- This paper deals with the trajectory planning of a soccer ball driven by a kicking robot. The trajectory of a ball is function of its initial velocity, launch angle, and some aerodynamic effect. Specially, the initial velocity is created by an instant impulse given to the ball. The external impulse exerted to a ball by a kicking robot is function of robot geometry and dynamic parameters. Initially, we analyze the external impulses for several kicking postures and simulate trajectories for several different kicking conditions. Based on this observation, a trajectory-planning algorithm of a ball, in which the initial velocity and the launch angle of the ball are calculated for a desired trajectory of the ball, is proposed, and then an external impulse required for that motion is calculated and applied to the kicking simulation. The aerodynamic effect such as drag force and lift force is also incorporated into the dynamic simulation of the soccer ball. A kicking robot has been developed...