Proceedings of DETC'01 Proceedings DETC’01 ASME 2001 Design Engineering Technical of Conference ASME 2001 Design Engineering Technical Conferences and Computers and and Computers and Information in Engineering Conference Information in Engineering Conference Pittsburgh, PA, September 9-12, 2001 Pittsburgh, Pennsylvania, September 9-12, 2001
DETC2001/VIB-21648
DETC2001/VIB-21648 WEB AND VIRTUAL INSTRUMENT BASED MACHINE REMOTE SENSING, MONITORING AND FAULT DIAGNOSTIC SYSTEM Peter W. Tse, Ling S. He Smart Asset Management Research Laboratory Department of Manufacturing Engineering and Engineering Management City University of Hong Kong, Tat Chee Ave., Hong Kong, P. R. China e-mail:
[email protected]
ABSTRACT Failure of equipment not only leads to loss of production, but also, in some serious situations, causes human casualty. Hence, the need of equipment condition monitoring becomes crucial for reliable operations. Since expensive hardware instruments are needed for condition monitoring, with the current powerful PCs, software based virtual instruments are possible to replace hardware instruments. However, the software must be maintained for each PC, and a technician must still visit the site of the PC and its monitored equipment. By connecting the PC to the Internet, remote sensing and equipment fault diagnosing are possible. As only one copy of software for each type of virtual instrument is required on the server, the maintenance of virtual instrument is much easier and substantial cost of hardware instruments is reduced. Moreover, remote collaborative maintenance becomes feasible as worldwide experts can provide just-in-time advice to technicians via the Web. With the new standards of IEEE 1451.2 for smart transducers, the new sensors are self-Web-ready. Sensor manufacturers, such as Hewlett Packard and Bruel & Kjaer, have proclaimed their next generation sensors are self-Web-ready. Therefore, the development of a Web-based maintenance is a must in the near future. This paper presents the design and development of a solution and a platform for the Web-based remote collaborative diagnosis and maintenance. It consists of remote data sensing and logging, signal analysis using virtual instruments, and intelligent fault diagnosis and prognosis.
stations, chemical plants, trains, HVAC systems in large commercial buildings, production machines in factories etc. Operational failures of the equipment not only leading to loss of production, but also, in some serious situations, causing human casualty. Recently, vibration based condition monitoring has become popular as the operating condition of equipment is being monitored continuously so that any abnormality occurring in the equipment can be detected. However, condition monitoring normally involves expensive instruments for signal processing and analyzing. As illustrated in Figure 1, each machine or each group of machines requires a set of instruments. For a company that has a lot of machines, the cost of instruments for condition monitoring is tremendous and unaffordable. Machines
KEYWORDS: Web-based Asset Management, e-Maintenance, Virtual Instruments, Remote Signal Processing.
Sensors
Analyzers (hardware)
Results
Fig. 1 Hardware based equipment condition monitoring requires intensive instrumentation.
1.
INTRODUCTION Reliable working of various kinds of equipment is crucial to the daily operations of most companies, especially for power
With the ever-improving power of PCs, it is possible to replace the hardware type instruments with software type virtual instruments (VI). Since VI can be as low as 1/10 of the cost of 1
Copyright © 2001 by ASME
features extraction and analysis, are also implemented using Java. Therefore, the VIs can be operated as browser applets in a multi-users environment. Moreover, a collaborative platform for intelligent fault diagnosis by using the active server pages (ASP) and the Web database has also been designed. With the help of the collaborative platform, worldwide experts can simultaneously participate in the processes of equipment fault diagnosis and prognosis so that they can discuss and share their valuable experience in maintenance on-line.
hardware instruments, substantial saving can be obtained by minimizing the need of hardware instruments. Although VI is cost-effective, the software of VI must be maintained for each PC installed with the monitored machine. Hence, the task of upgrading the software in each PC becomes tedious. By connecting the machine monitoring PC to an intranet or the Internet as shown in Figure 2, it is possible to remotely monitor the machine status from a central location costeffectively. Further, as the software of VI is implemented as a browser applet, there is no software to be maintained at each machine PC but only the one stored on the server. Also, worldwide experts can advise on machine condition if the monitoring information is available via the Internet. Therefore, the machine operators can obtain just-in-time technical supports from the experts of equipment suppliers, and improve the reliability of equipment. In this proposal, a Web-based remote sensing, monitoring and machine fault diagnostic system using VI is introduced to replace the current hardware based condition monitoring systems. Note that this Web-based system is different from other Websites where the benefits are dependent upon the vagrant number of sales transaction and advertisement. Actual benefits come from the substantial saving on instrument costs, remote monitoring, instantaneous fault detection, and worldwide collaborative maintenance. This, coupled with the future sensors which will be Ethernet integrated and Web ready [1] (IEEE standard 1451.2 [2]), the Web-based remote sensing, fault diagnosing and collaborative maintenance is not a future concept, but rather, it is a must for today’s research and development. Machines
2.
