Development of a Function to Evaluate Forearm Torsion Operations for Digital Human Model

Abstract

The purpose of this study is to add a function that evaluates the operations with the forearm torsion, such as screw driving and knob turning, to digital human models. The rotational ranges of an object gripped with a hand and the working postures of the upper limb were measured at various positions of the object. As a result, it was demonstrated that the rotational ranges of the object varied depending on the working posture. The degree of coincidence was defined among direction vectors for each segment in the link model consisting of the upper limb and the rotated object, and a method was proposed to estimate the rotational ranges of the object from the degree of coincidence. Finally software has been developed in order to evaluate the operations with the forearm torsion based on the method.