| In the construction of modern information society,location information service based on navigation and positioning has become a standard configuration in the construction of living infrastructure.Traditional outdoor positioning technology such as GPS and BDS has low indoor coverage and poor signal,so it is difficult to provide high-precision positioning services in the room.However,based on mature wireless electromagnetic wave communication technologies such as WLAN,RFID,Bluetooth and UWB,the indoor positioning technology needs not only add additional equipment in the deployment of indoor positioning system,but also be extremely limited in electromagnetic sensitive areas.Visible light communication takes LED as signal source,and in the society where environmental protection is prevailing,LED lighting equipment is everywhere.Indoor positioning technology based on visible light communication has been advanced in the promotion of positioning system.Visible light communication has the advantages of anti-electromagnetic interference,multi-function integration and strong confidentiality,which is one of the hot research topics of indoor positioning-technology.This paper focuses on the improvement of the comprehensive performance of indoor visible light positioning,and the main contents are as follows:(1)Firstly,this paper introduces the basic principle of indoor visible light positioning,and several common positioning methods in indoor positioning technology.Then the overall framework of indoor visible light communication and positioning system is introduced,and the link composition and transmission impulse response of indoor visible light transmission channel are analyzed emphatically.Then,the received optical power,channel delay spread and other channel characteristics of indoor visible light commu4 nication are simulated and analyzed in detail.The simulation results show that indoor visible light communication has obvious multipath delay effect,and the indoor channel propagation delay distribution has a certain randomness,so it is necessary to consider the change of positioning performance caused by multipath effect in the process of studying positioning methods.(2)Aiming at the problem that indoor visible light positioning performance is easily limited by LED layout structure,this paper proposes MLED-APIT positioning method referring to APIT node positioning algorithm in wireless sensor network,which relieves the limitation of LED layout on positioning accuracy,effectively avoids the occurrence of traditional APIT positioning errors,and reduces the redundant calculation process in the implementation process of positioning method.An average positioning error of 0.237 m and an average positioning time of 1.6562 seconds are obtained in the 5m×5m×3m indoor environment.(3)In this paper,a location method based on TOA / RSS is proposed to improve the comprehensive performance of indoor visible light location.Aiming at the nonlinear positioning error caused by multipath effect in indoor visible light positioning,particle filter algorithm guided by UKF is used to fuse TOA information and RSS information to correct the nonlinear error.Then,considering the inertial sensing parameters of the receiver,the motion of the receiver is analyzed to improve the accuracy of the estimated coordinates.In the 5m×5m×3m indoor environment,the average positioning error of 2.02 cm is obtained under 12 W transmission power.The experimental results show that the positioning method has good robustness and timeliness.After receiving inertial sensor data compensation,the problem of higher indoor edge positioning error is obviously improved. |
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