Research On High-precision Positioning Method Based On UWB

Due to the ever-changing navigation and positioning technology,people’s demand for high-precision positioning is becoming stronger and stronger.While satellite navigation and positioning technology has the characteristic of three-dimensional positioning at any moment,which can fully meet the positioning needs of outdoor environments,however,due to factors such as obstacles High-precision positioning cannot be achieved in indoor environments.Because Ultra-Wide Band(UWB)positioning technology has the advantages of low energy consumption,anti-interference,strong penetration and high security,it can be used for indoor navigation and tracking of people and objects.In view of this,this paper conducts related research on UWB positioning methods,the specific research contents are as follows:(1)Research and analysis of UWB positioning theory.Firstly,the basic theory of UWB is deeply analyzed;secondly,the four indoor positioning methods and realization methods of UWB are studied in detail,the main factors affecting the positioning accuracy of the UWB system are found.(2)Research and Improvement of UWB Ranging Algorithm.Since the traditional Single-Sided Two-Way Ranging(SS-TWR)and the ordinary Double-Sided Two-Way Ranging(DS-TWR)methods are greatly affected by the clock drift errors,an Improved Double-Sided Two-Way Ranging(IDS-TWR)algorithm is proposed to reduce the impact of the clock drift error.Finally,a comparative experiment is carried out between DS-TWR and IDS-TWR algorithms,and the results show that the ranging accuracy of the IDSTWR algorithm is increased by about 11%.(3)Research and Improvement of UWB Positioning Algorithm.UWB positioning algorithm has two models,linear and nonlinear,aiming at the disadvantage of the traditional Least Squares(LS)positioning algorithm in the linear model,which does not consider the position of the base station in the indoor positioning system and affects the positioning accuracy of the system,a weighted least squares(WLS)algorithm is proposed.Aiming at the shortcoming of the traditional Gauss-Newton iterative method in the nonlinear model,which only carries out Taylor first-order expansion,which results in large model deviation,a closed-form Newton iterative method considering higher-order terms is proposed.Finally,after experimental verification,the positioning accuracy of the WLS algorithm is increased by about 15%,and the positioning accuracy of the closed Newton algorithm is increased by about 9%,which proves that the two algorithms proposed in this paper can effectively improve the positioning performance of the system.(4)Research on the influence of UWB configuration on positioning accuracy.Geometric Dilution of Precision(GDOP)is widely used in the performance evaluation of navigation and positioning systems,while the positioning accuracy of UWB systems is closely related to its spatial geometry configuration,and the GDOP minimization condition is also suitable for the study of UWB system positioning configurations.Based on this,firstly,the GDOP minimization criterion is deeply analyzed;secondly,the influence of base station number and base station height on GDOP size is studied;finally,a typical layout of four base stations is studied,and a quadrilateral positioning structure with minimum GDOP is proposed,type-square configuration.The experimental results show that under the layout of four base stations,the square configuration is the optimal layout method under two-dimensional positioning,and this configuration can effectively improve the positioning accuracy of the UWB system under two-dimensional positioning.