High-precision Indoor Positioning Research And Application Based On Ultra-wideband Technology

With the rapid development of economy and technology,people's demand for indoor location aware service is increasing.Due to the lack of effective indoor positioning base station and corresponding technical means,there is no general scheme to achieve indoor precise positioning.Compared with other indoor positioning technologies,ultrawideband positioning technology has the advantages of low power consumption and high precision,which can better solve the problem of pedestrian,cargo or robot mobile positioning.In this paper,UWB positioning system is studied deeply,which has high application value and commercial value in goods management,personnel positioning and indoor positioning of small unmanned system.The theoretical basis of UWB indoor positioning system is studied.From the aspects of difficulty and precision,the common positioning information acquisition method is analyzed,and the two-way ranging method with high precision and easy realization is finally chosen.Then the error factors such as antenna delay,clock deviation and nonview-out phenomenon in the ultra-broadband positioning system are analyzed,and the corresponding solution is given.Finally,the positioning performance evaluation standards such as refresh frequency,system capacity and positioning accuracy are proposed,and applied to simulation experiments and system experiments.When using UWB positioning system,it is necessary to lay the anchor as reference information in advance,in order to reduce the cost of anchor placement,the anchor selfcalibration algorithm is proposed.A mathematical model of the anchor self-calibration algorithm is established.The location of the anchor is solved by LM algorithm,and the feasibility of the anchor self-calibration algorithm is verified by simulation experiments.Finally,the anchor self-calibration algorithm is applied in the system experiment,and the function of determining the anchor coordinates through the information interaction between the anchors is realized.In order to realize the indoor high-precision positioning of goods and pedestrians,the algorithm of using UWB positioning system alone is studied.According to the way of acquiring ranging information,the least square method with less calculation is selected for simulation experiment.Furthermore,in order to improve the positioning accuracy and smooth the trajectory,the tracking and positioning algorithm based on the extended Kalman filter is studied.The positioning performance of the least square method and the extended Kalman filter algorithm is compared and analyzed through the simulation experiment,and the effectiveness of the extended Kalman filter algorithm is verified.Finally,through the experiment platform for UWB positioning system experiment,for the fixed label(goods),the extended Kalman filter algorithm improves the positioning stability,positioning accuracy of 0.11 m;for the mobile label(personnel),the extended Kalman filter algorithm can improve the positioning accuracy,and smooth the motion trajectory,positioning accuracy of 0.21 m.In order to solve the problems of slow refresh frequency and easy to be affected by NLOS environment,a joint positioning scheme of UWB and INS is proposed.The theoretical basis of inertial navigation system is studied,and the advantages and disadvantages of UWB positioning system and inertial navigation system are analyzed.The algorithm of joint positioning based on error state Kalman filter is studied,the mathematical model is established,and the simulation experiment is carried out to provide theoretical support for practical application.Finally,the joint positioning system is applied to the indoor positioning of small quadcopter,and the positioning accuracy is 0.18 m.