Currito – Educational Robot

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March 2020. José Maestre Torreblanca –  the Professor of the Department of Systems and Automation Engineering at University of Seville School of Engineering (ESI) – had the idea of designing an educational robot for his students that could be easily manufactured using only open hardware and downloadable CAD files for 3D printing. He contacted us at Puppeteer Technologies to see if we’d be interested in getting involved. We said yes on the spot! Taking BOTSZY to the educational sector was always one of our original goals.

The initial idea was to create a simple robot, with basic functionality and without any type of character design. But we decided to go one step further, and following the current trend of emotional robotics, suggested a new approach. Our version would combine an attractive design to facilitate interaction with students with a high degree of personality and “acting” to increase its attractiveness and appeal to other users, important since the files would be available for anyone to download and DIY manufacture. 

Finally, based on recent history and the location of the ESI itself at the Isla de La Cartuja, what better way to connect students who were born in the years after the Universal Exposition of Seville in 1992 than with a design that pays homage to the event’s mascot. This is how “Currito” was born.

Curro vs Currito

A few months later and after intense work we finished the first prototype, Currito was created, successfully combining our goals for design, interactivity and technological development. Today the University works to promote Currito as a public platform for robotics teaching.

Design and Manufacture 

Since the parts had to be easily manufactured using basic 3D printing techniques widely available to students and makers, we used Fusion 360 by Autodesk to design the minimum number of pieces to suit a 20 x 20 3D printer. 

Currito 3d Print
Slicing parts with CURA software

For our first prototype, we used a Prusa MK3S and an Ender3 MAX from Creality with a premium quality Smartfil ABS plastic from Filament2print and strived to design all the parts to avoid the use of supports.

3D Printing with Prusa MK3S
3D Printing with Prusa MK3S

To ensure expressiveness, Currito incorporates several moving surfaces on his head such as eyebrows, mouth, and crest, as well as various sensors that allow it to interact with the outside world. There’s also a large ring of neopixels that allows the robot to transmit its moods and the health of its various components. In addition, the main eye houses a camera that helps it interact with its immediate surroundings. 

3D Printed Parts
3D Printed Parts
Detail of Currito's Eye
Detail of Currito's Eye
Curritos prototypes assembly
Curritos prototypes assembly
The body is moved by traction wheels and is able to rotate 360 degrees, avoid obstacles and navigate almost any environment through the use of various sensors.

The Technology

Currito’s brain is open hardware using a Raspberry Pi Model 4 board latest batch communicating with an Arduino Uno Rev3 in that’s in charge of managing sensors, motors and servos. For Currito we used high torque metal gear servos from Hobbyking for body movements and micro Turnigy TGY 5009M servos for the facial expressions
Electronics Components
Electronics Components ready to assembly

The camera located on the face is a Raspberry Pi Module 2 connected directly to the main board in order to be able to program functions such as object recognition, pattern creation and environment mapping through the use of OpenCV libraries

CAD model of the head
CAD model of the head

Being a robot specifically designed to interact with students, it needed a series of devices to communicate with the outside world and create an emotional bond. Currito incorporates PIR, light and temperature proximity sensors, and a 6DOF board that allows it to understand its position in the environment. It also incorporates two powerful speakers housed in the lower part of the body. 

Final assembly
Final assembly

On the face, the robot is capable of generating a wide range of expressions using micro servos and the large ring of neopixels located in its main eye, which allows it to create colour patterns and visual sequences.

Currito and BOTSZY 

For an engineering student, it is a novelty to have access to visual software like BOTSZY that allows them to design the robot control rigging in a fast and intuitive way by creating a robot ghost along with the associated variables that will be managed through the OSC protocol, for example, to create a safe movement envelope where no actuator will go outside the established limits, avoiding collisions and dangerous movements.

Botszy UI
Botszy UI

The real wow factor of BOTSZY in this project though, is the ease of interconnection with other software through the OSC protocol. In this case, we are able to use a connection with Matlab and any simulation and study software with Python scripting capacity immediately, overcoming the traditional inconvenience of collecting and storing scientific data.