Mechatronics Experiment in a Freshman Year Course

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Session R1G
Mechatronics Experiment in a Freshman Year
Course
Vinod K Lohani1, Pushkin Kachroo 2, Shripad Chandrachood 3, Tasha Zephirin 4, G V Loganathan5, and Jenny Lo6
Abstract - The paper presents design and pilot
implementation of a mechatronics hands on workshop for
engineering freshmen in spring 2006 at Virginia Tech,
USA. This activity is part of a research/curriculum
reformulation project funded by the National Science
Foundation, USA. One of the strategies for the proposed
reformulation is to develop activities that will engage
freshman students in a variety of lab experiences that
reflect different engineering disciplines.
About 180
students participated in the pilot. The experiment involved
building a robot using several mechanical (gears, wheels,
shafts, etc.) and electrical parts (resistors, capacitors,
motor driver integrated circuits, breadboard, battery,
diodes, micro switches). A pre-workshop assignment was
designed to assess the “prior knowledge” of students and a
couple of self-explanatory PowerPoint presentations were
made available to students through class Web site.
Assessment data were obtained using instant classroom
response system (i.e., clickers) and also by using in-class
assessment worksheets. Assessment data indicates a very
positive response from students. It is planned to scale up
this workshop to the entire freshman engineering class of
~1200 in fall 2006.
Index Terms: Assessment, Clickers, Engineering Freshman,
Mechatronics
INTRODUCTION
Virginia Tech (VT), USA created a new Department of
Engineering Education (EngE) within the College of
Engineering (COE) in May 2004 to improve engineering
pedagogy. The primary motivation is to promote collaboration
between engineering and education faculty within and outside
the university and to develop an active research program in
engineering education. A number of NSF funded projects are
ongoing in support of the enhanced research mission of the
department. One of the projects is funded under the
Department-Level Reform (DLR) program of the NSF
(www.dlr.enge.vt.edu). A number of EngE faculty members
are collaborating with faculty from other engineering
departments and the School of Education to reform the
freshman engineering program within the EngE and the
bioprocess program within the Biological Systems
Engineering (BSE) department using a theme based spiral
curriculum approach [1]. To accomplish this, one strategy
involves engaging freshman students in a variety of lab
experiences that reflect different engineering disciplines. This
paper discusses the design of one such experiment on
mechatronics. Assessment data was obtained by employing a
variety of instruments including surveys and use of clickers in
class.
HANDS ON EXPERINCES IN FIRST ENGINEERING
COURSE
All engineering freshmen at VT are required to take an
introductory engineering course called “Engineering
Exploration EngE1024” during freshman year. Students
transfer into various eleven engineering departments after
completing a set of required courses during freshman year.
EngE faculty members keep up their efforts to improve the
learning experiences of engineering freshmen by incorporating
innovative hands on activities in this course. As a result, this
course has undergone a number of revisions in last several
years. A major change in teaching format of EngE1024 was
piloted by the coordinators of this course (i.e., Lohani and Lo)
in spring 2005 when the course was taught in a 50-min lecture
in a large classroom (~150 seat) followed by a hands on
workshop in a 32-seat classroom. In fall 2005, this new format
was successfully implemented for the entire freshman
engineering class of ~1200 students [2]. The hands on
workshop activities are primarily designed to give glimpses of
various engineering disciplines by incorporating early design
and build experiences. In order to address the needs of all
eleven engineering departments the EngE faculty are
collaborating with faculty members from several engineering
departments including Civil and Environmental Engineering
(CEE), Electrical and Computer Engineering (ECE),
Biological Systems Engineering (BSE), etc. as a part of the
ongoing NSF/DLR project.
1
Vinod K. Lohani, Asso. Prof., Dept. of Engineering Education, Virginia Tech, [email protected]
Pushkin Kachroo, Asso. Prof., Electrical and Computer Eng. Dept., Virginia Tech, [email protected]
3
Shripad Chandrachood, Ph.D. student, Electrical and Computer Eng. Dept., Virginia Tech, [email protected]
4
Tasha Zephirin, , Undergraduate student, Electrical and Computer Eng. Dept., Virginia Tech, [email protected]
5
G V Loganathan, Prof., Dept. of Civil and Env. Engineering, Virginia Tech, [email protected]
5
Jenny Lo, Assist. Prof., Dept. of Engineering Education, Virginia Tech, [email protected]
2
San Juan, PR
July 23 – 28, 2006
9th International Conference on Engineering Education
R1G-23
Session R1G
Water Tower Experiment
Following sections provide details on the pilot implementation
of this workshop.