THE CURRENT TRENDS OF WEB-BASED MAINTENANCE AND DIAGNOSIS The world-wide-web (Web) enables universal access by having platform independent connectivity using open common standards for publishing (HTML, XML), messaging (HTTP), and networking (TCP/IP) [3]. The Web also enables multimedia support, interactivity and extensibility [4]. Having open and extensible design features, the Web can include new forms of content and media seamlessly [5]. Browser plug-ins can handle new data types, and Java applets can be downloaded and run on any browser. High bandwidth multi-media real-time applications make collaborative virtual immersion, such as instance virtual instrumentation with multi-users, possible [6]. Developments in database and object technologies, such as CORBA, IIOP and component-ware concepts, enable organizations to connect via user-friendly Web interfaces to back-end databases and legacy applications [7]. All these features make the Web the key enabler for future technology advancement, particularly for remote sensing and collaborative diagnosis. The concept of Web-based remote and collaborative diagnosis was initially proposed for medical care in 1988 so that people or small clinics located in rural area can obtain instantaneous consultations from specialists located in urban hospitals [8]. An ideal telemedicine system should include video conferencing, remote measurements as real-time as possible, remote medical diagnosis, medicine information services and supporting collaborative consultations from experts situated in different places [9]. Based on these initiatives, a Web-based medical diagnostic system has been developed by IOWA University. It links 54 small clinics in rural area to an urban central hospital and supports the necessary medical services to these clinics via the Internet [10]. Stefano et al. [11] used a similar concept for industry. They have developed a distributed system for distance monitoring and control of industrial plants. Lee [12] has laid out the framework on remote diagnostics and maintenance for manufacturing equipment and it has become a standard for others to follow. The first workshop on Internet based remote diagnosis for industry was organised by Stanford University and MIT, and held in January 1997. A Website has been established by these two Universities for testing the feasibility in applying to industry [13]. Similar work has also been accomplished by a group of researchers at Michigan University [14]. However, they are more concerned with system reliability and its evaluation method. To facilitate future expansion on Internet based remote measurement, the standard of smart transducers - IEEE 1451.2 has been formulated for the design of next generation Web ready sensors [2]. Research on the development of the Web ready sensor, which allows direct
PC-based Virtual Instruments
Via Internet
Fig. 2 Web-based monitoring system has only one copy of virtual instrument installed on the server. Due to the strong demands from industry, a system for the Web-based smart asset management and maintenance has been designed and implemented. The functions of the system include remote data sensing and logging, signal analysis using VI, and collaborative equipment fault diagnosis and prognosis. Through the use of the Internet or intranet, the system can remotely collect data from various sensors and adaptive to future Webready plug-and-play sensors that are designed according to the IEEE standards 1451.2. A variety of software based VIs, which are commonly used for signal processing and fault related
2
Copyright © 2001 by ASME
Therefore, the Web-based system can be built on these concrete foundations.
