## 3 Robotics-Academy Design
### Physical and Simulated Robots Availability: Gazebo  
One of the first design decisions was not to focus the exercises on a specific robot, but to choose a variety of platforms: drones, robot TurtleBot with wheels, cars, humanoids, etc. with the idea of being able to design practical sessions that cover different aspects of robotics without the limitation of a particular robot typology or model. This contrasts with other teaching suites focused on a specific robot platform like [17].  
Figure 2 shows some of the robots supported by the current version of the teaching suite. These include indoor robots with wheels and differential traction, such as the TurtleBot robot (real  
Figure 1: Design of exercises in Robotics-Academy.  
and simulated), or outdoor ones like a Formula-1 car and a simulated taxi. Drones typology is also supported, for instance, Parrot ArDrone is included in both real and simulated versions. It also offers the possibility of practical activities with sensors such as cameras, lasers, Global Positioning System (GPS), RGB-D cameras (Kinect, Xtion), etc.  
Simulators are frequently used in robotics, both in research and in teaching. Some of their advantages in education are:  
* Simulators allow robotics to be learnt with complex and powerful robots without the real hardware. They facilitate learning for many students, as sessions can be conducted with more learners than real available robots. They are ideal, for example, for mass online courses.
* In a simulator the programming failures by students do not damage any real hardware.
* It is possible to reduce the complexity of some problems taking information from the simulator. For example, the simulator provides the true absolute position of the robot at any time. The student may take it for granted and focus only on the control code, not the self-localization.
* They allow fair comparisons for gamification, and results indicate that games and/or simulations have a positive impact on learning goals [41]. With simulators, the code of all students can be executed exactly on the same machine and in the same simulated world.
* They enable development of automatic evaluators for the assessment of the student's solutions. These evaluators can be connected to the simulated world collecting all the data needed to evaluate the quality of the student's solution.  
Experience with real platforms is academically very valuable in itself, although it has some practical drawbacks too. The software design for Robotics-Academy allows a balance between practical sessions with simulated robots and with physical robots (when available). It permits the same  
Figure 2: Some of the robots supported in Robotics-Academy.  
academic application to be connected to a physical robot or its simulated counterpart with only a few configuration changes.  
There are many simulators available: V-REP, Webots, etc. All the practical sessions presented in this paper for teaching intelligent robotics were designed to work with the Gazebo simulator [42], which has been chosen as a reference ([[http://gazebosim.org](http://gazebosim.org)]([http://gazebosim.org](http://gazebosim.org))). It is free software, of high quality, maintained by the Open Source Robotics Foundation (OSRF) and has great acceptance in the international robotics community. The version currently used in Robotics-Academy is Gazebo-9.