Discrimination of the shot distance by putter head motions of golf

Abstract

In previous study, we proposed three dimensional motion measurement system which was composed of gyro sensor and infrared sensor to measure golf putter head motion. In this paper, we propose a method to discriminate the shot distance from the rotational and translational motions of the putter head. Rotational and translational motions of the putter head were measured by the proposed system with changing the distance to the cup from the rest position of the ball (Short:150 cm, Middle : 300 cm, Long : 450 cm). Four motion variables affecting the shot distance were selected by cluster analysis as follows: (1) The minimum displacement in the X axis direction before the impact, (2) The maximum displacement in the Y axis direction at the impact, (3) The angular velocity around the z axis at the impact, and (4) The angle around the x axis before the impact. The canonical discriminant analysis was used to distinguish among the shot distances. Objective variable was 3 kinds of the shot distances, and explanatory variable was 4 motion variables. As a result of the canonical discriminant analysis, accuracy rate was 93.4%. Next, the subjective data which isn't used for calculation of a discriminant was substituted for canonical discriminant equations. As a result, in short distance, the accuracy rate of all subjects was 100%. On the other hand, in the middle and long distance, the highest accuracy rate was 100%, and the lowest accuracy rate was 50%. In addition, the angular velocity around the z axis at the impact greatly contributed to shot distance.

Keywords

• sports engineering
• discrimination
• canonical discriminant analysis
• golf
• putter head motions
• shot distance