Micromouse: An Autonomous Robot Vehicle
Interdisciplinary Attraction to Education and
Research
Guillermo Lopez, Daniel Ramos, Kevin Rivera, Kelvin del Valle, Angel Rodriguez, Eduardo I. Ortiz Rivera IEEE Senior Member
University of Puerto Rico-Mayagüez, ECE Department and ME Department, guillermo.lopez@upr.edu,
daniel.ramos4@upr.edu, kevin.rivera1@upr.edu, kelvin.delvalle@upr.edu, angel.rodriguez59@upr.edu, eduardo.ortiz7@upr.edu
Abstract— The objective of this paper is to instill in students
motivation and interest for what they are studying a little bit
further of the theory they learn in classroom. Sometimes
students prefer more interactive classes and want to know why
the material given in class is helpful in their career. Do we have
a solution for this? Autonomous Robotic Vehicle (ARV)
projects can be the solution to this problem. This type of
project are interdisciplinary and offer students varieties of
challenges, while involving different areas of interest like
programming, design, assembling and testing. One of the best
ARV project is the Micromouse. The Micromouse is a small
robot that solves mazes. The basic idea is that the student
makes his own Micromouse from scratch using knowledge
acquired from different classes and the research done. This
project also helps the student to develop teamwork skills and
creativity to complete the different challenges and objectives
that appear when building a Micromouse. The student learns
the importance of working with students from other
engineering concentrations, which allows him to experience
how a career in engineer will be.
Keywords— Undergraduate Research, Education, STEM,
Micromouse, Autonomous Robot Vehicle
I. INTRODUCTION
In this century the courses should be appealing to students.
Why is this important? Because when the professors have
the student’s attention the lesson imparted is better received
and the student is able to recall more of the knowledge
acquired in the classroom [1]. Some studies reveal that 60%
of students feel bored in half of their classes, while other
30% said they feel bored in all classes. Even in this recent
research some “hands-on practical sessions achieved the
highest boredom ratings”. The author of this research
attributes the results of these hand-on session to the fact that
experiments were controlled exercises were the students
already knew the results [2]. The difference between those
hands-on experiences and the Micromouse project is that
they lack diversity of results, outcomes and challenges,
while the Micromouse does not. When the student finds an
obstacle there is no instructor or manual to tell him what to
do next, the student doesn’t know beforehand what the
outcome will be.
In today’s world efficient and effective communication is
essential in any career. This is especially true for engineers,
since many of the projects that they are involved in include
people from different areas and problems in communication
Sponsored by Industrial Affiliate Program, IAP. General Motors, GM.
could end up in fatalities like the Space Shuttle Challenger
Accident [3]. While the student learns the theory in the
classroom and practices it in the laboratory, there is lack of a
place where to integrate the knowledge acquired from
different classes and where to interact with people from
other majors. The Autonomous Robotic System (ARV)
Micromouse Project is ideal to give the students the
opportunity to expand their knowledge to these different
areas. To achieve this objective, the integration of three
different major was considered: Mechanical, Computer and
Electrical Engineering.
The integration of these three majors adds diversity and
variety to the project giving the students the opportunity to
have the experience of working with people from different
majors, to learn by social interaction and to develop social
and communications skills. Through this Project students
design and build a land robot able to travel across a maze. In
others words, students get the opportunity to improve their
skills by
II. WHY A MICROMOUSE?
This year a team was created for the research project: The
Quadcopter and the Micromouse: A Cooperative Robotic
System presented to Industrial Affiliates Program (IAP) at
the University of Puerto Rico, Mayagüez (UPRM). The
objective of this project was to engage two autonomous
vehicles: an aerial vehicle (quadcopter) and a land vehicle
(Micromouse), to work simultaneously to complete the
mission of solving an unknown maze. This paper focuses on
the Micromouse related part of the project. The Micromouse
group consists of 4 students, 1 of 4th year and 3 in 5th year.
One of the students is from Computer Engineering, 2 from
Electrical Engineering and 1 from Mechanical Engineering.
III. APPROACH OF DESIGN
The students from the three majors worked together to
design a working Micromouse prototype as seen in Fig. 1.
Since the micromouse is a relatively complex robot there are
mechanical, electrical and programing aspects that should be
considered before building the robot.
