Research On Base Station Deployment Method For UWB Indoor Location

With the increasing demand for Location Based Services,indoor location has gradually become a hot area of research and business.The Ultra Wideband Radio(UWB)location precision can reach centimeter-level,which attract more attention.Besides ranging precision and location algorithm,the geometric layout of the base station is also an important factor for location precision in UWB indoor location.When the range of the location area is large,reasonable layout of the base station can effectively reduce the layout cost of the base station.Therefore,the study of UWB indoor location base station layout is very important and has application value.First,to study UWB base station layout,this paper quantitatively analyzes the layout performance of the base station based on three evaluation indexes: Position Dilution of Precision(PDOP),coverage redundancy and base station node density.Then the research area is partitioned by the wall,because the UWB signal is influenced by the wall.We classify the location areas according to the UWB sensing radius and the location principle,which is divided into a single set of base station service space and multiple sets of base station service space.At last,this paper studies these two kinds of layout schemes.The research contains the following steps.1)To find out a method for optimizing the layout of the base station in a single group of base station service spaces.First,we analyze the indoor space structure to obtain a feasible solution area that is not obstructed by the wall and add constraints to the feasible solution area according to the actual situation.We establish the mathematical model of the optimal geometric base station layout using the position precision factor PDOP.Then,the model is iteratively solved by a genetic algorithm to find the overall approximate optimal base station layout position.Finally,a single set of base station service space is selected for the experimental verification and analysis of this method.Experiment results show that the approximate optimal base station layout can achieve an average PDOP value of 1.96.The static positioning and dynamic positioning experiments are carried out under this base station layout scheme.The static positioning precision is about 10 cm.The dynamic positioning accuracy can be clearly restored in the horizontal direction.Comparing with the static positioning and dynamic positioning precision under the common high-level parallel layout method,the experiment results show that the base station layout method obtained in this paper can obtain better positioning precision.2)We propose an algorithm for base station node selection and layout in multiple groups of base station service spaces.Due to the limitation of the UWB signal propagation distance,a single set of base stations cannot satisfy the entire area positioning service in a large positioning service area.In this case,multiple sets of base stations are required to cover the area.This thesis studies the optimal layout of the UWB base station for the case where a single set of base stations cannot satisfy the positioning requirement of any point in the space under any layout.This paper first analyzes the structure and performance of filled polyhedron units in detail and uses a single polyhedron to fill the target space area with three-dimensional space to achieve regional coverage.We calculate the number of polyhedrons of the required size for the specific target location service area.Then the base station node selection algorithm proposed in this paper is used to obtain a base station layout scheme that can satisfy a better base station geometry and minimize the number of required base stations.Finally,the UWB sensing radius is 15 m,and the above method is experimentally verified and analyzed in a multi-group service space of 100m*100m*8m base stations.Experiment results show that when the entire positioning space reaches 4 coverage,the number of required base stations is 169,and the mean value of PDOP is guaranteed at 2.54,and the coverage redundancy and node density are 0.866 and 0.0021,respectively.The paper focuses on the need for high-precision indoor positioning and studies the layout of UWB base stations.Three evaluation indicators were set to analyze the layout method of single base stations and multiple base stations respectively,which provides technical reference and theoretical support for high-precision indoor positioning base station layout methods.