Research On Indoor Visible Light Location System Based On Fingerprint Algorithm

Positioning technology is widely used in society.GPS is very convenient to set up and use outdoors,but when the signal of GPS satellite is blocked by walls or high-rise buildings,it becomes ineffective.In recent years,with the wireless sensor network and the rapid development of Internet technology,the indoor positioning technology has been widely applied in many areas,such as intelligent robot and large shopping mall shoppers,and becomes one of the key research object.Researchers have therefore proposed many alternatives,such as indoor positioning technology based on visible light,wi-fi,infrared(IR),ultrasound and image sensing.Some of the system need to install many sensors,made of the high cost of these methods on calculation of more complex,and also need to build complex equipment environment,not only cost is high,the positioning accuracy and safety also can not get effective guarantee.Visible light communication(VLC)using visible light instead of the radio frequency electromagnetic wave to communicate,has attracted widespread attention in recent years.This paper puts forward the positioning system based on VLC,is the use of these technology trends.It puts forward a kind of optical positioning system based on fingerprint algorithm,and introduces the positioning system of space layout,positioning model and hardware structure,also designed constant current driver + ID code baton encoding,which used to form and send the LED ID signal,and realize the normal lighting.In this paper,the indoor visible light positioning system is divided into the transmitter and the receiving end,and the system building process is divided into offline and online stages.In this paper,the hardware composition and the principle function of the system are introduced in detail,and the off-line stage is the generation stage of the system light intensity coordinate database,that is,the data acquisition stage.Online stage according to the search algorithm,it uses STM32 embedded chip matching anchor point coordinates.Then we use QT to write positioning client to get the coordinates of the transmission to the terminal,and displayed on the computer map.This paper also introduces the ID recognition algorithm and the strength position matching algorithm.In this paper,the matching algorithm has been repeatedly confirmed,and the multi-valued scheme is adopted.This algorithm eliminates the influence of some sudden disturbances on the measurement,and the error of the whole system is greatly reduced and the performance is greatly improved.Finally,we set up a space model of 3m by 2m x 2m.The experimental results show that when the spacing between points is 0.1m and 0.2m,there are only two coordinate errors in the moving target.The maximum errors were 0.14 m and 0.2m respectively.We optimized the coding algorithm and system hardware structure.The positioning system is less than 100 ms,and the positioning accuracy is 0.1m.Based on the fingerprint orientation,the indoor optical positioning system is designed with low power consumption,low cost of hardware and software,fast response,high positioning accuracy,and the advantages of adjustable has great advantages in terms of indoor location.