Development of a Remote Lab for Electrical Engineering Program.doc

Development of a Remote Lab for ElectricalEngineering ProgramAsma Khalil1,2, Mazen Hasna1, Mohieddine Benammar1, Mohamed Chaabane2 , Chokri Ben Amar21: College of Engineering, Qatar University; 2: ENIS, University of Sfax, T; .qa; .qa; chaabane_ucayahoo.fr; chokri.benamarenis.rnu.tnAbstract-A remote lab for electrical engineering experiments hasbeen designed and implemented. This has been intended as aplatform that supports existing traditional labs by offering labexperiments that serve some of the student learning outcomes ofthe program. This offers fully interactive environment to theremote user. A dedicated architecture that meets networksecurity and equipment safety requirements has beenimplemented. The remote control of the experiment is ensuredthrough the powerful and flexible shared variables engine ofLabVIEW. The remote lab has been successfully tested with twosample experiments. The infrastructure may accommodatemany more concurrently-running experiments. Full details ofthe proposed platform are given.Key words: Remote Control, Booking System, Network security,LabVIEW Technologies, Shared Variables.I.INTRODUCTIONThe widespread use of the internet and computing tools hasstrengthened interest in distance learning and remoteexperimentation in engineering programs. This is an area ofresearch that has been of interest for educational purposessince the mid 90s. A number of pilot projects from countriesall over the world have been reported in literature (e.g., 1-4). In a recent communication 5, the main characteristicsof some of the published remote laboratory experiences havebeen summarized.Educators are continuously searching for high qualityengineering programs to students who are constrained by timeand distance 6 as well as those with learning disabilities andrequiring special attention; access to remote laboratory enablethese users to perform experiments in a remote setting 7,8. In general, remote labs may resolve the problem of lackof work space and avoid the need for high investment inexpensive instrumentation. In addition, these may be accessedround the clock by users from various locations, and allowsharing scarce and expensive equipments even for users indeveloping countries. In some societies where male andfemale students access different campuses, such remote labscan avoid duplicating some lab facilities by offering the sameremote lab experience to both genders. In some applications,remote labs offer other advantages such as the reduction ofrisk to users and to facilities; examples of these include cleanrooms settings where contamination may be a threat 9. Oneof the prominent remote lab settings (iLAB) is beingdeveloped by MIT and is now aiming to define standardapproach to remote labs 10, 11. Such efforts will help inestablishing some kind of international standardization forFig.1. ReLEEP architecture.these platforms. It cannot be denied that with remote labs,students do not interact face to face with their professors butthey have enough tools to discuss their problems and learnfrom others through chatting rooms and forums available onthe remote lab. There is no intention to totally replace thetraditional hands-on lab, but it can be a supportive tool thatcan be used before or after a lab session to enhance thelearning lab concept and theory 12. Working on someapplications through remote labs may mean more freedomand less pressure on the student compared to the traditionallearning environment. In addition, such an experience mayfoster independent and lifelong learning skills 13, which aresome of the important engineering program outcomes of theAccreditation Board for Engineering and Technology Inc(ABET) 14 that are difficult to achieve with traditionallearning environment.In the present work, we present a pilot project for thedevelopment of a Remote Lab for Electrical EngineeringProgram, named ReLEEP, at Qatar University, accessiblethrough .qa. In this institution, and inaddition to the advantages listed above, this project offers thesame facilities to male and female students located in separatecampuses. The project also capitalizes on the high investmentmade in IT infrastructure and the use of IT in teaching,demonstrated for example by the fact that the universityoffers notebook computers to all its new student population.The ReLEEP is being developed as a platform for variousexperiments (analog and digital electronics, electricalmachines, power electronics, control, embedded systems,2.Software Platformetc). The platform includes cameras that provide high speedvisual feedback to remote users. Evidently, a managementsystem for user registration, authentication and booking hasbeen implemented. The data collected on the effectiveness ofReLEEP and its usage may be accessed through thedeveloped database for research and improvement purposes.The issue of internet safety was also addressed in this work.The development and