plug and play on the Internet without the need of connecting to a PC and having a separate Ethernet card, will be progressing aggressively [15]. Sensor manufacturers, such as Hewlett Packard and Bruel & Kjaer, have already proclaimed that their new directions on designing sensors are based on the Web ready sensor [1, 16]. Hence, the deployment of a Web-based maintenance system is not a trendy research but a must for the competitiveness in the near future. With the help of these Web ready sensors, distributive systems that enable the monitoring and control of a variety of machines located in various premises become feasible [17]. However, without the support of a reliable operating system, especially working in the Web environment, the uses of browser based VI and the Web ready sensor are in vain. An eligible operating system must support Web-based distributive computing, be reliable and friendly to servers, capable of coping with a variety of development tools for browser applets, and multi-tasking [18]. The programming language used for the design of VI in this project is Java as it is by far the most popular and can be included directly in HTML documents [19]. Successful applications on monitoring and control of equipment for industry automation have been written using Java [20, 21]. Today, the biggest advancement of database in Web environment is the development of the Internet Database Connector (IDC) and the Active Server Pages (ASP) [22]. The IDC allows the connection of a Web page to any Open Database Connectivity (OBDC) compliant database accessible to the Web server machine. The ASP helps the access of the database installed in a server being faster and requires less memory [23]. The architecture of a Web-based knowledge database has been proposed [24], and a knowledge-based expert system has been applied to medical care [25]. All these works show that the technology and support for building a Web-based maintenance system are feasible and mature. However, most of the works have been developed for medical care, with very little work and research being devoted to maintenance that is vital and one of the highest cost operations in the industry. Although comprehensive logistics and strategies on Internet-based intelligent e-maintenance have been drafted by Lee et al. [26], no workable system has been shown on the Web site for industrial use or even for demonstration purposes. Today, there is no research that combines all three important aspects of a Web-based maintenance system, namely the remote data acquisition and feature extraction, the signal processing and analysing using VI, and the collaborative and intelligent fault diagnosis and prognosis, together as a stand-alone, selfembedded system. With strong demands from future advancements in maintenance and the inevitable development of Web ready smart sensors, therefore, we have developed the Web-based remote sensing, fault diagnosing and collaborative maintenance system.
3.1 Effective Equipment Condition Monitoring and Fault Diagnosis The field of equipment fault diagnosis has developed in response to the demands of modern industry which has been concerned with such aspects as human safety, economic productivity and effectiveness. Machine fault diagnosis refers to the process of identifying a machine’s operating condition and investigating its possible source of fault. This is usually done in a way similar to medical diagnosis: observe symptoms by sensing and analyzing signals in such forms as cutting forces, vibrations, and acoustics, and relate them to the inherent conditions of the machine. Good diagnosis systems can provide managers and operators with information to determine accurate fault locations quickly. To ensure that the fault diagnostic system is both automatic and reliable, we have developed an intelligent fault diagnostic system which is using the Learning Vector Quantization neural networks and the innovative theory of harmony to enhance the robustness in fault diagnosis [27]. Moreover, we have also designed different types of wavelet transforms especially suitable for denoising the raw signals and extracting defects related impulsive signals directly from machine operating sound. With the help of this smart sensor, intensive analyses, which usually require expensive hardware type of instruments, are not necessary [28]. Therefore, substantial instrumentation cost and analyzing time can be reduced. Both effective methods have been implemented as VIs and are ready for the Web-based system. 3.2 Intelligent Equipment Condition Prognosis A comprehensive intelligent machine condition monitoring system should not limit its abilities to fault detection and diagnosis only, but should also be capable of identifying the seriousness of any damage, predicting the remaining life span of a defective machine, and to advising the operator. Therefore, the operator can schedule repairs at a time which will cause minimum interruption to production and prior to a fatal breakdown of machine. We have developed an intelligent system for forecasting the deterioration rate of a variety of equipment by using recurrent neural networks [29]. Equipped with this intelligent prognostic system, the current trend of fault related temporal symptoms can be used to determine the near future operating states of the machine. If the symptom shows signs of deterioration, the system will automatically predict the remaining life span of the machines and trigger early warnings to the operator. Therefore, the maintenance manager can preschedule the necessary remedies in advance to prevent shortages of manpower and resources. He can also order the spare parts just-in-time to avoid overstock of inventory. Such an intelligent equipment prognostic system can also be implemented using software based VI and be Web ready. More detailed descriptions of the above work can be found on the author’s Website: http://personal.cityu.edu.hk/~meptse, under the category of research as shown in Figure 3.
3.
PREPARATION FOR THE DESIGN OF THE WEBBASED SYSTEM Prior to the establishment of the Web-based asset management and maintenance system, reliable and effective methods must be developed in the fields of equipment condition monitoring, fault diagnosis, and equipment life span prediction.
3
Copyright © 2001 by ASME
4.
THE ARCHITECTURE OF THE WEB-BASED ASSET MANAGEMENT SYSTEM As defined by Lee [26] in the future strategies for advanced maintenance, the vision of an intelligent maintenance system is to bring about innovations on intelligent degradation assessment methodologies for equipment failure prevention as well as to develop advanced Web-based maintenance devices and service technologies to enable manufacturers and customers to have products, production line, and utility equipment with near-zerobreakdown conditions. Based on the above vision, the architecture of the Web-based asset management system has been designed according to the following three tasks.
