Single-LED based indoor visible light positioning system and realization on Android phone

• Main Author: He, Sheng
• Other Authors: Zhong Wende
• Format: Theses and Dissertations
• Language: English
• Published: 2018
• Subjects: DRNTU::Engineering::Electrical and electronic engineering
• Online Access: http://hdl.handle.net/10356/75960
• Institution: Nanyang Technological University

With the increasing demand for positioning and navigation to human as well as location-aware applications in indoor environment, indoor positioning technology attracts worldwide attention and investigation in recent years. To address the problem in the conventional multiple-LED based visible light positioning (VLP) systems whose service may be easily interrupted when less than three LEDs are captured, a more efficient and robust visible light positioning system is investigated, which utilizs a single LED and its geometry information. In this work, we experimentally implemented and investigated this single LED based VLP system using common LED lamps and a smartphone camera, and developed a JAVA programming based APP for the system. LED IDs are modulated on to the optical signals and broadcasted in the free space, which can be captured by exploring the rolling shutter effect of CMOS sensor, and thus to distinguish the transmitted LEDs. Meanwhile, circular LED is projected on the image plane whose geometric information indicates its relative location to the receiver. Demodulation and image processing schemes are developed and implemented on a smartphone to obtain the ID and geometry information from captured pictures in real-time. The receiver’s location is determined with this information. This method avoids using multiple LEDs or angular sensor, and the algorithm is easy to realize on a smartphone. In the experiment, we can realize capturing, image processing and positioning within 0.5s and achieve the indoor positioning in a square area of 2m x 2m. Index Term: Visible light Communication (VLC), Android, visible light positioning (VLP), light emitting diode (LED)