DIMLOC: Enabling High-Precision Visible Light Localization Under Dimmable LEDs in Smart Buildings

The blooming of Internet of Things enables our modern buildings to become more and more smart, e.g., the intelligent LED lighting system could automatically adjust LEDs' dimming levels based on the ambient sunlight. However, this brings blurring effects that could significantly affect the effectiveness of visible light localization. In this paper, we propose a high-precision visible light localization system DIMLOC under dimmable LEDs in smart buildings. We first propose to use a novel imaging processing framework that consists of efficient techniques of the second-order polynomial fitting, histogram equalization, and Sobel filter to cope with the blurring effects. We then propose a novel algorithm based on vision analysis and scaling factor that only needs two LEDs for positioning. We prototype our DIMLOC on commercial off-the-shelf devices, and extensive experiments demonstrate that DIMLOC could achieve centimeter precision, e.g., 4.5 cm. Overall, this paper could further broaden application scenarios of visible light localization in the era of smart buildings.