Keywords

1 Introduction

Laboratories are a fundamental part of engineering education due to the very nature of the engineering profession. Feisel and Rosa [1] classified engineering laboratories in three groups: development, research and educational (instructional). The last group is used by students during their engineering courses and this work is focused on them. Electrical Engineering courses rely on different types of labs – Analog and Digital Electronics, Control Systems, Microwave Circuits, Electrical Machines, etc. In many research institutions, students can also have access to research labs, but this fact does not mean that the institution can exclusively rely on them; educational labs are a need and are used by institutions worldwide.

Current ICT – Information and Communication Technology provides many options for engineering education. Some are solely software, like general-purpose products for numerical computation such as MATLAB® and Maple®, both commercial, and SciLab®, which is a free and open software. Other products are specific; CircuitLab®, Cadence®, LTSpice and Fritzing are based on numerical computation but they solve electric circuits problems. The first two are commercial; the others are free.

The use of ICT is so important that Froyd et al. [2] consider it the fifth major shift in Engineering Education in the last 100 years. The authors even extend the acronym to ICCT - Information, Communication and Computational Technologies.

ICT has also brought a new world of possibilities through the deployment of Remote Labs. The expression Remote Lab in the context of this work is “Remote Access - Real Resource” in the classification presented by Heradio et al. [3].

This paper presents preliminary results on the use of VISIR – Virtual Instrument Systems in Reality, a remote lab for Electric and Electronic Circuits (EEC). It was deployed and started being used at Pontifícia Universidade Católica do Rio de Janeiro (PUC-Rio) in the second semester of 2016 and it has been used for two semesters in different courses. This short experience with VISIR has indicated that its use must carefully be planned to suit the needs and the context of the institution and its courses. This paper is divided in 5 sections and describes the main actions and results. Section 2 addresses the context at PUC-Rio and presents VISIR. Its introduction and use as a learning supporting tool are discussed in Sect. 3 while Sect. 4 shows the main results in different courses. Conclusions and comments are in Sect. 5.

2 The Context at PUC-Rio and VISIR

PUC-Rio is a private and non-profit university in Rio de Janeiro, Brazil. The courses related to Electrical Engineering and Electricity Fundamentals in other engineering curricula have been using different types of ICT tools for about two decades. Blended learning (b-learning) was introduced in the first term of 2014 and since then some courses started being offered in this mode.

VISIR is a remote lab for doing real, physical experiments with EEC. The acronym VISIR stands for Virtual Instrument Systems in Reality.

This section is divided in two subsections: the first describes the context at PUC-Rio and the other focuses on VISIR.

2.1 The Use of ICT Supported Learning at PUC-Rio

The context of ICT supported learning is presented in three steps as follows:

  • The Maxwell System (http://www.maxwell.vrac.puc-rio.br/) is a platform that integrates an IR - Institutional Repository as defined by Lynch [4] and an LMS – Learning Management System as defined by Wright et al. [5]. The IR features of the system manage all types of digital contents from ETD – Electronic Theses and Dissertations to interactive courseware of many different types. It hosts both inputs to the learning process as well as its outputs. Since it is an integrated system, students and faculty using the LMS features have seamless access to all types of digital contents. Over and above, contents are items of the collection and not deposited on course folders; courses point to contents that are not replicated, each one has a unique existence on the platform. Maintenance is simple and storage space saved.

  • The first integration of the Maxwell System with an external system – focused on simulation that is an important tool in Engineering Education. In order to offer students learning objects that include simulation, the system was integrated with SciLab®. Students, both graduate and undergraduate, and faculty are developing objects that address important topics. When the implementation of VISIR in undergraduate courses began, a set of objects to support EEC was developed. Currently, there are 19 such objects in Portuguese and 10 translations into English; five additional objects are under development. Since SciLab® is a software product, it was installed on a server that is connected to the Maxwell servers.

  • The second integration – this was quite different, since the system to be integrated was a Remote Lab; it had not only software but hardware too. This integration had the same objective of the first – VISIR was considered one additional learning resource to be offered students and faculty, and it had to seamlessly be accessed. In order to achieve it, both the IR and the LMS features of the Maxwell System were used. The integration is presented in [6].

The objective of the use of ICT tools is to stimulate students to be more active and independent. Solutions to be integrated must be flexible enough to be expanded and to allow new ones to be added when necessary. Support must be provided to faculty.

