图。在VRML和Java技术的接口中，可以利用Java程序代码来完成一些复杂的任务，从而实现了用户与实验的交互。实验者感知实验台的各种仪器，程序完成相应的任务，然后返回相应的结果；3）仔细研究了车床车削加工方式的原理，对车床加工方式建立了相关的3D模型，并实现了动态仿真。4）实验台远程访问的实现。运用VRML和Java语言的跨平台性，特别是Java语言的字节码无需重新编译这一特性，实现了远程的用户可以通过Internet/Intranet在本地浏览器上直接访问。
最后对本课题的发展作了一个总结与展望，本课题所完成只是虚拟实验室的一个基本框架，实现了部分功能。还有一些方面，特别是在协同实验方面有待于深入的研究。
Nowadays, experimental learning and teaching is playing a very important role in modern education. It is an absolutely necessary procedure in education, especially for some practical courses. And it's very important for a student to improve his/her capability of analyzing, innovating and solving problems. The rapid development of the technology of network, multimedia and VRML, especially the distance education, accelerates the step of virtual experiment and virtual laboratory on the Internet.
The first part of this thesis recapitulates the development and application of virtual experiment and virtual laboratory, computer aided construction and distance education at home and abroad. The second part of this paper studies several available projects that establish virtual experiment and virtual laboratory, discusses the method which based on the VRML and puts forward my own project on the virtual experiment based on VRML, referred to other experience in this field. Based on the framework, this paper puts the cutting ways of the lathe into effect, combined VRML, EAI and Java program. And then this paper uses the ASP to develop user's and master's homepages and combines MS Access database to manager the website data. In this virtual laboratory framework, the remote operators can do their experiment through the Internet/Intranet.
This paper makes much detailed study on the follows: 1) With the aid of VRML, combining functions of 3DS MAX, I design a 3D model of the cutting experiment. Due to VRML's compatibility of multisystem and support of multiple browsers, this model can be visited in different users who are in different places. 2) Detailedly study the alteration between operators and the virtual world. Various sensors of operators' behaviors; Java byte codes that are besotted in the interface between VRML and Java through the "script" node can finish difficult tasks. So the alteration can be concluded as follows: Operators touch parts of the shelf, and the Java byte codes execute the relative function, finally results are reported to the operators. 3) Through detailedly studying the working function of the basic cutting ways of the lathe, I construct a 3D model of the lathe and simulate the basic cutting ways of the lathe. 4) Realizing the remote visit through Internet/Intranet. Because VRML and Java are both across operation systems, especially with the compatibility of Java byte codes, the remote users can directly visit the virtual experiment. In one sense, it's just like a 3D website.
At last, a summary and a prospect of this thesis are given. This paper only accomplishes the basic framework of the virtual laboratory and a part of functions. And further researches are also prospected, especially in concurrent working.
引文
1．Cortona VRML Client, http://www.parallelgraphics.com/products/cortona
2．Apkarian, J., and Dawes, A, Interactive control education with virtual presence on the web, Proceedings of American Control Conference, 2000, Volume:6, 3985-3990
3．Dongil Shin, En Sup Yoon, Sang Jin Park, and Euy Soo Lee. Web-based interactive virtual laboratory system for unit operations and process systems engineering education, Computers and Chemical Engineering, 2000, Volume:24, 1381-1385
4．Internation Organization for Standardization, The Virtual Reality Modeling Language, April 1997. ISO/IEC DIS 14772-1, http://www.vrml.org/Specifications/VRML97/DIS/.
5．Proposal for a VRML 2.0 Informative Annex—External Authoring Interface Reference. http://www.marrin.com/vrml/Interface.html.
6．The Virtual Reality Modeling Language Annex B—Java platform scripting reference. http://www.vrml.org/Specifications/VRML97/part1/java.html
7．J.Hartman and J.Werneckd, The VRML2.0 Handbook, Addison-Welsey Developers Press, Reading, Mass., 1996. http://vrml.sgi.com/handbook/index.html.
