Research On High Precision Positioning Technology Of Equipment Management Based On Bluetooth AOA

Physical distribution of military is an important part of military logistics support,and intelligentization of military logistics is the trend of modern war.Though the material classification and visual management of military logistics have been realized based on the current Internet of Things technologies,the real-time and accurate location information monitoring of materials have not been realized,and the intelligence of military logistics is still at a low level.Based on the positioning technology of Bluetooth Angle of Arrival,this paper studies the positioning method,direction finding algorithms based on Bluetooth antenna array and positioning based on multiple stations.A Bluetooth AOA positioning system is built to verify the application of the algorithms in practical engineering.The main research contents of this paper are as follows:(1)Analysis of Bluetooth AOA direction finding and positioning technology.Based on the working process of Bluetooth AOA technology,the communication and sampling process of transmitter and receiver are analyzed.A simplified two-antenna sampling model is used to analyze the calculation method of simultaneous sampling phase difference of antenna,and the influence of phase difference error on the AOA accuracy is simulated.The least-square fitting method is used to calculate the phase difference and AOA of switching sampling of two antennas,and the accuracy of AOA is verified by experimental data.(2)Aiming at the problem of direction finding and positioning of Bluetooth antenna array,a fitting method of multi-antenna received signals based on In-phase/ Quadrature(IQ)data is proposed.Multi Signal Classification(MUSIC)and Propagator Direct Data Acquisition(PDDA)algorithms are selected to calculate the Angle of arrival.Firstly,the phase value is calculated by using the IQ data of rf sampling,and the received signal matrix is calculated by signal fitting method.The signal model of array antenna of receiving device is established,two different signal direction calculation algorithms of array antenna are selected and analyzed,and the simulation of plane angle positioning and algorithm complexity are compared and analyzed.(3)Based on the known azimuth,the absolute position positioning method of multiple stations is researched to improve the positioning accuracy.Aiming at a rectangular positioning area,the positioning effect of different numbers of positioning stations is simulated and analyzed.To solve the problem that the azimuth error of Bluetooth AOA positioning system is large under high elevation,the Received Signal Strength Indicator is used for auxiliary positioning,so as to broaden the positioning area and improve the positioning accuracy.Filtering algorithm is used to filter the positions to improve the stability.(4)An indoor positioning system based on Bluetooth AOA is built to verify the effectiveness of the above algorithm through experiments.Python programming is used to process the positioning system data in real time and calculate the location of the positioning target.Multi-base station positioning results show that the proposed RSSI assisted multi-base station positioning method has high positioning accuracy,and the filtering algorithm can improve the positioning stability,and the average positioning accuracy of the real-time positioning system can reach 0.3m.