Trigonometry Algorithm for Ball Heading Prediction of Barelang-FC Goal Keeper

In the area of humanoid robot soccer, the goalkeeper has a crucial role in order to predict the ball coming. The keeper should understand whether the ball is attacking the goal field. So that, the robot can block the ball from opponent scoring. In this paper, we introduced another algorithm to predict the ball coming from the attacker. We used trigonometry algorithm to predict the ball directly to the current keeper position. This algorithm is used to estimate the distance between robot and ball while it on a line in horizontal position. The algorithm is implemented in real-time on humanoid robot goalkeeper of Barelang-FC. The experimental results show that this algorithm can predict the ball coming toward to the robot keeper properly and made the robot know the right position for slamming its body while ball is coming then avoid the scoring.