Fig. 1. UPRM’s Minds2CREATE Micromouse Prototype
A. Mechanical Egineering Approach
A mechanical engineering student learns to work, not
only with mechanical systems, but also to design thinking
about where and how the other students will place the
various circuits and sensors. The student must take into
account the needs of his peers to make an effective design.
The student also has to communicate the mechanical
constraints to the others so that these are taken into account.
When the students learn to communicate effectively with
each other the result is a design that integrates all the
mechanical and electronic system in the best possible way.
Besides improving technical communication tools of the
students, the Micromouse project allows the integration of
knowledge acquired in different classes, and furthermore, it
allows the student to go from theory to practice. It is true that
laboratories can implement the concepts learned in class, but
there are many classes that don’t have laboratories, and the
practices and laboratory experiments are limited to issues of
the class to which they belong.
In this project the mechanical engineering student puts
into practice knowledge acquired in design, static and
dynamic classes. When designing the vehicle it is necessary
to take into account the weight of the various static elements
and where those components will be placed because if the
weight distribution on the robot is not the desired, the
movement of the vehicle will be affected for worse. The
knowledge acquired in design classes is extremely important
for the student of mechanical engineering that belongs to the
Micromouse project. In Fig. 2 can be seen the design
consideration for positioning the infrared sensors and in Fig.
3 a possible design of a modular version of the Micromouse
[4].
Fig. 2. Top view of sensors with angles
Fig. 3. Next Generation Prototype
The main difference between the design process used for
the Micromouse and designs done in class is that for the
Micromouse, apart from considering other systems, the
student must take into account the availability of tools and
the skills the students have to build the robot and the time
available to do it. Now the student has to take into account
factors that were previously irrelevant. Finally the
Micromouse project provides mechanical engineer students a
close experience to what could be found in the workplace,
closer than classes and laboratories ever will.
B. Electrical Engineering Approach
Electrical Engineer students did a research of which
components where needed to design and build a Micromouse
considering the limitations and constraints of the maze.
Student’s research parted from the different components that
were be available at the laboratory with the intention of
making this Micromouse a modular and economic attraction
[5].
1) DC Motors and H-Bridge
There are several types of motors (stepper, servo and DC)
which could be used for this project; DC motors were the
chosen ones because they have higher revolutions per
minute. Because we are using a microcontroller we needed a
way to control the motors. An H-Bridge, which allows to
control the DC motors with the microcontroller, was used.
Thanks to the H-Bridge the rpms of the motors can be
controlled with the PWM (Pulse with modulation) pins of the
microcontroller, which means that now the DC motors can
go at different speeds, as desired.
2) Encoder
An encoder is a sensor of mechanical motion that
generates digital signals in response to mechanical motion.
There are available magnetic and optical encoders [6]. The
two types are linear which responds to motion along a path
and rotary that responds to rotational motion. The encoder is
able to provide information concerning position, velocity and
direction.
In this design rotary magnetic encoders were used, due to
their efficiency and they avoid three major vulnerabilities
that optical encoders have, which are: seal failures, bearing
failures and shattering due to vibrations. There are many
methods of detecting magnetic field changes, but the two
primary types used in magnetic encoders are the Hall Effect
and magneto resistive. The Hall Effect detects a change in
voltage by magnetic deflection of electrons and magneto
resistive detects a change in resistance caused by a magnetic
field.
Rotary magnetic encoders use two main components to
provide position feedback shown in Fig. 4. The first
component is the rotor which is magnetized with north and
south poles that are lined around the perimeter of the disk.
The second component is the sensor. The CPR stands for
counts per revolution of the motor shaft.
3) IR-Sensors And Microcontroller
Students found a variety of sensors for the Micromouse.
The sensor chosen was the IR-LED distance Sensor
(SHARP), because it could provide distance measures and
students were already familiar with this sensor. As it was
mentioned before one of the future works interest is making
a modular Micromouse, so it was decided by the students to
use of an Arduino Pro mini. Arduino Pro mini offers a plug
and play option with small dimensions, ideal for our design.
