Design And Implementation Of VLC-based High-precision Indoor Positioning System

With the rapid development of wireless networks and the popularization of mobile terminals,the location based service(LBS)has a vast application market.People are not satisfied with the positioning and navigation using only in the outdoors,indoor positioning is becoming a research hotspot.Visible Light Communication(VLC)is widely concerned because of its good confidentiality,electromagnetic radiation-free and long lifespan.Positioning technology based on visible light communication can achieve high-precision indoor positioning results without occupying any radio spectrum resources.This thesis presents an indoor positioning scheme based on the fusion of VLC and inertial measurement unit(IMU),and a high precision indoor positioning system(IPS)platform is built.The fusion algorithm based on weighted unscented Kalman filter is applied to achieve a high-precision positioning of mobile target in the indoor environment.The main work of this thesis is as follows.First,the background and significance of indoor positioning are briefly described.The current research status of indoor positioning based on VLC and IMU are introduced.To solve the practical problem and take advantage of VLC and IMU,an indoor positioning system based on VLC and IMU is developed.In Chapter two,the design scheme of IPS based on VLC is introduced.The overall implementation scheme of the indoor positioning system is designed according to the selected indoor positioning method.Then,the high-precision indoor positioning algorithm based on VLC is proposed.The new visible light propagation model based on received signal strength(RSS)and inertial navigation calibration model are established.The adaptively Kalman filtering(AKF)for error factors is adopted to optimize the model parameters.The position results are obtained through the fusion of VLC data and inertial navigation data.The weighted unscented Kalman filtering(WUKF)with data integration is developed to get the final positioning coordinates.The high precision indoor positioning system based on VLC is designed and implemented,and the software and hardware implementation of the four main modules of the indoor positioning system are completed.The positioning system includes anchor node,blind node,positioning server and terminal application.The proposed algorithm is applied in the positioning server to obtain the positioning results,and the blind node and the terminal are connected to the positioning server through the wireless local area network.The implementation of the four main modules including the functions,hardware components and software design of the four main modules are described in detail.Finally,the configuration and test of the high-precision IPS based on VLC are analyzed.The comparisons of positioning results and positioning errors at different speeds along different routes among different positioning algorithms are given.The results show that the proposed indoor positioning algorithm based on VLC and IMU fusion is more accurate than the single positioning method,which can expand the range of VLC positioning,calibrate the cumulative error of IMU positioning,and optimize the trajectory tracking by WUKF.The platform in the thesis has been awarded the Second Prize in the National Three-Innovation Competition in Internet of Things Technology and IV Application by China Institute of Communications(CIC)in 2017.