17-09-2012, 10:51 AM
Virtual Work Bench for Electronic Instrumentation Teaching
[attachment=33821]
Abstract
This article describes the design and implementation
of a virtual laboratory, computer-generated for the theoretical and
practical teaching of electronic instrumentation. The virtual laboratory
is implemented in a windows framework for which the
teacher or student requires no prior knowledge to manage the program.
The Virtual Instrumentation Workbench for Instrumentation
allows visualization of the time and frequency effects produced
in analog to digital conversion and in digital signal processing as
well as visualizing the effects of 16 different teaching topics. It incorporates
ten different waveforms, eight windows algorithms, five
digital filters, and five discrete/fast Fourier transform (DFT/FFT).
The use of the virtual laboratory has allowed more than 500 students
to understand the functioning of the new devices that are
flooding the instrumentation market. Although it has been developed
as an aid for electronic instrumentation teaching, it can also
be used for the teaching of digital signal treatment.
INTRODUCTION
TRADITIONALLY, theoretical teaching of electronic instrumentation
has been carried out in classrooms where
the theoretical concepts cannot be verified by laboratory work.
It is important in this practical laboratory work, to cover all the
concepts taught in the classroom, but due to time limitations, it
is difficult to create the conditions under which the comparative
merits of the techniques employed can be assessed. Taking into
account that in the last ten years, electronic instruments have increasingly
come to incorporate digital devices, analog-to-digital
converters, and the teaching of the techniques of sampling and
digital signal processing have become fundamental to the study
of electronic instrumentation.
BACKGROUND
Personal computers have, since they became affordable, been
seen as flexible and versatile teaching tools. Their efficiency has
been studied in the last 20 years by authors such as Cañizares
and Faur in [2]. Recently published applications cover the whole
teaching process; theory, practical experience, exams, evaluation,
as suggested by Bengu and Swart in [3], others have studied
the use of PC's in certain contexts only, among them Mosterman
et al. in [4], Oakley in [5], and Hollabaugh and Allen's virtual
workbench in [6].
The VIEW was conceived originally as a tool for theoretical/
practical teaching of analog-to-digital converters. A functional
model was produced [7] with the intention of utilizing to
best effect the teacher's time thus solving the above mentioned
time problem. It has since been modified and improved and is
now multidisciplinary and IBM-PC, Macintosh, and Workstation
(UNIX) compatible.
USER INTERFACE
Fig. 1, shows the on-screen appearance of the VIEW. The
left of the screen is for data entry and the right for graphical
representation. The data entry boxes can be modified as often
as necessary, the results of the operations selected appear with
a double click on the virtual DATA VALID button situated in the
control section. To finish a session, you must click on the virtual
STOP button or press ESC key on the keyboard.
As can be seen in the block diagram, Fig. 2, data entry is divided
into four sections; signal generation and sampling, device
under test (D.U.T.), digital signal processing, and graphical representation
and control. The capabilities are described below.
CONCLUSION
The VIEW is a program that offers the following fundamental
advantages; 1) It permits real-time viewing of the
effects of sampling, A/D conversion and signal filtering. 2) It
permits recording of the limitations of the DFT/FFT. 3) It is
tolerant of possible data entry errors. 4) It has no instructions,
therefore teachers and students require no prior knowledge of
its handling or of the digital signal treatment algorithms. 5) It
can be compiled so as to function on IBM-PC (Windows 95),
Macintosh orWorkstation (UNIX) platforms. 6) The program is
freeware (http://www.upv.es/view), allowing students to study
and to experiment outside the university teaching laboratories.
Thanks to the use of the VIEW, the problems explained in the
introduction have been minimized.
[attachment=33821]
Abstract
This article describes the design and implementation
of a virtual laboratory, computer-generated for the theoretical and
practical teaching of electronic instrumentation. The virtual laboratory
is implemented in a windows framework for which the
teacher or student requires no prior knowledge to manage the program.
The Virtual Instrumentation Workbench for Instrumentation
allows visualization of the time and frequency effects produced
in analog to digital conversion and in digital signal processing as
well as visualizing the effects of 16 different teaching topics. It incorporates
ten different waveforms, eight windows algorithms, five
digital filters, and five discrete/fast Fourier transform (DFT/FFT).
The use of the virtual laboratory has allowed more than 500 students
to understand the functioning of the new devices that are
flooding the instrumentation market. Although it has been developed
as an aid for electronic instrumentation teaching, it can also
be used for the teaching of digital signal treatment.
INTRODUCTION
TRADITIONALLY, theoretical teaching of electronic instrumentation
has been carried out in classrooms where
the theoretical concepts cannot be verified by laboratory work.
It is important in this practical laboratory work, to cover all the
concepts taught in the classroom, but due to time limitations, it
is difficult to create the conditions under which the comparative
merits of the techniques employed can be assessed. Taking into
account that in the last ten years, electronic instruments have increasingly
come to incorporate digital devices, analog-to-digital
converters, and the teaching of the techniques of sampling and
digital signal processing have become fundamental to the study
of electronic instrumentation.
BACKGROUND
Personal computers have, since they became affordable, been
seen as flexible and versatile teaching tools. Their efficiency has
been studied in the last 20 years by authors such as Cañizares
and Faur in [2]. Recently published applications cover the whole
teaching process; theory, practical experience, exams, evaluation,
as suggested by Bengu and Swart in [3], others have studied
the use of PC's in certain contexts only, among them Mosterman
et al. in [4], Oakley in [5], and Hollabaugh and Allen's virtual
workbench in [6].
The VIEW was conceived originally as a tool for theoretical/
practical teaching of analog-to-digital converters. A functional
model was produced [7] with the intention of utilizing to
best effect the teacher's time thus solving the above mentioned
time problem. It has since been modified and improved and is
now multidisciplinary and IBM-PC, Macintosh, and Workstation
(UNIX) compatible.
USER INTERFACE
Fig. 1, shows the on-screen appearance of the VIEW. The
left of the screen is for data entry and the right for graphical
representation. The data entry boxes can be modified as often
as necessary, the results of the operations selected appear with
a double click on the virtual DATA VALID button situated in the
control section. To finish a session, you must click on the virtual
STOP button or press ESC key on the keyboard.
As can be seen in the block diagram, Fig. 2, data entry is divided
into four sections; signal generation and sampling, device
under test (D.U.T.), digital signal processing, and graphical representation
and control. The capabilities are described below.
CONCLUSION
The VIEW is a program that offers the following fundamental
advantages; 1) It permits real-time viewing of the
effects of sampling, A/D conversion and signal filtering. 2) It
permits recording of the limitations of the DFT/FFT. 3) It is
tolerant of possible data entry errors. 4) It has no instructions,
therefore teachers and students require no prior knowledge of
its handling or of the digital signal treatment algorithms. 5) It
can be compiled so as to function on IBM-PC (Windows 95),
Macintosh orWorkstation (UNIX) platforms. 6) The program is
freeware (http://www.upv.es/view), allowing students to study
and to experiment outside the university teaching laboratories.
Thanks to the use of the VIEW, the problems explained in the
introduction have been minimized.