Research Of Indoor Visible Location Method Based On RSSI Ranging And Location Fingerprint

With the rapid development of technologies such as radio,Internet of Things and computers,positioning targets in life have become a reality,and people's demand for indoor positioning servicein daily operation and life is also increasing.For the common outdoor positioning systems include GPS,Beidou and other satellite navigation systems,the indoor positioning error is large due to the disturbing by the obstacles,so it can not be applied to indoor positioning situations.Therefore,it is of great significance to study an indoor positioning method with high accuracy and reliability.At present,indoor positioning methods mainly include ranging positioning and non-ranging positioning,which have their own advantages and disadvantages.The ranging positioning method is convenient for deploying the base station and easy to establish the indoor positioning system,but the position result has a large error due to the complex and changeable indoor environment.The non-ranging positioning method represented by fingerprint location,has the advantages of high accuracy and reliability.However,the construction of fingerprints in locating area is a heavy workload,which is not suitable to deploy the position system on a large scale.Therefore,to reduce the negative effect of each method's shortcomings and demonstrate the advantages of each positioning method,the ranging and non-ranging positioning methods are combined.Then the performance of indoor positioning can be improved by combined positioning methods.With the development of LiFi technology,optical communication technology has already matured.Compared with radio signal,the multipath effect of optical signal is weaker and the optical signal is more stable.Therefore,optical signals can be selected as a medium to study indoor positioning.Based on the above analysis,a scheme of range-assistance fingerprint localization(RAFL)for indoor visible light is proposed in this paper.Firstly,based on the ranging method of the Lamber model,the target multiple times in a multi-illuminant indoor environment is localized.Then we introduce the fingerprint construction method of bilinear interpolation method and Lagrangian interpolation method.The bilinear interpolation algorithm is used to construct the fingerprint in localized area,then using cosine similarity of vectors to match fingerprints within the target range.Finally,the actual location of the target is obtained by optimizing the results with K-means clustering algorithms.In addition,Kalman filter is used to track the trajectory of moving target.The scheme combines visible light ranging method,trilateral positioning and fingerprint location method to effectively improve the accuracy of indoor positioning.The bilinear interpolation algorithm is used to construct the localized area fingerprint which reduces the complexity of the project and the workload.Finally,K-means clustering algorithm is used to reduce the positioning error.Through simulation experiments,the feasibility of the scheme is verified.The research results show that the proposed scheme has strong reliability and can effectively improve the positioning accuracy.