In summer 2005, EngE faculty designed a “water tower”
experiment in collaboration with faculty from the CEE and
BSE departments for the EngE1024 course. Figure 1 shows a
set up for this experiment. The objectives are to give hands on
experiences to observe flow of water from a cone shaped
upper tank through an orifice into the lower tank and use the
method of selected points for developing the empirical
relationship to describe the rate of water drainage under falling
head conditions. In addition, problem solving and
programming exercises were designed to compute volume and
surface area of a conic frustum. This experiment has been
successfully implemented in EngE1024 in fall 2005 and spring
2006. Students going into departments like Civil and
Environmental Engineering, Mechanical Engineering,
Engineering Science Mechanics, Chemical Engineering,
Biological Systems Engineering, etc. will be able to relate
their first semester fluid experiences when they take upper
level courses like fluid mechanics / hydraulics typically in
junior year.
Pre-workshop assignment
A pre-experiment assignment was designed to assess the
“prior knowledge” of students and a self-explanatory
PowerPoint presentation explaining various associated
concepts is made available to students through class Web site
two weeks prior to the hands on workshop. This pre-workshop
presentation included a number of basic physics, algebra, and
geometry problems related to the mechatronics project and
was intended to prepare students for the experiment. Since
students had just completed the “water tower” experiment
discussed previously, students were explained the analogy
between water flow and electricity flow (see Figure 2). The
assignment also explained electronic concepts such as digital
logic, integrated circuits and bread boarding. Several
homework questions are included for getting students ready
for the hands on part of the workshop.
It may be mentioned that a clicker based classroom
response system was adopted in EngE1024 course to obtain
instant feedback from students in fall 2005. In order to get
early impressions of students about the workshop, a clicker
question was asked after 5 days of assigning the preworkshop assignment. The question and students’ responses
(~140 respondents) are given in brackets:
FIGURE 1
WATER TOWER EXPERIMENT SET UP
Piloting Mechatronics workshop in Spring 2006
In order to give meaningful experiences related to Electrical,
Computer Science/ Engineering and Mechanical Engineering,
a “mechatronics” workshop was developed by the authors
collaboratively and was piloted in spring 2006 with ~180
students in EngE1024 course.
Main objectives of this workshop are to: 1) Expose
freshman engineering students to mechanical construction,
electrical/electronic circuits, as well as digital circuits from
computer engineering, and 2) Build and test a two-wheel
driven mobile robot. The experiment involves building a robot
using several mechanical (gears, wheels, shafts, etc.) and
electrical parts (resistors, capacitors, motor driver integrated
circuits, breadboard, battery, diodes, micro switches, etc.).
Hands-on activities in the workshop included: (1) building a
gear box, (2) attaching motors, wheels, battery, switches, and
breadboard, (3) constructing a power supply for the robot, (4)
creating circuits on the Breadboard, and (5) testing the robot.
FIGURE 2
ANALOGY BETWEEN WATER FLOW AND ELECTRICITY FLOW
Clicker question: Please give your initial impression
about the "mechatronics" workshop we'll do after the
spring break:
a. I'm really excited about this workshop and am
eagerly looking forward to do this hands on
experiment. [22%]
b. The workshop seems complex but I may enjoy it at
the end. [18%]
c. I'm not sure I'm too excited about this workshop at
this point. [10%]
d. I didn't have time to review the "mechatronics"
slides and have no opinion at this point. [47%]
e. Invalid response [3%]
San Juan, PR
July 23 – 28, 2006
9th International Conference on Engineering Education
R1G-24
Session R1G
Workshop Assignment
Before conducting the hands on workshop, all questions from
pre-workshop assignment were discussed in a 50-min lecture
session in EngE1024. Again, in order to assess the impact of
the lecture on the interest level of students, a clicker based
question was asked in the class “before” and “after” the
lecture. The question and the responses are given below:
“Before” Lecture
1. I've reviewed the mechatronics slides and at this
point I am:
FIGURE 3
PARTS OF THE GEARBOX
A. very excited about this workshop [15%]
B. glad that we're doing this hands on workshop
[40%]
C. neutral about this workshop [14%]
D. really not sure whether I'll like this workshop or
not [10%]
E. I haven't reviewed the slides yet [14%]
G. Invalid response [ 7%]
“After” Lecture
1. After attending the mechatronics lecture I am now:
A. very excited about this workshop 44%
B. glad that we're doing this hands on workshop 41%
C. neutral about this workshop11%
D. really not sure whether I'll like this workshop or
not 4%
FIGURE 4
ASSEMBLED GEARBOX ALONG WITH WHEELS AND DC MOTORS
As can be seen, the lecture was obviously very effective in
communicating the excitement associated with this new
workshop. In addition to the pre-workshop slides, two
additional sets of PP slides were uploaded to class Web site
ahead of the workshop. These slides were used in the lecture
session discussed above to cover all associated activities.