8．Song You Tianmiao Wang Roy Eagleson etc.，A low-cost internet-based telerobotic system for access to remote laboratories，Artificial Intelligence In Engineering, 15（2001）265-279
9．H．Afsarmanesh E.C. Kaletas A.Benabdelkader，etc.，A lreference architecture for scientific virtual laboratories, Future Generation Computer systems 17（2001）999-1008
10．Dhruv Khettry Xian-He Sun, A Windows-NT virtual collaboratory for technical computing, Advances in engineering software 31（2000）717-722
11．Akira Suzuki Masao Kamiko Roichi Yamaoto，etc.，Molecular simulations in the virtual material laboratory, Computational Materials Science 14（1999）227-231
12．Renee M. Wachter Jatinder N.D. Gupta Mohammed A. Quaddus, IT takes a villager：Virtual communities in support of education, International Journal of Information Management 20（2000）473-489
13．Deanna Raineri, Virtual laboratories enhance traditional undergraduate biology laboratories, Biochemistry and Molecular Biology Education 29（2001）160-162
14．Dongil shin, En Sup Yoon, Sang Jin Park，etc.，Web-based interactive virtual laboratory system for unit operations and process systems engineering education, Computers and Chemical Engineering 24（2000）1381-1385
15．Architechture, Pratitioners grade the schools, Architechture 85（8）,1996,90-91
16．郭焱 李保国，虚拟植物的演技进展，科学通报。46（4），273-280
17．林海。浏览器/服务器应用开发。科学出版社，2000
18．浏览器/服务器应用模式。http://www.browser-server.com/compare.html
19．李文定。Intranet理论与务实。清华大学出版社，1998
20．康博。Web应用程序开发新技术。人民邮电出版社，1999
21．张杰。VRML2.0交互式三维图形编程。汕头大学出版社，1999
22．施寅，周葆芳。虚拟现实造型语言及应用。计算机辅助设计与图形学学报，1998：450-456
23．Ablan Jerry。用Java开发Intranet应用。机械工业出版社，1997
24．Schmuller Joseph。ActiveX轻松进阶。电子工业出版社，1998
25．Kate Gregory。CGI程序设计自学通。机械工业出版社，1998
26．武苍林。Web技术发展综述。电脑与信息技术，2000，2：48-50
27．蒋韬，秦扬 等。Internet/Intranet应用系统开发平台的研究与实现。小型微型计算机系统，2000，21（1）：28-31
28．张杰。VRML2.0交互式三维图形编程。汕头大学出版社，1999
29．李 亚，王 录 等。基于Internet 的远程虚拟实验室系统的开发。微型电脑应用，2001，17（8）
30．陆正兴。虚拟实验室，物理实验，2000，20（9）：41-42
31．周世雄，IIS4.0超级网站速成。青岛出版社，1999
32．蒋琴仙。用CAI课件实现虚拟实验。实验室研究与探索，2001，20（3）：18-19
33．王晓蒲 等。大学物理虚拟实验的网络教学系统。物理实验，2001，21（5）：19-22
34．阳化冰，刘忠丽 等。虚拟现实构造语言VRML。北京航空航天大学出版社，2000
35．汪兴谦，牛燕明 等。VRML与Java编程实例讲解。中国水利水电出版社，2001
36．赛博科技工作室。VRML与Java编程技术。人民邮电出版社，2001
37．http://sunsite.net.edu.cn/java-con/distantlab_ia_hust/
38．http://www.hust.edu.cn/lab/image/
39．江春华，蔡洪斌。Java程序设计基础与提高。电子科技大学出版社，1998
40．汪辰，廖文和。基于实体的数控车削动态仿真技术的研究与实现。计算机辅助设计与制造，2000（12）：30-32
41．王启义，葛研军 等。基于虚拟制造的数控车削加工仿真技术。大连铁道学院学报，2000，21（3）：49-55
42．夏德荣，贺锡生 等。金工实习。东南大学出版社，2001
43．殷志介。金属切削机床。西北电讯工程学院出版社，1984
44．北京市《金属切削理论与实践》编委会。金属切削理论与实践，上、中册。北京出版社，1985
45．李加种。金属切削动力学。浙江大学出版社，1993
46．黄向红。实验室改革与虚拟实验室探讨。实验室研究与探索，2000,19（6）：70-72
47．彭礼孝，梁乔 等。3D Studio MAX R3建模基础教程。北京希望电子出版社，2000
48．张秀山，徐荣花 等。虚拟现实技术及编程技巧。国防科技大学出版社，1999
49．[美]Bill Brogden。Java开指南—Servlets和JSP篇。电子工业出版社，2001
50．孙丽君，吴红普。ASP编程基础及应用实例集锦。人民邮电出版社，2001
51．机械工程手册编辑委员会。机械工程手册（第八卷机械制造工艺（二））。机械工业出版社，1982
2．Apkarian, J., and Dawes, A, Interactive control education with virtual presence on the web, Proceedings of American Control Conference, 2000, Volume:6, 3985-3990
3．Dongil Shin, En Sup Yoon, Sang Jin Park, and Euy Soo Lee. Web-based interactive virtual laboratory system for unit operations and process systems engineering education, Computers and Chemical Engineering, 2000, Volume:24, 1381-1385
4．Internation Organization for Standardization, The Virtual Reality Modeling Language, April 1997. ISO/IEC DIS 14772-1, http://www.vrml.org/Specifications/VRML97/DIS/.
5．Proposal for a VRML 2.0 Informative Annex—External Authoring Interface Reference. http://www.marrin.com/vrml/Interface.html.
6．The Virtual Reality Modeling Language Annex B—Java platform scripting reference. http://www.vrml.org/Specifications/VRML97/part1/java.html
7．J.Hartman and J.Werneckd, The VRML2.0 Handbook, Addison-Welsey Developers Press, Reading, Mass., 1996. http://vrml.sgi.com/handbook/index.html.