Fig. 4 The network of the equipment remote sensing and monitoring system. With the support of multi-media, the operating conditions of a machine can be monitored via the Internet as illustrated in Figure 5. If any malfunction occurs, the censuring server will send an alarm message attached to the video or the monitoring signals so that the remotely located engineer can be alerted and then prepare for remedy.
Fig. 3 The author’s Website with demonstrations on the current research work.
Fig. 5 Web-camera and recorder for remote equipment monitoring.
4.1 Design of a Web-based Remote Sensing and Monitoring System The design of a Web-based remote equipment sensing and monitoring system should include sensor interface devices; equipment monitoring techniques; e-compatible wireless communications & networking technologies; and a variety of popular NetWare. With ever processing development in IT techniques, it is possible to use the embedded computer and the embedded operation system to perform data acquisition and send data via the Internet/intranet. A Web-based platform can be implemented using PC, A/D card, Ethernet card and the embedded Windows NT operation system. Another possibility is using the Linux based operating system because of its free distribution, reliable, able to cope with a variety of development tools, and is multi-tasking [30]. A mini Web server program has been written on the Web platform to receive commands and transmit data via the Internet/intranet. The functions for data acquisition and condition monitoring have been integrated into the mini Web server. Thus, the server can receive commands from a user’s browser, and then perform data acquisition accordingly. Figure 4 shows a scheme of network for the remote sensing and monitoring.
The system has two layers of client/server structure as shown in Figures 6a and 6b. In Figure 6a, the first layer composes of browser/www server. Its role is to receive users’ commands, then send the desired results back to the users after performing some signal processing or data analysis, and display the results on the users’ stations.
Fig. 6a Layer of www browser/server for data communication. In Figure 6b, the second layer composes of DDE client/server. Its role is to perform the desired analyses according to the users' requests, control the Web traffic, and 4
Copyright © 2001 by ASME
comparison and phase measurements. Moreover, it is capable of analysing the data using WT and performing statistical analyses, such as RMS value, form factor, crest factor, and kurtosis as illustrated in Figure 7b. At present, there is no existing standalone hardware type of analyser that has so many functions and able to analyse signals using both FFT and WT yet. Because the virtual analyser is so versatile, much cheaper to implement, and easier to modify, we have been convinced that the concept of VI will be definitely welcome by the industry. The virtual analyser has proven to be able to capture the vibro-acoustic signals generated from a monitored machine in near real-time, and detect the faulty signals. Based on this successful experiment, other types of expensive instruments required for fault diagnosis can be also implemented using the similar concept. Since there are many different types of machines needing to be monitored. Each of them may use different methods for signal analysis and fault diagnosis. Hence, these require different kinds of VI interfaces. Each kind of VI may have a signal processing library of Java, a group of controls and functions, a facility for display, storage and retrieval of data, a variety of analyses related to this instrument, and iconic developing platform using Java. It is impossible to store all kinds of VIs with multi-copies on the local PCs as it is costly to implement and difficult to upgrade each version of VI installed on each local PC.
return the analysed results to users via the Internet/intranet. At present, a PC is required to be installed with the monitored machine for local data collection and transmission. In the near future, with the help of the Web-ready smart sensor, no PC is required. The smart sensor can obtain users' commands, performs automatic data acquisition according to the needs of users and return the requested data or signals to the users via the Internet/intranet.
Fig. 6b Layer for data collection and signal processing.
4.2 Design of Java Written Virtual Instruments for Fault Diagnosis Thanks to the concept of VI and ever-fast speed PC, cost effective signal processing and analysing instruments can be implemented to replace the expensive hardware-based instruments. The cost of software based VI can be as low as 1/10 of the cost of hardware instrument. For the Web-based equipment fault diagnostic system, we have built a virtual vibration-based analyser for performing both functions of fast Fourier transforms (FFT) and wavelet transforms (WT) as shown in Figures 7a and 7b respectively. The virtual analyser was developed using Java language as it is a powerful networking language and is deemed suitable for developing browser applets. The analyser can display signals collected from two different channels with different sampled frequencies and data points.
