Soccer Electronic

From controlling to measuring

Max
Lead

Timo
Kicker

Nino
Dribbler

Sven
Light Barrier

Jan
ESC

At Soccer Electronic we are developing and designing our own PCBs, test and iterate our designs, which are custom build for our robots. To Design the circuits and PCBs we are using KiCad and LTspice. Many of our circuits are fairly complex so that we have to test very detailed using one of our oscilloscopes. 

ESP32 Module

We are using an ESP32-Wroom Module to control most of the robots functions. The via the connection module incoming velocity commands are converted to motor speeds and passed to the ESC Modul.  In return the ESP-Module sends encoder data and data from the imu to our server. Besides  driving the kicking and dribbling devices have to be controlled by the ESP32. 

Kicker

The Concept

In the soccer small size league, the robots are playing with a standard golf ball, which may be accelerated up to a speed of 6.5 m/s, representing a total kinetic energy of roughly 1 joule. From a variety of options to do so, we have chosen to use an electromagnetic kicking-device, because it meets several crucial requirements like a high reliability and a sufficient „firing-rate“.

Transformation

Through a flybacktransformer energy is stored in a capacitor. While kicking, this energy is dumped into a coil within milliseconds and the coil is attracting a ferromagnetic plunger, which then hits and accelerates the ball.

In the Future

Our current focus of optimization is to choose a good ferromagnetic material allowing for a high flux-density and low eddy-currents and to develop a high speed, low noise capacitor charging circuit, which also meets high safety standards

Network Module

Since the Robocup Competitions are held in different countries around the globe the available radio frequencies may vary. To be more flexible we are using a sperate Network Module which can be switched with other modules to use different frequency areas. 

User Interface

To interact with our robots we need a user-friendly interface which can be accessed even if the robot is assembled and shell is mounted. We decided to use a removeable UI which can be plugin at the interface module on the right of our dribbling device. When the external UI is plugged in the ESP32 get notified and shows internal data on the display. Furthermore robot can be controlled thru a rotatory encoder mounted on the external UI. 

ESC

Task of the ESC Module is to control the BLDC-Motors of our robots. Since BLDC motors are relatively new in this speed region, there aren’t any prebuild speed controllers in out form factor, so we decided to design our own module. To safe space we split the module in half and arrange them on top of another forming a pcb sandwich. So every board has circuits and connectors for two motors. The communication between all boards is realised with our Main Hub.  

TMC4671

Main component of the ESC-Modul is the TMC4671 Chip which is controlling one motor each. Controller loops for position controlling are already integrated in the chip, but never the less it needs some additional circuits for power sensing and voltage switching.

Current sensing

In order to accurately control the motors, the controlling chip needs to know how much current is going thru the motor. We are archiving this by adding Shunt Resistors in line of the three phases of the Motor. The current in each phase is proportional to the voltage over the resistor.

Molex Micro-Fit 3.0

We are using Molex Micro-Fit connector to connect all power electronic on the robot. The connectors can delivery up to 10.5A which is just right for our purpose.

Interested in joining the team?