Robotic table tennis based on physical models of aerodynamics and rebounds

In this paper, we develop a robotic table tennis system based on explicit physical models of the ball motion with our developed real-time measuring method of the flying rotated ball. In order for a robot with a racket to hit the ball to a target point, a determination method of the racket motion is proposed. The motion determination method is performed by two sub inverse problems of the physical models. The first inverse problem is to solve the aerodynamics with respect to the velocity just after the time when the ball is hit. With the solved velocity, the second inverse problem is to solve the racket rebound model with respect to the orientation and velocity of the racket. In these problems, the elevation angle of the racket and the launch angle of the hit ball are the redundant parameters. The racket velocity is minimized with respect to these parameters in order not to break the speed limitation due to the robot performance. The effectiveness of the method is verified by some experiments.