PUC-Rio also offers students and faculty other IT solutions; the ones mentioned in this subsection are related to Electrical Engineering only (we are considering Computer Engineering and Control and Automation Engineering as Electrical Engineering subtypes). There is a campus agreement for MATLAB® - students can use it on the computers of the university labs, on-line from the company servers or download it to their own devices. The university also provides LabView® on computers in labs of the Electrical Engineering Department and CircuitLab® on-line from the company servers. There are different types of licenses for these and other products.

2.2 VISIR

VISIR is comprised of two parts – software and hardware. The VISIR software is an open-source released under a GNU General Public License (GPL) [8]. It includes (1) a user interface that handles all the administration, access, and authentication process. This interface may sometimes be invisible to the client depending on how VISIR is integrated into a given Learning Management System (LMS). In the case of PUC-Rio, where VISIR has been integrated into the Maxwell System, only (2) an experiment client interface is visible to the students. The experiment client is a simulated electronics workbench embedded in the HTML code of the user interface. It provides access to a triple-output DC power supply, a digital multimeter (DMM), a two-channel oscilloscope, a function generator and a solderless mounting board (breadboard), as depicted in Fig. 1. The top row of the interface shows the electric and electronic components that are available for a given experiment. The components are physically located on a relay-based matrix that is connected to a PXI® system which contains the 4 instruments previously referred. The matrix and the PXI® system form the hardware part of VISIR. The (3) measurement server is responsible for handling all the remote experiment requests. Every time a client clicks on the “Perform Experiment” button, it reads the circuit description (as built by the client in the experiment client interface), checks if the circuit is valid and then queues the request to (4) the equipment server. This server physically interconnects the components and the instruments on the matrix, applies the stimulus, reads the responses, and then passes this information back to the experiment server to transmit it to the active remote instrument panel. All the operations take a fraction of a second, so VISIR can be described as a batch-mode remote lab, capable of simultaneously serving several clients. In short: the user and experiment interfaces plus the experiment and instrument servers are the software, while the hardware part contains a relay-based matrix and a PXI® system with a DC power supply, a DMM, an oscilloscope, and a function generator.

Fig. 1.
figure 1

Experiment client interface (in HTML5) integrated into PUC-Rio Maxwell system.

Full size image

2.3 Final Remark

The experiments performed in the first semester of 2016 ran from the installation at CUAS – Carinthia University of Applied Sciences in Austria. All other experiments, from the second semester of 2016 on, were performed using the integrated platform at PUC-Rio. This shows the real meaning of the word remote.

3 The Use of VISIR

Different courses in one curriculum and courses in different curricula have distinct characteristics. The distinctions are even bigger when courses of different institutions are considered.

This yields an interesting challenge – examining courses characteristics to find suitable uses of the Remote Lab. They must be adapted to objectives of the course and the context of the institution. This is something that was learned in the second semester of 2016 when VISIR was used for some lab activities of the EEC course. As a result of this experience, it was decided to use it in other courses with different objectives and profiles of students. Two other courses at PUC-Rio were chosen – General Electricity (GE) and Introduction to Engineering/Electrical Engineering (ItE). At the same time, the VISIR+ Project requires that local partner institutions use the equipment. One of the partners decided to start using; it was Universidade do Estado do Rio de Janeiro (UERJ) and the course was Electric and Magnetic Measurements (EMM). The subsections that follow address the different uses and how their results are being considered to determine how best serve the learning process.

3.1 Learning to Use VISIR

VISIR was the first remote lab to be used at PUC-Rio, so faculty involved on the VISIR+ Project decided to get acquainted with the equipment and its use before the actual installation at the university. CUAS is PUC-Rio’s corresponding partner in the project, so its equipment was offered for this first use.

In the first semester of 2016, two experiments were held using the installation in Austria. The first was for one experiment in the EEC course and the second in an extracurricular activity (ECA) aiming at students that had not taken the Circuits course. ECAs are mandatory in the Engineering curricula in Brazil.

First Experiment in EEC.

One experiment in the EEC syllabus was selected for adding an extra step, using VISIR, between simulation and real-lab practice. There were 18 students enrolled in the class and 12 responded a three question survey. The three questions were: (1) I found VISIR easy to use; (2) VISIR helped reducing experimental setup errors/setup time; (3) Overall, VISIR had a positive impact in my learning experience. Assigning grades from 1 (“I completely disagree”) to 5 (“I completely agree”), the outcomes for the three questions were respectively averages 4.8, 3.5 and 4.6. Further research showed that question 2 had not a high score due to lack of circuit components for that specific lab class.

First Experiment in an ECA.

