Perceiving Surface Roughness via a Rigid Probe: Effects of Exploration Speed and Mode of Touch

Abstract

Two experiments investigated the psychophysical consequences for roughness perception of altering the speed of motion with which textured surfaces are explored using a rigid probe. Two speed ranges were used: a 10-fold change (Experiment 1) and a 4-fold change (Experiment 2). Relative motion was altered both by moving the probe actively over a stationary surface (active mode) and by moving the surfaces under the stationary probe (passive mode). Substantial effects of speed were obtained. The results are examined both in terms of the complex effects of speed on the attributes of the psychophysical roughness functions and in terms of the systematic change in the magnitude of the speed effect contingent on the size of the speed range. We also consider how best to minimize any potentially harmful effects of speed on haptic exploration of simulated textures using haptic interfaces. Two operator training procedures are proposed to achieve effective haptic exploration strategies.