Three Dimensional Model of Human Hands and Simulation Considering Elasticity of Fingers and Joints

Abstract

This paper describes a three-dimensional model of a human hand considering the softness of fingers and the revolving resistance of finger joints. They are expressed by nonlinear springs that can set limits to their possible displacements. To measure the elastic characteristics of nonlinear springs and the friction coefficients of finger ball skin, three measuring devices are developed. Based on the model with elasticity of fingers and joints, a simulation method is proposed which makes it possible to estimate torques by muscle, torques by elasticity, the distribution of acting forces between fingers and an object, and the stability of a grasped object. An example of the simulation in which a square object is grasped with a thumb and a middle finger is exlpained to evaluate the effectiveness of the simulation method proposed. © 1991, The Japan Society for Precision Engineering. All rights reserved.