The ECA offering an Electrical Engineering lab activity had 11 students from three engineering curricula: Electrical (6), Mechanical (3) and Computer (2). The students were surveyed and the results were: 6 students graded the activity 5 (highest grade in a 1 to 5 scale), 4 graded 4 and 1 graded 3. When asked if they would recommend their colleagues this ECA, 8 said they strongly would do it and 3 said they would recommend. In addition, this ECA helped the VISIR team to “rehearse” for the use of VISIR in regular courses.

Comment.

These two uses of VISIR were of paramount importance in learning how to prepare and run experiments in the following school terms. The insights from these experiences led to the view of the implementation process as presented in [7].

3.2 VISIR and the EEC Course in the Second Semester of 2016

EEC is a mandatory course in three engineering curricula at PUC-Rio: Computer, Controls & Automation, and Electrical. This course has had high rates of students who do not pass it, either they dropout or fail the exams. This is a serious problem since EEC is a prerequisite for many other mandatory courses. Two members of the VISIR team have taught this course and started collecting data about the students’ performances in 2011. Since then, many actions have been taken to enhance the results. Quite a few are based on the use of ICT tools – development of learning objects of different natures (animations, videos, simulators, etc.). The switching to b-learning in the first semester of 2014 is one of them. The EEC course has two lab hours per week taught in a traditional way. VISIR was included as an additional activity to offer one more way of experimenting with circuits.

The Experiments Students Must Perform.

In the last terms, students have performed 10 experiments: (1) Resistor ladder circuit; (2) Operational amplifier (inverter and non-inverter); (3) Amplifier and adder; (4) Sensor with graphic bar; (5) Super diode; (6) First order circuits (RL and RC); (7) Timer (RC); (8) Second order circuits (RLC); (9) Sinusoidal steady-state; and (10) Frequency response (RL, RC and RLC).

How Students Work at the Lab.

Students are required to study before going to the lab. They are assigned a study guide and they have to write an outline of the way the experiments will be performed and the expected results; they are graded for this activity. They also have to simulate experiments (using CircuitLab®) before going to the lab and the results are part of the outline. As mentioned before, they have two hours of lab classes each week but the labs are open from 7 AM to 7 PM every weekday and there are technical staff to support students all the time.

Experiments Using VISIR.

The use of VISIR was limited to three experiments: (1) Second order circuits (RLC); (2) Sinusoidal steady-state; and (3) Frequency response (RL, RC and RLC). Students were required to perform one additional task before going to the lab – use VISIR to remotely perform the experiments.

Preparation of the Course for the Use of VISIR.

In accordance with the view of the implementation process presented in [7], many items of courseware were developed. They can be found in the series Projeto VISIR+ (https://www.maxwell.vrac.puc-rio.br/series.php?tipBusca=dados&nrseqser=14). Many other supporting learning contents were developed and can be found in Open Access in two other series: Objetos Educacionais em Engenharia Elétrica (https://www.maxwell.vrac.puc-rio.br/series.php?tipBusca=dados&nrseqser=5) and Simulações em Engenharia Elétrica (https://www.maxwell.vrac.puc-rio.br/series.php?tipBusca=dados&nrseqser=12). All other courseware developed for the b-learning mode were available as well.

Grades and Results.

A lot of data were collected: the students’ GPAs, the numbers of times they had already attended the course, their curricula, etc. The class had 36 students and 3 dropped out; 33 was the final number. The students were handed a survey at the end of the term – 17 (51.51%) filled it but 3 were not identified. This remark is important because it was only possible to match grades with VISIR activities for 14 students. The students were graded by the outlines they presented; 3 had 3 parts (because they included VISIR) and the remaining 7 had only 2. This is something that is commented later. They were also graded by their performances and reports on the experiments. Finally, a test was applied and graded. The final grade of each student was 30% from the average of outlines (1), 30% from the average of experiments and reports (2) and 40% from the test. Table 1 shows the average grades (computed over 10) for all 33 students. When the results of the whole EEC course are considered (lab & theory), the results in terms of grades are shown in Figs. 2 and 3.

Table 1. Average grades for the EEC lab in the second semester of 2016.
Full size table
Fig. 2.
figure 2

(Left) numbers of students by final grade – set identified in the survey.

Full size image
Fig. 3.
figure 3

(Right) numbers of students by final grade – all students in the class.

Full size image

Gathered data show that students who were identified when replying the questionnaire: (1) represented 42.42% of the class and 50.00% of those who passed the course; and (2) 28.57% were taking the course for second time as compared to 30.30% of the class. The histograms show that the identified students had less unsuccesses. It yields the impression that more dedicated students were concerned in expressing their opinions on the use of VISIR.