widespread of the internettechnology has encouraged software developers to offercompatible products that capitalize on these advances.National Instruments LabVIEW software has been adoptedfor controlling the experiments. National Instruments hasdeveloped toolkits like Internet Toolkit with remote Panelsand web publishing Tool, Data Socket Technology and RDAII.ARCHITECTURE(Remote Data Access) technology 17, 18. Thesetechnologies provide different features and facilities forThe general software and hardware architecture of theproposed ReLEEP system is shown in Figure 1.1. Hardware PlatformThe first requirement addressed when designing theReLEEP was the compliance with the resources and networksecurity of the University. Typical three tiers web architecturewas adopted for the project (Figure 1); these are the client (orremote user), resource manager (server) and experimentworkstation 15. The adopted architecture is frequentlyadopted in commercial applications 16. This architecture isadequate for remote lab applications as it offers networksecurity and flexibility when improvement and updating ofthe services offered to the clients are required. The server ishosted in the IT department and the workstations are locatedin a lab of the Electrical Engineering Department. The remoteusers (clients) can be located anywhere in the world, and mayaccess the ReLEEP through a wired or wireless internetconnection. For video streaming acquisition of the live visualfeedback, it is recommended that the client uses high speedinternet connection.The Lab workstation is made up of a PC, an NI DAQ andan NI Elvis platform from National Instruments. Electronicsexperiments may be implemented on the NI Elvis platform.Control experiments, such as the inverted pendulum may beimplemented using dedicated Quanser kits that arecompatible with NI Elvis. All other experiments, includingpower electronics and machines laboratory exercises may bedesigned by using the analog/digital inputs/outputs accessiblethrough the NI Elvis platform. Data exchange with theserver is ensured through the Ethernet/ wired network of theuniversity. Every workstation is fitted with an IP camera toimplementing remotely-controlled applications. RemotePanels, Web Publishing Tools, Data Socket and TCP/IPSocket have been used in the achievement of many remotelabs. The advantages and disadvantages of some of thesetechnologies have been discussed in 19.Recently, LabVIEW has been coupled with the new andpowerful Shared Variables engine; this may be used toremotely operate, monitor and control a LabVIEWapplication when coupled to Front Panel Data Binding(Figure 2). Network-Published Shared variables are softwareitems which allow sharing data among LabVIEW VirtualInstruments (VIs) on the same machine or between differentstations in distant locations through the Shared VariableEngine. In our application, the input/output variables(terminals) in the workstation VI may be substituted byshared variables and then bound to correspondent Front Panelcontrols, indicators and graphs in the Server side. The SharedVariable Engine uses the NI Publish-Subscribe Protocol (NI-PSP) data transfer protocol to write on the workstation andallow the server to read live data. NI-PSP is a proprietarytechnology that provides fast and reliable data transmissionfor large and small applications and is installed together withLabVIEW.The NI-PSP networking protocol uses psp URLs totransmit data on the network. Shared variables on the networkmay be bound to other shared variables or to server anddevice data items 20. Many previous related projects haveused Data Socket Transfer Protocol (DSTP) to exchange data;however front panel data binding provides faster and morereliable data transmission and avoid seamless connections toshared variables and NI-PSP data items 20.provide a visual feedback to the remote user.Fig.2. LabVIEW Shared Variables and Front Panel Data Binding.In our application, the Network Published SharedVariables were configured for a single writer to beprotected from any misuse inside the university network.Firewall was configured to allow data exchange betweenthe Server and the Workstation. Through a network pathcomputers in the same network or manually registeredcomputers, project library names, and network-publishedshared variables are automatically identified. Using thisnetwork path, shared variables on the workstation VI areavailable to be bound to Front panel on the server.The server provides web access service, userauthentication management, interactive environment aswell as hosting the experiment dynamic web page 21generated with LabVIEW web Publishing Tool. In order toaccommodate as many remote ReLEEP users as possible,a booking system was implemented to avoid accessconflicts as well as to help students organize their time andactivities in the Remote Lab 22, 23, 24. Moodleplatform is widely used for such application, and this wasadopted in the present project. Moodle is a