A Study on Estimation of Rotational Radius in Alpine Ski Turns Using Inertial and Magnetic Field Sensors and GPS Receiver

This paper proposes a method for estimating the turning radius in alpine ski turns using inertial and magnetic field sensors and GPS receivers. Ski-turn radii were estimated using gliding speeds and angular velocities, and gliding speeds were estimated using output from inertial/magnetic field sensors and a GPS receiver. The authors estimated the turning radii of carving turns and skidding turns using run data collected from a skier equipped with inertial and magnetic field sensors and a GPS receiver. The estimated turning radii for skidding turns were found to be more accurate than those calculated from the gliding trajectories, and the estimated turning radii for carving turns showed continuous change. Finally, the system used in the proposed method could be developed as a compact and low-cost system, and this method has the potential to be used for the quantitative evaluation of skill in ski turns.