These include step by step description of the robot building
process. Figures 3-6 show some examples of the slides that
explain the workshop activity. All electrical and mechanical
parts were made available to a group of 2 students. First,
students built the gearbox (see Figure 4). Then the breadboard
operations were performed (see Figure 5). The electrical
operations were described in three stages: Stage 1: Powering
the breadboard with 9 volt battery, Stage 2: Deriving 5 volt
supply from the 9 volt battery circuit, and Stage 3:
Implementing motor drive circuit to control and protect the
operation of robot motors (see figure 6).
FIGURE 5
FAMILIARIZATION WITH THE BREADBOARD OPERATION
5V
Convert:
Convert:
9V
9Vtoto5V
5V
Voltage
Voltage
Regulator
Regulator
Stage 1
Stage 2
Motor
Motor
Drive
Drive
Stage 3
FIGURE 6
THREE STAGE CONTROL CIRCUIT – BLOCK DIAGRAM
.
San Juan, PR
July 23 – 28, 2006
9th International Conference on Engineering Education
R1G-25
Session R1G
After completing each stage students performed the required
tests for testing satisfactory completion of various stages.
Finally, the developed circuit and the gearbox assembly was
fit on to a CD and the two-wheel driven mobile robot was
ready to run by controlling its power through an input switch
as shown in Figure 7.
5) Now start building electronic circuit on the breadboard
following instructions given in the slides and by the GTA.
Start time:
……….
6) Make sure your breadboard is oriented properly as shown in
the manual (Tabs at the top).
7) Build circuit stage 1 on the breadboard. Note that for diode,
red side is the positive side and that should be connected to
positive of the battery
Use Multimeter to test this stage. Multimeter knob should be
on 20 volt DC.
Checkpoint for stage 1: Turn the input switch ON. Are you
getting approximately ‘9 volts’ at the stage 1 output?
Yes
No
FIGURE 7
SNAPSHOT OF THE TWO-WHEEL DRIVEN MOBILE ROBOT
WORKSHOP INSTRUCTIONS AND ASSESSMENT
SHEET
An instruction and assessment sheet was created to provide
stepwise instructions and to obtain feedback while students
did the hands on workshop. The data obtained is being
tabulated at the time of this writing. It will be included in the
final version of the paper. The content of this sheet are as
below:
Student Name(s):
Workshop Day & Time:
Kit identification #: 1) Gearbox kit # ………
2) Electronic Components kit # …………
3) Tool kit # …………..
1) Have you ever previously worked/played with mechanical
assembly type of toys?
Yes
No
2) Do you have any prior experience of working with
breadboard or electronic components?
Yes
No
8) If your stage 1 output is approximately ‘9 volts’ then
proceed to build stage 2 on the breadboard.
Checkpoint for stage 2: Are you getting approximately ‘5
volts’ at the stage 2 output?
Yes
No
9) If ‘stage 2’ output is correct then create the 5 volt bus and
join the two ground bus together as shown in the manual.
10) Now turn the input switch OFF and start building stage 3
on the breadboard. Once all the connections of the stage 3 are
done, turn the input switch ON again.
Checkpoint for stage 3: Are the gearbox motors and attached
wheels revolving?
Yes
No
11) If everything up to stage 3 is working fine then use double
sided tape to mount the gearbox and the breadboard on
Compact Disc.
Is your robot moving forward?
Yes
No
End time:
……….
12) What can be done to move your robot backward?
3) Start assembling the gearbox using components from the
given gearbox kit. Use a Philips head screwdriver from the
tool kit for fitting screws. Follow step by step instructions
provided in the gearbox assembly sheet.