Fig. 7b The similar type of virtual analyzer can also be used to perform wavelet transforms for the detection of faults that exhibit non-stationary impulsive signals and sudden changes. With the help of the Internet based signal analysis, only one copy of each kind of VI will be stored on the server. Therefore, the maintainability of VI becomes easier. However, since the Internet is a many-to-many working environment, problems may occur if many operators or experts are using a similar type of instrument instantaneously, making the server heavily loaded. To avoid the crashing of Web traffic, we intend to transmit the required type of VI, which is stored on the server, to the remotely located computer when a request from a user has been issued. The temporary version of VI will run on the local computer and perform the necessary tasks for the user. Once the tasks have been completed, the program of VI will be deleted automatically. If the user wants to show his analysed results to other experts, and
Fig. 7a A vibration based virtual analyser that is able to perform FFT for detecting faults that exhibit stationary and periodic impulsive signals. As shown in Figure 7a, it is capable of converting the data to its power spectrum, performing averaging, zooming of spectrum, and creating a 3D waterfall spectrum. Since it is equipped with two channels, it can also perform spectrum
5
Copyright © 2001 by ASME
access by having server-side scripting and provides an open type object model, hence, database integration and accessibility becomes more powerful by using ASP. When an enquiry for data is occurring, ASP will format a Structured Query Language (SQL) based query so that a connection is created to the database. Relevant records will be extracted according to the specifications in the SQL, and then an HTML page will be dynamically created to contain the information and send it to the enquirer. Modifying and adding new contents in the database are also feasible. Moreover, ASP supports Web type ‘plug and play’, and provide high-speed access with low memory overhead and small disk footprint. All these are essences for multi-user servers. To establish a collaborative environment for fault diagnosis, the ASP has been used to design the Web platform for discussion and information sharing. Worldwide experts can use the sharing VIs to express their opinions on analyses and diagnoses. Moreover, a dynamic Web database is available to store and retrieve the aggregated results from various experts. If necessary, permission will be granted to the experts so that they can renew the rules or algorithms in the current knowledge base of the fault diagnostic expert system. Equipped with ASP and a Web database, an intelligent fault diagnosis system has also been developed on the Internet/intranet. An example of a Web-based expert system developed for this project is illustrated in Figure 9. It can collect knowledge and rules from experts via a Web-based collaborative diagnostic platform and append them to the knowledge base automatically. The user or machine operator will select the fault related symptoms from the browser and send them to the expert system in the server. The system will match the selected symptoms with the rules stated in the knowledge base and complete the inference. The diagnostic results will be returned to the user via Internet. The user can review the results and prepare the necessary remedy for the machine if a fault has been diagnosed.
requesting them to help on the analysis, then the server will run a universal version of the required VI on the Internet and share it with others. Such a separate scheme for local and universal versions of VI will ease the loading of the Web server and the traffic on the Web. 4.3 Design of Remote Collaborative and Intelligent Diagnostic Web Platform Collaboration is the process of interaction among multi participants, with inter-linked but distinct roles and specializations, working together on inter-related activities towards a common goal [5]. The existence of a Web-based collaborative diagnostic platform will enable the technical personnel to perform diagnostics interactively from a remote distance as shown in Figure 8. To establish a collaborative diagnostic Web platform for worldwide experts, we must supply a multi-tasking and multi-user platform, and a fast and easy-tomanage Web database for storing their aggregated knowledge and experiences.
Fig. 8 The architecture of the collaborative asset management platform. A successful Web-based maintenance system must have a sophisticated database and fast accessibility. The Common Gateway Interface (CGI) is popular for the preparation access applications for Web database. Web servers can launch CGI applications that allows sending and receiving of data. The inputs, data sources and outputs of CGI applications must be specifically defined. Hence, when a new feature or function is introduced, a new CGI program must be written and recompiled to replace the existing CGI application. To avoid the tedious work, the Internet Database Connector (IDC) and Active Server pages (ASP) are used here to prepare the required database. IDC is a generic database connector that thru a template and an SQL script file, it allows Open Database Connectivity (OBDC) compliant database accessible to the Web server. It accepts data from different data sources, such as relational database or text files. Using ODBC, Web developers can write applications with a database that works on any Web platform as long as it is adhering to IDC and ODBC standards. ASP allows expanded
Fig. 9 A Web-based expert system for fault diagnosis. An intelligent machine condition prognostic system (IMCPS) as also been installed on the server. The rate of
6
Copyright © 2001 by ASME
breakdown of the pump will occur and cause inevitable loss of production.
deterioration of a defective machine and the remnant life of the machine can be predicted so that the operator can arrange repairs and order spare parts just in time. A demonstration of having a defective machine with only one month running life remained is shown in Figure 10.
