Visible Light Three-Dimensional Positioning System Based on LightEmitting Diode and Image Sensor

With the rapid development of the Internet of Things, smart devices require high-precision, real-time location services. However, only two-dimensional positioning can be achieved in existing visible light positioning technologies; furthermore, the system is complex and has a low positioning accuracy and extended positioning time. To address these issues, this study proposes a visible light three- dimensional positioning system based on two light-emitting diodes (LEDs) and image sensors. First, a simulation model is established by combining the pinhole imaging model and the distortion model. Next, a stripe search algorithm based on bisection and a double pointer is proposed to rapidly determine the position of the LED on the image. Finally, the geometric features of the LEDs on the image are used to achieve threedimensional positioning. After calculations, in a 100 cmx100 cmx300 cm space, the average positioning error of the simulation experiment is 0. 79 cm, and the average positioning error of the physical experiment is 5. 61 cm. The average positioning time is 64. 13 ms. In addition, the time performance of the proposed stripe search algorithm is improved by 70. 06% compared with that of the linear stripe search algorithm. Therefore, the proposed system can provide a good three-dimensional positioning service.