Start time:
End time:
Ans:
…………………………………………………………………
……………………….
4) Show the assembled gearbox to the GTA. Make sure all
the assembly is perfect. You will need this assembled gearbox
to build your robot.
San Juan, PR
9th International Conference on Engineering Education
R1G-26
July 23 – 28, 2006
Session R1G
13) Would it be possible to spin it clockwise around the center
of the wheel axle by changing any of the connections?
Yes
No
If Yes, which connections would you change?
If No, why is it not possible?
14) How would you rate this overall Mechatronics workshop
activity?
Excellent
Good
Average
Poor
15) After testing the robot, you need to disassemble
everything.
a) Remove the gearbox and breadboard from the CD.
b) Remove the double sided tape from all the locations that
you applied to.
c) Disassemble the gearbox and put the components back in
the gearbox kit.
d) Remove all the wires (except for the ones connected to the
motor) and keep aside. Don’t throw.
e) Do not remove the IC from the breadboard.
f) Keep all the electronic components back in to the electronic
kit zip lock bag.
g) Keep all the tools back in the tool kit.
Do make sure everything is back in the zip lock bag kits as it
was given to you at the start of the workshop (Refer item
check list given to you). Your classmates would be using this
same kit in the next workshop. Make it convenient for them! If
anything is missing, please notify your GTA.
FUNDING FROM THE STUDENT ENGINEER’S
COUNCIL (SEC)
Every year the Student Engineers’ Council at Virginia Tech
provides funding support for undertaking innovative
curriculum development projects for engineering students.
Given the huge success of the mechatronics pilot, the authors
submitted a proposal to the SEC for implementing the
mechatronics project in entire freshman class of 1200 in fall
2006. The authors made a presentation to ~50 SEC members
and were awarded $7,300 in March 2006 for continuing the
project in fall 2006. It is proposed to expand the scope of the
activity in fall to cover two workshop sessions.
SUMMARY
The mechatronics pilot workshop has been one of the very
successful workshops in the first engineering course at
Virginia Tech in spring 2006. It is proposed to expand the
scope of this workshop in fall 2006 to include activities like
sensor based movements of the robot. A proposal for the
Course Curriculum and Laboratory Improvement (CCLI)
program of the NSF for expanding the scope of the project is
under development at the time of this writing.
ACKNOWLEDGEMENT
The authors of this paper would like to acknowledge the
financial support of the National Science Foundation (grant
number 0431779, Department-level reform program). In
addition, the authors would like to express sincere thanks to
Jennifer Mullin, Ricky Liao, Brian Bluhm, Shawn Batterton,
and Ameet Pinto for conducting the mechatronics workshop in
spring 2006.
POST WORKSHOP ASSESSMENT
REFERENCES
Another clicker based question was asked in the class after
completing the mechatronics workshop. The question and
response (~120 students) are given below:
Having completed the mechatronics workshop, I’ll
rate this activity as:
A. Excellent [35%]
B. Very good [35%]
C. Average [12%]
D. Poor [3%]
E. Don’t want to rate [5%]
F. Invalid response [10%]
It can be seen that a good majority of students enjoyed the
mechatronics project. In April end, a focus group session and
an exit survey is planned. The results related to the
mechatronics workshop from these measures will be reported
at the time of presentation.
[1] Lohani, V. K., Wildman, T., Connor, J., Mallikarjunan, K.,
Wolfe, M. L., Muffo, J., Knott, T.W., Lo, J., Loganathan,
G.V., Goff, R., Gregg, M., Chang, M., Cundiff, J., Adel,
G., Agblevor, F., Vaughan, D., Fox, E., Griffin, H.,
Mostaghimi, S., 2005, Spiral Curriculum Approach to
Reformulate Engineering Curriculum, Proceedings of the
2005 Frontiers in Education Conference, Indianapolis, IN,
18-21 October 2005.
[2] Lo, J, V.K. Lohani, and O.H. Griffin, “Full Implementation
of a New Format for Freshmen Engineering Course”, to be
published in the Proceedings of the 2006 American Society
for Engineering Education Annual Conference and
Exposition, Chicago, IL, June 18-21, 2006.
San Juan, PR
July 23 – 28, 2006
9th International Conference on Engineering Education
R1G-27
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