Here we have the charging base for our intelligent robot controlled with ROS! First of all, I designed the electronic part, which was tested numerous times in a protoboard. As I told already, it works thanks to 3 IR leds that works as emitters. The beam of one of them creates the Right field, the second one the Left field, and the third one the Near field. These 3 zones allow the robot to know where it is and how it has to move in order to dock in the base. According to the signals that the robot receives, it will move (slower or faster), will turn (right or left) or both at same time, until it will reach to connect to the base. All the leds are connected to the Arduino Uno board with resistences of 220 Ohms and I used a potentiometer to regulate how far the robot can receive the signal of the third IR emitter. One of the functions of the Near field is to move the robot slower and more precisely than when the robot is farther. To control the angle of the beam of the IR leds and the zones that they create, it was necessary to do many tests with different solutions. The best and simplest one is to use a short tube with the leds inside, in this case, it is a hear shrink tube which facilitates the fixation to the leds. About the box and the connectors in the base, they were designed in FreeCAD and printed in one of the fantastic 3D printers of our lab. The 3D models will be shared later, but you can see some of the photos already here. As you can notice in the photos, the connectors were designed to be mounted inside the case with 3mm screws, plastic tubes and springs for each one. The connection surface was made with copper strip.