Three-Dimensional Position Presentation via Head and Waist Vibrotactile Arrays

This article introduces a novel system designed to convey the three-dimensional positions surrounding the user. The system incorporates circumferential vibrotactile arrays strategically positioned on both the user's head and waist. Through the synergy of this two-dimensional arrangement and modulations in vibration amplitude, the system adeptly presents comprehensive three-dimensional positional information. Two prototypes, namely a spherical model and a cylindrical model, were employed as mappings between three-dimensional positions and vibration amplitudes. In Experiment 1, we evaluated the system's performance in indicating positions in depth, orientation, and height. Notably, discrimination rates for depth (Task 1) and orientation (Task 2) were 60% and 54%, respectively. Regarding height discrimination in the head-to-waist condition (Tasks 3 and 4), the cylindrical model outperformed the spherical model (54% and 52% vs. 32% and 36%). Conversely, in the head-above and waist-below condition (Task 5), the cylindrical model achieved a discrimination rate of 45%, while the spherical model did not. In Experiment 2, we explored the use of the cylindrical model to convey a moving three-dimensional position. The results showed an impressive 81% correct response rate, affirming the system's effectiveness in presenting three-dimensional motion stimuli.