Morphing Hands and Virtual Tools (or What Good is an Extra Degree of Freedom

Abstract

Manipulators with large numbers of degrees of freedom, from the human hand to the trunk of an elephant, are common in the biological world. These freedoms allow highly flexible and robust performance of complex tasks. However, progress in developing and controlling artificial high-degree-of freedom manipulators has been slow. The main problem is that traditional robotics has focussed on the solution of systems of kinematic equations where there is a unique solution. Such approaches tend not to generalize well to situations with a high-dimensional solution space, and controlling redundant systems has acquired a reputation as a hard problem. However, this need not be the case. In this paper, we describe a behavioral method for using extra degrees of freedom to simplify rather than complicate manipulation problems, while at the same time obtaining more flexibility than would be available with a simpler system. The method is developed in the context of a high DOF robot hand, but it has the...