Design And Development Of Indoor Fusion Position System Based On LED

In recent years,location navigation and location based services(LBS)have been widely used in Outdoor scenes.They have brought many conveniences for people's daily life.However,indoor positioning navigation has not been well applied.Although there ar e already a variety of indoor positioning technology,but all of them have some limitations.They cannot provide high-precision indoor positioning for people in complex and changing indoor environment.Among them,the visible light indoor positioning is based on Visible Light Communication(VLC)technology,it have many advantages.For example,it can provide positioning and illumination at the same time,have not electromagnetic interference,easy to deploy,low cost,and so on.But the positioning accuracy of visible light indoor positioning is limited to visible light range.Based on the inertial sensor,Pedestrain Dead Reckoning(PDR)is a kind of relative positioning technology,which has the advantages of high precision in the short distance and cannot be affected by the external environment.However,for long distance it has large cumulative error.Therefore,based on the advantages and disadvantages of visible light location and PDR localization,this paper propose a fusion scheme based on visible light and PDR positioning technology.The research content mainly includes the following aspects:Firstly,after further studied several kind of visible light localization algorithm,LEDID positioning method is adopted.The method transmits the high-frequency flashing LED light.The light include coded signal which representing the position information to the illumination area.When the user enters the positioning area,the signal of the LED lamp can be received by the mobile phone,and the position information is decoded.Secondly,we researched PDR technology.We use PDR positioning between two LED lights to maintain system positioning accuracy.PDR positioning consists of four steps: step detection,step length estimation,orientation estimation and calculation of location information.In order to shave noise,this paper chooses low-pass filtering and sliding average filtering to denoise the original data.A dynamic threshold crest detection algorithm based on the peak and wave trough difference of acceleration is proposed for gait detection.Based on the original fixed parameter step length estimation model,a step length parameter correction algorithm is proposed.Finally,the transmitter and receiver of the fusion positioning system are design ed and implemented.The transmitter uses the singlechip and the control circuit to realize the LED signal transmission.The receiver uses Android smart phone.We have make an Android APP to implement LED signal reception and PDR positioning which include several modules.The accuracy of the gait detection,step length estimation,orientation estimation and positioning are tested.The experimental results show that the positioning system realized in this paper can meet the needs of indoor positioning.