A kicking system can be described as a mechanical manipulator used to accelerate a ball to a desired velocity to a desired trajectory. This can be achieved in many different ways with various actuators. Check out this research paper
Segway CMBalance Robot Soccer Player.
http://www.dtic.mil/cgi-bin/GetTRDoc...c=GetTRDoc.pdf
The paper presents information necessary to design and implement a soccer ball manipulation system for a mobile robot such as ours. We used to concepts in this paper to design the pneumatic kicking system we are going to use.