Biomimetic Design of Low Stiffness Actuator Systems for Prosthetic Limbs

Abstract

The various relationships that are possible between the mechanical properties of single actuators and the overall mechanism (in this case a human arm with or without a prosthetic elbow) are discussed. Graphical and analytical techniques for describing the range of overall limb stiffnesses that are achievable and for characterizing the overall limb stiffness have been developed. Using a biomimetic approach and, considering energetic costs, stability and complexity, the implications of choosing passive or active implementations of stiffness are discussed. These techniques and approaches are particularly applicable with redundant (agonist -antagonist) actuators and multiple degrees of freedom. Finally, a novel biomimetic approach for control is proposed.