On tactile sensing and display

With the aid of telerobotics it has become possible to manipulate an object across the world or even on another planet. But how can the user feel what the remote robot hand is touching? The challenges associated with displaying tactile sensations are formidable, requiring the ability to recreate changing contact geometries, pressure distributions and vibrations at the user's fingertips. Despite years of research, telerobotic consoles provide their operators mainly with visual feedback and overall handling forces. The experience is akin to manipulating an object with fireplace tongs. The goal of the research presented herein is to extend the capabilities of current systems by imparting tactile sensations to their users.; This thesis presents new methods of tactile sensing and display for dexterous telemanipulation, i.e., telemanipulation that involves imparting forces and motions with the fingertips. The motivating hypothesis for this work is that sensing and displaying contact location provides essential information for dexterous telemanipulation. A new tactile sensor is presented that consists of an array of curvature-measuring elements. The curvature measurements provide information for manipulation planning and control and provide an estimate of the local object geometry, useful for grasp stability analysis. The approach is validated in simulation and experimentally.; The companion to the sensor is a display that allows users to track finger/object contact locations. The tactile display renders the location of the contact centroid on a user's fingertip and thereby provides the user with cues about object motion and curvature. The ability of users to discriminate among different object curvature and motion conditions is investigated in a series of experiments involving real and virtual objects rendered via the display. The results indicate that contact location provides an important cue for dexterous telemanipulation and that, for gently curved objects, the performance of users with the display is comparable to their performance when they touch objects directly with their own fingertips.