A single LED lamp positioning system based on CMOS camera and visible light communication

In this paper, a positioning system framework based on a single light emitting diode (LED) lamp is introduced. The LED lamp is used to transmit the positioning information, and the commercial mobile phone is used as the receiver. A fringe image carrying information is acquired by the rolling shutter effect of the complementary metal oxide semiconductor (CMOS) image sensor. Based on this, a piecewise fitting method is proposed to instead of the overall fitting method, which improves the decoding success rate. We also propose a method of LED light source recognition, which detects the edge of the light source based on brightness weakening, the Sobel operator and the least-squares fitting. In addition, the imaging principle of the camera in horizontal and tilted scenarios is analyzed. Accurate indoor positioning is achieved by the imaging principle of the camera lens and the attitude information of the mobile phone. The experimental results show that the system established in this paper can achieve centimeter-level positioning accuracy whether the mobile phone is placed horizontally or obliquely.