High-speed 3D indoor localization system based on visible light communication using differential evolution algorithm

Indoor positioning system using visible light communication (VLC) is widely believed to be a cost-effective solution with the popularity of LEDs. However, most existing VLC-based systems can only achieve positioning in two-dimensional (2-D) planes, and fail to solve the problems of calculating speed and positioning accuracy well in three-dimensional (3-D) space. This paper proposes a 3-D visible light positioning system based on differential evolution (DE) algorithm. The positioning model is viewed as a global optimization problem by calculating the overlapped area of LEDs circular projections in the terminal plane. DE is only used to calculate Z-coordinate of the terminal, and the dimension reduction process from 3-D to 1-D greatly reduces the calculating time. Experimental results show that the average positioning error is 0.69cm in an indoor environment of 4m×4m×6m, especially the calculating time is reduced to 24.26 ms for a single point, which indicates that the proposed localization algorithm has a good practicability especially in real-time indoor positioning. In addition, the trajectory tracking experiment performs well when the motion trajectory is generated randomly, and 90% 3-D kinematic errors are within 1.4 cm.