Study On Indoor Fusion Localization Technology Based On WiFi And Bluetooth

With the development of information technology and position technology,location based service has been widely used in people's lives.The indoor positioning has become a hotspot of the position service,indoor positioning has broad application prospect and significance in wisdom logistics,emergency rescue,indoor navigation and other industries.WiFi and Bluetooth as the leading technology of indoor positioning,has good performance in terminal support,WiFi indoor covering area is broad,Bluetooth beacons are easy to deploy and the cost is low.So the study of WiFi and Bluetooth cooperative positioning technology has a relatively high theoretical significance and application value,this thesis mainly studies the following aspects of integration positioning technology and methods based on Wi Fi and Bluetooth:First of all,aiming at the influence of interference such as non line of sight error and Gauss noise on the ranging position precision,a position algorithm in indoor complex environment based on weighted least squares WiFi/Bluetooth is proposed.The algorithm is based on the modified huawei path loss model to calculate the pseudo moments,thereby reducing the impact of noise on the positioning accuracy,and finally calculate the optimal position of the terminal by weighted least squares algorithm.The simulation results show that the algorithm can effectively improve the indoor positioning accuracy and restrain the influence of position noise in indoor environment compared with the trilateration localization and the traditional least square method.Secondly,aiming at the problem of WiFi and Bluetooth cooperative positioning,a total least squares fusion algorithm based on Wi Fi and Bluetooth is proposed to further improve the positioning performance.The multi attribute cost function as the criterion to select WiFi and Bluetooth beacon nodes,and building WiFi and Bluetooth fusion positioning observation equations,then using the total least squares algorithm for positioning solution to weaken the ranging error and the position error caused by the beacons layout The simulation results show that the algorithm further improves the positioning accuracy and dramatically reduces the influence of Gauss noise on position algorithm compared with WiFi and Bluetooth separate position.Finally,in order to achieving the dynamic continuous positioning of the mobile terminal and modify the position results of the mobile terminal,a kalman filtering trajectory estimation algorithm based on WiFi and Bluetooth is proposed.First,according to position and velocity of the mobile terminal,the state equation and observation equation of dynamic positioning is established,and then by using the parameter information update of the kalman filter algorithm to constraint the trajectory of the mobile terminal and real-time estimation,weakening the effect of random error on the static positioning position,to make the trajectory of the mobile terminal position tends to be smooth.The simulation results show that the kalman filter algorithm can better estimate the position of the mobile terminal at the next time,track and predict the trajectory of the mobile terminal accurately,and achieve dynamic continuous position.