The Carpe Noctem Cassel robotic soccer team consisted of four field players and one goalkeeper. The robots came a long way since the team's foundation in 2005. Hardware as well as software underwent a continuous development in order to adapt to yearly rule changes.
Each robot moves on a platform equipped with an omni-directional drive. The wheels consist of a big wheel that can move forward and backward. Embedded in that are multiple smaller wheels which allow motion in a perpendicular direction of the big wheel itself. Thanks to this omni-directional drive, the robots can move easily in any desired direction and rotate at the same time.
To be able to localize itself and get important information about what is happening on the field, a variety of sensors can be used, such as cameras or laser range finders. The key element for the vision of our robots is a camera which is mounted at the top of the robot. Currently equipped is a Point Grey Flea 2. The camera is pointed up at a mirror which creates a 360° view and the robot is given the visual data of the reflection in the mirror to process.
Dribbling and handling the ball without giving the other team a chance to take it is another important ability the robots need. When the robot is in close range to the ball, two small wheels in the front are used to draw the ball towards the robot.
The kicking device for the robot is a set of shovels that is triggered by a magnetic coil. According to the amount of voltage and time the coil is short-circuited, the kick can be more or less strong, allowing for soft kicks in case of a pass or strong kicks when attempting to shoot a goal.
Any data that is given to a robot by its sensors needs to be processed by software running on an on-board computer. Together, the robots build a view of the current state of the world around them. This is especially challenging because sensory information can be faulty or inconsistent and the robots are in a highly dynamic environment. The base of our robot's cooperation is ALICA (A Language for Interactive Cooperative Agents). It has been developed by Carpe Noctem Cassel to model strategic game play and intelligent behaviors for our robots. In game play, the robots need to make decisions and work cooperatively in a team in order to reach their objective of scoring a goal.
For more information about the work of Carpe Noctem, we recommend to read our team description paper, that was part of the qualification material for the RoboCup World Championship 2016.