7 Years Experience with Web Laboratories - iNEER

7 Years Experience with Web Laboratories Author: Jim Henry, University of Tennessee at Chattanooga, Chattanooga, TN 37403 phone: 1-423-425-4398 [email protected]

Abstract  This paper describes the development of web-connected equipment for engineering laboratories at the University of Tennessee at Chattanooga in the USA. Beginning in 1995, we started putting controls lab equipment on line. Currently we have systems in controls, in chemical engineering, in environmental engineering and in mechanical engineering that are operable from the Internet. These are controlled either by web forms with a browser or by remote control panels with direct Internet connections. The systems allow multiple users to synchronously participate in remote lab experiments (graphical and data viewing, remote video and audio). The systems are ideally setup for asynchronous teamwork, also. Other universities have had their students use this equipment via the remote connections. The experiences of these other universities will be described. The paper discuses the successes we have had in technical (equipment and software) and equipment scheduling and in pedagogical uses. Index Terms  Chemical engineering, controls, engineering laboratories, international sharing of resources, weboperated laboratories.

BACKGROUND For several years before the Internet blossomed, we taught engineering controls laboratories at the University of Tennessee at Chattanooga (UTC) with computerized data acquisition and control of equipment. With this equipment students sat in front of computers in the controls laboratory and conduced a range of experiments. The experiments were for system identification and control of one of several laboratory stations. In 1995, we added the capability to conduct these experiments via the Web. The experiments can be run at any time (24 hours a day, 7 days a week) from anyplace that a student has Internet access. Students could design and conduct experiments with the real equipment in the laboratory by specifying the experiment on a Web form and submitting the request for the experiment to be conducted. When the experiment was conducted, the computer collected the data and plotted the graphs of the performance. The student then could retrieve this data via a browser and complete the analysis of it. The experiments are run as "batch" experiments. That is, the experiment is run after the Web server at UTC has received the request. The experiments are run first-come, first-served. This has been a successful model that we are still using to this day. Some of the systems' experiments can be completed in less than a minute; there is the potential for over 10,000 experiments being run per week. Some of the systems' experiments can be completed in several minutes; there is the potential for over 1,000 experiment being run per week. We now have added another method of remote operation. Using a remote operating panel for a LabVIEW control program, students can control equipment in real time now. This is still first-come, first-serve, however, if a student is running and experiment from his or her computer, other students can connect to the server and observe the operation as the first student is conducting the experiment.

THE EQUIPMENT The laboratory stations listed in Table 1 are available. Many of these have been described in detail elsewhere [1]. The equipment is a mixture of purchased lab equipment to which we have added extensive instrumentation, data acquisition and control capabilities and locally fabricated equipment that we designed specifically for these laboratories. The data acquisition is done mostly with plug-in boards in desktop computers. The boards are purchased from National Instruments Company. They provide for analog and digital signal inputs from the sensors on the equipment and analog and digital signal outputs to the actuators on the equipment.

International Conference on Engineering Education

July 21–25, 2003, Valencia, Spain. 1

THE SOFTWARE AND USER INTERFACE The software platform used is LabVIEW from National Instruments Company. We have used its facility of data acquisition and control as well as its presentation and communication capabilities. Additionally, we use Microsoft’s Internet Information Server as a Web server. The web address is http://chem.engr.utc.edu The Web server provides the Web interface for students. We have a hierarchical menu of stations and experiments for the students to choose from. Figure 1 shows the Web menu of stations for controls experiments; figure 2 shows the menu of experiments for the level control system. The final option for students is to completely specify the parameters of the experiment desired. After specifying the parameters, the student submits the request for the experiment. Figure 3 shows the Web form for specifying the experimental parameters. After the experiment is completed, the experimental data is returned to the student as well as several graphs showing the output performance of the experiment. An alternate remote-control interface is available for some of the systems. The alternate is an interactive image on a Web page that is a clone of the LabVIEW program that is running in at UTC. Figure 4 shows an example of one of these. That panel is modeled after the control panel that would be experienced in an industrial setting.

SHARING AMONG STUDENTS INTERNATIONALLY No matter which interface the student use, the results are archived on the Web server and can be observed by anyone else. This means that students working in a team can share results on their experiments. Students can share results with instructors and ask questions about the results. Additionally, as an experiment progresses, periodic response profiles are constructed and posted on the server. This gives students at least four advantages: • The data is saved on a medium that has been shown to be more reliable and is has larger capacity than floppy disks. • The data is saved in a location that is known by them, their team members and the laboratory staff. • The data is easily shared with and reviewed by team members. And • As a longer experiment is in progress, the system response can be viewed periodically. Students from around the world have used the various stations. Table 2 lists a selection of these. Students have been fascinated by the chances of this type of experimentation and usually were very motivated, though there can be some problems with the internet connection during some times. Most students repeat some of the experiments for the evaluation of the test results and discussed them in reports.

