Dynamic Manipulation Based on Thumb Opposability: Passivity-Based Blind Grasping and Manipulation

Abstract Force/torque closure is one of the most powerful tools to evaluate a grasp and while it is only a necessary condition to secure a grasp; another control strategy is, therefore, needed to robustly stabilize a grasped object. We will discuss about a robust grasp control method called blind grasping, based on thumb opposability and is one of the most important anatomical features of the hands. The controller can be easily implemented without force sensors and object sensing. Furthermore, it is easy to superpose lower-priority tasks on this controller. We implement this controller in several robotic hand systems, such as teleoperated and semiautonomous systems, and will show the robustness of the proposed method.