A Flexible Remote Electronics Laboratory for Engineering Education
|Document type:||Conference Presentations|
|Title:||A Flexible Remote Electronics Laboratory for Engineering Education|
|Translated title:||Flexibelt distanslaboratorium för ingenjörsutbildning|
|Conference name:||11th International Conference on Technology Supported Learning & Training|
|Organization:||Blekinge Institute of Technology|
|Department:||School of Engineering - Dept. Mathematics and Science (Sektionen för teknik – avd. för matematik och naturvetenskap)
School of Engineering S- 371 79 Karlskrona
+46 455 38 50 00
|Abstract:||The overall goal of engineering education is to prepare students to practice engineering and, in particular, to deal with the forces and materials of nature. Thus, from the earliest days of engineering education, instructional laboratories have been an essential part of undergraduate programs. However, during the last decades the author and others have noted a trend towards increased use of simulations replacing physical experiments in electrical engineering education. One obvious reason is the fact that instructional laboratories are expensive to maintain. Another possible reason is the persistence of the belief that simulations can replace physical experiments. However, physical experiments are indispensable for developing skills to deal with physical processes and instrumentation. The Internet provides new possibilities for universities and other teaching organizations to share laboratories.
Blekinge Institute of Technology (hereafter referred to as BTH) in Sweden has opened a traditional electronics laboratory for remote operation 24-7 and fitted the laboratory with a unique virtual interface where the students on the computer screen recognize the desktop instruments and the breadboard they have already used in the local laboratory. The fact that teachers in different countries can use existing teaching material in their own language is also unique for this laboratory. Instrument manuals can be downloaded from the web sites of the manufacturers. The activities started 1999 at BTH and the amount of work spent so far is approximately 12 man-years. The BTH design and has been awarded a Best Paper Award at the ASEE (American Society for Engineering Education) Annual Conference in Montreal 2002.
Most remote electronics laboratories elsewhere offer fixed experiments but in this one, students around the world can simultaneously wire circuits much like they do in the local laboratory. The BTH laboratory is a client/server application and the Internet is used as the communication infrastructure. The equipment provided comprises a dual channel oscilloscope, a digital multi-meter a triple DC power supply, a circuit wiring robot, and component sets selected by the teachers who have written the lab instruction manuals for the courses. The laboratory staff has mounted these component sets in the circuit assembly robot in the equipment server at BTH and photographs of the components in a set will be displayed in a component box on the client PC screens. Thus a certain set of components is provided for each lab session. The current laboratory supports only instrument models used at BTH. Other universities have other models and a virtual equipment shelf containing other instruments from different manufacturers will be added. The performance of the provided hardware matches most instrument models used in undergraduate education.
Students use the mouse to wire instruments and components from the component box to form a circuit on the breadboard displayed on each client PC. They thus control the robot by means of the wiring on the virtual breadboard, Figure 1. The robot is not a mechanical device but a switching matrix consisting of relays, sockets for components, and instrument connectors. Virtual instrument front panels are used to control and read the computer-based instruments by means of remote control, Figure 2. Most of the instruments in the equipment server are manufactured by National Instruments. To avoid damage to components and/or instruments, the teachers define maximum source voltages and all permitted current loops. However, harmless mistakes are allowed. A virtual instructor routine checks each desired circuit and acknowledges the circuit when the voltage levels are not too high and it only contains permitted current loops. Thus, if a user damages a component or an instrument the teacher is to blame not the user. A description of the laboratory can be found in: I. Gustavsson, J. Zackrisson, H. Åkesson, L. Håkansson, "A Flexible Remote Electronics Laboratory", Proceedings of the 2005 REV symposium, Brasov, Romania, June 30 - July 1, 2005.
Figure 1. An operational amplifier (μA741) circuit wired on the virtual breadboard.
Figure 2. The oscilloscope virtual front panel displaying the slew rate of the uA741 operational amplifier in the circuit on the breadboard illustrated in Figure 1.
Access to the laboratory is restricted by a reservation system. The main items of this system are students, courses, and lab sessions in order to fit the traditional university system. The teacher of a course makes time reservations for regular supervised lab sessions of the course and specifies also the sets of components to be used in the sessions. Only students enrolled in the course are permitted to perform experiments using the component sets belonging to the lab sessions of that course. However, there are two guest courses open to the public. In each of the guest courses there is a lab session and a set of components. Only a 56 kbit/s modem and a web browser are required to access these experimental resources. The laboratory is always open and can be used by registered students and guest users around the world. The time-sharing scheme used allows simultaneous access with acceptable response time for 8 client PCs. The address of the laboratory web site is http://distanslabserver.its.bth.se/.
Universities and other teaching organizations are invited to let their students conduct experiments and to provide regular lab sessions using their own components and learning material in the language of their choice. Expensive laboratory equipment can be provided for students with no time or space limitations. Apart from the fact that each student or team of students using a client computer works in a virtual environment with no face-to-face contact with the instructor or other students in the laboratory, the difference between a lab session in the laboratory presented here and a session in a local laboratory is that it is not possible for users to manipulate the components and the wires with their fingers in a remote laboratory. However, the latter constitutes a new educational tool which is ready for use in undergraduate education and in secondary schools as well as in vocational training and life-long learning. Remote experiments will not replace local lab sessions but supplement them and make experiments more accessible, especially for inexperienced or less confident people requiring more time. It may be possible to compensate for the reduction in the number of traditional lab sessions during the past few decades and even improve electronics courses without incurring any increase in cost. New more effective teaching methods may emerge. Experiments can, for example, easily be integrated into lectures.
How about opening a laboratory containing mechanical components? In most cases sound and/or video image transmission will be required. A remote vibration analysis laboratory is being set up at BTH and will provide a platform for an evaluation of the feasibility of remote vibration experiments using the same concept. A dynamic signal analyzer, Agilent 35670A, connected to a server and traditional vibration sensors and actuators for experimental vibration analysis will be used. As a first example this setup will enable estimation of the important quantities in experimental vibration analysis based on measurements on a boring bar. Such bars are responsible for the majority of vibration problems in turning. The intention is to provide the students with vibration experiments related to an authentic important vibration problem in the industry.
The research field has wider implications. Engineering education is not as popular today as it should be given the spread of technology in society. However, it is not so exciting to disassemble a modern digital alarm clock as grandmother’s one! Technical devices in our everyday life are no longer transparent. It has been reported that most teachers in, for example, nursery schools influencing our children have no technical courses whatsoever in their own professional training. The ultimate goal for the research at BTH is ubiquitous physical experimental resources accessible 24-7 for everyone to inspire and encourage children, young people and others to study engineering and become good professionals or to be used as means for long life learning of teachers and other professionals.
|Keywords:||Remote labs, Electronics, Laboratory|