Indoor 3D Localization with Low-Cost LiFi Components

Indoor positioning or localization is an enabling technology expected to have a profound impact on mobile applications. Various modalities of radio frequency, ultrasound, and light can be used for localization; in this paper we consider how visible light positioning can be realized for 3D positioning as a service comprised of optical sources as part of an overarching lighting infrastructure. Our approach, called Ray-Surface Positioning, uses one or more overhead luminaires, modulated as LiFi, and is used in conjunction with a steerable laser to realize position estimates in three dimensions. In this paper, we build and demonstrate Ray-Surface Positioning using low-cost commodity components in a test apparatus representing one quadrant of a 4m × 4m × 1m volume. Data are collected at regular intervals in the test volume representing 3D position estimates and is validated using a motion capture system. For the low-cost components used, results show position estimate errors of less than 30cm for 95% of the test volume. These results, generated with commodity components, show the potential for 3D positioning in the general case. When the plane of the receiver is known a priori, the position estimate error diminishes to the resolution of the steering mechanism.