PEDAGOGY Such remote operation experiences are fully learn-by-doing with nearly all the positive and negative aspects of true hands-on laboratory work. Education materials have been developed for Web-based laboratory experiments; this includes the tutorials, assignments and supporting materials needed to assist learning on the part of the students. It also includes the teaching aids for use by instructors. The educational materials developed at UTC include descriptions of the equipment, examples of experiments, procedures for conducting the experiments and sample topics for discussion. These educational materials are on a Web site that has interactive programming, extensive photos and diagrams as well as video and audio components. UTC is developing and evaluating the materials for implementing extensive use of Web-based laboratory learning experiences. Another aspect of the educational materials will be an expert system that will monitor the use of the Web-based laboratory system. This system will monitor the performance of the users of the system and give suggestions and feedback to the users (students) and give reports to the instructors. The nature of many universities presents special problems and opportunities in conducting traditional laboratory learning experiences. For example, it is difficult for commuting, part-time, working students to bond and form groups. This asynchronous, Web-based program where there is teamwork and student-based learning facilitated on the Web helps establish a "community of learners." The UTC Program incorporates current ideas in engineering education including increased cooperative learning and active problem-based learning strategies in the courseware. We have designed the features of the UTC program to accommodate the full-time, part-time students and working students, addressing the broad range of preparation students have and insuring that they have full learning opportunities. A database of usage of the Web-laboratories is being built. An expert observer system will be developed to give feedback and guidance to users of the system. This feedback will be timely. The "coaching" function of the software ("expert observer") will mediate student functions by providing assistance during the planning, implementation, analysis, and application phases of the laboratory experimentation.



The expert performance monitor will aid in the mentoring, instruction, tutoring and assessment of students. The expert performance monitor will be a system to monitor weak or irregular performance by the students and give feedback to the students and reports to the instructors. This system can collect information on what topic and when students need help. As such, it can be a powerful tool to develop better laboratory teaching materials. It will also be a powerful tool for the evaluation and assessment. As instructors move from lecturing roles to auxiliary facilitator and coach roles, students engage as active participants in the learning team and also gather and study learning issues to share and present to the learning team. Problem-based learning is used to promote student motivation, relevance and context of the learning, higher order thinking skills, authenticity, and self-regulated learning. All of these are available in Web-connected laboratories.

VISION FOR WEB-EMPOWERED LABORATORIES As a result of more Web-empowered laboratories as outlined here, we envision that: • Students will have access to on-line labs with a variety of experimental systems in engineering • Students will be able to easily design and conduct experiments from home, dorm, computer lab or office • Students will be able to compare local lab experimental results with on-line, remote lab results • Students will be able to easily use on-line labs for assignments outside of the classroom • Faculty will have materials to implement remote laboratory experiments in their own institutions • Faculty will have more diverse laboratory offerings available • Faculty will be able to easily use on-line labs in classroom demonstrations • Faculty will be able to easily use on-line labs in office consultation with students

ACKNOWLEDGEMENT The Web lab has been supported with significant funding from the Center for Excellence in Computer Applications at UTC, the National Science Foundation (USA), the University of Chattanooga Foundation and the Opffice of the Dean, College of Engineering.

REFERENCES [1]

Henry, J. M., "Laboratory Teaching via the World Wide Web," ASEE SouthEast Annual Meeting, April, 1998. Available via the Web at http://chem.engr.utc.edu/Documents/ASEE-SE-98d-full.htm

FIGURES AND TABLES TABLE I. EXPERIMENTAL SYSTEMS AVAILABLE ON-LINE AT UTC

Controls lab • Flow control • Level control • Position control • Pressure control • Speed control • Temperature control • Voltage control

Chemical engineering • Batch dryer • Dehumidification • Distillation column • Gas-fired water heater • Heat exchanger • Pressure-swing adsorption

Environmental engineering • Flow through porous media • Packed-bed absorption column

Mechanical engineering • Forced vibrations • Hydraulics of a journal bearing • Kinematics of a slider-crank mechanism



TABLE 2. SHARING OF UTC REMOTE LABS BY OTHER SCHOOLS

• • • • • •

School Technical University of Sydney (Australia) Diponegoro University, Indonesia University of Michigan, USA Washington State University, USA University of Tennessee Space Institute, USA University of Applied Sciences in Koeln, Germany

• • • • • •

Laboratory experiments Controls for anatomy students Controls for chemical engineers Distillation for chemical engineers Controls for chemical engineers Controls for mechanical engineers Controls

FIGURE 1 WEB MENU OF EXPERIMENTAL STATIONS FOR CONTROLS ENGINEERING.



FIGURE 2 WEB MENU OF EXPERIMENTS AVAILABLE FOR THE LEVEL CONTROL SYSTEM.

FIGURE 3 WEB FORM TO ENTER THE EXPERIMENTAL PARAMETERS FOR AN EXPERIMENT.



FIGURE 4 CONTROL PANEL FOR REAL-TIME EXPERIMENT.

