Abstract: The placement determination control part 103 determines whether a ball was placed in a left trigger zone within the left detecting zone of the left capturing zone or a right trigger zone within the right detecting zone of the right capturing zone, using left and right cameras. The appearance determination control part 104 determines if an object appeared in a placement detecting zone, including a placement trigger zone, using the infrared sensor corresponding to the camera of that zone. The disappearance determination control part 105 determines if the ball disappeared from the placement detecting zone where the object appeared, using the corresponding infrared sensor. The next appearance determination control part 105 checks whether the ball appeared in a launch detecting zone, using the infrared sensor corresponding to the launch detecting zone adjacent to the placement detecting zone. The signal transmission control part 106 transmits a trigger signal accordingly.

Abstract: The prediction control part 204 predicts a three-dimensional position and a three-dimensional velocity of the world coordinate system of the flying ball at a specific time after the initial time as a predicted position and a predicted velocity based on initial position and initial velocity of flying ball, and an equation indicating a parabolic shape of the flying ball. The conversion control part 205 converts the predicted position into a two-dimensional position of a camera coordinate system as a temporary position. The acquisition control part 206 specifies a flying ball image and acquires a two-dimensional position of the camera coordinate system of the flying ball image as an observation position. The correction control part 207 corrects the predicted position and the predicted velocity as a corrected position and a corrected velocity based on the predicted position and the predicted velocity, the observation position, and a Kalman filter.

Abstract: The ball existence determining part 301 determines a specific infrared zone where the stopped ball exists as a ball existing zone in plural infrared zones. The first object appearance determining part 302 determines the front and end infrared zones being adjacent the ball existing zone as front and end object appearance schedule zones, and determines whether or not the object for launching the ball appeared in either one of the front and end object appearance schedule zones. The second object appearance determining part 303 determines whether or not the object appeared in the remaining object appearance schedule zone when the object appeared in either one of the front and end object appearance schedule zones. The ball disappearance determining part 304 determines whether or not the ball in the ball existing zone disappeared when the object appeared in the remaining object appearance schedule zone.