Psychophysical evaluation of a variable friction tactile interface

Humans perceive a force applied to their fingertips by integrating skin and proprioceptive sensations. In this study, we investigated the relative contribution ratios of these sensations using two approaches. Decoupled forces were applied to the finger pad and proximal interphalangeal joint of the index finger of the participants. First, we calculated the ratios from the point of subjective equality between the skin and the proprioceptive perceptions. Second, we obtained discrimination limens of the two perceptions to compute their contribution ratios. The results of these two approaches showed good agreement. Additionally, we investigated how the magnitudes of forces, which were 1.0 and 0.3 N, applied to a fingertip affect the relative contribution ratios of the two sensory channels. When humans perceived the force of 1.0 N, the relative contribution ratios of skin and proprioceptive sensations were 16-28 and 72-84 percent, respectively. In contrast, when humans perceived the force of 0.3 N, the relative contribution ratios were 37-55 and 45-63 percent, respectively. These relative contribution ratios can be utilized for the design of efficient haptic interfaces.

Section: Review Of Dls In Related Studiessupporting

confidence: 92%

Relative Contribution Ratios of Skin and Proprioceptive Sensations in Perception of Force Applied to Fingertip

Matsui

Okamoto

Yamada

2014

“…Considering that the base friction was approximately 0.2 N as shown in Fig. 5(a), the just noticeable difference (JND) in this measurement was approximately 20%, which coincides with a study reporting that the JND of friction is 18% [29]. The results show that the device can provide wide range of perceptible haptic feedback from, at least, 0.04 N to beyond 1 N.…”

Section: Threshold Of Haptic Feedbacksupporting

confidence: 82%

A Multi-User Surface Visuo-Haptic Display Using Electrostatic Friction Modulation and Capacitive-Type Position Sensing

Nakamura

Yamamoto

2016

This paper proposes a visuo-haptic feedback system that can provide haptic feedback to multiple users on an LCD monitor using electrostatic adhesion and built-in capacitive sensors. The prototype system consists of a 40-inch LCD monitor, an ITO electrode sheet arranged on the monitor, and multiple contact pads for electrostatic adhesion. By applying low-frequency haptic voltage and high-frequency sensing voltage to each pad, the system realizes passive haptic feedback, as well as position sensing using the same components. The passive haptic feedback force exceeds 1 N at 300 V rms. The performance of the sensing system is investigated in terms of interference, which shows the haptic voltage and existence of multiple pads can affect the sensing and can shift the output by a few millimeters. A pilot application, virtual hockey game, successfully demonstrates the sensing and haptic rendering capability of the proposed system. The effect of the interference on the demonstration is discussed.

“…Hence, in order to modulate friction on a touch surface properly, it is important to understand our tactile perception of change in friction and the contact mechanics behind it. Although, the earlier studies have investigated the contact mechanics of friction [5], [10]- [17] and our perceptual ability to discriminate two different surfaces based on friction [18]- [20], the number of studies investigating the intermittent contact mechanics during a change in friction on a touch surface is very limited [21]- [24]. Furthermore, the factors affecting our tactile perception of this change have not been investigated in depth yet [22]- [26].…”

Section: Introductionmentioning

confidence: 99%

Tactile Perception of Virtual Edges and Gratings Displayed by Friction Modulation via Ultrasonic Actuation

Saleem

Yılmaz

Başdoğan

2020

To render tactile cues on a touchscreen by friction modulation, it is important to understand how human perceive a change in friction. In this study, we investigate the relations between perceived change in friction on an ultrasonically actuated touchscreen and parameters involved in contact between finger and its surface. We first estimate the perceptual thresholds to detect rising and falling friction while finger is sliding on the touch surface. Then, we conduct intensity scaling experiments and investigate the effect of finger sliding velocity, normal force, and rise/fall time of vibration amplitude (transition time) on the perceived intensity of change in friction. In order to better understand the role of contact mechanics, we also look into the correlations between the perceived intensities of subjects and several parameters involved in contact. The results of our experiments show that the contrast and rate of change in tangential force were best correlated with the perceived intensity. The subjects perceived rising friction more strongly than falling friction, particularly at higher tangential force contrast. We argue that this is due to hysteresis and viscoelastic behavior of fingertip under tangential loading. The results also showed that transition time and normal force have significant effect on our tactile perception.