Fig. 12 Alert warning with special service requested by the continuously deteriorating pump.
Fig. 13 Final damage warning which may lead to fatal breakdown of pump and loss of production. Currently, the equipment remnant life prognostic system has been implemented on the Web environment. However, it has not opened to public trail yet. In the near future, after the successful completion of tests by selected industries, the IMCPS will be opened on our Website for research and public uses.
Fig. 10 The intelligent machine condition prognostic system. With the help of the IMCPS, the time for service will be determined by the current operating condition of the monitored system. For the case of a cooling water pump installed in a power generation plant, the maintenance is originally scheduled at every fourth week. Since the IMCPS finds the monitored machine will be working normally at least for another 8 weeks, hence, the IMCPS has put a green flag on the pump, meaning that the pump is working normally, and extended the next maintenance to the eighth week as shown in Figure 11.
5.
CONCLUSIONS This paper outlines a Web based asset management and maintenance system. The system is capable of remotely sensing the operating conditions of equipment and monitoring its performance. If any abnormality is occurring on the equipment, alarm will be triggered automatically. By using the concept of software based VIs, expensive hardware type of instruments can be eliminated, hence, substantial cost for instrumentations can be reduced. Moreover, if all the PCs used for monitoring the equipment are connected via the Internet/intranet, only one copy of software for each type of VI is required to be installed on the server. Therefore, the maintainability and expansibility of the VIs become easier. With the addition of collaborative diagnostic platform installed on this Web system, worldwide experts can share their experiences and provide instantaneous advice to the equipment operators. Hence, the reliability in equipment fault diagnosis and prognosis can be significantly enhanced. The current Web-based asset management and maintenance system will be opened to public for the purposes of testing and demonstration. Other types of intelligent or effective methods for asset management and maintenance, which can be implemented on the Web environment, are also welcome to be installed on our Website. Therefore, by visiting our Website, the users can simultaneously get access to new methods developed for fault diagnosis and prognosis by other researchers. They can compare the effectiveness of each method, share their opinions, link to other relevant Websites, and learn the newest trend in asset management via the Web-based interactive courses - a one stop for all.
Fig. 11 The IMCPS predicts that routine inspection is not required as the pump is operating normally. In case if the pump is defective and is deteriorated above the alert level, then a yellow warning will be stamped on the schedule of the pump as shown in Figure 12. A letter ‘S’ represents ‘special service request’ will also be issued automatically and warning the operator or manager to prepare the inspection within this week. If the pump continuous to deteriorate without repair, a brown color alarm warning or even more seriously a red damage warning will be issued by the IMCPS. As shown in Figure 13, a red damage warning has been issued. The letters ‘P ‘ and ‘O’ urge the operator to shut down the pump and perform an overhaul immediately. Otherwise, fatal 7
Copyright © 2001 by ASME
6.
ACKNOWLEDGMENT
16 Ginn B., and Bruel & Kjaer, 2000, ”Practical Applications of Intelligent Test Systems”, Proceedings of the Seventh International Congress on Sound and Vibration, 6, Germany, pp. 3221-3228. 17 Lee, K., and Schneeman, D., 1999, “Internet-Based Distributed Measurement and Control Applications”, IEEE Instrumentation & Measurement Magazine, 2(2), pp.23 – 27. 18 Bernes-Lee, T., 1996, “WWW: Past, Present, and Future,” IEEE Computer, 29(10), pp.69-77. 19 Atherton, R., 1998, “Moving Java to the Factory,” IEEE Spectrum, pp. 18-23. 20 Hoshi, T., 1996, “Current and Future Java Technology for Manufacturing Industry,” Proc. of IEEE Conference on Systems, Man, and Cybernetics, 6, pp. 404 –409. 