Lehrstuhl für Bildverarbeitung
Institute of Imaging & Computer Vision
Practicing Engineering in a First-Year Student Project:
MATLAB meets LEGO Mindstorms
Alexander Behrens1, Linus Atorf1, Robert Schwann2, Johannes Ballé3,Thomas Herold4 and Aulis Telle5
1Institute
of Imaging and Computer Vision, 2Chair of Electrical Engineering and Computer Systems,
and Institute of Communications Engineering, 4Institute of Electrical Machines, and
5Institute of Communication Systems and Data Processing, RWTH Aachen University, 52056 Aachen, Germany
3Chair
Introduction
™ Practical undergraduate courses of electrical
engineering can strongly motivate students by
situations in which they “feel like engineers”, and
can give them insights in practical methods and
basic engineering concepts.
™ Against this background the Faculty of Electrical
Engineering and Information Technology at
RWTH Aachen University established a new first
semester laboratory, called “MATLAB meets
LEGO Mindstorms”.
Learning Targets
Practical Project Activities
Basic Exercises:
™ Student groups of two
™ Six basic exercises (Fig. 2, 3)
address NXT sensors
(touch, sound, light, ultrasonic) and motors (Fig. 1).
™ Teaching programming
principles in MATLAB.
Fig. 5: 2D Scanner with rotation angles of the joints (left),
sampled image (middle), interpolation (right).
Presentation:
Fig. 1: LEGO Mindstorms
NXT hardware.
™ Measuring NXT hardware characteristics.
™ Transfer of mathematical and DSP methods to
MATLAB algorithms and programs.
Three educational objectives:
™ Practical Engineering: Performing real-world
applications and challenging tasks by using
programmable and remote-controlled LEGO
Mindstorms NXT robots. Students handle tasks
with limited project resources in a limited time
period. Peer learning and soft skills like
collaboration and team work are supported.
Project Structure & Management
™ Eight day full-time block course.
™ 309 freshman students, >60 supervisors at 23
institutes, >150 computer work places,
100 LEGO Mindstorms NXT robotics sets.
™ Focus on mathematical methods, DSP, and
mechatronics using MATLAB.
™ Small core team of supervisors developed
practical exercises and “RWTH – Mindstorms NXT
Toolbox” for MATLAB.
Fig. 2: Exercise 4: Complex Phase Machine. Left: MATLAB plot of
complex phases, right: Mechanical simulation displayed by LEGO
pointers.
Fig. 6: Evaluation Results (Rates: A: excellent, B: good,
C: average, D: below average, E: inadequate).
™ 48% of the students improved their MATLAB
programming skills from “average” to “excellent”.
Fig. 3: Exercise 6: Explorer Robot scans the local environment
(left: 360° distance profile, right: Enclosure with an open gate).
Major Tasks:
™ Student groups of four could choose between
different tasks (Fig. 4, 5):
ƒ 3D Robot Arm: Grabs and sorts colored balls
ƒ Parcours Robot: Enters and maps a maze
ƒ 2D Scanner: Acts as an image scanner
ƒ Definition of an own creative application
™ Room for creativity, individual robot constructions and design, and creative problem solving
methods.
RWTH – Mindstorms NXT Toolbox
™ Number of shared Mindstorms kits and Bluetooth
latencies, which prohibit a real-time controlling
were critically mentioned.
™ 45% of the students
developed their own
individual applications,
e.g. bowling robot,
sorting machine,
morse en-/decoder.
Fig. 7: Morse En- and Decoder
Î First semester students were highly encouraged
to transfer mathematical principles to robotics by
broadening their MATLAB skills at the same time.
Î Less creative students were encouraged by
predetermined and documented applications.
™ Toolbox functions provide low and high-level
functions for comfortable usability to control
different NXT sensors and actors.
™ http://www.mindstorms.rwth-aachen.de
Established as a free open source software.
™ High motivation was also expressed by group
dynamics, debates and critical reflections.
Î Social skills like team work, managing assigned
tasks in a given time frame were supported.
™ Supports a direct Bluetooth communication
between MATLAB and Mindstorms robots.
ƒ Example Code:
>> OpenUltrasonic(SENSOR_1);
>> distance = GetUltrasonic(SENSOR_1)
distance = 36
Evaluation & Results
™ 175 students participated in anonymous online
evaluation.
™ Mathematical methods: Broadening and
applying student’s mathematical basic
knowledge, digital signal processing (DSP), and
system theory, which are taught by the
associated lecture “Mathematical Methods of
Electrical Engineering”.
™ MATLAB: Acquisition of MATLAB programming
skills and transfer of mathematical methods to
programming algorithms. Introduction of
MATLAB is motivated by the direct and intuitive
access to vectors and matrices.
™ Student groups present their individual robots
and discuss their MATLAB algorithms in a
20 minute presentation.
http://www.lfb.rwth-aachen.de/mindstorms
Acknowledgements
Fig. 4: Upper row: 3D Robot Arm with monitored status,
lower row: Parcours Robot with route mapping.
™ We like to thank Prof. Dr.-Ing. Til Aach, Institute
of Imaging & Computer Vision, and Prof. Dr.-Ing.
Tobias G. Noll, Chair of Electrical Engineering and
Computer Systems, RWTH Aachen University,
who supervised this project as faculty.
Institute of Imaging & Computer Vision, RWTH Aachen University
Prof. Dr.-Ing. Til Aach, Sommerfeldstr. 24, D-52074 Aachen
http://www.lfb.rwth-aachen.de, lfb@lfb.rwth-aachen.de