Measurement of Three-dimensional Orientation of Golf Club Head with One Camera

We developed a method to measure the three-dimensional orientation of a golf club head with one camera using the Newton-Raphson method which requires less calculation time. In this method, the orientation is calculated from the relation between the coordinates of markers on the head in the coordinate system of the club head and the coordinates of markers on the photo. Golfers hit balls with Irons whose club lie angles were 62° and 60° or 64°, and we took photos of the club head hitting balls. We calculated impact lie angles and face angles of the club head using this method and also measured the ball flight with a flight measuring machine. The results are as follows: (1) When the golfers used 64° (60°) clubs, all of them hit balls at larger (smaller) impact lie angles than when using 62° clubs. (2) Most of the landing points of the ball when the golfers used 64° (60°) clubs were more to the left (right) than 62° clubs. However, the reverse was the case with some golfers, because they changed face angles. In fitting, we need to find advanced methods to change lateral deviation adding on changing club lie angle.