21 Weaver, A., Luo, J., Zhang, X., 1999, “Monitoring and Control Using the Internet and Java,” Proc. of Industrial Electronics Society, 3, pp.1152 –1158. 22 Wille, C., and Koller, C., 1999, Teach Yourself Active Server Pages in 24 Hours, Sams Publishing , pp. 57-89. 23 Tang, L., and Tse, P., 2000, An Interactive Product Information System on the Web Environment for Album Manufacturing Company, Master Degree Dissertation, City University of Hong Kong. 24 Berberich, M., and Bamberger, S., 1998, “Building Webbased Knowledge Clusters,” Proc. of IEE Colloquium on Web-Based Knowledge Servers, pp. 1/1 -1/4. 25 Atalay, B., Potter, W., and Haburchak, D., 1999, “HIVPCES: a WWW-based HIV Patient Care Expert System,” Proc. of IEEE Symposium on Computer-Based Medical Systems, pp. 214 –219. 26 Lee, J., Industry/University Cooperative Research Center for Intelligent Maintenance Systems (IMS), http://www.uwm.edu/Dept/IME/IMS/. 27 Tse P., Wang D. and Atherton, D., 1996, “Harmony Theory Yields Robust Machine Fault Diagnostic System Based on Learning Vector Quantization Classifier”, Engineering Applications of Artificial Intelligence, 9(5), pp. 487-498. 28 Tse P., Xu G.H., and L.S. Qu, 2000, "An Effective, LowCost, and Fast-to-Process Electronic Ear for Fault Diagnosis", Proceedings of the Seventh International Congress on Sound and Vibration, Garmish-Partenkirchen, Germany, 6, pp. 3487-3494. 29 Tse P., and Atherton, D., 1999, “Prediction of Machine deterioration Using Vibration based Fault Trends and Recurrent Neural Networks”, Transactions of the ASME: Journal of Vibration and Acoustics, 121(3), pp. 355-362. 30 Apache Online Documentations and User Manual, The Apache Group, http://www.apache.org.
The work described in this paper was supported by the Competitive Earmarked Research Grant No. 9040223 obtained from the Hong Kong Research Committee Council, which is gratefully acknowledged.
7.
REFERENCES
1
Warrior J., 1999, Hnew Industry Automation Architectures: The Impact of Ethernet and Internet Technology, HP Industrial Ethernet, www.hpie.com, Hewlett Packard Co. IEEE Std 1451.2, 1998, IEEE Standard for a Smart transducer Interface for Sensors and Actuators, IEEE Instrumentation and Measurement Society. Treese, G., and Stewart, L., 1998, Designing Systems for Internet Commerce, Addision –Wesley, Reading, MA. Mougayar, W., 1998, Opening Digital Markets, McGraw Hill, New York. Balakrishman, A., Kumara, S., and Sundaresen, S., 1999, “Manufacturing in the Digital Age: Exploiting Information Technologies for Product Realization,” Information Systems Frontiers, 1(1), pp. 25-50. Reed, D., Giles, R., and Atlett, C., 1997, “Distributed Data and Immersive Collaboration,” Communications of the ACM, 40(11), pp.39-48. Evans, E., and Rogers, D., 1997, “Using Java Appltes and CORBA for Multi-User Distributed Applications,” IEEE Internet Computing, 1(3), pp.43-55. Sacile, R., 2000, “Telemedicine Systems for Collaborative Diagnosis Over the Internet: Towards Virtual Collaboratories", Proceedings of Research Challenges, pp.191 –196. Rudolph, B., and Petersen, I., 1999, “Collaborative Diagnosis Over the Internet: a Working Experience”, IEEE Internet Computing, 3(6), pp.29 –37. National Laboratory for the Study of Rural Telemedicine, http://telemed.medicine.uiowa.edu. Stefano, A., Bello, L., and Mirabella, O., 1997, “Virtual Plant: a Distributed Environment for Distance Monitoring and Control of Industrial Plants”, Proceedings of IEEE Intelligent Engineering Systems, pp.445-449. Lee, J., 1997, “Strategy and Challenges on Remote Diagnostics and Maintenance for Manufacturing Equipment”, Proceedings of the Annual Symposium on Reliability and Maintainability, pp.368 –370. Remote Fabrication and Diagnosis, Microsystems Technology Laboratories, MIT, http://wwwmtl.mit.edu/CAPAM/demo-posters/aarong/slides.htm.l Remote Diagnosis and System Reliability Evaluation, S. M. Wu Manufacturing Research Center, Michigan University, http://rmt-diagnosis.engin.umich.edu/html/ Project/MainMenu.html. Johnson, R., 1999, “IEEE-1451.2: The IEEE Effort to Network Smart Sensors”, Technique Report of Telemonitor Inc.
2
3 4 5
6
7
8
9
10 11
12
13
14
15
8
Copyright © 2001 by ASME