8．Song You Tianmiao Wang Roy Eagleson etc.，A low-cost internet-based telerobotic system for access to remote laboratories，Artificial Intelligence In Engineering, 15（2001）265-279
9．H．Afsarmanesh E.C. Kaletas A.Benabdelkader，etc.，A lreference architecture for scientific virtual laboratories, Future Generation Computer systems 17（2001）999-1008
10．Dhruv Khettry Xian-He Sun, A Windows-NT virtual collaboratory for technical computing, Advances in engineering software 31（2000）717-722
11．Akira Suzuki Masao Kamiko Roichi Yamaoto，etc.，Molecular simulations in the virtual material laboratory, Computational Materials Science 14（1999）227-231
12．Renee M. Wachter Jatinder N.D. Gupta Mohammed A. Quaddus, IT takes a villager：Virtual communities in support of education, International Journal of Information Management 20（2000）473-489
13．Deanna Raineri, Virtual laboratories enhance traditional undergraduate biology laboratories, Biochemistry and Molecular Biology Education 29（2001）160-162
14．Dongil shin, En Sup Yoon, Sang Jin Park，etc.，Web-based interactive virtual laboratory system for unit operations and process systems engineering education, Computers and Chemical Engineering 24（2000）1381-1385
15．Architechture, Pratitioners grade the schools, Architechture 85（8）,1996,90-91
16．郭焱 李保国，虚拟植物的演技进展，科学通报。46（4），273-280
17．林海。浏览器/服务器应用开发。科学出版社，2000
18．浏览器/服务器应用模式。http://www.browser-server.com/compare.html
19．李文定。Intranet理论与务实。清华大学出版社，1998
20．康博。Web应用程序开发新技术。人民邮电出版社，1999
21．张杰。VRML2.0交互式三维图形编程。汕头大学出版社，1999
22．施寅，周葆芳。虚拟现实造型语言及应用。计算机辅助设计与图形学学报，1998：450-456
23．Ablan Jerry。用Java开发Intranet应用。机械工业出版社，1997
24．Schmuller Joseph。ActiveX轻松进阶。电子工业出版社，1998
25．Kate Gregory。CGI程序设计自学通。机械工业出版社，1998
26．武苍林。Web技术发展综述。电脑与信息技术，2000，2：48-50
27．蒋韬，秦扬 等。Internet/Intranet应用系统开发平台的研究与实现。小型微型计算机系统，2000，21（1）：28-31
28．张杰。VRML2.0交互式三维图形编程。汕头大学出版社，1999
29．李 亚，王 录 等。基于Internet 的远程虚拟实验室系统的开发。微型电脑应用，2001，17（8）
30．陆正兴。虚拟实验室，物理实验，2000，20（9）：41-42
31．周世雄，IIS4.0超级网站速成。青岛出版社，1999
32．蒋琴仙。用CAI课件实现虚拟实验。实验室研究与探索，2001，20（3）：18-19
33．王晓蒲 等。大学物理虚拟实验的网络教学系统。物理实验，2001，21（5）：19-22
34．阳化冰，刘忠丽 等。虚拟现实构造语言VRML。北京航空航天大学出版社，2000
35．汪兴谦，牛燕明 等。VRML与Java编程实例讲解。中国水利水电出版社，2001
36．赛博科技工作室。VRML与Java编程技术。人民邮电出版社，2001
37．http://sunsite.net.edu.cn/java-con/distantlab_ia_hust/
38．http://www.hust.edu.cn/lab/image/
39．江春华，蔡洪斌。Java程序设计基础与提高。电子科技大学出版社，1998
40．汪辰，廖文和。基于实体的数控车削动态仿真技术的研究与实现。计算机辅助设计与制造，2000（12）：30-32
41．王启义，葛研军 等。基于虚拟制造的数控车削加工仿真技术。大连铁道学院学报，2000，21（3）：49-55
42．夏德荣，贺锡生 等。金工实习。东南大学出版社，2001
43．殷志介。金属切削机床。西北电讯工程学院出版社，1984
44．北京市《金属切削理论与实践》编委会。金属切削理论与实践，上、中册。北京出版社，1985
45．李加种。金属切削动力学。浙江大学出版社，1993
46．黄向红。实验室改革与虚拟实验室探讨。实验室研究与探索，2000,19（6）：70-72
47．彭礼孝，梁乔 等。3D Studio MAX R3建模基础教程。北京希望电子出版社，2000
48．张秀山，徐荣花 等。虚拟现实技术及编程技巧。国防科技大学出版社，1999
49．[美]Bill Brogden。Java开指南—Servlets和JSP篇。电子工业出版社，2001
50．孙丽君，吴红普。ASP编程基础及应用实例集锦。人民邮电出版社，2001
51．机械工程手册编辑委员会。机械工程手册（第八卷机械制造工艺（二））。机械工业出版社，1982
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