Evaluation of Grasping Comfort for Screw Driver Considering Individual Differences and its Optimization

Abstract

The aim of this study was to formulate the grasping comfort of screw driver considering the individual difference of participants and optimize its shape. The shape parameters used in this study were the grip length L, end diameter d_e, and middle diameter d_m. The subjective scores of grasping ease were measured with 12 subjects. The relationship between the grasping comfort and shape parameters was modeled by the hierarchical Bayesian modeling. Regression coefficients were expressed by a combination of a global term for the whole participants and an individual term of each participant so as to consider the individual difference. Optimal shape parameters were determined by the predicted regression equation of grasping comfort, and the posterior distribution of grasping comfort for the optimal shape was investigated.