Modulating Fine Roughness Perception of Vibrotactile Textured Surface using Pseudo-haptic Effect

Abstract

Fig. 1. Our proposed method modulates the fine roughness perception of vibrotactile textured surfaces using pseudo-haptic effect. Our user study showed that users felt the surface rougher in response to a parameter configuration of visual feedback.Abstract-Playing back vibrotactile signals through actuators is commonly used to simulate tactile feelings of virtual textured surfaces. However, there is often a small mismatch between the simulated tactile feelings and intended tactile feelings by tactile designers. Thus, a method of modulating the vibrotactile perception is required. We focus on fine roughness perception and we propose a method using a pseudo-haptic effect to modulate fine roughness perception of vibrotactile texture. Specifically, we visually modify the pointer's position on the screen slightly, which indicates the touch position on textured surfaces. We hypothesized that if users receive vibrational feedback watching the pointer visually oscillating back/forth and left/right, users would believe the vibrotactile surfaces more uneven. We also hypothesized that as the size of visual oscillation is getting larger, the amount of modification of roughness perception of vibrotactile surfaces would be larger. We conducted user studies to test the hypotheses. Results of first user study suggested that users felt vibrotactile texture with our method rougher than they did without our method at a high probability. Results of second user study suggested that users felt different roughness for vibrational texture in response to the size of visual oscillation. These results confirmed our hypotheses and they suggested that our method was effective. Also, the same effect could potentially be applied to the visual movement of virtual hands or fingertips when users are interacting with virtual surfaces using their hands.

Surface Roughness Judgment During Finger Exploration Is Changeable by Visual Oscillations

“…As for texture perception, some studies attempted to generate texture perception using the pseudo-haptic effects without sophisticated haptic devices [1,2,5,9,10]. Previously, we proposed a pseudo-haptic method for modulating the vibrotactile roughness of virtual surfaces during pen-surface interactions, and our user study showed the effectiveness of the proposed method [9]. In the method, users watched a visually perturbed contact point.…”

“…This study adopted the same pseudo-haptic method using visual oscillation as [9]. Please see details there.…”

“…The pseudo-haptic sensation [3,7] is produced by an appropriate sensory inconsistency between the physical movement of the body and the observed movement of a virtual pointer [4]. As for texture perception, some studies attempted to generate texture perception using the pseudo-haptic effects without sophisticated haptic devices [1,2,5,9,10]. Previously, we proposed a pseudo-haptic method for modulating the vibrotactile roughness of virtual surfaces during pen-surface interactions, and our user study showed the effectiveness of the proposed method [9].…”

Sense of Resistance for a Cursor Moved by User’s Keystrokes

“…Changing the visual appearance of the visual object often provides illusory haptic sensations to the users manipulating the object. For example, previous studies have shown that pseudo-haptic feedback can modulate the perception of virtual spring compliance ( Lécuyer et al, 2000 ), friction ( Lécuyer et al, 2000 ; Ujitoko et al, 2019a ), object edge angle ( Ban et al, 2012 ), mass ( Dominjon et al, 2005 ; Issartel et al, 2015 ; Yu and Bowman, 2020 ), weight ( Brewster et al, 2019 ), and texture ( Ujitoko et al, 2019b ; Sato et al, 2020 ). A key principle of pseudo-haptic feedback is the spatio-temporal dissociation of vision, haptics, proprioception, and motor control.…”

“…So far, pseudo-haptic feedback has been studied in situations, where a user manipulates a virtual object (e.g., a cursor) by operating a computer mouse ( Lécuyer et al, 2004 ; Dominjon et al, 2005 ; Kumar et al, 2017 ), tablet PCs ( Ujitoko et al, 2015 ; Costes et al, 2019 ), pen devices ( Ujitoko et al, 2019a , b ), virtual hands ( Sato et al, 2020 ), real objects ( Brewster et al, 2019 ), and mixed reality technologies ( Ban et al, 2012 ; Issartel et al, 2015 ; Kawabe, 2020 ). The use of these devices involves hand movements that are more or less consistent in direction with the movement of the virtual object.…”