Research And Realization Of Indoor Location System Based On Android

In recent years,there is an increasing demand for Location Based Service(LBS).As we all know,outdoor positioning technology has been developed quite mature and reached a high positioning accuracy.It can well satisfy the needs of users of precision in the outdoor environment.However,due to the complexity of the indoor environment,as well as satellite signals difficult to penetrate the building,resulting in outdoor positioning technology can not be applied to the indoor environment.Therefore,how to accurately locate in the indoor has become a hot and difficult research.With the growing popularity of indoor Wi-Fi hotspot and the popularization of mobile intelligent terminals,the indoor Wi-Fi positioning technology based on Android platform is favored.Therefore,this paper takes the position fingerprint method of Wi-Fi positioning technology as the object of study,deeply studies the shortcomings of the commonly used methods,and makes the corresponding improvements.Finally,the Wi-Fi indoor positioning system was designed and implemented in the Android platform.First of all,in this paper,on the premise of access to a lot of information about indoor positioning technology,in-depth study of a variety of indoor wireless positioning technology and positioning methods,by comparing their strengths and weaknesses,and ultimately selected the subject of research programs.Secondly,the algorithm used in position fingerprinting and RSS statistical distribution are studied,and two improvements are made.On the one hand,the offline phase is improved.The available APs are filtered before information acquisition to reduce the amount of information storage.Then,Gaussian filtering and 4-neighborhood mean filtering are applied to the collected data to reduce the noise interference more effectively.On the other hand,the online positioning phase is improved.The real-time information is filtered to preserve the stable information for matching operation.Then,the K-weighted neighbor algorithm is improved.The wireless signal propagation attenuation model is introduced.The improved algorithm is used as the online matching algorithm.The experimental results show that the improved method can improve the positioning precision and speed.Finally,according to the actual needs of the system,to develop the overall design.The system uses server-side structure,is divided into three modules,namely: offline client,online client and server.To determine the realization of each module algorithm and the preparationof specific code to complete the system design.And in the actual environment,place the AP and test the system with offline and online.The system whether in accuracy or stability have achieved good results.Through the statistical analysis of the experimental data,the positioning accuracy of the positioning system is within 2.61 m,50% of the cases is within 2m,which can meet the requirement of most indoor location.