A Fingertip Glove with Motor Rotational Acceleration Enables Stiffness Perception When Grasping a Virtual Object

We developed a 3D virtual reality system comprising two fingertip gloves and a finger-motion capture device to deliver a force feedback sensation when grasping a virtual object. Each glove provides a pseudo-force sensation to a fingertip via asymmetric vibration of a DC motor. In this paper, we describe our algorithms for providing this illusionary force feedback, as well as visual feedback, which involved deforming the shape of a virtual object. We also conducted an experiment to investigate whether presenting pseudo-force sensation to the tip of the thumb and index finger during grasping enabled participants to interpret the material stiffness of a virtual object. We changed the initial vibration amplitude, which represents the reaction force when the thumb and the index finger initially contact the surface of an object, and asked participants to match each haptic feedback condition with a visual feedback condition. We found that most participants chose the rubber or wood material (task 1) and highly deformable material (task 2) when the initial vibration was weak, and chose the wood or aluminum (task 1) and non-deformable material (task 2) when the initial vibration was strong.