IEEE Robotics & Automation Magazine - March 2017 - 78

using professional computer-aided design (CAD) tools and the
difficulty to distribute the development. Our solution to
these being to increase the awareness of CAD editors to
open-source hardware and to provide a two-layer development model for hardware.
Background
As mobile robots sense the environment and take actions
based on their perception, they seem to display intentions of
their own [1]. This impression of intelligence, the permeating
presence of robots in science fiction, and their projected use in
our society give a sense of touching the future. Among the
possible reasons robots are not as widespread in schools as
they could be, we believe that the following five play a key role:
1) Although many research projects are developing innovative and interesting educational robots, few reach sufficient
maturity to become distributed and accessible to schools.
2) A versatile robot performing interesting behaviors is a
complex piece of technology and, therefore, expensive.
This prevents most schools, which have a limited budget
for equipment, from acquiring educational robots.
3) Introducing robotic tools into teaching activities requires
investment in time and training for the teachers [2].
Therefore, to be accepted by teachers, robots must be both
accessible with minimal effort and accompanied by wellprepared educational material shared among colleagues.
4) Robot construction, use, and programming are often perceived as boyish activities in Western society [3], [4]. This
strongly limits the potential of robots as general-purpose
educational tools, especially in schools.
5) Finally, many teachers are reluctant to follow volatile
trends, especially if these are based on purely commercial
arguments. Teachers prefer to invest in stable tools, in contrast to trends in current consumer technology.
Open-source hardware projects can address several of these
issues in a different way than closed-source, purely commercial products. By open-source hardware, we mean, following
the definition of the Open Source Hardware Association
(http://www.oshwa.org/definition/), "hardware whose design
is made publicly available so that anyone can study, modify,
distribute, make, and sell the design or hardware based on that
design." In this article, we show that this concept, implemented
in the Thymio project through a community of users, developers, and manufacturers, brings a strong added value to the
robot and to the educational methods. In addition, we compare our experience with other robotics open-source hardware
projects not focused on education and highlight challenges
and opportunities specific to education.
Related Work
Many publications present educational robots, from lowcost systems targeting Africa [5], [6] to extremely sophisticated humanoids [7], [8]. Among those, only a handful are
commercially available, limiting their validation by educational scientists, who are typically not roboticists. As a
result, 90% of publications about validation of educational
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IEEE ROBOTICS & AUTOMATION MAGAZINE

March 2017

results have been based on LEGO Mindstorms [9], a widely
available commercial product. The latest version, EV3
(http://mindstorms.lego.com), is expensive ^. US$400 h but
offers a wide range of possibilities, especially at the mechanical level, using LEGO bricks, and at the software level with
its graphical programming environment. Among the recent
new players on the market is the Edison robot (https://
meetedison.com/), which is extremely low cost (US$49),
robust, and compatible with LEGO bricks. The low price has
pushed drastic design choices: very few sensors, three buttons, two light-emitting diodes (LEDs) as the user interface,
and a unidirectional communication with the computer by
audio jack. These choices strongly limit its possible usage.
Among the robots available on the market, only a few are
open source and used in schools: Scribbler2, produced and
sold by Parallax (http://www.parallax.com) ^. US$180h, is a
large 188-mm robot, designed to move around on the ground
and equipped with a few light sensors, one distance sensor,
two ground sensors, and few LED displays. It runs on standard AA batteries and has a hacker port for interfacing electronic extensions. It is programmable with a graphical or a
textual code interface. The main weakness of Scribbler2 is its
limited number of sensors and compatibility with other systems. Moreover, there seems to be no active community
around its development. The e-puck [10] robot targets university-level education. Well equipped with sensors and actuators, modular, and compact, it can be programmed with
industry-standard environments. Several simulators allow
running highly complex experiments. Its main weakness is its
high price ^. US$870h . Finch (http://www.finchrobot.com/)
^. US$99 h is a very simple robot that has been designed
around a wired connection to the computer. This connection
reduces electronics requirements, such as batteries or wireless
communication, and allows control to be implemented
entirely on the computer. This results in availability of a very
broad set of possible programming languages, which is the
real strength of this robot. However, the cable does not allow
real autonomy and mobility. Finally, the mBot (http://www
.makeblock.cc/mbot/) is a mobile platform based on an Arduino board. Its electronics are simple and inexpensive, and the
robot features only a couple of sensors, which allows drastic
reduction in its price ^. US$75h but also limits the perception possibilities and therefore the span of use.
With respect to these robots, Thymio has a compact size
(110 mm), many interaction possibilities, an affordable price
(US$130), and a large set of sensors. To the best of our
knowledge, beside Thymio, there are no educational products providing a similar integration of sensors and actuators
at a lower price.
Teachers, from primary school up to high school, are a primary target user group of the Thymio project. They decide
which tools are used in their class and are key people in the
education ecosystem. For teachers, the motivation to use
robotic tools depends on many factors [11]. Among them, the
availability of materials and training plays a key role. The
development of educational material and courses to train

http://mindstorms.lego.com http://https:// http://www.meetedison.com/ http://www.parallax.com http://www.finchrobot.com/ http://www http://www.oshwa.org/definition/ http://www.makeblock.cc/mbot/

Table of Contents for the Digital Edition of IEEE Robotics & Automation Magazine - March 2017