A Multi-DoF Exoskeleton Haptic Device for the Grasping of a Compliant Object Adapting to a User's Motion Using Jamming Transitions
Ryohei Michikawa, Takahiro Endo, Fumitoshi Matsuno
Abstract
In the recently growing field of virtual reality, the virtual grasping sensation remains in its infancy, and the discrepancy between real and virtual grasping has become a problem. This article develops a new haptic glove that presents the sensation of different types of grasping (e.g., power/precision/intermediate grasping) a compliant object. To this end, we develop an exoskeleton that fixes the movements of fingers to present a braking force and a flexible pad that reproduces a wide range of stiffness. By applying the “string jamming mechanism,” our exoskeleton has functions that existing devices do not. In that, it constrains the motion of finger extension/flexion and adduction/abduction with only one actuator and presents the braking force to all surfaces of the finger. In addition, we propose a lightweight and compact variable-stiffness pad that reproduces an extensive stiffness range based on the layer jamming technique. We conducted experiments to evaluate the mechanical performance of the prototype integrating the exoskeleton and the variable-stiffness pad and demonstrated the usefulness of the proposed glove.