四ローラ式ピッチングマシンの投球性能に関する研究

抄録

Studies with respect to the ball games, such as baseball, tennis, and table tennis, have been attracted more and more attention of scholars. Among these studies, development of the ball pitching machine is very helpful for training ball players. However, up to now, there are only a few developed pitching machines that can pitch a ball (e.g. football) considering the gyro spin, where the axis of the ball spins is in the same direction of the ball travels. In this study, we develop a baseball pitching machine with new launch mechanism by utilizing four rollers (two launch rollers and two gyro rollers). The developed pitching machine can pitch balls repeatedly with certainly controlling speeds and pitch types towards to the batter desires. According to the results of the pitching tests, the four-roller type pitching machine can pitch baseball balls with a wide range of speeds from 22.2 m/s (80 km/h) to 44.4 m/s (160 km/h) and can perform all pitch types (no-spin, fastball, curveball, slider and gyro ball) in any direction. Moreover, comparing to the existing baseball pitching machines, the new four-roller type pitching machine has capable of pitching balls within a higher control accuracy (less than 116 mm).