Research On Indoor Positioning Technology Of Visible Light Communication System

With the rapid development of mobile Internet,people's demand for location services and indoor positioning is growing.At the same time,visible light communication technology has been applied in indoor positioning field.Visible light positioning technology is to transform the existing LED lighting equipment into a signal transmitter and design a specific receiver to achieve high precision positioning.However,at present,visible positioning devices are often limited in application scenarios because of the complex design of the receiver.With the popularity of smart devices,people have become accustomed to using smart phones and other devices to deal with various matters in work and life.Therefore,relying on smart terminal devices to achieve indoor visible light positioning is an important development direction.Based on the Android intelligent terminal,according to the actual situation of the terminal,combined with visible light positioning technology,this paper designs an indoor visible light positioning system which integrates the sensor information of the terminal.The main contents of this paper are as follows:1.The classical algorithm of indoor visible light positioning technology is studied,and the positioning principle is analyzed.The positioning algorithm is evaluated from the aspects of system complexity and positioning error.Generally speaking,the RSS-based algorithm has the advantages of low complexity,easy implementation at the receiver and high positioning accuracy.2.On the basis of intelligent terminal,the theoretical model of indoor visible light positioning system is established,and the illumination intensity,light source distribution and receiver deflection which affect the performance of the system are analyzed.For the receiver deflection,from the engineering point of view,quadratic fit is used in the intensity change,and the signal intensity is corrected by combining the empirical formula obtained from multiple measurements.The deviation can be reduced to 20 lux.Kalman filter is introduced to deal with the noise problem,which can improve the accuracy of intensity measurement and effectively reduce the error in the edge area.3.An indoor visible light positioning system based on multi-channel information fusion is designed.The operation mode of the sender and the function design of the receiver are introduced.Based on the advantages of intelligent terminals,multi-terminal optimal positioning and multi-source optimal positioning methods are proposed.The former considers that the terminal will integrate more receivers in the future,so the location can be determined by the distance and angle of the receiver.The latter is based on the position fingerprint method,and introduces the magnetic field intensity easily measured by Android device as the visible light correction quantity,which reduces the complexity of the system and improves the accuracy.4.The design of Android terminal software for indoor visible light positioning system is introduced in detail.By using external receivers and self-contained sensors such as light intensity,acceleration and magnetic field,the functions of acquisition,decoding,light intensity measurement and positioning of visible light signals are realized,and the related functions are tested.