A Novel Three Degrees of Freedom Haptic Device for Rendering Texture, Stiffness, Shape, and Shear

Abstract

Rendering haptic feedback, particularly tactile feedback of various objects or the environment, extends its usage in a wide variety of applications in order to provide a realistic experience for the user. Conventional methods for reproducing tactile sensations involve utilizing piezoelectric, electro-tactile, and other types of actuators, which do not lend themselves the flexibility to reproduce various surface textures in real time. In this paper, we present the design and development of a novel three Degrees of Freedom (DoF) tactile haptic device to acquire haptic feedback from a known virtual/remote environment. The haptic sensations are rendered to the user through a two-DoF spherical segment of the device consisting of an array of surfaces. The roll and pitch motion of the spherical segment provides tactile cues like texture and shear. Additional DoF provides the stiffness and shape variations based on the feedback it receives. A semi-compliant four-link mechanism, mounted on a gimbal setup, provides the necessary stiffness/shape variation effects. A prototype of the device has been fabricated and tested. The preliminary experimental results confirm the fidelity of haptic feedback to the user while interacting with the environment.