Design And Implementation Of Indoor Positioning System Based On BLE

Due to the severe attenuation of satellite signals after arrival,the GPS cannot meet the needs of indoor positioning.Nowadays,with the development of society and the progress of urbanization,80% of the time of day is consumed indoors,and the research of indoor positioning technology has become one of the focuses,combined with the development of location-based service(LBS).So far,there are many research on indoor positioning,but also good results,but are in the local improvement,there is no universally applicable indoor positioning system or products.This article aims at RSSI-based(Received Signal Strength Indicator)the fingerprint algorithm has poor stability,high cost of establishing the fingerprint bank,and is limited to the static small range of indoor positioning,which is not suitable for the dynamic continuous indoor positioning,while the pedestrian dead reckoning(PDR)algorithm is suitable for the dynamic continuous positioning,and the result is relative position.An indoor location algorithm based on ranging and fingerprinting(Indoor Position Method Based On Distance Measurement and Location Fingerprint,DMLF)and the optimized PDR algorithm.The DMLF algorithm is based on the improved Bluetooth Low Energy(BLE)algorithm,which combines the three-sided localization method with the fingerprint method.The combination algorithm makes up for the singular value and the large fluctuation in the independent localization of the three-sided localization algorithm,and improves the fingerprint method of the matching efficiency,the average error of the algorithm is 1.73 m;the optimized PDR algorithm is implemented on the smart phone,mainly using Kalman filter to optimize the step size,particle filter to optimize the estimation results(further optimized on the basis of step size optimization),and the average error of the algorithm after two optimizations is1.67 m,1.08 m,respectively.In order to further improve the localization effect of the algorithm,we propose to fuse the DMLF algorithm with the optimized PDR algorithm,andpropose three test schemes to complete the test under the two scenarios of trajectory straight line and curve respectively.Finally use BLE node,smart phone,PC,and programming(for Java and android development)build an indoor positioning system and complete the test.