Human hand kinematic modeling based on robotic concepts for digit animation with dynamic constraints

Abstract

The recent development of highly anthropomorphic avatars in computer graphics has emphasized the importance of accurate hand kinematic models. Although kinematic methods derived from robotics have recently been applied to the modeling of hands, we consider that original/new and relevant results can be brought into play with the use of more advanced applications of robotic techniques to human hand kinematic modeling. Our chapter analyses some of these questions both in the non-differential and differential fields. More specifically, we study how to integrate the peculiar natural digit movement constraints into robotics-based inverse kinematic modeling. As a result, we propose an original approach based on an interpretation of each joint dynamic constraint as a linear joint synergy. This leads to defining the considered digit as a serial chain kinematically redundant in position and reducing the dimension of its joint space by associated joint synergies. The method is applied to the Cartesian positioning simulation of a 4 d.o.f. index model; a comparison with a Jacobian pseudo-inverse-based approach emphasizes its relevance. © 2009 Springer-Verlag London.