Tightly coupled VLP/INS integrated navigation by inclination estimation and blockage handling

Abstract

Abstract Visible Light Positioning (VLP) has emerged as a promising technology capable of delivering indoor localization with high accuracy. In VLP systems that use PhotoDiodes (PDs) as light receivers, the Received Signal Strength (RSS) is affected by the incidence angle of light, making the inclination of PDs a critical parameter in the positioning model. Currently, most studies assume the inclination to be constant, limiting the applications and positioning accuracy. Additionally, light blockages may severely interfere with the RSS measurements but the literature has not explored blockage detection in real-world experiments. To address these problems, we propose a tightly coupled VLP/INS (Inertial Navigation System) integrated navigation system that uses graph optimization to account for varying PhotoDiode (PD) inclinations and VLP blockages. We also propose to simultaneously estimating the robot’s pose and the locations of some unknown Light-Emitting Diodes (LEDs). Simulations and two groups of real-world experiments demonstrate the efficiency of our approach. Despite inclination changes and blockages, one group achieved an average positioning accuracy of 10 cm during movement, inclination accuracy within 1 degree, and a 100% blockage detection success rate, while the other group achieved an average accuracy of 11.5 cm, showing the effectiveness and robustness for VLP-based localization applications.

Keywords

• Visible light positioning (VLP)
• Received signal strength (RSS)
• INS
• Inclination
• Blockage
• Graph optimization