Human capability of discriminating relief-like 2D figures in tactile displaying

Abstract

To enhance tactile display capability, we performed a series of experiments based on psychophysics in which we adopted a circle and eight kinds of ovals as stimuli of the convex line (hereafter tactile image). The circle's diameter is 10 mm, the minor axes of the eight ovals are decreased in 3% steps from the circles, and each major axis is adjusted so that the area of each oval equals the circle area. Human subjects judged which stimuli (presented on the left or the right tactile images) equal the circle. The experiment was conducted on both the finger pads and the thenar parts to compare their experimental sensitivity ratios with the sensitivity ratio estimated on the basis of mechanoreceptor density. The discrimination sensitivity for the thenar part is inferior to that for the finger pad in terms of the low density of the mechanoreceptor in the thenar part. The tactile image was mainly recognized by a slowly adaptive type I unit, but the first adaptive type II unit was not affected by specimen cooling due to discrimination precision. Subsequently, discrimination sensitivity was not different between the free and restricted haptic motions. Since this result implies that the tactile image is modified by a motor signal for the haptic motion to prevent blurring of the tactile image, perhaps the motion movement in the tactile display is changed based on the design convenience.

Crosstalk-Free Position Mapping for One-Step Reconstruction of Surface Topological Information via Eigenfrequency-Registered Wearable Interface

“…The ability of the intelligent robot to extract information from the environment will be greatly enhanced if the haptic sensors can quickly sense and output the patterns which are distributed on the surface. 46 Conventionally, most studies applied flexible sensor arrays for pressure mapping, which alternatively provides a solution to reestablish the surface information via combining the signals from each sensing unit (Figure 5a). To avoid the crosstalk among devices, this approach inevitably involves a number of electrodes and signal acquisition channels.…”

“…Embossment is a common sculpting technique that can be processed to detach the desired information from the original surface. The ability of the intelligent robot to extract information from the environment will be greatly enhanced if the haptic sensors can quickly sense and output the patterns which are distributed on the surface . Conventionally, most studies applied flexible sensor arrays for pressure mapping, which alternatively provides a solution to reestablish the surface information via combining the signals from each sensing unit (Figure a).…”

Evaluation of Pressure-Slippage-Generating Tactile Mouse using Edge Presentation

“…In these fields, several mechanisms have been tentatively presented for tactile displays. Since VR requires virtual object handing, researchers have paid particular attention to tactile displays (Salisbury and Srinivasan, 1997;Shinohara et al, 1998;Shimojo et al, 1999;Konyo et al, 2000;Iwata et al, 2001;Nara et al, 2001;Arata and Ikei, 2006;Ohka et al, 2007;Zhou et al, 2010). On the other hand, the mechanoreceptive units of human tactile organs are known as the Fast Adapting type I unit (FA I), the Fast Adapting type 2 unit (FA II), the Slowly Adapting type I unit (SA I) and the Slowly Adapting type II unit (SA II).…”