4) Printed Circuit Board Design
One of the jobs in this research project was working with
Printed Circuit Board (PCB) design. This design is achieved
based on a computer program (software) together with a
special machine to make these designs called PCB
Controlled Numerical Control (CNC) router. The program
used to design the PCB was Eagle 6.1.1 and the program that
the CNC works is called Mach 3, this is the program that gets
the g-code generated by Eagle and converts in to coordinates
for the CNC machine to draw the PCB. This part of the
project is interesting because there is no electrical
engineering class that teaches how to do a PCB design and
how to use a CNC machine. In Fig. 5 you can see our design
using Eagle.
C. Computer Engineering Approach
The students of computer engineering have the
responsibility to understand the different components of the
Micromouse. It is important that students doing both
mechanical and electrical design provide the students
programming how the components work and their
limitations. Also computer engineering students should know
is the task that the Micromouse should do. In our project we
were building a land robot able to travel through a maze. The
computer students, knowing this, programmed the
Micromouse to be able to travel in straight line and to take
turns. To move in straight line the Micromouse was
programed to measure the distance between the IR sensors
and the walls, if the distances are constant the robot is
moving straight if the distances change then the Micromouse
has to correct its course. With this information the
microcontroller sends more voltage through the H-Bridge to
the motor that is moving less to correct the trajectory. When
the Micromouse is going to take a corner it uses the encoders
to determine how much the wheels are rotating and the IRsensors to give distance to the walls, as feedback, to know
how much it has turned.
Fig. 4. Rotary Magnetic Encoder [8]
Fig. 5 Eagle Design of the Micromouse
IV. EDUCATIONAL THEORIES FOUND IN THE MICROMOUSE
PROJECT
In the field of education there can be found a lot of theories
describing what should be the correct method and approach
to teach and give the lessons to students. One of the most
used in our times is learn by doing. The most influent person
in this kind of approach to student education was John
Dewey. Learn by doing consist in students using the theory
learned in classes to do hands-on activities [7]. An example
is that the student is assigned to achieve an objective (build
a Micromouse capable of navigating through a maze) and
doing it with all the information learned in class and
research (Micromouse navigating through maze). This
hands-on activity gives the opportunity to the student to
apply the lesson received in class to a real life problem with
different levels of difficulty and types challenges. Learn by
doing provides the student interactions with materials and
equipment used for the construction of the Micromouse,
often not known from previous university courses.
This project also provides the students the opportunity to
|interact and work with students from others majors such as
Mechanical Electrical and Computer Engineering. Here is
another of the theories found; learning by social interaction.
When in the group there is a more skillful peer the others
students learn in a faster way. Also by this social interaction
students are able to share their knowledge acquired in their
respective areas of studies and they learn how to simplify it
for others to understand their work [8]. By doing this,
students develop social and communication skills which are
very important in STEM careers. Students here get the
closest experience to a career job in engineering and begin
to understand the importance of diversity in a project.
V. SKILLS DEVELOPED
The students were able to develop a variety of skills during
this research. The skills that students developed can be
easily demonstrated with Criterion 3. Students Outcome
used by Accreditation Board for Engineering and
Technology (ABET) [9]. During the academic year the
students made progress reports where they mentioned the
research done and the objectives achieved.
•
•
•
•
•
•
•
•
Ability to apply knowledge of mathematics, science,
and engineering – This can be seen through all the
process of the construction of the Micromouse.
Ability to design and conduct experiments, as well as to
analyze and interpret data - Students conducted various
experiments with encoders and sensors. Also they
interpreted the dated received by encoders and sensors
and programmed based on that data.
Ability to design a system, or process to meet desired
needs within realistic constraints such as economic and
manufacturability.
Ability to function on multidisciplinary teams - The
group was composed of three different mayor
Electrical, Mechanical and Computer engineering.
Ability to identify, formulate, and solve engineering
problems
Understanding of professional and ethical responsibility
Ability to communicate effectively - To achieve the
project’s objective students needed to communicate
efficiently to get the work done.
Ability to use the techniques, skills, and modern
engineering tools necessary for engineering practice
VI. SUGGESTED COURSES
For this research is expected that students have taken
several courses before working on the Micromouse project.
In Table I, there are some courses that the student should
take, or is expected to have some knowledge before taking
part in the design and development of the Micromouse
project. Since this project is multidisciplinary, the table will
have courses from the three majors involved in the project.