The overall average of points in the evaluation of VISIR was 1.99 over a maximum of 5.00. The average number of accesses was 3.96. Some comments were interesting: (1) the weight (in the grade) of experiments outlines requiring different numbers of tasks was the same – a bigger workload was not recognized; (2) the labs are open many hours a day, so the use of a remote equipment does not add that much value; (3) it was difficult to tell the difference between VISIR and a software product; and (4) students cannot perform experiments that are not assembled on the equipment (this can be done in the traditional lab). It is important to remark that experiments used in the course did not explore the potential of the equipment to perform tasks that would not be possible in the traditional lab, as for example, the determination of a Thévènin Equivalent Circuit or the identification of a transfer function of a 1st or a 2nd order circuit; the use of VISIR would allow components to be “hidden” from students.

3.3 Open House to High School Students in the First Semester of 2017

PUC-Rio regularly invites students from public and private schools to visit the University and attend lectures and perform technical activities. In the first semester of 2017, 60 high school students had the opportunity to use an Electrical Engineering lab. It was possible because they used VISIR. For 1 h the students performed basic experiments. The objective was to present results of a real laboratory in a safe way. The activity was successful and the students liked it.

3.4 VISIR and the GE Course in the First Semester of 2017

This course is mandatory to all engineering students who are not required to take EEC. It has a very large number of students and the number of lab classes in the first semester of 2017 was 14 – the total number of students was 273. The number of students who filled the survey was 235 (80.08% - much higher than that of EEC).

This course offers only one hour of lab sessions per week and they are on different days and times. This poses a problem – to keep the experiments in sync; the number of experiments to be performed each term used to be 8. Faculty became very enthusiastic with the use of VISIR in order to: (1) increase the number of experiments each term; (2) offer more lab time to the students; and (3) motivate students who are not involved with electricity related curricula by the use of a new tool. Concerning the number of experiments, it is important to remark that holidays do not impact a remote equipment and, also, experiments can be available for any day since no technical supervision is required; students cannot work in the traditional lab if a technical staff is not present. Three new experiments were added – one divided in 3 steps. This meant a significant enhancement in the number of practical activities.

It is important to remark that GE deals with voltages and currents much higher than VISIR supports. At the same time, basic concepts like Ohm’s Law, voltage divider, current divider, linear and nonlinear circuits can be addressed with VISIR with no loss of generality. So VISIR could really add value to the GE lab.

The computation of the results of the survey yielded an average grade of 2.48 out of 5.0; a better result than that of EEC. The average number of accesses was 7.63; almost twice as much as that in EEC. An inspection of the logs of accesses on the Maxwell System showed significant numbers late at night and during weekends. Thus a “mission” of a remote solution seemed to be fulfilled – offer students access to resources when the university is closed.

To illustrate the impact of the VISIR, Fig. 4 presents the grades as functions of numbers of accesses. In addition to that, a trend line was drawn to show that, in the average, the more the students have accessed the VISIR the higher their grades were. As in the EEC course one may think that students who are more committed to their course study more hours per week and access VISIR more times too.

Fig. 4.
figure 4

Grades as functions of accesses.

Full size image

This course is using VISIR in the second semester of 2017.

3.5 VISIR and the ItE Course in the First Semester of 2017

Introduction to Engineering is a Problem Based Learning (PBL) course that is mandatory to all students admitted to one of the engineering curricula. It is taken in the first semester and students are generally grouped in classes the same area of interest. VISIR was used in a class with 17 students distributed in the curricula: (1) Computer Engineering – 1; (2) Control and Automation Engineering – 4; (3) Electrical Engineering – 4; and (4) Mechanical Engineering – 9. The focus of their PBL projects was electromechanical systems controlled by microcontrollers. The faculty responsible for the class was in the area of Electrical Engineering.

The computation of the results of the surveys yielded an average grade of 2.50 out of 5.0; also a better result than that of EEC. The number of students who finished the course was 17, the same number of students who filled the survey. Among the 17, 13 wrote comments and 9 said that they liked a remote lab because they could use it any time and any place. One interesting comment was that the student felt comfortable by not risking damaging the equipment. The average number of accesses was 19.35.

3.6 VISIR and the EMM Course in the First Semester of 2017

As mentioned before, the VISIR+ Project requires that participating institutions have local partners. UERJ is one of the partners and was the first to use VISIR. It is a public institution that belongs to the State of Rio de Janeiro. The course that was chosen by UERJ was Electric and Magnetic Measurements which is mandatory for the curriculum of Electrical Engineering. The average number of accesses was 10.93 and the average grade was 3.0. The number of students was 15 and 7 replied the survey. All students wrote comments – 2 students liked the any place any time possibility of use and three had problems with the instruments. One interesting comment was that the student felt comfortable by not risking damaging the equipment, the same as in ItE. This course is using VISIR in the second semester of 2017.

