We have improved personal identification accuracy using dynamic center of pressure (COP) data during stepping on and stepping off the balance board. Wii Balance Board data was resampled at 50Hz, log-transformed, smoothed (Savitzky-Golay), and classified into five segments (S1-S5) based on X-axis acceleration. To reduce variability, only stabilization (S2), standing (S3), and pre-fall (S4) were analyzed. In 10-subject experiments using 36 features (including mean, standard deviation, and skewness of position and velocity), SVM (>99%) and random forest (>98%) outperformed XGBoost (∼95%). SHAP analysis confirmed lateral dynamic characteristics in S2 and S4 contribute to classification, demonstrating high accuracy and interpretability.
Kojima et al. (Sun,) studied this question.