Tactile roughness of grooved surfaces: A model and the effect of friction

Abstract

Previous experimental data on the roughness of grooved aluminum tiles provide a data base against which to test theories of roughness perception. A model based on the static deformation of the skin to.uching the stimulus tile is developed, and 11 parameters of the deformation are individually compared with the experimental data. All parameters were tested first in an approximate way, and then the better parameters were recalculated in a more exact manner. Three parameters, the depth to which the finger penetrates the groove, the cross-sectional area of the finger within the groove, and the cross-sectional area of the deviation of the skin from its resting position, all predict the roughness well as a function of finger force and groove width. The last of the three predicts roughness best as a function of land width, and is tentatively preferred as "the stimulus for roughness." All predictions from the static model indicate that variation of the coefficient of friction between skin and tile should have little or no effect. This counterintuitive prediction was confirmed by an experiment.Although psychophysics has been with us for over a century, there has been little discussion and no agreement on what constitutes the stimulus for roughness. There are two probable reasons for this lack: stimuli graded in an appropriate physical dimension are hard to manufacture, and knowledge of the tactile receptor systems and their functions is quite limited. There is so little agreement on the stimulus for roughness that the present authors were able to engage in a difference of opinion with their co-author in a recent chapter on texture perception (Taylor, Lederman, & Gibson, 1973). Gibson claimed that the perceived roughness of a surface depended on the frequency of vibration induced by the passage of the finger over the surface, while Taylor and Lederman held that vibratory energy, rather than its frequency, was responsible. The present paper introduces the hypothesis that neither vibratory frequency nor vibratory energy is the stimulus for perceived roughness; the deformation of the skin rather than the energy involved in the deformation is the important factor.

The perception of surface roughness by active and passive touch

“…The finding' that the magnitude estimates are identical, whether subjects move their hands across a stationary surface or the surface is moved across the stationary hand , confirms the prediction made by the Katz (1925) and Taylor and Lederman (1975) interpretations of roughness perception. The study also indicates that perceived roughness does not depend upon movements of the hand perse.…”

“…The study also indicates that perceived roughness does not depend upon movements of the hand perse. As Katz (1925) and Taylor and Lederman (1975) have argued , relative motion is required between hand and object; however, this motion can be produced by a moving object or by the moving hand . Either way, the vibrations, which the above investigators consider necessary for the perception of roughness, are produced in the skin.…”

“…Regarding the outcome of the current experiment, therefore, the Taylor and Lederman (1975) model and, likely, Katz's (1925) work would predict that magnitude estimates of roughness should be identical, whether active or passive touch is used (provided that force remains constant). The relative consistency of the judgments by active and passive touch is also considered, although neither interpretation makes a specific prediction regarding the outcome.…”

Haptic perception: A tutorial

“…Neither changing hand speed (see also Meftah, Belingard, & Chapman, 2000) nor preadapting the surface/object is manually explored. Surface properties have been extensively studied, and one of the most important factors found to affect perceived roughness is the gap between the elements that constitute the surface; the width of the elements has a smaller effect (M. M. Taylor & Lederman, 1975). Lederman and Taylor (1972;M.…”

“…Surface properties have been extensively studied, and one of the most important factors found to affect perceived roughness is the gap between the elements that constitute the surface; the width of the elements has a smaller effect (M. M. Taylor & Lederman, 1975). Lederman and Taylor (1972;M. M. Taylor & Lederman, 1975; see also Lederman, 1974Lederman, , 1983) developed a mechanical model of roughness per- Bensmaïa, & Risner, 1998).…”