Modeling golf ball roll with a variable coefficient of friction

Engineering of Sport 15 - Proceedings from the 15th International Conference on the Engineering of Sport (ISEA 2024)

A golf putt can be broken down into three main sections: a bouncing phase, a skidding phase, and a rolling phase. In many current models of the rolling phase, the interaction between the golf ball and turf is represented with a retarding force, modeled with a constant applied to the normal force (either a coefficient of rolling friction or a measure of the off-center center of gravity created by grass blade deformation). Hubbard and Always (1999) found that using a constant coefficient of friction models a putt well, but a high speed camera showed thisrolling coefficient of friction can vary about 10% over the course of a putt. It has not been investigated whether this range is the same for all putting surface types, nor whether incorporating this range has any significant effect on the ability of a model to predict a putt’s length given some initial conditions. This work presents results supporting the use of a nonconstant coefficient of rolling friction for modeling golf putts and additionally provides fitted values of these coefficients over various initial velocity ranges and putting surfaces.