4 Main Outcomes

The first outcome of the VISIR+ Project at PUC-Rio was the introduction of a remote lab in Engineering Education which has been benefitting from other ICT tools. This was important because a real lab was made available through the LMS. Before its deployment, only software products had been in use through this platform.

The second is that the original idea presented in [7] seemed to be right – the inclusion of a remote lab is a project that has many different aspects. It is an educational project that must be integrated with the ongoing learning activities. Students and faculty must feel that a new tool is available to be added to others. Faculty must make sure that course activities using the remote labs must carefully be planned.

The third is that VISIR is very well suited to some courses but not to others. In the EEC course, results were not good when VISIR was employed in many different lab experiments. There was not a real need of a remote lab to provide support to experiments that can be performed in the many hours that the traditional lab is available. At the same time, faculty did not implement the experiments that would only be possible using VISIR. Another point to be examined is the training of the students in the use of the remote lab. In EEC, there was no organized effort in this activity (it as informal) and maybe this contributed to the students’ not fully appreciating the equipment.

Nevertheless, there is a huge opportunity for VISIR in EEC in the near future. Students of Electrical, Control and Automation and Computer Engineering enrolled in the university since the first semester of 2017 are now required to attend two EEC courses – EEC I and EEC II – where the traditional lab is not used until the second course. This means that students of EEC I will not have hands-on lab experiments, and VISIR will be used as the sole lab activity. It is also in EEC I that Thévènin Equivalent Circuit is addressed and this is an experiment that perfectly fits VISIR.

In the first semester of 2017, the second with VISIR installed at PUC-Rio, two important things happened. The first is that the VISIR team was more proficient in the use of the remote lab and was able to understand the importance of training students on how to use it. The second was the decision to try VISIR in courses with different characteristics.

The use of VISIR in GE was successful – the number of experiments was increased. The 24/7 availability and the remote access allowed students to experiment for a longer time. Faculty of GE are enhancing the management of VISIR from the experience they got the first time they used it – enhancing the courseware, devoting more time to training students, and allowing students more time when needed to fulfill the tasks. GE has many students, so this yields a big impact, especially because students in this course are not really motivated to courses related to electricity. It is the authors’ opinion that the use of VISIR in GE is irreversible in the near future.

ItE yielded results that were considered satisfactory, specially concerning the average number of accesses – 19.35. This class had a very young group of students (first semester of the freshman year) who were involved with PBL activities and did not have traditional circuit lab classes – they easily accepted this new tool since they did not have another lab activity to compare.

EMM is a course with a different profile and taught at another institution. It has 4 weekly hours and traditional lab activities for measurements in high and low levels AC and DC circuits. The experiments the students performed using VISIR were different from the ones of the traditional lab and the most remarkable fact was that they never came to PUC-Rio. This course yielded the highest overall grade in the surveys.

5 Conclusions and Comments

The use of VISIR as one of the steps before traditional laboratory classes of the same experiment did not yield good perceptions among students, since they could compare with the traditional lab where there was a lot more flexibility. At the same time, using VISIR to introduce experiments that are not performed in the traditional way seemed to please students. Faculty were specially satisfied that they could add more experiments to the courses and/or better motivate their students. The use of VISIR in courses other than EEC yielded better results. It is important to observe that the EEC course is in the core of the three engineering curricula, thus students have higher expectations. The grading process was also a problem in EEC.

With the introduction of a new curriculum where EEC will be divided in two courses, there is an opportunity for VISIR in the first course (EEC I), since all traditional lab experiments were left to EEC II. This is expected to add real value to EEC I since students will be able to experiment using concepts that are theoretically taught.

The results discussed in this paper are limited by a very short time frame – one semester in each course. For this reason, it is not possible to state that VISIR helps students achieve better results. Maybe students who access the remote lab more times than the others are more committed to learning regardless of the tools that are used. Two courses (GE and EMM) are currently using VISIR for the second time, so there will be more data to analyze. The VISIR team has no doubt that this study will have to be performed once the equipment has been used for more semesters and different sets of students are exposed to it.

A more extensive and intensive study was performed by Marques et al. [9]. Many of results of this first use at PUC-Rio are in agreement to the results presented in this work. When more data are collected at PUC-Rio, a more detailed comparison on the implementations in two different institutions will be performed to check similarities and differences. Their methodology will be an inspiration for the new study.

A comment is necessary to wrap up: there is a large amount of data already available on the Maxwell System that will be analyzed and presented in a next publication.