Some of this courses have been suggested to other
undergraduate research experiences at UPRM [10], [11].
TABLE I. Suggested Courses [12].
Course
Course Description
INEL 3105 Basic
Circuit Analysis
Analysis of direct current and alternating current
linear electric circuits; laws and concepts that
characterize their behavior
INEL 4102
Intermediate
Circuit Analysis
Networks functions; Circuit analysis by Laplace
Transforms and Fourier series; Two-port
Networks; Butterworth and Chebyshev Filters;
Computer aided Analysis of these System.
INGE 3016
Algorithms and
Computer
Programming
Development
of
algorithms
and
their
implementation in a structured high level
language. Programming techniques applied to the
solution of engineering and mathematical
problems.
INEL 4505
Introduction to
Control Systems
Analysis of Control Systems and their
mathematical models; analysis and design of
Control Systems for single input plants; Computer
solution of problems will be emphasized.
INEL 4201 Basic
Electronics
Circuits Analysis
INEL 4206
Microprocessors
INEL 4416
Introduction to
Power
Electronics
INGE 3809
Creative
Design I
INME 3810
Creative
Design II
INGE 3031
Eng. Mechanics
Statics
INME 4011
Design of
Machine
Elements
ICOM 4015
Advanced
Programming
ICOM 4035
Data Structures
Semiconductor
device
characteristics:
Semiconductor,
Diodes,
Bipolar
Junction
Transistors and Field Effect Transistors; analysis
of basic digital circuits; analysis and design
considerations
of
Transistor
Amplifier
Introduction to Integrated Circuits.
Architecture, organization and operation of
microprocessors and their supporting devices;
design of Microprocessor based systems.
Introduction to basic power electronic topologies
including but not limited to rectifiers (AC-DC),
buck, boost, buck-boost converters (DC-DC),
inverters (DC-AC), cycloconverters (AC-AC).
Introduction to the underlying principles and
methodologies of engineering graphics
communications. Fundamentals of graphic
visualization, sketching, PC-based ComputerAided-Design (CAD), and technical presentations.
Product dissection, hands-on dissection exercises
to develop in students the ability to understand a
machine in not only its functionality but also in
terms of its history, social impact and the design
methodology. Use of proper technical vocabulary
to describe mechanical and electrical components.
Analysis of Force Systems; The Laws of
Equilibrium; Analysis of Simplestructures;
Distributed Loads; Friction; Centroids and
Moments of Intertia.
Application of strength of materials and material
science in machine element design. Introduction
and use of static and dynamic failure theories in
the design of machine elements.
Advanced programming techniques applied to the
solution of engineering problems; extensive use of
subprograms, logical and specification statements.
Principles of multiprogramming, multiprocessing,
and real-time systems.
Data structures in programming languages,
representation of information as data. List in
linear, orthogonal, strings and array distribution,
collection, and sorting data. Tree structures.
Techniques for storage allocation, distribution,
collection, and sorting data.
VII. FUTURE WORK
During the process of research and design it was known
to the students that using the IR Sensors would require a
bigger Micromouse. For further works it is planned to use
smaller IR Sensors so the design would be smaller. Also it is
planned the implementation of a maze’s solving algorithm to
this new version of the Micromouse so it can solve the maze
autonomously. The research group noticed that it was needed
a modular Micromouse for this kind of activities that is way
the robot presented in this paper have some parts and
components considered for our next design.
VIII. CONCLUSION
The students in this research were able to design and
build a Micromouse capable of navigating through a maze.
They were able to identify problems in design and overcome
them with different approaches. At the end the Micromouse
responded to the commands send via Bluetooth. This kind of
research takes the students to a whole new level of
experience and challenge. They can acquire knowledge with
the interaction of students from different majors. While they
interact they develop team work and oral skills. The
experience working in the lab with the different programs
and design tools gives the student a close approach of what
a STEM career will be.
ACKNOWLEDGMENTS
The authors gratefully acknowledge the contributions of
General Motors (GM), Minds2CREATE Research Team,
UPRM’s ECE Industrial Affiliates Program (IAP), Eng.
Daniel Merced, Eng. Carlos Molina and Eng. Fernando
Bird.
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