CourseManagement System (CMS), also known as LearningManagement System (LMS) or Virtual LearningEnvironment (VLE). It is a Free and Open Source webapplication used worldwide for online learning sites 25.The Management Room Booking System (MRBS) is abooking system used as a Moodle block to share resourcesand provide access to the remote user in an organizedmanner. This block was adapted to the ReLEEP needs bymaking a small coding modification on the MRBS phpfiles. This modification add to the MRBS block the abilityto redirect the user to the experiment after checking theuser details against identity and time slots schedule storedin Moodle database. After this validation, the experimentweb page can be viewed and accessed for the durationfixed by Moodle administrator. The overall of the remoteuser access path is described in the diagram presented inFigure 3.The Moodle package and MRBS block have beeninstalled on the server. Additionally, LabVIEW and itsInternet Toolkit have been installed on this machine toallow publishing the VIs on the server and also to makethe VI front panel available for the remote user who maycontrol the experiment through the Shared VariableEngine.The network security issue was treated in collaborationwith the IT department of the university. Severeconstraints were required by the University InformationTechnology Policy and Guidelines when establishing theremote Laboratory. Indeed, the use and management ofQatar University electronic communications resources andnetwork infrastructure must comply with the securitypolicies and guidelines issued by the managementcommittee of Qatar University. These rules are necessaryto preserve the integrity, availability and confidentiality ofQatar University information assets 26. Effectivehardware and software implementation of this policy onReLEEP minimize unauthorized access to the universityproprietary information and technology. High levelsecurity precautions have been implemented in theReLEEP architecture. Safe use of equipment associatedwith the experiments has been addressed in the publishedVI itself (Figure 4).Fig.3. Remote user access diagram.Fig.4. Security Layers of Published VI.III. SAMPLE RESULTSThe architecture of the developed ReLEEP allowsimplementation of various experiments. In the presentwork, two experiments have been tested. A firstexperiment for the current-voltage characterization of PNjunction diodes has been developed. The experimentallows the user to plot the diode characteristics, tointeractively estimate the dynamic resistance at anyoperating point on the curve using cross hair tool, and toestimate the thermal voltage, the saturation current, and thediode temperature based on the diode exponential model.The front panel viewed by the user is shown in Figure 5.The second experiment is a classical rotary invertedpendulum based on a Quanser product compatible with NIElvis platform. The experiment allows the user to remotelyswing up the pendulum, and to control few parameterssuch as the time required for the swing up and someparameters of the controller. The user can receive the datain a graphical form. Additionally, the IP camera provideslive visual feedback to the user (Figure 6). For safetyreasons, the experiment is initialized at the end of eachbooking time slot in order to ensure that subsequent usersalways start the experiment with the same initialconditions. This task is integrated in the server architecture(Figure 4).Fig.5. Screen view of a remote user characterizing a PN junction diode.Fig.6. Sample results of the rotary inverted pendulum experiment: a view from remote user screen.IV.CONCLUSIONS14 J.E. Ashby, “The Effectiveness of Collaborative Technologies inRemote Lab Delivery Systems,” 38th Annual Frontiers inRemote labs can complement traditional labs, and helpin reducing equipment needs and cost. In addition, suchlearning environments are available to students round theclock and are accessible from all over the world thanks toadvances in internet service quality. A custom maderemote lab was set up to service electrical engineeringstudents by offering a wide range of typical laboratoryexercises. This paper has presented the architecture of thelab and some initial experiments that are successfullyimplemented remotely. The infrastructure mayaccommodate many more concurrently-runningexperiments.ACKNOWLEDGMENTThe present work is supported by Qatar UniversityGrant # 07007E. The authors are grateful to Eng. M. El-Sayed and to the ITS team at Qatar University for theirassistance.REFERENCES1 C. C. Ko, B. M. Chen, J. Chen, Y. Zhuang and K. C. Tan,“Development of a Web-based laboratory for control experimentson a coupled tank apparatus”, IEEE Trans. Education, vol. 44, n. 1,pp. 76-86, February 2001.2 S. Das, L. N. Sharma, A. K. Gogoi, “Remote CommunicationEngineering Experiments Through Internet,” Int. J. OnlineEngineering (iJOE), vol. 2, n.1, 2006.3 K. Yeung and J. 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